Human T-Lymphotropic virus type 1 and human immunodeficiency virus co-infection in rural Gabon

Abstract

Introduction Human T-cell lymphotrophic virus type-1 (HTLV-1) and human immunodeficiency virus (HIV-1) co-infection occur in many populations. People living with HIV-1 and infected with HTLV-1 seem more likely to progress rapidly towards AIDS. Both HTLV-1 and HIV-1 are endemic in Gabon (Central Africa). We investigated HTLV-1 and HIV-1 co-infection in the Haut-Ogooué province, and assessed factors that may favor the rapid evolution and progression to AIDS in co-infected patients. Methods Plasma samples from HTLV-1 patients were tested using ELISA, and positive samples were then tested by western blot assay (WB). We used the polymerase chain reaction to detect HTLV-1 Tax/Rex genes using DNA extracted from the buffy coat of ELISA-positives samples. Results We recruited 299 individuals (mean age 46 years) including 90 (30%) men and 209 (70%) women, all of whom are under treatment at the Ambulatory Treatment Centre of the province. Of these, 45 were ELISA HTLV-1/2 seropositive. According to WB criteria, 21 of 45 were confirmed positive: 20 were HTLV-1 (44%), 1 was HTLV-1/2 (2%), 2 were indeterminate (4%) and 22 were seronegative (49%). PCR results showed that 23 individuals were positive for the Tax/Rex region. Considering both serological and molecular assays, the prevalence of HTLV-1 infection was estimated at 7.7%. Being a woman and increasing age were found to be independent risk factors for co-infection. Mean CD4+ cell counts were higher in HTLV-1/HIV-1 co-infected (578.1 (± 340.8) cells/mm3) than in HIV-1 mono-infected (481.0 (± 299.0) cells/mm3) Individuals. Similarly, the mean HIV-1 viral load was Log 3.0 (± 1.6) copies/ml in mono-infected and Log 2.3 (± 0.7) copies/ml in coinfected individuals. Conclusion We described an overall high prevalence of HTLV-1/HIV-1 co-infection in Gabon. Our findings stress the need of strategies to prevent and manage these co-infections.

Risk Factors Associated with Opportunistic Infections among People Living with HIV/AIDS and Receiving an Antiretroviral Therapy in Gabon, Central Africa

“…In this study, we describe opportunistic infections (OIs) among people living with HIV/AIDS (PLWHA) in the south-east region of Gabon, with the majority of participants consisting of women, as reported in previous studies on this population. Most HIV-1 infected patients receiving ART in that CTA in Gabon are women, and there is no new finding in this regard [ 17 , 18 , 23 ]. Previous studies conducted in other countries on a similar type (female vs. male) of population have also described that women were the predominant gender [ 24 , 25 ].…”

“…The same population has been considered to study other pathogen-induced infections, including hepatitis viruses (HCV), and human T-lymphotropic virus type 1 (HTLV-1) [ 17 ]. The prevalence rate of 57.9% for OIs found among infected people confirms the vulnerability of PLWHA in Gabon with a high risk of exposure to viral, parasitic, and bacteriological agents.…”

“…For determining HIV viral load (VL) and CD4 counts, blood specimens were collected from each patient using 5 mL EDTA tubes and transferred to a reference national laboratory, located at the Unit of Retroviral Infection and Associated Pathology, CIRMF. On arrival at the facility, samples were centrifuged, and then plasma and buffy coat fractions were collected and stored at −80 °C until testing, as previously described [ 17 ]. Specifically, CD4 counts at enrolment were determined using flow cytometry (Fascount, Becton Dickinson, San Jose, CA, USA).…”

“…Specifically, CD4 counts at enrolment were determined using flow cytometry (Fascount, Becton Dickinson, San Jose, CA, USA). Plasma HIV-1 VL was determined using the Generic HIV Viral Load test (Biocentric, Bandol, France) performed according to the manufacturer’s instructions, using 200 µL of plasma and the protocol with a detection limit of 300 copies/mL [ 17 , 18 ].…”

“…No study on OIs was found concerning PLWHA in rural or semi-rural areas, including the Haut-Ogooué province of Gabon. Recently, we reported a high prevalence of HTLV-1/HIV-1 co-infection among PLWHA followed-up at the outpatient or ambulatory treatment centre (CTA) of Franceville, the major city of Haut-Ogooué province, Gabon [ 17 ]. The need for preventive strategies to effectively manage the scenarios of co-infections in PLWHA was clearly identified and recommended.…”