An outbreak of salmonellosis occurred among 63 wedding participants. The outbreak was
investigated through cohort, laboratory, and environmental studies. Consumption of rice-dressing
made from a commercially cooked, meat-based, rice-dressing mix was strongly
associated with illness. Nineteen patient isolates, six company/grocery store isolates cultured
from the rice-dressing mix, and one environmental isolate from a pump in the production line
were of an identical outbreak strain of Salmonella Infantis characterized by pulsed-field gel
electrophoresis. In the production line, cooked rice-dressing mix tested negative for S. Infantis
before and positive after contact with the contaminated pump. The dressing-mix had an
estimated 200 colony-forming units of salmonella per gram of product, and > 180 000 pounds
were distributed in 9 states for [ges ] 2 months before contamination was recognized. Food
manufacturers should be required to use systematic, hazard analysis critical control point risk
management practices for all processed meat products, validated by periodic microbiologic
monitoring of the end product.