Hepatitis A and hepatitis E virus seroprevalence in Paraguay: first survey among blood donors

Background: Hepatitis A virus (HAV) and hepatitis E virus (HEV) continue to represent a significant global public health challenge. This study aims to assess the seroprevalence of anti-HAV immunoglobulin G (IgG) and anti-HEV IgG antibodies among blood donors in Paraguay, a region where epidemiological data on these infections are scarce. Methods: Serum samples were collected from 452 blood donors in five regions of Paraguay and the presence of anti-HAV IgG and anti-HEV IgG antibodies was assessed. Results: Overall, 68.1% of donors tested positive for anti-HAV IgG, with a higher prevalence in older age groups (p<0.001) and significant regional differences (p<0.001). Notably, a low seroprevalence was found in the 18- to 25-y age group (36.4%), highlighting a potential gap in immunity. In contrast, anti-HEV IgG was detected in 6.0% of samples, with no significant differences observed across age groups or regions. Men exhibited a non-significant trend toward higher anti-HEV IgG seroprevalence compared with women (p=0.082). Conclusions: The high seroprevalence of anti-HAV IgG among older blood donors contrasts sharply with low coverage in younger adults, underscoring the critical need to prioritize and expand HAV vaccination efforts in younger adults. Furthermore, the low HEV seroprevalence suggests an opportunity for proactive surveillance and prevention, potentially addressing recent introduction or limited transmission. These results offer a valuable epidemiological foundation to guide effective disease control strategies and public health programs in Paraguay.