HIV-2 infection with a long asymptomatic period.

We give details of a patient infected with HIV-2 which had what we believe to be the longest asymptomatic period so far reported. The infection was probably acquired though a blood transfusion in Africa 27 years ago. At present the patient remains asymptomatic and her cellular defence mechanisms, evaluated by CD+4 lymphocyte counts and hypersensitivity skin tests, are not severely compromised. HIV-2 has come distinct epidemiological, clinical and biological features which are different from the related HIV-1 and deserve investigation in order for its natural history to be better understood.