Serological and molecular screening for viruses in blood donors from Ntcheu, Malawi: High prevalence of HIV-1 subtype C and of markers of hepatitis B and C viruses

The prevalence of antibodies to human immunodeficiency virus type 1 (HIV-1), hepatitis C virus (HCV), human T lymphotropic virus I (HTLV-1), and hepatitis B (HBV) surface antigen (HBsAg) was determined in blood donors from Ntcheu, Malawi. Each donation was also screened for HIV-1 RNA and HCV RNA. Among 159 blood donations, the prevalence of HIV-1 infection was 10.7%, 8.1% for HBV carriage, 6.8% for anti-HCV, and 2.5% for anti-HTLV-1. HIV-1/HTLV-1 and HIV-1/ HCV dual infections were observed in 1.2% of the donations. Consequently, 13% of blood donors from Ntcheu should be deferred for retroviral infections and 15% for hepatitis viral infections. Sequence analyses of the HIV-1 strains revealed a relatively homogeneous circulation of subtype C viruses in Malawi. These findings confirm the high endemicity of blood-borne viruses in Malawi and the need for a sensitive viral screening of blood donations to improve blood safety.