Purpose of review: Human T-lymphotropic virus (HTLV)/HIV co-infections are often undiagnosed, with important clinical implications. The literature is relatively sparse with key observations derived in the pre-highly-active antiretroviral therapy era.
Recent findings: The epidemiology of co-infection, the impact of each virus on the other, with particular reference to clinical manifestations and the impact of antiretroviral therapy on HTLVs are described.
Summary: Important clinical effects of HTLV/HIV co-infection include the higher rates of myelopathy and other neurological disorders and the poor predicative value of CD4+ cell counts as a surrogate for immune suppression. Current antiretroviral therapies in isolation have no proven effect on HTLV-1/2 proviral load.