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

Abstract

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. Blood samples with T. pallidum were tested for the presence of HBV, HCV and HDV by ELISA and confirmed by real-time PCR. The factors associated with syphilis were identified using Poisson regression models. Results Overall, 41.1% FSWs tested positive for syphilis and 23.5% were infected with strains having A2058G/A2059G point mutations. HBV (23.0%) and HCV (8.1%) were detected among FSWs with syphilis. Six factors were associated with syphilis: low levels of education, reduced income, drug use, unprotected sex, a lengthy career in prostitution and a lack of regular medical check-ups. Conclusions These findings indicate an urgent need for implementation of effective strategies to diagnose, prevent and treat syphilis, as well as other STIs, in this Brazilian region.

Treponema pallidum among Female Sex Workers: A Cross-Sectional Study Conducted in Three Major Cities in Northern Brazil

“…Unprotected sexual relations, anal sex, and multiple sexual partners are commonly associated with exposure to T. pallidum among FSWs in Pará [ 14 , 15 ], in other areas of Brazil [ 23 ], and in several other countries, such as Colombia [ 24 ], China [ 25 ], and India [ 26 ]. Low perception of the risk of syphilis was associated with poor education, low monthly income, and use of psychotropic drugs (licit and illicit), which has been reported in Brazilian epidemiological studies, including in the state of Pará [ 14 , 15 , 16 , 27 , 28 , 29 , 30 , 31 ]. Although this study investigated only the presence of T. pallidum , other epidemiological reports conducted with FSWs in northern Brazil have already registered the presence of multiple infectious agents, which highlights the history of STI as a risk factor [ 16 , 32 ].…”

“…Low perception of the risk of syphilis was associated with poor education, low monthly income, and use of psychotropic drugs (licit and illicit), which has been reported in Brazilian epidemiological studies, including in the state of Pará [ 14 , 15 , 16 , 27 , 28 , 29 , 30 , 31 ]. Although this study investigated only the presence of T. pallidum , other epidemiological reports conducted with FSWs in northern Brazil have already registered the presence of multiple infectious agents, which highlights the history of STI as a risk factor [ 16 , 32 ].…”

“…In the present study, the prevalence of active syphilis (recent infections) among FSWs in three cities in the interior of Pará was 14.1% [ 15 ], in which Belem showed a prevalence of recent infections of 16.7% and of past infections of 19.7% by T. pallidum . An expanded seroepidemiological investigation in 10 municipalities and 18 riverside communities in northern Pará, including the Marajó Archipelago and women working along highways, detected a range of active syphilis of 36.9–41.1% and identified strains containing mutations of resistance to treatment and coinfections with hepatotropic viruses [ 14 , 16 ]. Continuous epidemiological studies with vulnerable people are needed in northern Brazil and elsewhere.…”

“…Epidemiological aspects of syphilis among FSWs in northern Brazil are still poorly understood. In the state of Pará, the second largest in the North Region, high prevalence of syphilis was shown among FSWs who worked along highways (36.94%) in three countryside cities of the state of Pará (14.1%) and the Marajó Archipelago (41.1%) [ 14 , 15 , 16 ]. The presence of T. pallidum strains with the A2058G and A2059G resistance point mutations in the rRNA gene was also a common finding among FSWs in the Marajó Archipelago [ 16 ].…”

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

“…Recently, an epidemiological report with 180 FSWs offering sexual services in 25 locations in the Marajó Archipelago showed that syphilis was clinically present in 41.1% of the women investigated [156]. In addition to the low levels of income and education, the use of illicit drugs, a long period of prostitution and the lack of regular medical appointments were factors associated with exposure to T. pallidum.…”