Western blot seroindeterminate individuals for human T-lymphotropic virus I/II (HTLV-I/II) in Fortaleza (Brazil): a serological and molecular diagnostic and epidemiological approach.

How to handle Western blot (WB) seroindeterminate individuals for Human T-lymphotropic Virus 1/2 (HTLV-1/2) constitutes a challenge for blood banks and families. We made a cross-sectional study of 191 enzyme linked immunoassay (EIA) reactive individuals from the hematological center (HEMOCE) of Fortaleza (Brazil), examining their serological (WB) and molecular (PCR) diagnosis, and demographic profiles, as well as a possible association of their condition with other infectious pathologies and risk factors. Ethical institutional approval and personal consent were obtained. Out of 191 EIA reactive individuals, 118 were WB seroindeterminate and 73 were seropositive for HTLV-1/2. In the PCR analysis of 41 WB seroindeterminate individuals, 9 (22%) were positive and 32 (78%) were negative for HTLV-1/2. The demographic analysis indicated a trend towards a predominance of males among the seroindeterminate individuals and females in the seropositive ones. The seroindeterminate individuals were younger than the seropositive ones. We did not find any association of these conditions with syphilis, Chagas disease or HIV or hepatitis, and with risk factors such as breast-feeding, blood transfusion, STD (syphilis) and IDU.