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The Silent Epidemic
<CITE sizset="21" sizcache="4">Henry I. Miller</CITE>, 04.06.10, 05:24 PM EDT
Noroviruses cause more than half of all food-borne disease outbreaks.
While the H1N1 swine flu outbreak has received most of the public and media attention during the past year, another virus has sickened a huge number of Americans (and others). The Centers for Disease Control and Prevention estimates that more than 21 million cases of acute gastroenteritis in the U.S. each year are due to infection with noroviruses, and more than half of all food-borne disease outbreaks can be attributed to them. The most recent outbreak was caused by consumption of oysters that were harvested in March from the Gulf of Mexico and distributed nationwide.
Because exposure to very few norovirus particles can result in infection, these organisms spread rapidly through confined communities such as dormitories, prisons and nursing homes. They are a particular nuisance on cruise ships, often sickening a large fraction of the passengers and crew. So far this year there have been a total of 8 norovirus outbreaks on U.S.-flag cruise ships, compared with 15 for all of 2009. The contaminated ships have since been disinfected but with only mixed success, perhaps because a sick passenger (or one who is incubating the virus) can board and infect others.
Norovirus can make you very sick, very fast. It causes a highly contagious gastrointestinal illness with symptoms of nausea, vomiting and/or watery diarrhea and occasionally a low-grade fever. (The malady is sometimes erroneously called "stomach flu," but noroviruses are unrelated to influenza, which causes a respiratory disease.)
Norovirus spreads easily via contaminated food or drinking water, but a more insidious route is from a person touching a surface contaminated with the residue of stool or vomit from an infected person and then touching his or her mouth before hand-washing. What kind of surface?
Almost anything that numerous people touch between cleaning. Just picture the possible exposures for most people during an average day: door handles, elevator buttons, vending machines, paper currency and coins, credit cards, public transport, magazines in the dentist's office, food samples at the supermarket, a borrowed pen to sign a credit card charge slip, and on and on. (Ironically, one of the worst is the pharmacy, a venue populated by many people who are ill and infectious and where scores each day might use the same pen when paying with a credit card.)
It is difficult to get laboratory confirmation of a suspected norovirus outbreak, so the "Kaplan Criteria" often are applied to determine the likelihood that the outbreak is of viral origin. These criteria are: 1) average illness duration of 12 to 60 hours, 2) average incubation period of 24 to 48 hours, 3) more than half of victims suffering from vomiting and 4) no bacterial agent found. When all four criteria are present, there is a high likelihood that the outbreak is attributable to norovirus.
...
Complete article at:
<CITE sizset="21" sizcache="4">Henry I. Miller</CITE>, 04.06.10, 05:24 PM EDT
Noroviruses cause more than half of all food-borne disease outbreaks.
While the H1N1 swine flu outbreak has received most of the public and media attention during the past year, another virus has sickened a huge number of Americans (and others). The Centers for Disease Control and Prevention estimates that more than 21 million cases of acute gastroenteritis in the U.S. each year are due to infection with noroviruses, and more than half of all food-borne disease outbreaks can be attributed to them. The most recent outbreak was caused by consumption of oysters that were harvested in March from the Gulf of Mexico and distributed nationwide.
Because exposure to very few norovirus particles can result in infection, these organisms spread rapidly through confined communities such as dormitories, prisons and nursing homes. They are a particular nuisance on cruise ships, often sickening a large fraction of the passengers and crew. So far this year there have been a total of 8 norovirus outbreaks on U.S.-flag cruise ships, compared with 15 for all of 2009. The contaminated ships have since been disinfected but with only mixed success, perhaps because a sick passenger (or one who is incubating the virus) can board and infect others.
Norovirus can make you very sick, very fast. It causes a highly contagious gastrointestinal illness with symptoms of nausea, vomiting and/or watery diarrhea and occasionally a low-grade fever. (The malady is sometimes erroneously called "stomach flu," but noroviruses are unrelated to influenza, which causes a respiratory disease.)
Norovirus spreads easily via contaminated food or drinking water, but a more insidious route is from a person touching a surface contaminated with the residue of stool or vomit from an infected person and then touching his or her mouth before hand-washing. What kind of surface?
Almost anything that numerous people touch between cleaning. Just picture the possible exposures for most people during an average day: door handles, elevator buttons, vending machines, paper currency and coins, credit cards, public transport, magazines in the dentist's office, food samples at the supermarket, a borrowed pen to sign a credit card charge slip, and on and on. (Ironically, one of the worst is the pharmacy, a venue populated by many people who are ill and infectious and where scores each day might use the same pen when paying with a credit card.)
It is difficult to get laboratory confirmation of a suspected norovirus outbreak, so the "Kaplan Criteria" often are applied to determine the likelihood that the outbreak is of viral origin. These criteria are: 1) average illness duration of 12 to 60 hours, 2) average incubation period of 24 to 48 hours, 3) more than half of victims suffering from vomiting and 4) no bacterial agent found. When all four criteria are present, there is a high likelihood that the outbreak is attributable to norovirus.
...
Complete article at:
