Unusual HIV transmissions through blood contact: analysis of cases reported in the United Kingdom to December 1997.

It is important to establish the likely route of infection for all reported HIV infected individuals if the HIV epidemic is to be understood. Investigating routes of infection may bring unusual infection routes to light. Steps have been taken in the United Kingdom (UK) to establish the likely mode of HIV acquisition for everyone reported as infected. If an initial report is incomplete the clinician caring for the patient is asked for relevant information. If further information is needed, and an interview is feasible and acceptable to both the clinician and the patient, information is collected from the patient through face-to-face semistructured interview. Such follow up has identified 19 cases (among 34,000 records of individuals with HIV and/or AIDS for which probable routes of infection have established) who seem to have acquired HIV infection in unusual circumstances. Seven of the 19 cases described in this paper are thought to have acquired HIV infection in the UK, two in Spain, and ten in countries with a high prevalence of HIV infection. This paper describes the circumstances in which HIV transmission is believed to have occurred.