Contamination of streams by Francisella tularensis, a fastidious pathogen, was discovered by Miller in Russia.14 Subsequently that contamination was found to be the source of extensive human outbreaks, and to occur as well in North America. Circumstantial evidence supports a hypothesis that infected voles are responsible for the contamination, but when freshly isolated F. tularensis palaearctica is inoculated parenterally, only acute illness and death result whereas long-term contamination of streams would seem to demand a more chronic process. Laboratory studies have demonstrated that voles have an apparent predilection to tularemic nephritis when partially immunized before parenteral infection, but also when naive voles are infected orally. Associated chronic bacteriuria would seem to fulfill requirements for protracted contamination of watersheds.
