Anti-HEV seroprevalence rate in the Americas

Background:

While hepatitis E virus (HEV) infections have become a relevant topic in Europe, knowledge about HEV in the U.S. and South-America is still limited as no study or meta-analysis has yet compared the anti-HEV rate in the Americas. Therefore, the aim of this study was to develop a clearer understanding of anti-HEV IgG seroprevalence in the Americas identifying risk factors associated with anti-HEV seroprevalence.

Methods:

North/South American HEV-seroprevalence studies from 1994 – 2016 were reviewed (Pubmed) and stratified by country, assay, patient cohort (general population, immunosuppression, chronic liver disease, contact with swine/wild animals) and methodological quality. Socioeconomic data were collected from Food and Agricultural Outlook of the Unites Nations and United Nations Human Development Reports. Data were pooled using a mixed-effects model, which estimated seroprevalence rates basing on pooled studies.

Results:

281 studies were initially identified, of which 68 (with 84257 individuals) studies were included in the final analysis (Fig. 1). Seroprevalence estimates in general population ranged from 7% to 14%. The country with highest estimated seroprevalence (14%) was Chile, the country with the lowest was Antigua (0.7%). Largest datasets were available for the U.S. (18 studies) and Brazil (18 studies). Seroprevalence in the U.S. was higher than in Latin/South America (OR = 1.7 [95% CI 1.0 to 2.8]). In detail, U.S. had significantly higher estimated seroprevalence rate (9.5%) in comparison to Brazil (4.9%) independently of assay, patient cohort and methodological quality (p < 0.05).

Seroprevalence correlated inversely with HDI (human development index for assessment of social and economic development) (r: -0.4), improved health care system by means of physician density (r: -0.8) and proportion of elderly in the population (r: -0.4). With respect to meat consumption and HEV seroprevalence there was a clear inverse correlation with beef/calf (r: -0.6).

Conclusion:

Access to improved health care system as well as socio-economic status were negatively associated with HEV seroprevalence. Surprisingly, as the U.S. have improved sanitary and health conditions in comparison to their poorer South American neighbors, the anti-HEV-seroprevalence rate was higher than in many South American states, in particular in comparison to brazil. This may indicate that these factors may not be sufficiently protective.