Hepatitis E Accounts for Small Share of Suspected Acute Hepatitis in Brazil

Hepatitis E virus accounted for 16 of 124 confirmed acute viral hepatitis cases in a multicenter Brazilian study, with hepatitis A virus responsible for the remaining 108. The study enrolled 1,721 adults aged 18 years or older who presented with suspected acute hepatitis at public healthcare institutions across 16 Brazilian states between October 2019 and May 2023. Serum samples from every participant were tested for anti-HEV and anti-HAV antibodies of the IgG and IgM classes by immunoassay, and for HEV and HAV RNA by reverse transcription PCR, which detects viral genetic material in the blood. Demographic, behavioral, clinical, and laboratory data were collected with a standardized questionnaire, and group comparisons were performed using univariate analyses and logistic regression with statistical significance set at p < 0.05.

The serological results revealed a marked asymmetry between the two viruses. Antibodies indicating past HEV exposure, the anti-HEV IgG class, were detected in 89 individuals, or 5.2 percent of the cohort. In contrast, anti-HAV IgG, a marker of previous hepatitis A infection or vaccination-acquired immunity, was present in 1,352 participants, amounting to 78.6 percent. Anti-HEV IgG seroprevalence was not uniform across the country: it was higher in the South, Southeast, and Central West regions than elsewhere, and it increased with age, reaching 13.0 percent among participants aged 65 years or older. Seropositivity was also more frequent among heterosexual participants. In addition, anti-HEV IgG positivity was associated with serological markers of previous exposure to other pathogens, including hepatitis A virus, hepatitis B virus, Leptospira, and Toxoplasma. Because these antibody findings come from a cross-sectional analysis, the associations indicate overlapping exposure histories within the enrolled population rather than proven causal links between the infections.

When the analysis turned to confirmed acute disease, the numbers narrowed considerably. Among the 1,721 participants, 124 cases of acute viral hepatitis were identified. Of these, 16 cases, or 12.9 percent, were acute hepatitis E, while 108 cases, or 87.1 percent, were acute hepatitis A. The comparison of these two groups exposed clear demographic differences. Acute hepatitis E cases occurred in older individuals than acute hepatitis A cases, and they were more frequent among women and among heterosexual participants.

Geography and setting also separated the two diseases. Every acute hepatitis A case in the study arose in an urban area, whereas acute hepatitis E cases were observed in both urban and rural settings. The clinical laboratory findings added a further distinction: acute hepatitis A cases showed higher aminotransferase levels, the liver enzymes that rise when hepatocytes are damaged, and jaundice was reported more frequently in hepatitis A cases than in hepatitis E cases. These are measured differences between the two groups in this cohort, and the study did not evaluate why HEV remains underrecognized where routine testing is limited.

The authors conclude that HEV accounts for a small but distinct proportion of suspected acute hepatitis cases in Brazil and that its epidemiological and clinical characteristics differ measurably from those of hepatitis A. On that basis, they argue that incorporating HEV testing into routine diagnostic algorithms for acute hepatitis may improve etiological clarification and strengthen surveillance of acute hepatitis in the country. The study’s observational design and its recruitment from public healthcare institutions mean the findings describe patients who reached the public system with suspected disease, and the seroprevalence figures reflect this enrolled population rather than a random sample of the national population. Even so, with nearly 80 percent of the adults tested showing evidence of prior hepatitis A exposure and about 5 percent showing prior HEV exposure, the two viruses occupy clearly different positions in Brazil’s hepatitis profile, and the 16 confirmed acute hepatitis E cases show that the virus contributes to the acute hepatitis burden recorded in this surveillance population.

Subject of Research: Comparative epidemiology and clinical features of acute hepatitis E and hepatitis A in Brazilian adults with suspected acute hepatitis

Article Title: Hepatitis E in suspected acute hepatitis cases in Brazil: A comparison with hepatitis A

Article References: Oliveira, K. G. D., Vasconcelos, M. P. A., Ton, J. T., Uehara, S. N. D. O., Sitnik, R., Ornelas Pereira Salvador de Oliveira, D., Sousa, L. O. C., Siqueira, R. A., Robinson, P. J., Domingues, T. S. D. P., Panico, C. T., Inoue, C. A., Sucupira, M. C. A., Maluf, M. M., de Mello Malta, F., Amgarten, D., Dorlass, E., Sebe, P., Pinto, A. S., … Pinho, J. R. R. (2026). Hepatitis E in suspected acute hepatitis cases in Brazil: A comparison with hepatitis A. PLOS Neglected Tropical Diseases, 20(10), e0014834. https://doi.org/10.1371/journal.pntd.0014834

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014834

Keywords: hepatitis E virus, hepatitis A virus, acute viral hepatitis, seroprevalence, Brazil, anti-HEV IgG, anti-HAV IgG, RT-PCR, public health surveillance, diagnostic testing, epidemiology, liver enzymes