Outbreak of fever caused by Streptobacillus moniliformis.

A large outbreak of streptobacillary fever, confirmed by the isolation of Streptobacillus moniliformis from blood culture, affected 304 people, 43% of the total population of 700 in a boarding school. Raw milk initially appeared to be the vehicle of infection, but detailed epidemiological investigation showed significant statistical associations between the development of illness and the consumption of both milk and water. Further analysis showed that the association with water was independent of that with milk and that water was therefore more likely to have been the vehicle of infection. Opportunity for contamination of water by rats existed, although contamination was not confirmed by the isolation of S moniliformis from either rats or the water supply.