Serologic and molecular typing of human T-lymphotropic virus among blood donors in Maputo City, Mozambique

Abstract

Background: Screening for human T-lymphotropic virus-1/2 (HTLV-1/2) infection is not performed in blood banks in Mozambique. The aim was to determine the prevalence of HTLV-1/2 among blood donors of the Maputo Central Hospital Blood Bank and measure the coinfection rate of HTLV-1/2 with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and syphilis.

Study design and methods: A total of 2019 consecutive blood donors were screened for HTLV-1/2 antibodies, HIV-1/2 antibodies, hepatitis B surface antigen (HBsAg), and rapid plasma reagin (RPR) for syphilis. Specimens reactive on a first HTLV-1/2 enzyme immunoassay (EIA) were retested using a second EIA. Specimens that were dually reactive on both EIAs were further tested using Western blot (WB) and real-time polymerase chain reaction (PCR).

Results: All 18 dually reactive specimens (0.89%; 95% confidence interval, 0.48%-1.30%) were positive for the presence of HTLV-1 by WB and real-time PCR. HTLV-2 was not detected. The prevalences of anti-HIV, HBsAg, and reactivity in the RPR test were 5.72, 6.01, and 0.98 percent, respectively. There was no significant association between HTLV-1 infection and demographic variables (age and sex) or serologic markers (HIV, HBsAg, and RPR). For the 17 HTLV-1-positive donors for whom serologic data for HIV, HBsAg, and syphilis RPR were available, 2 showed coinfection with HIV and 1 with HBV.

Conclusion: Compared to other infectious agents, HTLV-1 is present at relatively low levels among blood donors in Mozambique. Cost and logistics will present as major challenges for introducing HTLV-1/2 screening in blood banks. In blood banks in Southern Africa where EIA testing is possible, a sequential algorithm of two EIAs may be a cost-efficient option for HTLV-1/2 screening.