Syphilis and Co-Infections with HIV-1, HBV, and HCV among People Who Use Crack-Cocaine in Northern Brazil

Abstract

The rates of syphilis and viral co-infections among people who use crack-cocaine (PWUCC) were assessed in this study. This cross-sectional study relied on biological and self-reported socio-behavioral data from a convenience sample of 990 PWUCC from twenty-six municipalities in the states of Amapá and Pará, northern Brazil. Blood samples were collected to assess the presence of Treponema pallidum using the Rapid Qualitative Test (RQT) and the Venereal Disease Research Laboratory (VDRL). Reactive samples by RQT were used to assess the presence of HBV, HCV, and HIV-1 using Enzyme Immunoassay (EIA) and Polymerase Chain Reaction (PCR). Logistic regression models were used to determine the association of variables assessed with syphilis. In total, 287 (29.0%) of the PWUCC sample had reactive results for syphilis. HBV (15.7%), HCV (5.9%), and HIV-1 (9.8%) were detected among PWUCC with syphilis. Young age, low monthly income and education level, long duration of crack-cocaine use, condomless sex, multiple sex partners, and exchange of sex for money/drugs were associated with syphilis. The present study provides unique insights on the epidemiological status of syphilis among PWUCC in northern Brazil, with multiple implications for improving urgent interventions for diagnosis, prevention, and treatment.

Keywords: Brazil; co-infections; crack-cocaine use; epidemiology; interventions; public health; syphilis.

Figure 1

Location of the municipalities from where people who use crack-cocaine were accessed in in the states of Amapá (AP) and Pará (PA), northern Brazil. The numbers from 1 to 26 indicate the municipalities: Soure (1), Salvaterra (2), Ponta de Pedras (3), Curralinho (4), Breves (5), Melgaço (6), Belém (7), Benevides (8), Bragança (9), Castanhal (10), Marituba (11), Abaetetuba (12), Cametá (13), Capanema (14), Marabá (15), Parauapebas (16), Altamira (17), Santarém (18), Tucuruí (19), Augusto Corrêa (20), Laranjal do Jari (21), Macapá (22), Mazagão (23), Santana (24), Vitória do Jari (25), and Porto Grande (26). More details in the supplementary material (Table S1).

Figure 2

Flowchart of actions and laboratory tests used in this study. VDRL: Venereal Disease Research Laboratory; EIA: Enzyme immunoassay; PCR: Polymerase Chain Reaction; HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV-1: Human immunodeficiency virus type 1.