Treponema pallidum in female sex workers from the Brazilian Marajó Archipelago: prevalence, risk factors, drug-resistant mutations and coinfections.

Background: Female sex workers (FSWs) are an especially vulnerable group for syphilis and other sexually transmitted infection (STIs). This study determined the prevalence of syphilis in FSWs and factors associated with this disease in the Marajó Archipelago (northern Brazil), as well as the frequency of point mutations (A2058G and A2059G) in the 23S rRNA gene of Treponema pallidum and coinfections with hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV).

Methods: FSWs were diagnosed using a rapid qualitative test and the isolates were evaluated for the presence of point mutations by real-time PCR.

Hepatitis B Virus Infection among People Who Use Illicit Drugs: Prevalence, Genotypes and Risk Factors in the State of Amapá, Northern Brazil.

Several records of high prevalence of HBV have been made in northern Brazil. Among risk groups for viral infection, people who use illicit drugs (PWUDs) stand out, especially if they inject drugs and engage in risky sexual behavior. In this study, the prevalence, genotype distribution and factors associated with hepatitis B virus (HBV) exposure in PWUDs were estimated.

Hepatitis C virus infection status and associated factors among a multi-site sample of people who used illicit drugs in the Amazon region.

Background: Elevated rates of Hepatitis C Virus (HCV) infection have been reported in epidemiological studies with people who used illicit drugs (PWUIDs) in different Brazilian regions. In Brazil's Amazon region, studies have already identified the common use of illicit drugs among adolescents and the high prevalence of HCV infections among PWUIDs. However, all studies done with PWUIDs were conducted with small samples and within limited geographic coverage.