Persistence of cholera in the United States.

In 1973, 1978, and 1981, cases of cholera were acquired along the Gulf Coast of the United States. The isolates from all of the cases were toxigenic Vibrio cholerae O-group 1, biotype El Tor, serotype Inaba, hemolytic, and of the same phage sensitivity pattern, and all had the same restriction endonuclease pattern by molecular genetic analysis. The strain from one of the two 1981 cases differed from the others in having a small plasmid and a negative Voges-Proskauer reaction. Multiple importations, chronic carriers, and continuous occurrence of undetected cases are unlikely explanations for these findings, which suggest that toxigenic V. cholerae 01 can multiply and persist for years in some environments, making eradication of cholera a formidable task.

Single-site localization of rabies virus: impact on laboratory reporting policy.

Information accumulated by our rabies laboratory during 1977-1979 was retrospectively analyzed for patterns of rabies localization in brain. Of the 1,730 specimens reported positive during that period, 37 were positive at a single site, 27 involving only the cerebellum. Therefore, we recommend that those laboratories which offer the fluorescent rabies antibody test (FRA) examine both cerebellum and hippocampus. Definitive reports based on the FRA should be offered only when both sites have been shown negative for viral particles, or when a positive result is unquestionable.