Genetic characterizations and seroprevalence of hepatitis B virus among non-human primates and human caretakers in Indonesia

Abstract

Hepatitis B virus (HBV) is a major human pathogen also detected in non-human primates (NHPs), yet its cross-species and zoonotic transmission potential remains poorly defined. We screened 237 NHPs across 10 species together with 65 human caretakers from four major Indonesian islands. We report, to our knowledge, the first detection of HBV DNA in the East Javan langur (Trachypithecus auratus; 2/46 langurs), accompanied by serological evidence of exposure. HBV DNA was also detected in gibbons (17/68), orangutans (4/50), and humans (5/65), but not in macaques (0/73). Viral DNA levels in langurs were low and undetectable on resampling six months later in one case. Serology revealed HBcAb and HBeAb positivity in this langur, alongside HBsAb positivity in six additional langurs (bringing evidence of HBV exposure to 8/46) and in 6/68 macaques, consistent with prior HBV exposure across Old World monkeys. HBsAb was likewise prevalent in gibbons (7/47) and orangutans (16/46), consistent with widespread circulation among apes. Phylogenetic analyses placed the langur HBV strains within the gibbon HBV clade. Given the phylogenetic distance between langurs and gibbons, along with divergence of their HBV entry receptor Na+-taurocholate cotransporting polypeptide (NTCP), these preliminary observations require further mechanistic investigation and continued surveillance at the primate–human interface. Screening of non-human primates and caretakers in Indonesia reveals hepatitis B virus DNA in East Javan langurs, clustering with gibbon strains despite divergent NTCP entry receptors, marking a host-tropism paradox at the primate–human interface.