Binding Preference of Anti-HEV Antibodies in Sera Collected in Algeria for Antigens Derived From HEV Genotype 1‏

BACKGROUND Two hepatitis E virus (HEV) outbreaks occurred in Algeria (1979 - 1980 and 1987 - 1988). However, to date, no study on the prevalence of anti-HEV antibodies has been conducted in Algeria, and the genotype of the circulating strains remains unclear. OBJECTIVES This study was conducted to investigate the presence of anti- HEV antibodies among outpatients and blood donors in three different hospitals in Northern Algeria and to determine the genotype of the circulating strains through the characterization of the immunoreactivity of anti-HEV antibodies. METHODS A total of 590 blood samples (379 from blood donors and 211 from outpatients) were collected in three health facilities in Northern Algeria and assessed for anti-HEV antibodies using an in-house double-antigen sandwich immunoassay. HEV open reading frame 2 recombinant proteins p166 (aa 452 - 617) generated from the four HEV genotypes were used as antigens. The genotype of the strains circulating in Algeria was predicted by an indirect ELISA by assessing the anti-HEV antibodies in serially diluted positive sera using the different p166 proteins. RESULTS Anti-HEV antibodies were detected in 20.17% of the samples. A significant correlation was found between the age of the subjects and the presence of anti-HEV antibodies (P < 0.001). Among blood donors, 83 (21.9%) were diagnosed positive for anti-HEV antibodies with two cases weakly positive for anti-HEV IgM antibodies. Moreover, 9.9% of the subjects aged less than 25 years old (born after the last HEV outbreak) were positive for anti-HEV antibodies. The indirect ELISA revealed that the anti-HEV antibodies within the positive sera reacted more strongly against the p166 antigens generated from genotype 1. CONCLUSIONS The present findings reveal a relatively high presence of anti-HEV IgGs and clearly indicate that HEV infection is still present in Northern Algeria. Further, the prediction of HEV genotype using different antigens generated from the different HEV genotypes shows that the causative strains are more likely to be of genotype 1.