Severe and Norwegian scabies are strongly associated with retroviral (HIV-1/HTLV-1) infection in Bahia, Brazil.

Severe scabies has been associated with HTLV infection. To evaluate the impact of HTLV-I/HIV-1 co-infection on the clinical presentation of scabies, we reviewed 91 cases of scabies in Bahia, Brazil, during a 3 year period. Infections by HIV-1 (50%), HTLV-I (32%), and both (20%) were highly prevalent. Crusted or severe scabies were strongly associated with HTLV-I and, to a lesser degree, with HIV-1 infection. Co-infected patients had a higher risk of death (P = 0.01). Severe forms of scabies were highly predictive of double retroviral infection.