Nov 26, 2008 (CIDRAP News) – A widely publicized Salmonella outbreak that was linked to frozen pot pies last year involved 401 cases in 41 states and put more than 100 patients in hospitals, the Centers for Disease Control and Prevention (CDC) said today in a final report on the episode.The outbreak prompted changes in the label instructions for Banquet pot pies and warnings about the importance of thoroughly cooking frozen, not-ready-to-eat foods. And in today’s report, the CDC says the food industry and regulators should examine manufacturing processes for such foods to determine how safe it is to cook them in microwave ovens.Cases in the outbreak began in February and continued until December, peaking in September, according to the article in the Nov 28 issue of Morbidity and Mortality Weekly Report. Of patients for whom the information was available, 144 of 289 (50%) had bloody diarrhea, and 108 of 338 (32%) were hospitalized, the CDC says. The outbreak strain is known as Salmonella enterica serotype I 4,5,12:i:-.Rajal Mody, MD, a CDC Epidemic Intelligence Service officer, said a hospitalization rate of 32% is “close to average” for Salmonella outbreaks. He said a recent study that compared the hospitalization rates for many different Salmonella serotypes found that the average is 22.8%. The study was published in the Journal of Infectious Diseases (see link below).”There are definitely some strains that are lower, some in the 16% range, and there’s one as high as 67%, but that is a fairly rare serotype,” Mody told CIDRAP News. He said the same study indicated that the average hospitalization rate for the I 4,5,12:i:- strain is about 25%.The first cluster of cases involving the outbreak strain with matching DNA fingerprints was detected by Pennsylvania disease detectives in June, the CDC report says. But the source of infection was not discovered until a case-control study was launched in October.As part of that effort, epidemiologists in the Minnesota Department of Health determined that four case-patients had eaten Banquet pot pies in the week before they got sick. Further investigation of cases and neighborhood matched controls pointed to Banquet turkey pot pies as the only food associated with the outbreak.In subsequent interviews, 174 of 236 case-patients reported they had eaten frozen pot pies in the week before they fell ill, and more than 90% of these were Banquet or other brands made in the same plant. In addition, the outbreak strain was found in 13 unopened Banquet turkey pot pies collected from patients, all of them produced on Jul 13 or Jul 31, 2007.ConAgra Foods on Oct 8, 2007, suspended production of pot pies at the plant linked to the outbreak, and a few days later the company recalled all pot pies made there. Previous reports listed the plant location as Marshall, Mo.The CDC report indicates that many of the outbreak cases might have been related to undercooking of the pot pies in microwave ovens. “Banquet pot pie microwave instructions might have been confusing because different parts of the package recommended different preparation times,” the article says. Also, the microwave instructions varied by wattage, but few of the patients who were interviewed knew the wattage of their microwave. The report notes that ConAgra revised the labeling and instructions on the pot pies before resuming production.However, improper microwave cooking could not explain the entire outbreak, because 23% of case-patients who ate a pot pie reported cooking the pies in conventional ovens, the CDC says. The case-control study was not large enough to determine whether using a microwave rather than a conventional oven was a risk factor for illness.Several previous salmonellosis outbreaks have been linked to frozen, not-ready-to-eat foods, including several tied to frozen chicken entrees, the report notes. The pot pie outbreak differed from the previous ones in that all the meat ingredients in the pies were supposed to be precooked, with the crust being the only raw part, it says. The report suggests that contamination could have come from “raw frozen poultry pastes” used in making the pies. However, an intensive investigation of the ConAgra plant and its suppliers failed to pinpoint any source of contamination.In view of the likely role of microwave cooking in the outbreak, the CDC says, “Industry and regulators should consider examining the manufacturing processes for frozen not ready-to-eat foods to determine the extent to which microwave cooking is safe for these products.”Besides calling for clear instructions and warnings on frozen microwavable foods, the agency says that clear and prominent listing of the wattage on microwave ovens might improve consumer compliance with the cooking instructions.CDC. Multistate outbreak of Salmonella infections associated with frozen pot pies—United States, 2007. MMWR 2008 Nov 28;57(47):1277-80 [Full text]See also: Oct 12, 2007, CIDRAP News story “ConAgra recalls pot pies as Salmonella cases rise”Study from Jul 1, 2008, Journal of Infectious Diseases: “Salmonellosis outcomes differ substantially by serotype”
Americans not worried about H1N1 but will get vaccineMore than 60% of Americans say they are not worried about the novel H1N1 flu, but 55% plan to get the H1N1 vaccine for themselves or someone in their household, according to a Washington Post ABC News Poll. The poll indicates that about one in eight Americans is very worried that the pandemic will affect his or her family, while twice as many are not at all worried, the Post reported. Nearly 75% were confident that the government will be able to cope effectively with the epidemic.http://www.washingtonpost.com/wp-dyn/content/article/2009/08/19/AR2009081901585.htmlAug 19 Washington Post storyMany British firms have had H1N1-related absencesIn a survey of 429 small and medium-sized British companies, 72% said they had weathered staff absenteeism because of the H1N1 flu and 38% expected that their sales would suffer, Reuters reported yesterday. The survey by the law firm Eversheds also found that one in five businesses said they expected to have to close or partially close premises, and 87% said they had introduced new sanitation measures to combat the virus.http://www.reuters.com/article/internal_ReutersNewsRoom_ExclusivesAndWins_MOLT/idUSTRE57I42920090819Aug 19 Reuters reportCanada expects November vaccination launch, adequate supplyCanadian officials hope to license the country’s novel flu vaccine and begin immunizing people in November, the Canadian Press reported yesterday. Canada’s vaccine supplier, GlaxoSmithKline, will ship about 10 to 15 million doses and will be able to quickly replenish supplies as healthcare workers administer the vaccine to patients. Officials project that GSK’s antigen production will outpace its fill-and-finish capacity but said finishing the vaccine elsewhere would cause delays.Australian doctors question country’s vaccination plans Australia’s major infectious disease society is questioning the safety of the country’s novel H1N1 vaccination plans, the Australian Broadcasting Corp. reported today. In a letter to the government, the Australasian Society for Infectious Diseases cited a risk of cross-contamination when using multidose vials and said the flu epidemic has subsided, so the campaign needn’t be rushed. A spokeswoman for vaccine maker CSL countered that the single-dose approach would be slower and more expensive.http://www.abc.net.au/news/stories/2009/08/20/2662321.htm?section=justinAug 20 Australian Broadcasting Corp. storyNovel H1N1 deaths in Latin America exceed 1,300Deaths from H1N1 flu in Latin America, the world’s hardest-hit region, have reached 1,303, more than 70% of the global total of 1,799 listed by the World Health Organization, Agence France-Presse reported yesterday. Argentina has had 404 deaths, the second-highest toll after the United States’ 477, and Brazil has 368, the story said. Trailing Brazil are Mexico, with 164 deaths; Chile, 105; and Peru, 62.Zimbabwe, Belarus report first novel flu casesZimbabwe’s health ministry today announced the confirmation of the country’s first novel H1N1 cases, in five private-school children who got sick in early August, Agence France-Presse reported. Doctors at Zimbabwe’s state hospitals are on strike over wage and allowance issues, but the health minister said the medical system is coping. Meanwhile, Belarus confirmed its first novel flu case yesterday, in a Chinese man who had recently returned from visiting China, the Interfax news agency reported.