A silent threat behind bars: Serosurvey and associated risk factors for strongyloidiasis in female inmates and correctional officers.

Strongyloidiasis has been a neglected parasitic infection caused by Strongyloides genus parasites. Despite assessment of S. stercoralis exposure in different vulnerable populations, seroprevalence in inmates worldwide remains to be fully established. Due to poor sanitation and lack of personal hygienic practices, incarcerated individuals have been considered prone to spread infectious illnesses. Accordingly, the present study has assessed exposure and associated risk factors for strongyloidiasis in women inmates and correctional officers at the Women's State Penitentiary of Parana, part of the third largest incarceration complex in Brazil at the time. Blood samplings were performed in 2020 and 2021from a total of 503 women inmates and 92 correctional officers. Participants voluntarily responded to an epidemiological questionnaire to assess associated risk factors to strongyloidiasis. Serological analysis was performed by ELISA for anti-S. stercoralis IgG detection. Statistical analysis was performed using R software, adopting a 5% level of significance. The data were submitted to univariate analysis by chi-square or Fisher´s Exact test for assessing the association among seropositivity and the variables. The variables with p-value < 0.2 in the univariate analysis were considered fit to be included in the logistic regression. In overall, 356/503 (70.8%; 95% CI: 66.7-74.6) inmates were seropositive for anti-S. stercoralis antibodies, with no statistically associated risk factor to seropositivity. A total of 57/92 (62.0%; 95% CI: 51.8-71.2) correctional officers were seropositive, and logistic regression revealed that individuals older than 50 years were more likely seropositive. In conclusion, the high endemicity observed herein has indicated a history of previous exposure to S. stercoralis and warned for a systematic strongyloidiasis screening for inmates, to prevent long term morbidity and disseminated infection during incarceration.