CD40LG and hepatitis A virus infection: No sample had a positive reaction for IgM anti-HAV, suggesting that 88.1% of the participants had previously been exposed to HAV since none of the participants had received vaccination against hepatitis A. Prisons located in the cities of Campo Grande and Corumbá had higher anti-HAV prevalence than the other prisons enrolled in this study, 90.9% (95% CI: 87.6–94.1) and 98.3% (95% CI: 91.0–99.7), respectively.