Hepatitis A and E Virus Seroprevalence and Water, Sanitation and Hygiene Levels in Rural Areas of Khammouane Province, Lao People's Democratic Republic: A Cross-Sectional Study.

There have been several Water, Sanitation, and Hygiene (WASH) interventions in Lao People's Democratic Republic (Lao PDR). We aimed to determine the relationship of exposure to two faecal-orally transmitted pathogens, hepatitis A virus (HAV) and hepatitis E virus (HEV), with WASH levels and other factors. A cross-sectional study conducted in three districts in Khammouane Province enrolled 2300 participants aged 5 to 87 years by random sampling. Anti-HAV and anti-HEV antibodies were detected by enzyme-linked immunosorbent assay. The relationship between serology (outcome), WASH and other variables was determined by bivariate and multivariable analysis. Overall, 12.0% of participants had surface water as a water source, 22.0% practiced open defecation and 66.9% had basic hygiene facilities. Anti-HAV IgG seropositivity was 63.2% and 57.5% were anti-HEV seropositive. The mean age at which 50% of the population were positive for anti-HAV and anti-HEV was 24 and 27 years old, respectively. Anti-HAV seroprevalence was lower in those with improved sanitation than those practicing open defecation (OR = 0.6, 95%CI = 0.4-0.8, p = 0.001) and higher in adults consuming undercooked meat (OR = 1.5, 95%CI = 1.1-2.0, p = 0.01). It also varied by district, ethnicity, education and age. Anti-HEV seroprevalence was lower in those with improved water source than those using surface water (OR = 0.6, 95%CI = 0.4-0.8, p = 0.002) and higher in adults consuming raw meat (OR = 1.3, 95%CI = 1.0-1.7, p = 0.04). Anti-HEV seroprevalence varied by district, sex, education, and age. Khammouane province has low levels of WASH leading to high transmission of HAV and HEV. Reducing the practice of open defecation and other risk practices such as undercooked meat consumption may reduce transmission as well as consideration of HAV vaccine introduction for younger ages.