If there ever was a reason (in addition to the risk of bio-terrorism) to apply more resources to national and state surveillance of bacterial outbreaks, the 2008 Salmonella outbreak that sickened 1500 people in 43 states, the District of Columbia, and Canada is one that I hear (from consumers and industry) most often. Now thanks to:
Casey Barton Behravesh, D.V.M., Dr.P.H., Rajal K. Mody, M.D., M.P.H., Jessica Jungk, M.P.H., Linda Gaul, Ph.D., M.P.H., John T. Redd, M.D., M.P.H., Sanny Chen, Ph.D., M.H.S., Shaun Cosgrove, B.A., Erin Hedican, M.P.H., David Sweat, M.P.H., Lina Chávez-Hauser, M.A., Sandra L. Snow, M.D., Heather Hanson, M.P.H., Thai-An Nguyen, M.P.H., Samir V. Sodha, M.D., M.P.H., Amy L. Boore, Ph.D., M.P.H., Elizabeth Russo, M.D., Matthew Mikoleit, M.A.S.C.P., Lisa Theobald, B.S., Peter Gerner-Smidt, M.D., D.M.S., Robert M. Hoekstra, Ph.D., Frederick J. Angulo, D.V.M., Ph.D., David L. Swerdlow, M.D., Robert V. Tauxe, M.D., M.P.H., Patricia M. Griffin, M.D., and Ian T. Williams, Ph.D. for the Salmonella Saintpaul Outbreak Investigation Team,
and, the New England Journal of Medicine, we have some answers:
The results of multiple investigations (in 2008) indicated that jalapeño peppers were the major vehicle for transmission, and serrano peppers were also a vehicle. These findings include epidemiologic associations between illness and consumption of hot peppers, the convergence of tracebacks to a single farm in Mexico that grew both types of peppers but not tomatoes, and isolation of the outbreak strain from agricultural water and serrano peppers collected on that farm.
Recall, however, that early in the outbreak, raw tomatoes were thought to be a vehicle because there was a strong association between illness and consumption of raw tomatoes. Tomatoes had been implicated in many Salmonella outbreaks. The initial finding that tomatoes were a source was supported by the observation that the number of new cases decreased shortly after the national tomato alert. The observed epidemiologic association with tomatoes may reflect collinearity between tomatoes and hot peppers, meaning that an association was identified because tomatoes were often eaten with hot peppers. It could also reflect amplified growth of salmonella in food items, such as salsa, containing both tomatoes and contaminated hot peppers. The decline in cases shortly after the nationwide tomato advisory could be explained if avoidance of raw tomatoes indirectly reduced exposure to contaminated hot peppers. The low frequency of reported hot-pepper consumption in the Texas survey could be due to unrecognized exposure to hot peppers as ingredients in other foods.
Bottom line, if you want to stop outbreaks earlier (less people sick – and less lawsuits) and get the right product identified as the culprit, put money into public health – PERIOD. Read the full article at (10.1056/NEJMoa1005741) was published on February 23, 2011, at NEJM.org.