Bioscope '03

by Dr. Barbara Price

          In the October 3, 2003 issue of MMWR, the CDC published a short article in MMWR that dealt with recognizing illness from chemical agent exposure. “Recognition of illness associated with exposure to chemical agents.” MMWR 2003 Oct 3;52(39):938-40. In the article, CDC identified examples of chemical-induced illness and summarized epidemiologic clues and clinical signs or patterns of illness that might suggest covert release of a chemical agent. Using the example of a nerve agent in a subway, the CDC defined an overt event as one whose nature reveals itself. In contrast, a covert event is an unrecognized release, in which the presence of ill persons might be the first sign of an exposure; putting cyanide in Tylenol bottles or contaminating food are covert events. A selected list of categories of clinical symptoms includes cholinergic crisis, generalized muscle rigidity, oropharyngeal pain and ulcerations, peripheral neuropathy and/or neurocognitive effects, and severe gastrointestinal illness and dehydration. In addition, in the editorial CDC noted that they are working with American Association of Poison Control Centers (www.aapcc.org) to use its Toxic Exposure Surveillance System to identify index cases, evolving patterns, or emerging clusters of hazardous chemical or toxin exposures.

          A nice complement is the article in the November 28, 2003 issue: vol.52(47);1155-1157 “Hepatitis A Outbreak Associated with Green Onions at a Restaurant --- Monaca , Pennsylvania , 2003.” This article describes how CDC and Pennsylvania 's State Department of Health were tallying up and tracing back the unintentional contamination of green onions eaten by patrons of a restaurant between October 3 and 6. As of November 20, 555 people had contracted the hepatitis A infection. The first report in ProMed was November 6. The pair of articles demonstrates how long an obvious contamination can take to trace, and, hepatitis is one of the national reportable diseases. It had been reported in Georgia and Tennessee in October 2003 and traced to green onions.

          New Scientist's December 6-12 issue discusses the current flu. The vaccine is a mix of killed or inactivated viruses from Influenza A(H1N1), A(H3N2), and influenza B strains. The particular strains selected are based on collections of the previous season's influenza viruses. The current flu vaccine was decided in early 2003 because it takes from 4 to 8 months to prepare (test and accept) the vaccine. However, the Fujian flu strain appeared too late to be included in this winter's mix for the northern hemisphere. But a closely related strain was included and should offer some protection.

          The current spread of the flu should remind us all of how fast the flu and other viruses can spread. We should also remember that the scientists who make the vaccine selections generally have done a good job. After the vaccine is selected, a second decision is how much to make. Based on the previous year, when the flu was not spreading as fast, fewer people chose to be vaccinated, which lead to a surplus, so less of the vaccine was manufactured this year. We should also remember basic hygiene: cover sneezes and coughs and wash hands frequently. A vaccine is a back-up protection for when other steps fail.