Demographic changes in tuberculosis: high risk groups.

We conducted a statistical analysis of all verifiable tuberculosis (TB) cases in Tennessee from 1990 through 1996 to determine the demographic changes in TB. We studied variables, including age, sex, race, site of the disease, and possible impact of known risk factors such as human immunodeficiency virus (HIV) infection, homelessness, foreign birth, and residency in extended care facility. The percentage increase in all such categories, except in the nursing home population, had a statistically significant increase. Unlike national epidemiologic findings, foreign-born TB comprised less than 1% of the total cases. Association of HIV as a co-infection increased from 16 (2.7%) in 1990 to 41 (8.1%) in 1996. These findings will have significant impact on TB control measures and the clinical practice of TB cases in Tennessee and other areas of the southeastern US.

Development of a diagnostic approach to the identification of rabbit haemorrhagic disease.

Haemagglutination and ELISA tests, and negative contrast electron microscopy, have been used to identify rabbit haemorrhagic disease virus in naturally occurring cases of the disease and in experimentally infected rabbits in the United Kingdom. Haemagglutination tests alone are not satisfactory for the diagnosis because non-haemagglutinating isolates of the virus, otherwise indistinguishable from others, have been found in some outbreaks. Haemagglutination inhibition tests have shown that a proportion of both commercial laboratory and wild rabbits in the UK are seropositive to the virus although they have not been associated with clinical disease. This observation, made previously in other parts of Europe, may indicate the longstanding circulation of a related but non-pathogenic strain of virus. Naturally occurring antibody appears to afford a high degree of protection against experimental challenge with virulent virus.