Minnesota Department of Health (MDH) Bug Bytes
March 29, 2001
Vol. 2: No. 7
1. Sewage on the Half Shell?
We are working with the Hennepin County Community Health Department and the Minneapolis Health Department on an investigation of an outbreak of Norwalk-like calicivirus infections at a Minneapolis restaurant due to the consumption of raw oysters. After receiving a complaint on our foodborne illness hotline (1-877-366-3455, which can be remembered as 1-877-FOODILL), investigation by sanitarians from the Minneapolis Health Department revealed that the restaurant had recently received several other complaints. Meal dates ranged from March 3 through March 16. Interviews of complainants revealed that they had consumed raw oysters. The average incubation period of 36 hours and a high prevalence of vomiting suggested viral gastroenteritis, and we confirmed calicivirus in the stool of one patient by polymerase chain reaction. Because oysters from the same packer may be implicated in similar outbreaks in other states, the U.S. Food and Drug Administration has joined the investigation. Oysters are filter feeders and do not discriminate - human sewage that happens to make its way to a bay will be filtered along with everything else in the water. Besides Norwalk-like viruses, raw oysters also may harbor other human pathogens, such as hepatitis A virus and Vibrio parahaemolyticus. This begs a question - were these raw oyster connoisseurs really surprised that they got ill?
2. Neisseria meningitidis - College Students
Two weeks ago, a case of meningococcal meningitis was reported to us in
a Winona State University freshman who resided in a dormitory. Close contacts
were provided prophylaxis. An isolate from the case was submitted to us
and was determined to be serogroup C. In 2000, the ACIP modified its recommendations
regarding the use of meningococcal vaccine http://www.cdc.gov/mmwr/preview/
mmwrhtml/rr4907a1.htm. Attention: Non-MDH link Recent studies have demonstrated that while the overall rate for all college students is lower than the rate for all 18-23 year-olds, the rates are higher for specific subgroups of college students (freshmen, dormitory residents). The ACIP recommends that health care providers inform incoming freshmen, particularly dormitory residents, about the risks of disease and benefits of vaccination. College students should consider vaccination either from their own health care provider or from their college health service. The meningococcal vaccine protects against serogroups A, C, Y and W-135.
3. Students and Needles
We routinely receive telephone calls about situations where a sharp instrument (needle, lancet, thumbtack) has been used to draw blood or otherwise puncture the skin of one person and then the same sharp instrument re-used on other persons. Often there is an inverse amount of time and energy spent by all parties in relationship to the risk of disease. The situation usually involves multiple exposures in school science classes. Last week, one such incident was reported in the media. We assess the risk for bloodborne pathogens (hepatitis B, hepatitis C, HIV) based on the likelihood of infection being present, mode of exposure, and immune status of the exposed persons. In general, hepatitis B vaccination is invariably recommended. In some instances, baseline and follow-up testing for hepatitis B and C, and HIV are recommended.
4. Measles Update
No secondary cases of measles have been reported from the two separate cases of measles recently reported and discussed in the last two issues of Bug Bytes.
Bug Bytes is a combined effort of the Infectious Disease Epidemiology, Prevention and Control Division and the Public Health Laboratory Division of MDH. We provide Bug Bytes as a way to say THANK YOU to the infection control professionals, laboratorians, local public health professionals, and health care providers who assist us.
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