Fw: [BITES-L] bites Aug. 19/10 -- II
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Date: Thu, 19 Aug 2010 17:33:19 -0500
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Subject: [BITES-L] bites Aug. 19/10 -- II
bites Aug. 19/10 -- II
Food at folk pavilion suspected source of E. coli; 16 sick in Canada, kidney failure in child
NEW YORK celebrity hot spot La Esquina shut down, again
Toasted tastes better: Salt Lake City Quiznos on hepatitis A alert after sandwich maker tests positive
NEW YORK: Consumer alert – Salmonella in alfalfa sprouts
GEORGIA: U.S. Marshals seize food from rodent-infested Ga. warehouse
US: CDC: Salmonella from eggs may have sickened 1,300
INDIANA: Food safety violations reported at state fair
UK: Food Hygiene Rating Scheme update
US: AMI opposes making non-O157:H7 STECS adulterants
UK: Toddler risks losing eye to dog parasite....maybe
Report published on factors contributing to the spread of Campylobacter in the European Union
Value of syndromic surveillance in monitoring a focal waterborne outbreak due to an unusual Cryptosporidium genotype in Northamptonshire, United Kingdom, June – July 2008
Laboratory-based surveillance for Cryptosporidium in France, 2006–2009
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Food at folk pavilion suspected source of E. coli; 16 sick in Canada, kidney failure in child
19.aug.10
barfblog
Doug Powell
http://www.barfblog.com/blog/143735/10/08/19/food-folk-pavilion-suspected-source-e-coli-16-sick-canada-kidney-failure-child
I don't know what Folklorama is in Winnipeg (that's in Canada) but food served at the Russian pavilion is the suspected source of an E. coli outbreak that has sickened 16 including one confirmed case at emergency rooms between Aug. 1 and Aug. 16.
The Winnipeg Free Press reports the parents of a two-year-old boy who suffered kidney failure want tougher food-handling rules imposed on the fair.
The boy's mother said tests confirmed the boy had verotoxigenic E. coli and was
in acute renal failure. The tot spent two nights in the pediatric intensive care unit and now has a central dialysis line in his neck and hip.
Executive director Ron Gauthier said nothing like this has ever happened before in Folklorama's 41 years and he doesn't know what potential changes the festival could make until the review is complete.
http://winnipeg.ctv.ca/servlet/an/local/CTVNews/20100818/wpg_ecoli_100818/20100818/?hub=WinnipegHome
http://www.cbc.ca/canada/manitoba/story/2010/08/18/mb-ecoli-outbreak-winnipeg.html
NEW YORK celebrity hot spot La Esquina shut down, again
19.aug.10
barfblog
Doug Powell
http://www.barfblog.com/blog/143732/10/08/19/new-york-celebrity-hot-spot-la-esquina-shut-down-again
Celebrities are a terrible source of information about all things food, and worse when it comes to food safety.
DNAinfo reports the New York City Department of Health closed down taco hot spot La Esquina after a Monday restaurant inspection, marking the celeb-frequented eatery's second shutdown since May.
La Esquina's "critical" violations included inadequate refrigeration and holding large amounts of food above maximum temperatures.
In total, the restaurant racked up 64 violation points — well above the 28 necessary to earn a "C" letter grade under the department's new system.
DNAinfo says that La Esquina's "secret" underground passageway and cellar level restaurant have helped it earn big name fans including George Clooney, Kate Hudson and Julia Roberts.
But "combustible ceilings and inadequate egress" in those same area's provoked the Department of Building's spring shutdown.
http://dnainfo.com/20100817/greenwich-village-soho/celebrity-hot-spot-la-esquina-shut-down-mdash-again
Toasted tastes better: Salt Lake City Quiznos on hepatitis A alert after sandwich maker tests positive
19.aug.10
barfblog
Doug Powell
http://www.barfblog.com/blog/143734/10/08/19/toasted-tastes-better-salt-lake-city-quiznos-hepatitis-alert-after-sandwich-mak
People who ate a Quiznos at 30 East Broadway (300 South) in Salt Lake City on August 6 or 7 may have been exposed to Hepatitis A via an infected food worker and should receive an injection of immune globulin (IG) or hepatitis A vaccine as soon as possible.
Those individuals may receive a vaccination at
Salt Lake Valley Health Department (SLVHD) City Clinic,
621 South 200 East, on:
* August 19 until 5 p.m.
* August 20 from 8:30 a.m. to 6:30 p.m.
* August 21 from 8 a.m. to 12 p.m.
People who ate at Quiznos at 30 East Broadway (300 South) in Salt Lake City between July 27 and August 5 may also have been exposed but would not benefit from immunizations because immunizations must be given within 14 days of exposure. These people should watch for signs of hepatitis A and contact their health care provider if they develop illness.
http://www.slvhealth.org/html/hepA1.html
NEW YORK: Consumer alert – Salmonella in alfalfa sprouts
19.aug.10
readMedia
New York State Department of Agriculture & Markets
http://readme.readmedia.com/Consumer-Alert-Salmonella-in-Alfalfa-Sprouts/1696529
ALBANY, NY -- New York State Agriculture Commissioner Patrick Hooker today alerted consumers that Snow White Food Products Inc., located at 621 Bergen Street in Brooklyn, New York, is recalling certain packages of "Alfalfa Sprouts" due to the presence of Salmonella.
The recalled "Alfalfa Sprouts" is packaged in a 3.5 ounce plastic clamshell container which is uncoded. It has a UPC code of 0-46421-11236-6. The product was distributed in New York State.
Salmonella is an organism that can cause serious and sometimes fatal infections in young children, frail or elderly people and others with weakened immune systems. Healthy persons infected with Salmonella often experience fever, diarrhea that may be bloody, nausea, vomiting and abdominal pain. In rare circumstances, infection with Salmonella can result in the organism getting into the bloodstream and producing more severe illnesses such as arterial infections, endocarditis and arthritis. No illnesses have been reported to date to this agency in connection with the recalled product.
The contamination was discovered after a sample analyzed by the New York State Food Laboratory revealed the presence of Salmonella in some 3.5 ounce containers of Snow White Food Products "Alfalfa Sprouts." Production and sale of the product have been suspended.
Consumers who have purchased 3.5 ounce containers of Snow White Food Products "Alfalfa Sprouts" are urged to return them to the place of purchase or discard the product. Consumers with questions may contact the company directly at 718-230-5625.
GEORGIA: U.S. Marshals seize food from rodent-infested Ga. warehouse
19.aug.10
FDA
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm223284.htm
U.S. Marshals, acting under a court order sought by the U.S. Food and Drug Administration, today seized packaged food products from a rodent-infested warehouse in Athens, Ga. A variety of products, including crackers, cookies and potato chips, were intended for sale to jails and prisons throughout the southeastern United States.
The U.S. District Court for the Middle District of Georgia issued a warrant for the seizure of all of the food in the warehouse from Mid-States Services Inc., that the FDA and the Georgia Department of Agriculture (GDA) determined to be susceptible to contamination by rodents. The food was valued at $859,000.
The government's complaint alleges that the products are adulterated under the Federal Food, Drug, and Cosmetic Act because they have been held under insanitary conditions, whereby they may have become contaminated with filth.
The two agencies investigated the Mid-States Services facility from July 14 through July 21, 2010, and found "widespread active rodent infestation both inside and outside the facility" according to the government's complaint.
Investigators found 14 live rodents, seven dead rodents, 23 gnaw holes on multiple food containers, multiple containers of food containing rodent pellets, four rodent nests, and apparent rodent pellets too numerous to count, on and around food packages, as well as finding structural defects making the facilities accessible to rodents.
"This is an example of quick action by the FDA and our state partner to prevent contaminated food from reaching consumers," said Michael A. Chappell, acting associate commissioner for regulatory affairs. "The FDA took this action because the company failed to provide adequate safeguards to ensure that products they produce or hold for sale remain free of contamination."
On July 15, 2010, GDA placed all food in the warehouse under a stop sale order. Four days later, the firm voluntarily destroyed some of the food but, as alleged in the complaint, a significant amount of food was not destroyed. On July 21, 2010, FDA investigators provided the warehouse manager a list of inspectional observations documenting the violations, but the company did not formally respond.
"As soon as we heard about this unlicensed warehouse and the conditions under which food was held, we took action with FDA," said Tommy Irvin, Georgia commissioner of agriculture. "We used our authority under the Georgia Food Act to immediately stop the sale and movement of food from the warehouse. We also promptly alerted the facilities in Georgia that had received food from this warehouse."
US: CDC: Salmonella from eggs may have sickened 1,300
19.aug.10
USA Today
Liz Szabo
http://www.usatoday.com/yourlife/food/safety/2010-08-20-salmonella20_st_N.htm?csp=34news&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+UsatodaycomNation-TopStories+%28News+-+Nation+-+Top+Stories%29&utm_content=Google+Reader
The ongoing salmonella outbreak from eggs may have sickened about 1,300 people from May to July, officials from the Centers for Disease Control and Prevention said today. Health officials have reports of at least 1,953 cases from May through July 17, a period when there are normally only about 700 cases, says Christopher Braden of the CDC. Many more people have probably become sick with salmonella since then, he said, noting that local health officials first noticed spikes in salmonella as early as April.
The outbreak has been tracked to in-shell eggs from Wright County Egg in Galt, Iowa, which has recalled 380 million eggs, says Sherri McGarry of the Food and Drug Administration. FDA officials are "on site" at the egg producer to inspect facilities and test for salmonella. Officials haven't yet received the results of those tests, she says.
McGarry called the recall "one of the largest shell-egg recalls in recent history."
Although a new FDA egg-safety rule took effect July 9, officials can't say "with 100% certainty" that it would have prevented the current outbreak, said Jeff Farrar, associate commissioner of food protection in the FDA's office of foods. But the new rules, which affect producers with more than 50,000 hens, will greatly reduce the risk of outbreaks, he said.
Smaller producers have two more years to prepare.
INDIANA: Food safety violations reported at state fair
19.aug.10
Fox59
http://www.fox59.com/news/wxin-state-fair-food-violations-081910,0,4859060.story
Indianapolis -- According to the Indiana State Health Department, more than half of returning vendors had at least one food-related violation on the fair's first day.
A couple of cases, we're told, were severe enough that two different vendors had to stop selling certain items. According to new documents, there were 15 food safety violations and 14 problems related to sanitation.
The health department doesn't publicly reveal the violations until after a 10-day waiting period that allows vendors to fix any problems.
UK: Food Hygiene Rating Scheme update
19.aug.10
Food Standards Agency
http://www.food.gov.uk/news/newsarchive/2010/aug/fhrs
The Agency has today written to all local authorities in England, Wales and Northern Ireland to tell them about local launches of the national Food Hygiene Rating Scheme (FHRS), its branding and other developments.
FHRS will help consumers choose where to eat out or shop for food by giving them information about the hygiene standards in restaurants, pubs, cafes, takeaways, hotels, supermarkets, and other places they eat out and buy food.
Local launches this autumn
Local launches of the FHRS are due to begin in the autumn. All 22 local authorities in Wales are planning to roll-out the scheme from 1 October. In England, 'early adopter' local authorities are planning to launch the scheme in the South West, and East and South East regions.
Catriona Stewart, Head of the Food Hygiene Ratings Team, said: 'It's a really exciting time for the scheme as things are moving on apace. We are really impressed with the enthusiasm of the "early adopters" for getting the scheme up and running and we share their commitment to making it a success. We are very pleased with the look and feel that the new branding gives to the scheme as it makes it easy for consumers to see at a glance what the hygiene rating is.'
Name and branding for scheme has been agreed
In line with the findings of independent research with consumers, the national scheme will be called the 'Food Hygiene Rating Scheme' and ratings will be shown on a simple numeric scale. The newly designed branding that is published today makes it easy for consumers to understand and use food hygiene ratings.
Searching for hygiene ratings online
The Agency also announced today that the IT system – including the online consumer search facility and the local authority data upload system – is now in the testing phase. The search facility will allow consumers to search for hygiene ratings of businesses in areas where the scheme is run.
The systems, which will be tested by consumers and local authorities, are expected to go live in mid-September.
Further information
Read the full update letter to local authorities and see the FHRS branding via the link below. A bilingual version (Welsh and English) of the branding is also available.
US: AMI opposes making non-O157:H7 STECS adulterants
19.aug.10
Meatingplace
Rita Jane Gabbett
http://www.meatingplace.com/MembersOnly/webNews/details.aspx?item=17987
Designating non-O157:H7 shiga-toxin producing Escherichia coli (STEC) as adulterants would result in a regulatory program that will do more harm than good, the American Meat Institute said in a letter to USDA Secretary Tom Vilsack.
There have been discussions within USDA and pressure from some legislators to broaden the adulterant criteria on E. coli in various ways, including expanding the list of pathogens considered adulterants on some beef products to include at least six of the many non-O157:H7 strains of E. coli.
(See USDA looking at pathogen vs product adulterant determinations on Meatingplace Aug. 5, 2010)
"Non-O157:H7 STECs in beef products may be a reason forpotential public health concern, but it is not a public health emergency," AMI said in a news release in which it outlined eight actions it suggested USDA take to combat STECs in the beef supply.
1. Focus on Prevention: Any new regulatory programs that USDA contemplates should be addressed within the framework of the existing Hazard Analysis Critical Control Point regulation. USDA should commission a group of qualified experts to review the current science related to the development of a comprehensive farm-to-table preventative strategy for non-O157:H7 STECs in beef products and report their finding to USDA and other stakeholders.
2. Conduct a Comprehensive Public Health Risk Assessment: Conducting a public risk assessment that is subjected to public review before regulators embark on any regulatory program to control non-O157:H7 STECs in raw beef products will provide a better understanding of the public health issues association with non-O157:H7 STECs. For example, why have no confirmed outbreaks associated with beef products occurred in the U.S.? Why have non-O157:H7 STEC outbreaks occurred in other foods, but not in beef products? Why have non-O157:H7 STEC outbreaks associated with beef products occurred in other countries, but not in the U.S.?
3. Validate Analytical Laboratory Test Methods: USDA should openly share with the meat and poultry industry, testing laboratories and test kit manufacturers the sampling and analytical methods that the agency will use to implement any regulatory program and ensure that the analytical methods are peer-reviewed before any regulatory program is initiated. An accurate, validated rapid analytical test must be available to the industry to effectively implement any regulatory program that would make it illegal to enter product containing non-O157:H7 STECs into commerce.
4. Conduct a Baseline Survey of Non-O157:H7 STECs on Beef Products: It is imperative that FSIS conduct a baseline survey of beef products to include beef carcasses, ground beef and the raw materials used to manufacture ground beef in order to assess the impact of any new regulatory program that the agency may be contemplating. The baseline survey design and sampling and analytical methods should be published for public comment to solicit the advice and counsel of scientific and technical experts before proceeding with any such survey. A very limited amount of research has been conducted to assess the prevalence of non-O157:H7 STECs on beef products.
5. Measure Progress Based on the Public Health Outcome: If FSIS decides to further regulate non-O157:H7 STECs, it is prudent to evaluate the success or failure of any such initiative by actual illness reductions. In the case of beef, however, this is nearly impossible given that no non-O157:H7 STECs illness outbreaks have been confirmed in the U.S. This lack of documented outbreaks associated with beef products is remarkable given that approximately 95 percent of the public health laboratories reported in a recent survey that they are screening for non-O157:H7 STECs. If regulatory efforts to reduce non-O157:H7 STECs in beef products cannot generate measurable, positive public health outcomes, the underlying point of the exercise must be drawn into serious question.
6. Expedite Approval of New Microbial Interventions: USDA should convene a joint task force of all federal agencies that are involved in the approval of new microbial intervention technologies and the affected meat and poultry industry to identify approval roadblocks and to develop a better, expedited approval process that can rapidly move new technology to commercialization. New preventive technologies that are effective against all STECs are needed to control these pathogens before USDA considers making non-O157:H7 an adulterant on beef products.
7. Determine Impact on International Trade: USDA, the U.S. Trade Representative, and the Department of State should commission a study to determine the impact on international beef trade that would result from declaring non-O157:H7 STECs an adulterant on beef products. Such a policy shift will be viewed by our trading partners as erecting a non-tariff trade barrier to prevent entry of beef products into the U.S.
8. Provide an Open and Transparent Public Policy Process: If FSIS decides to further regulate non-O157:H7 STECs in beef products, it should only be done through notice and comment rulemaking. The questions surrounding non-O157:H7 STECs demand a disciplined, open, and transparent regulatory process. Any new regulatory program to control non-O157:H7 STECs will likely impose significant financial and regulatory burdens on the meat industry and these costs must be weighed against any public health benefit.
To see a copy of the letter in its entirety, click here.
UK: Toddler risks losing eye to dog parasite....maybe
19.aug.10
Worms & Germs Blog
Scott Weese
http://www.wormsandgermsblog.com/2010/08/articles/animals/dogs/toddler-risks-losing-eye-to-dog-parasitemaybe/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+WormsAndGermsBlog+%28Worms+and+Germs+Blog%29
A few UK news outlets published a story the other day about a toddler with a severe eye infection that was attributed Toxocara canis, the canine roundworm. Some parts of it didn't make a lot of sense so I held off commenting, but the story's spreading around more widely now so I might as well raise a few issues.
The story is about a toddler that fell into a pile of dog feces while playing at the park, then wiped her eye. Her mother took her right home and washed the eye out. Then, according to the BBC,
"She woke up in the early hours screaming and her eye was bright purple and red and swollen shut with the eyelashes inside. She had a temperature and was very lethargic and in a lot of pain." Hospital tests confirmed toxocariasis, which resulted in Amiee contracting optical lobe cellulosis, which can lead to blindness and death if not treated within 72 hours.
Here's where I start to get confused. Eye infections are one problem cause by Toxocara canis. However, the disease (ocular larva migrans) develops when someone ingests T. canis larvae from feces. It takes a few days to a few weeks after being passed in feces before the larvae become infective, so this would have to have been an old pile of feces (something that's certainly possible).
However, ocular larva migrans develops when someone ingests the larvae, which then migrate out of the intestinal tract, journey through the body and end up in the eye. This doesn't happen in a few hours, as is described here. It takes much longer. Even if infective T. canis larvae were injected in the eye, you wouldn't see the type of severe inflammation around the eye that is shown in the picture on the BBC website. Fever is also rarely present with ocular larva migrans. The parasite gradually causes inflammation within the eye, not around it.
She's being treated with 3 antibiotics and an eye ointment. Again, this makes no sense for toxocariasis, since it's a parasitic infection within the eye. Antibiotics aren't going to be useful.
The rapidity of onset, the involvement of tissues around the eye, the presence of a fever and the reported treatment suggest to me that this is actually a bacterial infection of the eye and surrounding tissues, something that certainly could be related to the multitude of bacteria present in dog feces.
Regardless of the cause, the notion that dog owners need to be responsible and clean up after their dogs remains. Let's hope the physicians know what's going on and are treating her properly.
Report published on factors contributing to the spread of Campylobacter in the European Union
19.aug.10
Eurosurveillance, Volume 15, Issue 33
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19641
The European Food Safety Authority (EFSA) recently published a report on factors that may contribute to the spread of Campylobacter in live chickens and chicken carcasses. The findings of the report [1], based on an European Union (EU)-wide survey [2] will provide the basis for further work by scientific experts to investigate further how Campylobacter-contaminated chicken meat affects the levels of human campylobacteriosis.
The report states that it is about 30 times more likely that a Campylobacter-colonised broiler batch produces findings of sampled carcasses being contaminated with Campylobacter, compared with a non-colonised batch. Risks for contamination increase with the age of the slaughtered broilers as well as during certain months of the year. The contamination of carcasses with Campylobacter, higher Campylobacter counts on carcasses and Campylobacter colonisation of batches vary between countries and between slaughterhouses within countries, even when taking into account associated factors [1].
Over the last five years, campylobacteriosis is the most commonly reported zoonosis in the EU followed by salmonellosis and yersiniosis. The annual trends on the occurrence of zoonoses are reported on an annual basis in the joint European Centre for Disease Prevention and Control (ECDC) and EFSA annual report on zoonoses and food-borne outbreaks [3].
It is estimated that the handling, preparation and consumption of broiler meat may directly account for 20 to 30% of human cases of campylobacteriosis in the EU [4].
References
1. European Food Safety Authority (EFSA). Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses, in the EU, 2008; Part B: Analysis of factors associated with Campylobacter colonisation of broiler batches and with Campylobacter contamination of broiler carcasses; and investigation of the culture method diagnostic characteristics used to analyse broiler carcass samples. EFSA Journal 2010; 8(8):1522. [132 pp.] doi:10.2903/j.efsa.2010.1522. Available from: http://www.efsa.europa.eu/en/efsajournal/new.htm
2. Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses in the EU, 2008, Part A: Campylobacter and Salmonella prevalence estimates. EFSA Journal 2010;8(03):1503). [99 pp.]. doi:10.2903/j.efsa.2010.1503. Available from: http://www.efsa.europa.eu/en/efsajournal/scdoc/1503.htm
3. European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA). The Community Summary Report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in the European Union in 2008 Stockholm, Parma; 2010. Available from: http://www.efsa.europa.eu/en/scdocs/scdoc/1496.htm
4. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on Quantification of the risk posed by broiler meat to human campylobacteriosis in the EU. EFSA Journal 2010; 8(1):1437. [89 pp.]. doi:10.2903/j.efsa.2010.1437. Available from: http://www.efsa.europa.eu/en/efsajournal/scdoc/1437.htm
Value of syndromic surveillance in monitoring a focal waterborne outbreak due to an unusual Cryptosporidium genotype in Northamptonshire, United Kingdom, June – July 2008
19.aug.10
Eurosurveillance, Volume 15, Issue 33
S Smith, A J Elliot, C Mallaghan, D Modha, J Hippisley-Cox, S Large, M Regan, G E Smith
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19643
The United Kingdom (UK) has several national syndromic surveillance systems. The Health Protection Agency (HPA)/NHS Direct syndromic surveillance system uses pre-diagnostic syndromic data from a national telephone helpline, while the HPA/QSurveillance national surveillance system uses clinical diagnosis data extracted from general practitioner (GP)-based clinical information systems. Data from both of these systems were used to monitor a local outbreak of cryptosporidiosis that occurred following Cryptosporidium oocyst contamination of drinking water supplied from the Pitsford Reservoir in Northamptonshire, United Kingdom, in June 2008. There was a peak in the number of calls to NHS Direct concerning diarrhoea that coincided with the incident. QSurveillance data for the local areas affected by the outbreak showed a significant increase in GP consultations for diarrhoea and gastroenteritis in the week of the incident but there was no increase in consultations for vomiting. A total of 33 clinical cases of cryptosporidiosis were identified in the outbreak investigation, of which 23 were confirmed as infected with the outbreak strain. However, QSurveillance data suggest that there were an estimated 422 excess diarrhoea cases during the outbreak, an increase of about 25% over baseline weekly levels. To our knowledge, this is the first time that data from a syndromic surveillance system, the HPA/QSurveillance national surveillance system, have been able to show the extent of such a small outbreak at a local level. QSurveillance, which covers about 38% of the UK population, is currently the only GP database that is able to provide data at local health district (primary care trust) level. The Cryptosporidium contamination incident described demonstrates the potential usefulness of this information, as it is unusual for syndromic surveillance systems to be able to help monitor such a small-scale outbreak.
Introduction
As syndromic surveillance systems usually capture data already collected for other purposes, and monitor generic symptoms and/or clinically diagnosed disease, they provide information at an earlier stage of illness (compared with laboratory-confirmed diagnoses), so that action can be taken in time to substantially reduce the impact of disease. Some systems, for example, the Royal College of General Practitioners Weekly Returns Service, are now well established, with many years of historical data that allow monitoring of longer-term disease trends [1]. They have the ability to provide early warning of, for example, seasonal rises in influenza and can trigger public health action, such as a recommendation to prescribe antiviral drugs in line with national guidance [2-4]. They can also provide reassurance to incident response teams and the general public that an incident has not caused adverse health effects – for example, following an explosion at the Buncefield oil storage depot in Hemel Hempstead, United Kingdom (UK), in 2005, syndromic surveillance confirmed that there were no unusual rises in community-based morbidity linked to the incident [5]; following the eruption of the Eyjafjallajökull volcano in Iceland in April 2010 similar assurance was given about lack of impact on community morbidity [6].
Health departments are increasingly expected to monitor health effects of natural events such as heat wave or flooding, or implement surveillance – of which syndromic surveillance plays a major role – for mass gatherings such as the Olympics or football World Cup [7-9]. Systems in France, Australia and Taiwan use data from emergency departments [10-12], a Canadian system uses over-the-counter pharmacy sales [13,14], and in the Netherlands data from both syndromic and surrogate data sources, such as employee absence records and prescription medications dispensed by pharmacies, are included in surveillance systems [15,16]. Currently systems based on Internet searches via search engines or on queries submitted to medical websites are being developed [17,18].
In the UK, the HPA/NHS Direct syndromic surveillance system uses pre-diagnostic syndromic data collected from the NHS Direct telephone helpline [19], while the HPA/QSurveillance national surveillance system uses clinical diagnosis data extracted from general practitioner (GP)-based clinical information systems [20].
The HPA Real-time Syndromic Surveillance Team is a small team that coordinates a number of syndromic surveillance systems within the HPA and takes a lead for syndromic surveillance in England [21]. This paper describes the support provided by the team to the local incident management team during a local cryptosporidiosis outbreak and shows the use of syndromic surveillance in monitoring the extent of an outbreak using the HPA/NHS Direct and HPA/QSurveillance national surveillance systems.
Cryptosporidiosis
Cryptosporidium is a protozoan parasite that can cause an infection in people, cattle and sometimes other animals [22]. Cryptosporidiosis is most common in children aged between one and five years, but it can affect all ages. Those with impaired immune systems are likely to be most seriously affected. Symptoms usually appear between three and 12 days after initial exposure and include watery diarrhoea, stomach pains, dehydration and fever. In its transmissible form, called an oocyst, the parasite is protected by an outer shell, which allows it to survive in the environment for a long time. Transmission occurs most often via the faeco-oral route through person-to-person or animal-to-person contact, but people may also be infected by consuming contaminated water or food or by swimming in contaminated water. Although uncommon, the largest outbreaks have occurred following contamination of drinking water [23,24]. Normal chlorine disinfection procedures do not kill the oocysts, so they are removed by filtration and water companies carry out routine monitoring of treated water.
Description of the incident
On 25 June 2008 the local Health Protection Unit was informed by Anglian Water of an exceedence in the level of Cryptosporidium oocysts found in water supplied from the Pitsford Reservoir in Northamptonshire, United Kingdom, during 19 to 24 June 2008 [25]. The reservoir supplied a population of more than 250,000 in the Northampton area. A notice advising people in the affected areas to boil all drinking water was issued on 25 June 2008 and public health messages were circulated to local health services and to the general public via the media. Those members of the public who were concerned about health risks associated with the incident were asked to ring NHS Direct for clinical advice [26]. The HPA wrote to local GPs and hospitals asking them to monitor potential patients for signs and symptoms of Cryptosporidium infection and to submit faecal specimens to the local hospital diagnostic laboratory if patients presented with diarrhoea. Samples from 34 patients where Cryptosporidium infection was identified were sent to the UK Cryptosporidium reference unit for typing.
On 30 June 2008, the Cryptosporidium oocysts found in the reservoir water were confirmed as being of the rabbit genotype Cryptosporidium cuniculus [27]. Subsequently, a dead rabbit was found in a treated water tank at the water treatment works. The genotype of Cryptosporidium oocysts in the rabbit's large bowel was indistinguishable from that of the oocysts found in the water [27].
After remediation of the water supply and distribution, the 'boil water notice' was lifted on 4 July and the following day the first case of cryptosporidiosis linked to the incident was identified by the reference laboratory (this case was infected with C. cuniculus). During the course of the outbreak (24 June – 18 July 2008, the dates of symptom onset in the first and last case, respectively), 23 cases of cryptosporidiosis were confirmed as being infected with C. cuniculus; one of the 23 was a secondary case.
The HPA Real-time Syndromic Surveillance Team provided data in order to aid the response to this incident and the first syndromic surveillance report was circulated to the incident management team and other relevant people in the HPA on 27 June 2008. Data from the HPA/NHS Direct and HPA/QSurveillance systems were provided in a series of regular reports, initially daily and eventually weekly, until the final report on 21 August 2008. Each report included a summary interpretation and more detailed data on diarrhoea, gastroenteritis and vomiting indicators.
Methods
Surveillance systems
HPA/NHS Direct surveillance system
NHS Direct is a 24-hour nurse-led telephone helpline that provides health information and advice to the general public. Nurses use a computerised clinical decision support system – the NHS Clinical Assessment System (NHS CAS) – to handle calls. This assessment system uses approximately 200 computerised symptom-based clinical algorithms. Nurses assign the call to the most appropriate algorithm and the patient's symptoms determine the questions asked and the action to be taken following the call (call outcome), which could be guidance on self-care or they could be referred to their GP or advised to attend a hospital emergency department. No attempt is made to provide a formal diagnosis.
Daily NHS Direct data are received by the Real-time Syndromic Surveillance Team, where the number and type of calls received during the previous day are analysed and interpreted. Call proportions are calculated by age group and algorithm against the total number of calls received.
HPA/QSurveillance system
The HPA/QSurveillance national surveillance system was set up by the University of Nottingham, United Kingdom, and Egton Medical Information Systems (EMIS), a supplier of general practice computer systems, in collaboration with the HPA. It comprises a network of more than 3,500 general practices throughout the UK, covering more than 22 million patients (about 38% of the population [28]). Aggregated data on GP consultations for a range of indicators are automatically uploaded daily from GP practice systems to a central database. Data are routinely reported on a weekly basis; however, daily reporting is possible for specific incidents. Reports are provided at national or regional level (strategic health authority, SHA) and by local health district (primary care trust, PCT).
Analysis of surveillance data
NHS Direct call proportions for gastrointestinal syndromes (diarrhoea and vomiting) for the East Midlands region in England, where Northampton is situated, were examined during the outbreak (24 June – 18 July 2008) and compared with those for England and Wales. A series of control charts for diarrhoea calls are routinely used to monitor significant rises in the numbers of calls received. Control charts are calculated by assuming that calls follow a Poisson distribution with the total number of calls as an offset: a model is fitted to each region and symptom separately [29]. The model takes into account call variation caused by weekends, public holidays and the time of year – variables that can affect the number of calls received by NHS Direct. A value above the upper limit of the 99.5% confidence interval would be considered to be unusual. The seven-day moving average for diarrhoea calls was also monitored. The number and percentage of calls for diarrhoea in the East Midlands region were presented by call outcome and the number of calls in the Northampton (NN) postcode districts and in particular the number of calls in the NN11 and NN12 postcode districts, which were most affected by the incident.
QSurveillance national consultation rates per 100,000 population for diarrhoea (in the age groups under five years, five years and over, and all ages), gastroenteritis (all ages) and vomiting (all ages) were compared with rates for the same period in 2007 (data not presented). Consultation rates by region for 2008 for diarrhoea (all ages), gastroenteritis (all ages) and vomiting (all ages) were compared with those for the East Midlands region. The gastroenteritis indicator includes all cases of diarrhoea and/or vomiting.
Consultation rates and standardised incidence ratios (SIRs) – calculated using the UK as the standard population – for diarrhoea, gastroenteritis and vomiting were compared for the UK, Yorkshire and Humberside, East Midlands, Leicestershire, Northamptonshire and Rutland SHA, and Daventry and South Northants PCT, Northamptonshire Heartlands PCT and Northampton PCT. Yorkshire and Humberside was not an affected region but was included as a control. The area supplied by the Pitsford Reservoir included the three PCTs, which were all within the Leicestershire, Northamptonshire and Rutland SHA. The consultation rates and SIRs were compared for the period from week 16 to week 35 of 2008 in order to compare the rates before and after the Cryptosporidium exceedance, which took place in week 26.
Estimates of excess numbers of cases of diarrhoea occurring during and following the Cryptosporidium outbreak were made by calculating the mean consultation rate over a period of five weeks before and after the incident (weeks 20–24 and weeks 31–35, respectively). For each of the three PCTs, the calculated mean rate was applied to the PCT population to estimate the number of cases that would be expected each week. The actual consultation rates for diarrhoea for weeks 25 to 30 were used to estimate the number of cases for the PCT population each week. The expected number of cases was subtracted from the estimated number of cases in the PCT population to give the estimated number of excess cases.
Results
HPA/NHS Direct surveillance system
A peak in the number of calls for diarrhoea in the East Midlands was recorded in 25–26 June 2008, the period that coincided with the contamination incident and the associated media coverage (Figure 1). The neighbouring areas of the West Midlands, Yorkshire and the Humber, and East of England showed no increase in the number of calls for diarrhoea.
The peak produced a control chart exceedance for calls for diarrhoea on 25 June 2008 (Figure 2), when the proportion of calls exceeded the upper limit of the 99.5% confidence interval. There were further confidence interval exceedances on 26 and 28 June (which were not control chart exceedances).
There was no peak in calls for vomiting or control chart exceedance for these calls in the East Midlands.
HPA/QSurveillance national surveillance system
The East Midlands region had significantly high consultation rates for diarrhoea and gastroenteritis in week 25 (16–22 June), week 26 (23–29 June 2008, when the contamination incident was reported) and in the following four weeks. Within this region. Leicestershire, Northamptonshire and Rutland SHA had slightly raised consultation rates and significant SIRs across weeks 25 to 30 that were not seen in the neighbouring Trent SHA. At PCT level, all three of the PCTs in the area affected by the incident showed increased consultation rates for diarrhoea (Table 1) and gastroenteritis (Table 2) with SIRs significantly above the UK rate in week 26. Daventry and South Northants PCT also had a raised SIR for both indicators in week 25, and although Northamptonshire Heartlands and Northampton PCTs did not have SIRs significantly above that of the UK in week 25, the rise in consultation rates for diarrhoea and gastroenteritis began during week 25.
In Northampton PCT, consultations for both diarrhoea and gastroenteritis peaked in the week following the contamination incident, week 27, returning to normal levels by week 30 (Figure 3A and 3B). A similar effect can be seen in Northampton Heartlands PCT. Daventry and South Northants PCT also showed an increase, but appeared to have consistently higher rates for both indicators. This was the area with the smallest population so the rates were more variable than in the other PCTs and we therefore interpreted these results with caution.
Table 3 shows that there were an estimated 422 excess cases of diarrhoea in the affected PCTs (Daventry and South Northants PCT, Northamptonshire Heartlands PCT and Northampton PCT) in weeks 25 to 30. Approximately half of the estimated excess cases were in Northampton PCT.
The consultation rates for vomiting during weeks 25 to 30 in the East Midlands were not unusual at SHA or PCT level (data not presented).
Discussion
We have demonstrated the sensitivity of syndromic surveillance in detecting this small Cryptosporidium outbreak and the value of the surveillance in being able to describe the extent of its spread. Both the HPA/NHS Direct and HPA/QSurveillance systems showed demonstrable increases in calls and consultations for diarrhoea that were linked to the outbreak. QSurveillance consultations appeared to increase across the PCTs immediately affected but not in the surrounding area. Both the HPA/NHS Direct and HPA/QSurveillance systems showed a clear signal at the time of the incident and we were able to describe the extent of the impact on pre-primary care and primary care services. The HPA/QSurveillance system showed a rise in consultation rates for gastrointestinal symptoms that began the week before the outbreak, consistent with the period when Cryptosporidium was present in the water leaving the Pitsford Reservoir (19–24 June 2008) and with the onset of symptoms in the first outbreak case on 24 June. Although only 33 cases were identified by the outbreak investigation team, of which 23 were confirmed as having the outbreak Cryptosporidium strain, our syndromic surveillance data detected this limited outbreak.
Data also suggested a more widespread increase in general gastrointestinal symptoms around the time of the outbreak, with an estimated 422 excess diarrhoea cases; these excess cases represented an increase of about 25% above normally expected levels. It is highly probable that a proportion of these excess cases may have resulted from the increased publicity surrounding the incident – for example, it is likely that media reports contributed to the large peak in calls detected by the HPA/NHS Direct surveillance system on the day the boil water notice was issued, and could also have impacted on the GP consultation rate. It has been previously shown that reporting of mumps cases is sensitive to media coverage, with a rise in clinically reported cases following newspaper reports [30]. A similar mechanism could account for some of the excess GP consultations as cases experiencing gastrointestinal symptoms may have been more likely to consult their GP, whereas in normal circumstances they would have cared for themselves at home. It is also possible that the surveillance shows outbreak-associated cases that did not come to the attention of the outbreak team, perhaps because symptoms were not sufficiently severe to warrant further investigation, or stool samples were not provided for testing.
It is interesting to note that there was no demonstrable impact on the number of calls for vomiting (which is not a prominent clinical feature of cryptosporidiosis). Other common community-based pathogens such as norovirus and rotavirus were at low levels, as is normal for that time of year [31].
In this instance, public health authorities had already been alerted to a potential problem by the water company, although the extent of the outbreak was detected by syndromic surveillance. In 2003 the syndromic surveillance systems in the city of New York, United States, were able to detect an increase in diarrhoeal illness following a power outage when there was no other indication of citywide illness [32]. The New York system covers a population of nine million, but does not regularly detect localised outbreaks [33]. It has been shown previously that the HPA/NHS Direct surveillance system would be unlikely to detect a Cryptosporidium outbreak unless call volumes are high (72% chance of detection if nine-tenths of cases called NHS Direct) [29], although the value of syndromic surveillance for such outbreaks has been recognised [34]. The system detected the East Midlands Cryptosporidium outbreak that affected a smaller population than that covered by the New York system. The three PCTs affected have a combined population of around 600,000, of which just over half use GP practices reporting to QSurveillance, yet this syndromic surveillance system was able to describe an increase in consultation rates for diarrhoea and gastroenteritis around the time of the outbreak.
Limitations of the data
There was extensive media reporting of the incident that may have affected both the HPA/NHS Direct and HPA/QSurveillance systems and contributed to the increase in reported gastrointestinal symptoms around the time of the contamination incident. However, the rise in consultation rates for diarrhoea began before the outbreak had been detected and therefore cannot be attributed to media coverage.
The HPA/NHS Direct and HPA/QSurveillance systems monitor general symptoms and so could only monitor the relevant symptoms of diarrhoea and vomiting. They are not able to detect Cryptosporidium cases, as this would require laboratory confirmation of diagnosis, so some of the estimated excess cases could be unconnected with this incident. This outbreak was discovered by other means but both the HPA/NHS Direct and HPA/QSurveillance systems were able to describe the extent of the disease in the general population and provide reassurance that there was no widespread impact.
Compared with other populations, older people and ethnic minorities are less likely to call NHS Direct [29], and although this should not prevent detection of gastrointestinal symptoms as a result of drinking water contamination as this would affect the whole population, this may reduce the signal from the system [35]. With such large surveillance systems, there will be 'background noise' in the data, so procedures must be in place to correctly interpret the data and set appropriate thresholds for action.
Conclusion
To our knowledge, this is the first time that PCT-level data from a syndromic surveillance system, the HPA/QSurveillance national surveillance system, have been able to show the extent of such a limited outbreak at a local level. QSurveillance, which covers about 38% of the UK population, is currently the only GP database that is able to provide PCT-level data and this Cryptosporidium contamination incident demonstrates the potential usefulness of this system.
Acknowledgments
We thank NHS Direct for the use of call data and the University of Nottingham, EMIS and the EMIS practices for the QSurveillance data extraction and Dr Rachel Chalmers, Director UK Cryptosporidium Reference Unit, Swansea, for comments on the manuscript.
References
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Laboratory-based surveillance for Cryptosporidium in France, 2006–2009
19.aug.10
Eurosurveillance, Volume 15, Issue 33
The ANOFEL Cryptosporidium National Network
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19642
In 2002, the French Food Safety Agency drew attention to the lack of information on the prevalence of human cryptosporidiosis in the country. Two years later, the ANOFEL Cryptosporidium National Network (ACNN) was set up to provide public health authorities with data on the incidence and epidemiology of human cryptosporidiosis in France. Constituted on a voluntary basis, ACNN includes 38 hospital parasitology laboratories (mainly in university hospitals). Each laboratory is engaged to notify new cases of confirmed human cryptosporidiosis, store specimens (e.g. stools, duodenal aspirates or biopsies) and related clinical and epidemiological data, using datasheet forms. From January 2006 to December 2009, 407 cryptosporidiosis cases were notified in France and 364 specimens were collected. Of the notified cases, 74 were children under four years of age, accounting for 18.2%. HIV-infected and immunocompetent patients represented 38.6% (n=157) and 28% (n=114) of cases, respectively. A marked seasonal pattern was observed each year, with increased number of cases in mid to late summer and the beginning of autumn. Genotyping of 345 isolates from 310 patients identified C. parvum in 168 (54.2%) cases, C. hominis in 113 (36.4%) and other species in 29 (9.4%), including C. felis (n=15), C. meleagridis (n=4), C. canis (n=4), Cryptosporidium chipmunk genotype (n=1), Cryptosporidium rabbit genotype (n=1) and new Cryptosporidium genotypes (n=4). These data represent the first multisite report of laboratory-confirmed cases of cryptosporidiosis in France.
Introduction
Cryptosporidium infection is increasingly recognised as a major cause of diarrhoeal disease worldwide, in all age groups [1]. The range of people affected is broad including immunosuppressed people and children, especially in developing countries. Sporadic or outbreak cases are also seen among immunocompetent individuals. Symptoms of the disease are diverse: 90% of patients have diarrhoea, which is often associated with other gastrointestinal symptoms such as vomiting, nausea or abdominal pain [1]. Asymptomatic infections are also reported. In immunocompromised individuals, such as people receiving immunosuppressive drugs and acquired immunodeficiency syndrome (AIDS) patients with low CD4 lymphocyte counts, cryptosporidiosis is often chronic, leading to important weight loss and cachexia. Currently, very few drugs are active against Cryptosporidium and none is curative: the only antiparasitic drug proven to be effective in immunocompetent adults and children is nitazoxanide, and none has proven effective in severely immunocompromised patients [2].
Over the past 20 years, Cryptosporidium has been responsible for numerous waterborne outbreaks of gastrointestinal disease, mainly in North America and the United Kingdom, but also throughout the world [3,4]. These outbreaks have been described in relation to drinking contaminated water or recreational use of contaminated water, consumption of contaminated food, person-to-person spread and animal-to-person contact [5]. Cryptosporidium species are of major concern for regulatory agencies, water industries and consumers [6], because they are widespread zoonotic pathogens and because oocysts (the transmissible form of the parasite) are resistant to chemical disinfectants used for treating drinking water.
Although the role of water and food in the epidemiology of cryptosporidiosis is now clearly recognised, the prevalence of Cryptosporidium spp. infection in humans is not well known. In several countries, notification of confirmed cases to public health agencies is an essential stage of national strategies to improve both prevention of Cryptosporidium infection and the understanding of cryptosporidiosis epidemiology [4,5,7-10]. In France, most laboratories do not test for Cryptosporidium in stool specimens submitted for routine parasitological examination and sporadic cases are not reported at regional or national level. For this reason, cryptosporidiosis remains underdiagnosed and underreported. Nevertheless, three cryptosporidiosis outbreaks have been documented in France. The first occurred in Sète (Hérault) in 1998, the second in Dracy-le-Fort (Saône et Loire) in 2001, and the last in Divonne-les-Bains (Ain) in 2003, involving 150, more than 480 and 727 estimated cases, respectively [11-13].
To deal with a recognised but poorly defined risk of cryptosporidiosis in immunocompetent and immunocompromised populations, the French Food Safety Agency (Agence française de sécurité sanitaire des aliments, Afssa) asked an expert group to assess the risk of food-borne and waterborne cryptosporidiosis in France. The group was set up in January 2001: on the basis of its final report in 2002, Afssa pointed out the lack of information on human cryptosporidiosis in France and strongly suggested improving surveillance by improving investigation means for Cryptosporidium in humans, animals and foods (including water resources) [14]. As a result of this report, a network of laboratories – the ANOFEL Cryptosporidium National Network (ACNN) – covering most of the French territory was established in October 2004 to provide public health authorities with information on the incidence and epidemiology of human cryptosporidiosis in France. It was set up on a voluntary basis by the French association of medical parasitologists (Association des enseignants et des praticiens hospitaliers titulaires de parasitologie et mycologie médicales, ANOFEL) with the support of Afssa and the national institute of disease surveillance (Institut de veille sanitaire, InVS). Established with 31 hospital parasitology laboratories (mainly university hospitals) distributed all over the national territory (metropolitan France and overseas departments of French Guiana, Guadeloupe and Martinique), the network initially focused on internal organisation and interlaboratory tests for microscopic diagnosis of cryptosporidiosis. Reporting of cryptosporidiosis cases and specimen collection started in January 2006. By the end of the year, there were 36 participating laboratories; a further two joined in 2008 (Figure 1). This article summarises the Cryptosporidium-related data, including genotyping, collected from 2006 to 2009.
Since testing for Cryptosporidium is not included in routine parasitological stool tests in France, it is only performed at the physician's request or following the recommendation of the director of a laboratory, on the basis of available clinical or epidemiological patient data suggesting Cryptosporidium infection. An ACNN internal survey carried out in February 2010 revealed that routine testing for Cryptosporidium in stools of HIV-infected patients is performed by 27 participating laboratories (almost three quarters), by 50–60% of laboratories in stool samples from patients with organ transplantation (n=18), stem cell transplantation (n=21) or lymphoproliferative disorder (n=19) and by around 40% of laboratories in faecal samples from immunocompetent patients with diarrhoea (n=15 for samples from children; n=13 for samples from adults).
Methods
Data and specimen collection
Each laboratory in the ACNN was engaged to notify every new case of laboratory-confirmed human cryptosporidiosis. Diagnosis was based on the demonstration of Cryptosporidium spp. in stools, duodenal aspirates or intestinal biopsies (or in other sample in case of extraintestinal cryptosporidiosis) by microscopy, using modified Ziehl–Neelsen stain alone or in conjuction with polymerase chain reaction (PCR) (36 laboratories), Heine stain (one laboratory) and auramine stain (one laboratory) [15]. Diagnostic laboratory staff were asked to provide details (including age, sex and sample collection date) of cryptosporidiosis cases upon notification, using a standardised form. Related clinical and epidemiological data were also collected: patient's place of residence, history of recent foreign travel, animal and water exposure and whether the case was considered to be part of a family or household cluster or an outbreak. Faecal samples were collected, preserved in 2.5% (volume by volume) potassium dichromate solution and stored at +4 °C until they were sent to the Lille or Lyon laboratories, which were in charge of Cryptosporidium spp. sample collection. More rarely, DNA extracts were sent to the collection and stored at –20 °C.
Molecular characterisation of isolates
Except for two laboratories that carried out genotyping by themselves (Dijon and Paris Pitié Salpétrière), molecular characterisation of isolates from other laboratories was performed in Lille. Genomic DNA was extracted from stool samples using the UltraClean Fecal DNA Kit (MoBio, Ozyme) according to the manufacturer's protocol. The species and genotype were determined using 18S ribosomal DNA sequence analysis [16].
Data analysis
Case notifications were centralised in one laboratory (Lille). All collected information was entered into a Microsoft Excel database. Epidemiological analysis was published each year for members of the network. The comparative distribution of C. parvum and C. hominis cases in the dataset was analysed by Fisher's exact test.
Results
Details of laboratory-confirmed cryptosporidiosis cases
During the four-year study period, 42,004 stools samples from 24, 915 patients were tested for Cryptosporidium oocysts. A total of 407 laboratory-confirmed cases of cryptosporidiosis were notified. The number of cases was fairly similar over the first three years: 96 in 2006, 89 in 2007 and 92 in 2008; in 2009, the number was higher, with 135 cases reported (five cases were reported twice, in two different years, and were therefore removed from the total). Cases were reported in almost all months of the study period, with peaks from mid/late summer to autumn each year (Figure 2). In 2007, the high number of notifications in March was related to a suspected outbreak in French Guiana.
Of the 407 cases, 253 (62%) were male, 148 (36%) were female (the sex of six patients was not documented). Overall, the male to female ratio was 1.7 (2.2 in 2006, 2.1 in 2007, 1.5 in 2008 and 1.4 in 2009). All age groups were represented (Figure 3). The age distribution was bimodal, with the greatest number of cases reported among children under the age of four years (n=74, 18.2% of cases), and among adults aged 35–49 years (n=125, 30.7% of cases). In 2007, the cases in the age group 0–4 years included clustered cases (n=9) of the suspected outbreak in Guiana (discussed below).
Information about immune status was available for 372 patients. Immunocompetent patients accounted for 28% (n=114), mainly children and young adults (under 24 years old) (Figure 3). A large proportion of the reported cases were HIV infected (38.6%, n=157), accounting for 58.3% (56 of 96), 39.8% (35 of 88), 34.1% (31 of 91) and 26.5% (35 of 132) of reported cases in 2006, 2007, 2008 and 2009, respectively. Most of the HIV-infected patients had CD4+ lymphocyte counts of less than 200 per mm3 (data not shown) and were in the age group 35–49 years (Figure 3). Other causes of immunosuppression accounted for 11.5% (n=11), 18.2% (n=16), 27.5% (n=25) and 39.4% (n=52) of cases in 2006, 2007, 2008 and 2009, respectively.
A total of 372 (91.4%) cases had diarrhoea; 19 did not (unknown for 16 patients).
Cryptosporidiosis clustered cases
During March and April 2007, 10 laboratory-confirmed cryptosporidiosis cases were passively reported in Cayenne, French Guiana. Nine were children under the age of two years and one adult. No epidemiological link between the cases was found (such as exposure to contaminated water or infected animals, or the location of the cases' homes) and the causative species of Cryptosporidium could not be identified (as samples were not sent for genotyping).
Isolate collection and genotyping
Over the study period, a total of 364 faecal specimens (or DNA extracts) from 328 patients were collected, corresponding to 80.6% of the notified cases. Of the 364 samples, 345 (94.8%) were genotyped from DNA by PCR-sequencing of the 18S rDNA locus. Among these, 35 specimens were received from 14 patients who were sampled at different dates during their cryptosporidiosis episode. In all these cases, the Cryptosporidium species identified in the sequential samples was indistinguishable from that of the initial specimen. Molecular characterisation of Cryptosporidium species in the 310 first specimens identified C. parvum in 168 (54.2%) and C. hominis in 113 (36.5%) (Table 1).
Other species or genotypes were identified in 29 patients (9.4%). They were C. felis (n= 15), C. meleagridis (n=4), C. canis (n=4), Cryptosporidium chipmunk genotype (n=1), Cryptosporidium rabbit genotype (n=1) and four different Cryptosporidium new genotypes (for each, n=1). 18S rDNA sequences of the four new genotypes presented 97% homology with both C. parvum and C. meleagridis, 99% with both C. hominis and Cryptosporidium rabbit genotype, 99% with Cryptosporidium cervine genotype and 96% with C. hominis. Species other than C. parvum and C. hominis were mostly found in patients with immune deficiencies (24 of 29); they were found in only five immunocompetent patients (Table 2).
The proportion of cases infected with C. parvum and C. hominis varied during this study. In 2006, each species was almost equally represented: 32 patients with C. parvum and 30 with C. hominis. In 2007, cases with C. parvum infection were present in a higher proportion (33 cases with C. parvum versus 22 with C. hominis) whereas cases with C. parvum were markedly over-represented in 2008 (51 with C. parvum versus 14 with C. hominis) (Table 1). The 2008 distribution could not be related to an outbreak or another identified cause. In 2009, the proportion of cases with C. parvum (48.6%, n=52) and C. hominis (43.9%, n=47) was again similar. The monthly distributions of C. parvum and C. hominis cases did not reveal any specific seasonal pattern, but the case numbers per month were too small to determine seasonality (data not shown).
The comparative distribution of C. parvum and C. hominis cases was analysed, looking at the following parameters: age, sex, immune status, symptoms (diarrhoea, nausea, abdominal pain, fever and weight loss), location (rural or urban), whether the patient was part of a household cluster, and animal and water exposure (data not shown). C. parvum was more prevalent than C. hominis in patients above 60 years of age (p=0.01) and weight loss was more frequently reported by patients infected with C. parvum than by those infected with C. hominis (p<0.03). No difference in the distribution of C. parvum and C. hominis was found between immunocompetent and immunocompromised patients. Within the group of immunocompromised patients, C. parvum was more prevalent than C. hominis in patients with haematological disorders (lymphoproliferative diseases and stem cell transplantations) (p<0.001). C. hominis was more frequently associated than C. parvum with travel-related cryptosporidiosis (p<0.001), untreated drinking water (p<0.02) and the presence of diarrhoea in household contacts (p=0.001).
Discussion
This article constitutes the first human cryptosporidiosis epidemiological report in France, based on a four-year national survey. Data analysis indicates that Cryptosporidium spp. are geographically widespread in France and can infect both sexes in all age groups. As already reported but not explained in other surveillance studies, males were more frequently infected than females. In our study, this could be related in part to the over-representation of HIV-infected patients, who were mainly male.
Cryptosporidiosis affected particularly children under four years of age. A high incidence of the disease in this age group has been reported in Canada [7], the United States [10], New Zealand [9] and Europe [4], particularly in England and Wales [5,8]. The reason for this high incidence is unknown. It is possible that children are less likely to have pre-existing immunity and would therefore tend to have relatively more symptomatic disease than adults. Moreover, young diarrhoeic children attend a physician more frequently and are also more easily hospitalised for rehydration therapy, thus increasing the chance of Cryptosporidium detection and notification.
Data reported here suggest a seasonal trend of cryptosporidiosis in France. Seasonal variations have also been seen in other countries [4,5,10] and could be related to seasonal changes in the environment (e.g. the birth of farm animals) or to human behaviour that increase the risk of exposure (e.g. bathing in recreational water). Differences between the epidemiology of C. parvum and C. hominis are known [8,17]. Travel abroad, household contact with diarrhoea and untreated drinking water, already known to be significant risk factors for C. hominis infection [8,17], were found in this study to be more frequently associated with C. hominis than C. parvum infection.
Cryptosporidium species other than C. parvum and C. hominis were identified in 9.4% of the patients analysed: most of them were HIV-infected. This proportion is in agreement with data from Caccio et al.: approximately 3% of 3,500 immunocompetent cryptosporidiosis cases and 19% of 600 immunocompromised cases, were infected with less common Cryptosporidium species (C. meleagridis, C. felis, C. canis, cervine genotype and monkey genotype) [18]. We also report here the first cases of human infection by C. canis and Cryptosporidium chipmunk genotype in France.
Our study has limitations associated with the hospital-based structure of the ACNN. The patients studied by the network are probably more clinically patent cases of cryptosporidiosis as well as immunocompromised patients, who are admitted to hospital or who attend as outpatients from the surrounding towns. In the study, 70% of patients were hospitalised and 24.3% were not (not documented for 5.7% of patients, data not shown). This accounts for the overrepresentation of HIV-infected (although the proportion of cases with HIV infection halved over the study period) and immunocompromised patients and the probable patient age imbalance in our study. Indeed, from the annual record of the number of parasitological examinations that were performed by participating laboratories, which included the search of Cryptosporidium, the incidence of cryptosporidiosis in the population studied by the network can be estimated at 2.3% in 2006, 1.48% in 2007, 1.1% in 2008 and 1.96% in 2009. But we cannot assume such incidence in the general population in France.
There are, in fact, several major difficulties in defining the real prevalence or incidence of cryptosporidiosis in France. First, the search for Cryptosporidium oocysts in stools is not routinely performed by laboratories unless requested by the treating physician. This probably accounts for misdiagnosis since healthcare practitioners may be not familiar with this practice and since cryptosporidiosis is still considered a rare disease in France, far less frequent than some other causes of diarrhoea. Obviously, there is a need for wide dissemination of comprehensive information on the epidemiology, risk factors and diagnosis of cryptosporidiosis among general practitioners and laboratory staff. The second reason is more technical, due to the difficulties encountered routinely by laboratories in the diagnosis of cryptosporidiosis, which requires skills and experience [19]. Interlaboratory tests performed within the ACNN (which comprise only experienced parasitology laboratories) initially showed some discrepancies between laboratories for diagnosis and parasite burden estimates (data not shown) and several interlaboratory blind tests were necessary to improve the sensitivity of detection when the level of oocyst shedding was low. Setting up interlaboratory tests at a national or European level would probably substantially improve the detection rate of Cryptosporidium in all laboratories. Alternatively, or to complement microscopy, other methods such as PCR or antigen detection could be used (several commercial test kits are available), but they are costly and the ability of some of these tests to detect all Cryptosporidium species needs to be ascertained.
This study, while providing new information about Cryptosporidium infection in hospitalised patients in France, does not provide sufficient denominator or comparative data to estimate the burden of disease. Extension of this study to a more representative sample of the French population, provision of information on diagnosis to practitioners, assessment of how well diagnosis is performed in laboratories and extension of the network to veterinarians is expected to lead to a better understanding of the epidemiology and transmission of cryptosporidiosis.
Members of the ANOFEL Cryptosporidium National Network (ACNN) in alphabetical order (except for coordinator and reference and genotyping centres)
Corresponding author: K Guyot (karine.guyot@pasteur-lille.fr), Pasteur Institute of Lille, Lille, France
Coordinator: F Derouin, Saint-Louis Hospital, Paris
Reference and genotyping centres: E Dutoit, University Hospital Centre (UHC), Lille, France; F de Monbrison, UHC, Lyon; K Guyot, Pasteur Institute of Lille, Lille.
Other members of the network: I Accoceberry, Saint-André Hospital, Bordeaux; P Agnamey, UHC, Amiens; A Angoulvant, Saint-Antoine/Tenon Hospital, Paris; D Aubert, Maison Blanche Hospital, Reims; C Aznar, Andrée Rosemon Hospital, Cayenne, French Guiana; D Basset, UHC, Montpellier; P Beaudeau, InVS, Saint-Maurice, Paris; G Belkadi, Saint-Antoine Hospital, Paris; A Berry, Rangueil UHC, Toulouse; A Bonnin, Bocage Hospital, Dijon; F Botterel, Henri Mondor Hospital, Paris; M-E Bougnoux, Necker Hospital, Paris; P Bouree, Kremlin Bicêtre Hospital, Paris; P Buffet, Pitié Salpétrière Hospital, Paris; M Cambon, Hôtel-Dieu UHC, Clermont-Ferrand; B Carme, Andrée Rosemon Hospital, Cayenne, French Guiana; G Certad, Pasteur Institute of Lille, Lille; C Chartier, Afssa, Niort; B Couprie, Saint-André Hospital, Bordeaux; F Dalle, Bocage Hospital, Dijon; E Dannaoui, Georges Pompidou European Hospital, Paris; M-L Darde, Dupuytren UHC, Limoges; A Datry, Pitié Salpétrière Hospital, Paris; L de Gentile, UHC, Angers; E Dei-Cas, Pasteur Institute of Lille, Lille; B Degeilh, Pontchaillon Hospital, Rennes; N Desbois, UHC, Fort de France, Martinique; JM Dewitte, UHC, Lille; C Duhamel, Côte de Nacre UHC, Caen; TH Duong, Bretonneau Hospital, Tours; J Dupouy-Camet, Cochin Hospital, Paris; A Faussart, Bichat Hospital, Paris; L Favennec, Charles Nicolle Hospital, Rouen; P Flori, UHC, Saint Etienne; N Gantois, Pasteur Institute of Lille, Lille; G Gargala, Charles Nicolle Hospital, Rouen; F Genouillet, Jean Minjoz Hospital, Besançon; M-L Grillot, UHC, Le Havre; D Haouchine, Bichat Hospital, Paris; S Houze, Bichat Hospital, Paris; D Jamet, Morvan UHC, Brest; N Kapel, Faculty of Pharmacy, Descartes University, Paris; M-D Linas, Rangueil UHC, Toulouse; D Magne, Saint-Antoine/Tenon Hospital, Paris; P Marty, UHC, Nice; C-J Mary, Timone Hospital, Marseille; J Menotti, St-Louis Hospital, Paris; M Miegeville, UHC, Nantes; G Nevez, Morvan UHC, Brest; M Nicolas, UHC, Pointe à Pitre, Guadeloupe; C Paraud, Afssa, Niort; C Pinel, A Michallon Hospital, Grenoble; P Poirier, Hôtel-Dieu UHC, Clermont-Ferrand; C Pomares-Estran, UHC, Nice; M Rabodonirina, UHC, Lyon; C Raccurt, UHC, Amiens; M-H Rodier, La Miletrie Hospital, Poitiers; C Sarfati, St-Louis Hospital, Paris; M Thellier, Pitié Salpétrière Hospital, Paris; A Totet, UHC, Amiens; F Touafek, Pitié Salpétrière Hospital, Paris; O Villard, UHC, Strasbourg; I Villena, Maison Blanche Hospital, Reims; H Yera, Cochin Hospital, Paris.
Acknowledgments
The ANOFEL Cryptosporidium National Network (ACNN) is supported by a grant from InVS and ANOFEL. The genotyping was also supported financially by the French Ministry of Research (EA 3609). We thank Nathalie Lelieur for providing useful assistance in data analysis, Anthony Pinon for his advice on statistics and Annie Sulahian for English revision of the manuscript.
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