Human immunodeficiency virus infection and syphilis among homeless people in a large city of Central-Western Brazil: prevalence, risk factors, human immunodeficiency virus-1 genetic diversity, and drug resistance mutations

ABSTRACT Homeless people are at high risk for sexually transmitted infections (STIs), such as human immunodeficiency virus (HIV) infection and syphilis. We investigated the epidemiology of HIV-1 infection and syphilis among homeless individuals in a large city in Central-Western Brazil. In this cross-sectional study, we interviewed and tested 355 individuals from September 2014 to August 2015. Rapid test samples positive for syphilis were retested using the Venereal Disease Research Laboratory (VDRL) test. Blood samples from HIV-infected participants were collected for POL sequencing using HIV-1 RNA extracted from plasma, reverse transcription, and nested polymerase chain reaction. Anti-HIV-1-positive samples were subtyped by sequencing the nucleotides of HIV-1 protease and part of the HIV-1 reverse transcriptase genes. Transmitted and acquired drug resistance mutations and susceptibility to antiretroviral drugs were also analyzed. Anti-HIV was positive in 14 patients (3.9%; 95% confidence interval [CI]: 2.3-6.4). HIV-1 RNA was detected in 8 of the 14 samples. Two of the eight (25%) isolates showed HIV-1 drug resistance mutations. Furthermore, 78 (22%; 95% CI: 17.9-26.5) and 29 (8.2%; 95% CI: 5.6-11.4) homeless individuals tested positive for syphilis using the rapid test and VDRL test, respectively. Two individuals were anti-HIV-1 and VDRL test positive. Daily alcohol use (adjusted odds ratio [AOR]: 3.2, 95% CI: 1.0-10.4), sex with people living with HIV (PLWH) infection (AOR: 6.8, 95% CI: 1.9-25.0), and sex with people of the same sex (AOR: 5.4, 95% CI: 1.7-17.5) were predictors of HIV infection. Age ≤35 years (AOR: 3.8, 95% CI: 1.4-10.8), previous syphilis testing (AOR: 3.5, 95% CI: 1.4-8.4), history of genital lesions (AOR: 4.9, 95% CI: 1.3-19.1), and crack use in the last six months (AOR: 3.1, 95% CI: 1.3-7.6) were predictors of syphilis. Our findings highlight the importance of STI prevention and control strategies among the homeless.

HIV-1 genetic diversity and drug resistance mutations in the northern Brazilian region

ABSTRACT Brazil is a huge continental country with striking geographic differences which are well illustrated in the HIV/AIDS epidemic. Contrasting with the significant decline in the national AIDS detection rate in the last decade, a linear growth has been reported in the Northern region. Despite its public health and epidemiologic importance, there is scarce HIV-1 molecular data from Northern Brazil. This scoping review summarizes recent epidemiologic data with special emphasis on HIV-1 genetic diversity and antiretroviral drug resistance mutations in patients from the seven Northern states of Brazil. Studies from the Northern Brazil on different HIV-1 genomic regions, mostly pol (protease/reverse transcriptase) sequences of naïve/antiretroviral treated adults/children were retrieved from PubMed/MEDLINE electronic database. These studies indicate a consistent molecular profile largely dominated by HIV-1 subtype B with minor contribution of subtypes F1 and C and infrequent detection of other subtypes (A1, D, K), recombinants (BF1, BC), circulating recombinant forms (CRF) as the new CRF90_BF1 and CRF02_AG-like, CRF28-29_BF-like, CRF31_BC-like, and a potential new CRF_BF1. This pattern indicates a founder effect of subtype B and the introduction of non-B-subtypes and recombinants probably generated in the Southern/Southeastern regions. In naïve populations transmitted drug resistance (TDR) can impact the outcome of first-line antiretroviral treatment and prophylactic/preventive regimens. In the Northern region TDR rates are moderate while patients failing highly active antiretroviral therapy (HAART) showed high prevalence of acquired drug resistance mutations. The limited HIV-1 molecular data from Northern Brazil reflects the great challenges to generate comprehensive scientific data in isolated, underprivileged areas. It also highlights the need to invest in local capacity building which supported by adequate infrastructure and funding can promote robust research activities to help reduce the scientific asymmetries in the Northern region. Currently the impacts of the overwhelming COVID-19 pandemic on the expanding HIV/AIDS epidemic in Northern Brazil deserves to be closely monitored.