Cyclospora outbreak linked to bagged salad

The cyclospora outbreak centered in Iowa has been linked to bagged spinach. The brand has not yet been identified. At this point, there is a reported 378 cases in 15 states.

 Cyclospora is a parasite, most often seen in tropical and subtropical regions, results in watery diarrhea, stomach pain, etc (http://pennstatefoodsafety.blogspot.com/2013/07/cyclospora-outbreak-in-ia-and-ne-may-be.html ). If one had to guess, cyclospora oocysts would have contaminated the produce in the field probably from contaminated irrigation water and then it would be unlikely that washing would be sufficient to destroy the oocysts, perhaps even spreading it to more more product and thus more bags in the washing system. Although it could also be that the wash water used was contaminated. Hopefully the investigation will provide that information.

CDC has a listing of organisms and their inactivation by chlorine. (Bottom of this and http://www.cdc.gov/safewater/effectiveness-on-pathogens.html. ) As can be seen, parasites are much more resistant, especially cyclospora (listed in the footnote on the CDC table).

At this point, they have not yet released the information surrounding the brand name. This is interesting in that they know the product is no longer on the shelf. As a consumer, I would be interested in knowing that information so that I could avoid that brand, and then would also have more confidence in buying other brands. Therefore, I think delaying the release of this information, it has the potential to negatively impact sales of other brands of bagged salad.


Salad Mix Behind Food Poisoning Outbreak, Health Officials Say 
By GRANT SCHULTE and MARY CLARE JALONICK 07/30/13 08:02 PM ET EDT  http://www.huffingtonpost.com/2013/07/30/salad-mix-food-poisoning_n_3679072.html

 LINCOLN, Neb. — Health officials in Iowa and Nebraska on Tuesday identified prepackaged salad mix as the source of a severe stomach bug that sickened hundreds of people in both states, but federal authorities said it's not clear whether cyclospora outbreaks elsewhere in the U.S. are also linked to that produce.

Cyclospora is a rare parasite that causes a lengthy gastrointestinal illness, and outbreaks of the illness have been reported in 15 states. The U.S. Centers for Disease Control and Prevention said Tuesday that it's not clear whether all of the illnesses are linked to a single source. The outbreak has sickened at least 145 residents in Iowa and 78 in Nebraska.

Nebraska officials said the salad mix in question included iceberg and romaine lettuce, along with red cabbage and carrots, which came through national distribution chains. They did not identify specific brands. A Nebraska health department spokeswoman said the agency was working with the U.S. Food and Drug Administration to get a "clear picture" of which were involved and whether they're tied to one common source, such as the same farm or producer.

"Our goal is to protect Nebraskans, pinpoint the source of the illness and make sure the risk is eliminated," said Dr. Joseph Acierno, the department's chief medical officer and director of public health.

In Iowa, officials said they were confident that most if not all of the product was no longer on the shelves. The affected products were traced to grocery stores and restaurants, said Steven Mandernach, the state's top food-safety inspector. Mandernach said cases were reported throughout the state, but the largest number was in the eastern Iowa city of Cedar Rapids.

Mandernach said officials have traced 80 percent of the Iowa cases to a common source, which he did not identify because officials believe there's no longer any immediate safety threat. Mandernach said it's possible that the parasite spread through contaminated floodwater and onto farm fields after arriving in the state. Before the outbreak, he said, Iowa had seen about 20 cases of cyclospora in the last decade.

Local health departments are working with the U.S. Food and Drug Administration to identify exactly where the contamination originated in the food production chain and where the product was distributed.

The CDC says 372 cases of the cyclospora infection, which causes diarrhea and other flu-like symptoms, have been reported in 15 states: Iowa, Texas, Nebraska, Florida, Wisconsin, Illinois, New York, Georgia, Missouri, Arkansas, Connecticut, Kansas, Minnesota, New Jersey and Ohio.

The CDC said at least 21 people have been hospitalized and most of the reported illnesses occurred from mid-June to early July. The CDC and the Food and Drug Administration are investigating the cyclospora infections but have not yet pointed to a source.


"CDC is still actively pursuing all leads and hasn't implicated any single food item as the cause of the outbreak in all states," said CDC spokeswoman Sharon Hoskins. "We're still not sure if the cases in all of the states are linked to the same outbreak."

Hoskins said that in some previous outbreaks of cyclospora, the cause was never discovered. The illness is rare in the United States but is sometimes contracted abroad or from imported food, according to the CDC.

The FDA said investigators are trying to trace the paths of food eaten by those who fell ill. That process is "labor intensive and painstaking work, requiring the collection, review and analysis of hundreds and at times thousands of invoices and shipping documents," the FDA said.

The agency said it has a seven person team in its Maryland headquarters and specialists in 10 field offices across the country working to identify the source of the outbreak.

Cyclospora illnesses are spread when people ingest food or water contaminated with feces. The illnesses are most often found in tropical or subtropical countries and have been linked to imported fresh fruits and vegetables in the past.

In Texas, public health officials have received 122 reports of the illness but have not yet found a link. The state issued an advisory that urged health care providers to test patients if they show symptoms of the infection, said Christine Mann, a spokeswoman for the Texas Department of State Health Services.

Connecticut has two reported cases, state Department of Public Health spokesman William Gerrish said Tuesday. Gerrish said the agency interviewed the two people to determine if there is any relation to the national outbreak. One patient likely acquired the infection while traveling internationally and the case is not related to the multistate outbreak, he said

In Kansas, state health department spokeswoman Miranda Steele said two cyclospora cases were tied to the outbreak. Steele said officials there believe both illnesses were caused by food eaten in Nebraska.
 

CDC News

Investigation of an Outbreak of Cyclosporiasis in the United StatesUpdated: 8/1/13
http://www.cdc.gov/parasites/cyclosporiasis/outbreaks/investigation-2013.html



On June 28, 2013, CDC was notified of 2 laboratory-confirmed cases of Cyclospora infection in Iowa residents who had become ill in June and did not have a history of international travel during the 14 days before the onset of illness. Since that date, CDC has been collaborating with public health officials in multiple states and the US Food and Drug Administration (FDA) to investigate an outbreak of cyclosporiasis. Preliminary details of the ongoing investigation are highlighted below.

Highlights

Epidemiologic Investigation


As of July 31, 2013 (5pm EDT), CDC has been notified of 397 cases of Cyclospora infection from the following 17 health departments: Iowa, Texas, Nebraska, Florida, Wisconsin, Illinois, New York City, Georgia, Kansas, Louisiana, Missouri, Arkansas, Connecticut, Minnesota, New Jersey, New York, and Ohio.
Most of the illness onset dates have ranged from mid-June through early July.
At least 22 persons reportedly have been hospitalized in five states.
Nebraska and Iowa have performed investigations within their states and have shared the results of those investigations with CDC. Based on their analysis, Cyclospora infections in their states are linked to a salad mix. CDC will continue to work with federal, state, and local partners in the investigation to determine whether this conclusion applies to the increase in cases of cyclosporiasis in other states.
It is not yet clear whether the cases from all of the states are part of the same outbreak.
Additional cases are currently under investigation and will be included on this page as states confirm them. Cases in this outbreak are defined as laboratory-confirmed Cyclospora infection in a person who became ill in June or July, 2013, and had no history of travel outside of the United States or Canada during the 14 days prior to onset of illness.
Previous outbreak investigations have implicated various types of fresh produce.

Laboratory Investigation


To date, CDC has confirmed 40 cases of Cyclospora infection in CDC laboratories. One of the cases was confirmed via telediagnosis.
CDC encourages laboratories to obtain confirmation of cases using telediagnosis. Telediagnosis allows for rapid laboratory confirmation. State health laboratories may submit images showing suspected Cyclospora oocysts to CDC. Images may be captured from modified acid-fast stained smears or from wet mounts examined by UV fluorescence microscopy. Both techniques require concentrated stool specimens. Instructions for submitting images for telediagnosis are found on the DPDx site


Effect of Chlorination on Inactivating Selected Pathogen
http://www.cdc.gov/safewater/effectiveness-on-pathogens.html

Chlorine inactivates most pathogens that cause diarrheal disease in humans. The tables below detail the effectiveness of chlorine against disease-causing bacteria, viruses, and protozoa. The Ct factor can be used to compare the effectivenessof chlorine against different pathogens, and is calculated by multiplying the concentration of chlorine (in mg/L or ppm/parts per million) needed to inactivate a certain percentage of the pathogen by the time (in minutes) the pathogen was exposed to that concentration of chlorine. Higher Ct factors indicate relatively higher tolerance to chlorine, while lower Ct factors indicate relatively low tolerance to chlorine. The Ct factors shown in the tables below were calculated from data in peer-reviewed research articles. The efficacy of disinfection using chlorine is dependent not only on the pathogen itself, but also on the pH and temperature of the water. In general, disinfection is more effective at higher temperatures and lower pH. Attachment to particulate matter, aggregation, encapsulation of the pathogen, ingestion by protozoa, and water turbidity may also affect chlorine efficacy. The results below reflect conditions of low water turbidity (<1 NTU), chlorine demand-free water systems. The Safe Water System accounts for variations in water quality by doubling the chlorine used for turbid drinking water. The maximum Ct factor created by adding 1.9 mg/L sodium hypochlorite to water for 30 minutes (the minimum chlorine dosage recommended by the Safe Water System for clear, non-turbid, demand-free water) is 56 mg·min/L 1. For turbid water, the dose is doubled to 3.8mg/L, with a resulting maximum Ct factor of 112 mg·min/L.

 

Inactivation of Bacteria
Pathogen	From WHO guidelines for drinking water quality				Concentration of chlorine (mg/L)	Time of chlorine exposure (min)	Ct factor	% Inactivation	Variables affecting Ct factor
	Health significance	Persistence in water supplies	Tolerance to chlorine	Relative infectivity					Temp (C)	pH
Burkholderia pseudomallei 2	Low	May multiply	Low	Low	1.0	60	60	99%	22.0- 25.0	6.25- 7.0
Campylobacter jejuni 3	High	Moderate	Low	Moderate	0.1	5	0.5	99-99.9%	25.0	8.0
Escherichia coli 4	High	Moderate	Low	Low	0.5	<0.5	<0.25	99.99%	23.0	7.0
E. coli (entero- hemhorrhagic) 4	High	Moderate	Low	High	0.5	<0.5	<0.25	99.98-99.99%	23.0	7.0
Salmonella typhi 5	High	Moderate	Low	Low	0.05	20	1	99.2%	20-25	7.0
Shigella dysenteriae 5	High	Short	Low	Moderate	0.05	<1	<0.05	99.9%	20-25	7.0
Shigella sonnei 6	-	-	-	-	0.5	1	0.5	99%	25.0	7.0
Vibrio cholerae (smooth strain) 7	High	Short	Low	Low	0.5	<1	<0.5	100%	20.0	7.0
Vibrio cholerae (rugose strain) 7	High	Short	Low	Low	2.0	20	40	99.99%	20.0	7.0
Yersinia enterocolitica 8	High	Long	Low	Low	1.0	>30	>30	82-92%	20.0	7.0

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Inactivation of Viruses
Pathogen	From WHO guidelines for drinking water quality				Concentration of chlorine (mg/L)	Time of chlorine exposure (min)	Ct factor	% Inactivation	Variables affecting Ct factor
	Health significance	Persistence in water supplies	Tolerance to chlorine	Relative infectivity					Temp (C)	pH
Enteroviruses
Coxsackie A 9	High	Long	Moderate	High	0.46-0.49	0.3	0.14-0.15	99%	5.0	6.0
Coxsackie B 9	High	Long	Moderate	High	0.48-0.50	4.5	2.16-2.25	99%	5.0	7.81- 7.82
Echovirus 9	High	Long	Moderate	High	0.48- 0.52	1.8	0.86- 0.94	99%	5.0	7.79- 7.83
Hepatitis A 10	High	Long	Moderate	High	0.41	<1	<0.41	99.99%	25.0	8.0
Poliovirus 11	High	Long	Moderate	High	0.5	12.72	6.36	99.99%	5.0	6.0
Adenoviruses 11	High	Long	Moderate	High	0.17	4.41	0.75	99.99%	5.0	7.0
Noroviruses 11	High	Long	Moderate	High	1.0	0.07	0.07	99.99%	5.0	7.0
Rotavirus 12	High	Long	Moderate	High	0.20	0.25	0.05	99.99%	4.0	7.0

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Inactivation of Protozoa
Pathogen	From WHO guidelines for drinking water quality				Concentration of chlorine (mg/L)	Time of chlorine exposure (min)	Ct factor	% Inactivation	Variables affecting Ct factor
	Health significance	Persistence in water supplies	Tolerance to chlorine	Relative infectivity					Temp (C)	pH
Entamoeba histolytica 13	High	Moderate	High	High	2.0	10	20	99%	27-30	7
Giardia intestinalis 14	High	Moderate	High	High	1.5	10	15	99.9%	25.0	7.0
Toxoplasma gondii 15	High	Moderate	High	High	100	1440	>144,000*	-	22.0	7.2
Cryptosporidium parvum 16	High	Long	High	High	80	90	15,300*	99.9%	25.0	7.5
*Toxoplasma and Cryptosporidium oocysts are highly resistant to chlorine disinfection. Chlorine alone should not be expected to inactivate these pathogens in drinking water. Filtering water supplies with a 1 micron absolute filter is recommended to physically remove the oocysts before chlorination if these pathogens are of concern. Cyclospora cayetanensis oocysts are also thought to be highly chlorine tolerant but there are no Ct values derived at this time.