Serosurvey of anti-treponema pallidum (syphilis), anti-hepatitis C virus and anti-HIV antibodies in homeless persons of São Paulo city, southeastern Brazil.

Homeless persons have been considered as one of the most susceptible populations to sexually transmitted infections. In Brazil, these population experienced an increase of 140% from 2012 to 2020. Accordingly, the present study aimed to assess the seroprevalence of anti-Treponema pallidum, anti-HCV, anti-HIV antibodies, and the risk factors associated with homeless persons in a daytime attendance shelter of São Paulo city during the syphilis epidemic in Brazil. Blood samples of 116 volunteers and epidemiological data were conveniently collected in the shelter from June through August 2018. Detection of syphilis, HCV, and HIV antibodies was performed by chemiluminescent microparticle immunoassay (CMIA). CMIA-reagent samples for anti-T. pallidum antibodies were confirmed by Venereal Disease Research Laboratory (VDRL) non-treponemal test. VDRL non-reagent samples were confirmed by treponemal rapid immunochromatographic test. A rapid immunoblot assay confirmed seropositivity to HIV. Overall, anti-T. pallidum antibodies were observed in 29/116 (25.0%), anti-HCV antibodies in 4/116 (3.4%), and anti-HIV antibodies in 2/116 (1.7%) individuals, both co-infected with anti-T. pallidum antibodies. Associated risk factors for syphilis in homeless persons were being born or previously living in another city (p = 0.043) and becoming homeless due to family conflicts (p = 0.035). Besides homeless vulnerability, worldwide shortage of benzathine penicillin supply and increasing of syphilis testing access through rapid testing in primary health care services may have also impacted disease spreading at the time. The prevalence of syphilis found herein is the highest worldwide to date in this population.

Serosurvey of Anti-Toxoplasma gondii Antibodies in Homeless Persons of São Paulo City, Southeastern Brazil.

Seroprevalence of Toxoplasma gondii has been extensively studied in a variety of different human populations. However, no study has focused on homeless populations. Accordingly, the present study aimed to assess the seroprevalence of anti-T. gondii antibodies and the risk factors associated in homeless persons from homeless shelter of São Paulo city, southeastern Brazil. In addition, anti-HIV antibodies and associated risk of T. gondii and HIV coinfection have been evaluated. Anti-T. gondii antibodies were detected by indirect fluorescent antibody test. In addition, anti-HIV levels were tested by chemiluminescence enzyme immunoassay, with positive samples confirmed by rapid immunoblot assay. Overall, IgG anti-T. gondii seropositivity was found in 43/120 (35.8%) homeless persons, with endpoint titers varying from 16 to 1,024. The only two pregnant women tested were negative for IgM by chemiluminescence enzyme immunoassay, with normal parturition and clinically healthy newborns in both cases. There were no statistical differences in the risk factors for anti-T. gondii serology (p > 0.05). Anti-HIV seropositivity was found in 2/120 (1.7%) homeless persons, confirmed as HIV-1. One HIV seropositive individual was also sero-reactive to IgG anti-T. gondii, and both were negative to IgM anti-T. gondii. This is the first study that reports the serosurvey of T. gondii in homeless persons worldwide. Despite the limited sample size available in the present study, our findings have shown that the prevalence of anti-T. gondii antibodies in homeless persons herein was lower than the general population, probably due to homeless diet habit of eating mainly processed food intake. No statistical differences were found regarding risk factors for anti-T. gondii exposure in homeless persons. Future studies should be conducted to fully establish risk factors for anti-T. gondii exposure in homeless persons.