Evidence of Serological Cross-Reactivities with Human Immunodeficiency Virus Types 1 and 2 and Human T-Lymphotropic Virus Types I and II in Sera of Pregnant Women in Ibadan, Nigeria

Background. Our previous studies have indicated that the human immunodeficiency virus (HIV) and human T-Iymphotropic virus (HTLV) groups of retroviruses are endemic among various populations in Nigeria These viruses are antigenically distinct and antibodies to HIV and HTLV do not cross-react, so we studied the prevalence of HIV-1, HIV-2, HTLV-I and HTLV-II antibodies in sera of pregnant women attending an antenatal clinic in Ibadan, Nigena. Methods. In all, 364 sera were screened using three different enzyme immunoassays, Including those that distinguished HIV-1 antibodies from HIV-2, and HTLV-I antibodies from HTLV-II. All repeatedly reactive sera were confirmed by Western blots and synthetic peptide assays for the respective viruses. Results. Overall, 71 sera (19.5%) had antibodies to HIV, HTLV or both groups of retroviruses. Most (95.8%) of the reactive samples were from women 20–29 years old. Two of five sera from individuals