Seroprevalence and determinants of hepatitis E virus infection among people living with HIV in Chiang Mai, Thailand: a cross-sectional analysis

Hepatitis E virus (HEV) is increasingly recognized as a cause of acute viral hepatitis, with particular concern in immunocompromised populations, including people living with HIV (PLHIV). Despite global interest, data on HEV epidemiology among PLHIV in Thailand remain limited. This study aimed to estimate the seroprevalence of anti-HEV IgG antibodies among PLHIV in Chiang Mai, Thailand, and to identify demographic, behavioural, and clinical factors independently associated with HEV exposure. A cross-sectional study was conducted among 200 PLHIV attending four referral hospitals in Chiang Mai province. Plasma samples were tested for anti-HEV IgG using enzyme-linked immunosorbent assay (ELISA). Other hepatotropic viruses including hepatitis B and C were also assessed. Logistic regression was employed to assess predictors of HEV seropositivity. Anti-HEV IgG antibodies were detected in 13.0% (26/200) of participants. Seroprevalence did not significantly differ by sex (15.0% in males vs. 11.0% in females; p = 0.543). HBsAg and anti-HCV were observed in 6.5% and 8.0% of participants, respectively, with anti-HCV significantly more prevalent among males (15.0%) than females (1.0%; p < 0.001). Multivariate analysis identified three independent factors associated with HEV seropositivity: age ≥ 50 years (adjusted OR 3.40; 95% CI 1.47-7.86; p = 0.004), history of needle stick injury (adjusted OR 3.33; 95% CI 1.20-9.24; p = 0.021), and renal failure (adjusted OR 15.69; 95% CI 2.93-83.87; p = 0.001). HEV exposure among PLHIV in northern Thailand is not uncommon and is associated with older age, history of renal dysfunction, and potential parenteral exposures. These findings support targeted HEV screening and reinforce the need for broader HEV surveillance and preventive strategies within vulnerable HIV-positive populations in Southeast Asia.