Molecular Epidemiology of HIV-1 and HTLV-1/2 Among Female Sex Workers in Four Cities in the State of Para, Northern Brazil

Abstract

Female sex workers (FSWs) represent a key population for the acquisition of sexually transmitted infections (STI) due to their social vulnerability and the risks associated with their occupation. This study was conducted to describe the sociodemographic characteristics and sexual behavior among FSWs in cities in northern Brazil, to determine the prevalence of human immunodeficiency virus 1 (HIV-1) and human T-cell lymphotropic virus (HTLV-1/2) infections and to identify the circulating subtypes of these agents in this key population. A cross-sectional study using the Time Location Sampling (TLS) method was conducted among 339 FSWs in cities in the state of Pará from 2005 to 2006. Serological and molecular tests were performed to identify infections and viral subtypes, and bivariate and multivariate analyses were conducted to identify risk factors. Most FSWs were young, single, less educated and had at least one child. The prevalence of antibodies against HIV-1 and HTLV-1 was 2.3 and 1.7%, respectively. HIV-1 subtypes B (87.5%) and F1 (12.5%) were identified among FSWs, as were Cosmopolitan subtype (1a) and Transcontinental subgroup (A). Unprotected sex and illicit drug use were associated with HIV-1 and HTLV-1 infections using bivariate and multivariate analyses, and age ≥27 years was associated only with HIV. The important information highlighted here clearly indicates that the lack of actions to control and prevent pathogens in FSWs and the lack of strategies for health promotion in key populations can further aggravate the epidemiological scenario of viral infections in remote areas with low human development indices. Neglecting these facts may be causing the spread of these two viruses and their respective subtypes in the general population of northern Brazil.

HTLV-1 Is Also a Sexually Transmitted Infection

“…Patients infected with these STIs were considered responsible for HTLV-1 expansion into non-endemic areas. In Pará, Brazil, a study of 339 FSW determined the practice of unprotected sexual relations as a significant risk factor for HTLV-1 infection (adjusted OR/AOR 9.3; 95% CI; 4.9–14.2; p = 0.01) ( 15 ).…”

Work-Related Human T-lymphotropic Virus 1 and 2 (HTLV-1/2) Infection: A Systematic Review

“…A cross-sectional study was conducted from 2005 to 2006 in four cities in the State of Parà (Brazil) amongst 339 female SWs, to analyze sociodemographic characteristics, sexual habits, frequency, circulating molecular subtypes of HIV-1 and the HTLV-1/2 seroprevalence [ 33 ]. The HTLV-1 prevalence was 1.8%, while no HTLV-2 infection was detected.…”

“…Analysis of the variables influencing the HTLV-1/2 prevalence showed higher rates of seropositivity among SWs who referred to a history of blood transfusions or illicit drug use, and in those reporting low condom use [ 33 , 42 ]. Moreover, the prevalence of infection seems to be related to increasing age, duration of sex work, age at the time of starting sex work, number of partners per day [ 33 , 35 , 36 ].…”

“…Analysis of the variables influencing the HTLV-1/2 prevalence showed higher rates of seropositivity among SWs who referred to a history of blood transfusions or illicit drug use, and in those reporting low condom use [ 33 , 42 ]. Moreover, the prevalence of infection seems to be related to increasing age, duration of sex work, age at the time of starting sex work, number of partners per day [ 33 , 35 , 36 ]. Generally, the prevalence of HTLV-1/2 was lower than that of HIV and other STD, except for Japanese and Taiwan SWs, and in the paper by Trujillo et al [ 42 ], whereas co-infection of HTLV-1/2 with HIV or other STD was also described.…”

The Epidemiological Impact of STIs among General and Vulnerable Populations of the Amazon Region of Brazil: 30 years of Surveillance

“…The population of female sex workers (FSWs) is a highly vulnerable group for the acquisition of several STIs, and there are few studies on the epidemiology of HIV-1 in the Brazilian Amazon. A sharp increase in the prevalence of HIV-1 infection was observed from 2005–2006, from 2.3% [ 39 ] to 15.33% in 2017 [ 40 ], showing the spread of the virus towards the interior of the state of Pará over the years.…”