Prevalence of Hepatitis E virus in the Ha Giang province, Vietnam

Background/Aim: Despite the growing urgency of hepatitis E virus (HEV) infection throughout the world, hepatitis E is not studied enough in the low- and middle-income countries in Asia and Africa where HEV infection is a leading cause of acute hepatitis. HEV poses a threat to immunocompromised individuals, organ transplant recipients, people with liver cirrhosis, and especially pregnant women. Vietnam is a HEV endemic region; however data on the actual prevalence of hepatitis E in rural areas remains limited. In this study we investigated the prevalence of HEV among indigenous population of the northern rural province Ha Giang, Vietnam. Material and Methods: Serum samples were collected from 1427 rural inhabitants aged 18-83 years (mean age 42.7±8.1) from different ethnic groups in five districts in the Ha Giang Province (Yen Minh, Bac Me, Đong Van, Vi Xuyen, Bac Quang). Ha Giang is a northern rural province, located near the Chino-Vietnamese border. The population of the province is represented by 43 ethnic minorities with their unique culture. Residents of these communities, due to their lifestyle, are in close contact with livestock and/or poultry and are constantly exposed to zoonotic diseases. The majority of participants were belonged to three large ethnic groups H'mong (44.4%), Tay (33.1%), Dao (11.3%). Serum samples were tested for anti-HEV IgG, anti-HEV IgM using an enzyme-linked immunosorbent assay kit (RPC «Diagnostic Systems», Russia). All samples positive for anti-HEV-IgM were tested for HEV RNA by RT-PCR. Results: Totally, 1029 participants (72.1%; 95% CI 69.7-74.4) were positive for anti-HEV IgG. The highest seroprevalence rates were detected in Vị Xuyên district (99.3%), the lowest in Yên Minh district (38.9%). Serological markers of HEV were determined regardless of gender and age. Anti-HEV IgG prevalence in the H'mong ethnic (86.3%; 547/634) population was higher than that in the Tày (71.9%, 340/473), and the Dao (65.1%; 302/464) ethnic populations (p<0.00001). Participants (n=907) from Đông Văn, Vị Xuyên, Bắc Quang districts were tested for anti-HEV IgM. The prevalence of anti-HEV IgM was detected in 13.5% (122/907) participants. Single anti-HEV IgM was detected in 1.1% (10/907). HEV RNA was not detected in the anti-HEV IgM positive samples. Conclusion: Our findings indicate a high prevalence of HEV infection among the indigenous population of the Ha Giang Province in Vietnam. The research of HEV infection among the general population in Asia and Africa will contribute to a better understanding of the epidemiology of HEV, and developing of effective preventive measures.