One health approach on serosurvey of anti-Leptospira spp. in homeless persons and their dogs in South Brazil.

Although leptospirosis has been described as a worldwide bacterial zoonosis primarily affecting vulnerable populations, to date no study has focused on concomitant serosurvey of homeless persons and their dogs. The aim of the present study was, to use a One Health approach to serologically assess homeless persons and their dogs in 3 major cities of south Brazil (São Paulo, Curitiba, and Foz do Iguaçu). Environmental information was obtained with an epidemiological questionnaire given to all participants. A total of 200 human and 75 dog samples were tested for anti-Leptospira spp. antibodies to thirty different serovars using the microscopic agglutination test. None of the homeless persons were positive while 5 of the 75 (6.7%) dogs were positive. Among homeless population, 89% (177 of 200) were male, 61% (122 of 200) self-declared Non-white, and 67% (134 of 200) were educated up to the 8th school grade. Lower exposure of homeless persons to Leptospira spp. in the present study when compared to other vulnerable populations (slum and low-income residents) may be result of less direct exposure as they are able to rapidly change locations in response to flooding events. In addition, these results may reflect the effectiveness of a specific healthcare service provided to people living in the streets in the 3 cities. While dogs may be used as environmental sentinels for leptospirosis, the low seropositivity results found in this report may indicate low transmission risk to homeless owners in direct daily contact with their dogs.

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.

EXPOSURE OF WILD BOAR (SUS SCROFA) TO THE COMMON VAMPIRE BAT AND LACK OF IMMUNE PROTECTION TO RABIES VIRUS IN BRAZILIAN HUNTERS.

Rabies virus is recognized as one of the most fatal zoonotic agents affecting all mammals. Wild boars (Sus scrofa), classified as a large-size exotic invasive species in Brazil with nationwide hunting permitted, may serve as an extra blood source for the common vampire bat (Desmodus rotundus). Our aim was to document wild boar exposure to vampire bats to determine the seroprevalence of rabies virus antibodies in wild boars and to determine the immune status of hunters in southern and central-western Brazilian regions. Serum samples were collected from 80 wild boars and 49 hunters from natural and degraded areas of the Atlantic Forest biome of southern Brazil and in degraded areas of the Cerrado biome of central-western Brazil. The rabies-modified rapid fluorescent focus inhibition test was performed to detect the presence of rabies virus neutralizing antibodies in wild boars and considered seropositive when ≥0.10 IU/mL. The simplified fluorescence inhibition microtest was used for samples from hunters with a titer of ≥0.50 IU/mL and considered indicative of seroconversion. While 11% (9/80) of wild boars had serum titers for rabies exposure (≥0.10 IU/mL), 88% (43/49) of corresponding hunters lacked immune protective titers (<0.50 IU/mL). Wild boars showed serum titers for rabies likely due to contact with contaminated saliva of vampire bats or from infected carcass consumption. Additionally, Brazilian wild boars can be exposed to rabies and may play an important role in the sylvatic rabies cycle by providing a blood supply for vampire bats, highlighting the possibility of direct transmission of rabies virus to hunting dogs and hunters. These findings suggested hunters are a potential risk group for contracting rabies, and the World Health Organization may consider adding this occupation to their recommendations of who should receive the pre-exposure rabies vaccination.

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

ABSTRACT 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.