Environmental determinants of hepatitis E seroprevalence in internally displaced populations: a geospatial study from Sudan.

BACKGROUND

Hepatitis E virus (HEV) is a major cause of viral hepatitis in humanitarian and resource-limited settings. Internally displaced persons (IDPs) are especially vulnerable due to overcrowding and inadequate water, sanitation, and hygiene (WASH) conditions. However, spatial variation in HEV exposure within camps remains poorly characterized. The objective of the current study was to determine the seroprevalence, spatial distribution, and environmental correlates of HEV exposure among IDPs in Al-Azaza Camp, Blue Nile State, Sudan.

METHODS

A cross-sectional study was conducted among 1078 IDPs from August to December 2021. Serum samples were tested for anti-HEV IgG and IgM using ELISA. Household environmental and behavioral data were collected through questionnaires and observation. GPS coordinates were mapped in ArcGIS Pro to assess spatial clustering. Multivariable logistic regression identified independent predictors of seropositivity.

RESULTS

Overall HEV seroprevalence was 76.4%, with low IgM positivity (1.85%), suggesting limited recent transmission. Significant spatial clustering was observed, driven mainly by IgG-positive cases. Independent risk factors included proximity to open defecation sites, unsafe water storage, poor solid waste disposal, and animal husbandry.

CONCLUSION

HEV exposure was widespread and spatially clustered, reflecting cumulative transmission. Targeted, sustained improvements in WASH infrastructure are crucial to reduce ongoing risk among displaced populations.