Hepatitis A seroprevalence among special populations in the Rio de Janeiro Metropolitan Area, Brazil.

Flavio de Carvalho, Luciana Gomes Pedro Brandão, Margaret Catoia Varela, Mari Tuyama, Danusa Ferreira Correa, Ananza Taina da Silva Santos, Alberto Dos Santos de Lemos, Marcellus Dias da Costa, José Cerbino-Neto, Pedro Emmanuel Alvarenga Americano do Brasil

The objectives were to estimate hepatitis A virus seroprevalence in subjects attending to a travel medicine and immunization clinic in Rio de Janeiro, Brazil, and to develop a prediction model for hepatitis A virus seroprevalence. This retrospective research included individuals sequentially from April 2011 to June 2019 at a travel medicine and special population immunization clinic with an anti-hepatitis A virus IgG chemiluminescence result. Participants' data were verified via electronic medical records. Data were split into development and validation set taking 2018 as the date break. A cross-validated elastic generalized linear model with binomial distribution was performed. In total, 2,944 subjects were analyzed. Hepatitis A virus overall seroprevalence was 67.8%. Health professionals, travelers, and those who had contact with immunocompromised subjects had lower seroprevalence (40%-55%), whereas subjects with chronic conditions (heart, lung, and liver) ranged from 89% to 94%. The retained predictors in the final model were sex, age, year of birth, travelers, HIV/AIDS, spleen dysfunction, transplant candidates, household communicators, cancer-related immunosuppression, health care professionals. Area under the curve was 0.836 and maximum error was 0.051. Users can make predictions with the following calculator: https://pedrobrasil.shinyapps.io/INDWELL/. The groups with lower seroprevalence should be evaluated more carefully regarding need for hepatitis A virus vaccination even when they seek immunization clinics for other purposes.