Epidemiological and virological characteristics of symptomatic acute hepatitis E in Greater Cairo, Egypt

The aim of the study was to describe the characteristics of acute hepatitis E in Greater Cairo. Patients with acute hepatitis E were identified through a surveillance of acute hepatitis using the following definition: recent (<3 weeks) onset of fever or jaundice, alanine aminotransferase at least three times the upper limit of normal (uln), negative markers for other causes of viral hepatitis and detectable hepatitis E virus (HEV) RNA. Comparison of the liver tests between acute hepatitis E and hepatitis A virus (HAV), case-control analysis (four sex-matched and age-matched (±1 year) HAV controls per case) to explore risk factors and phylogenetic analyses were performed. Of the 17 acute HEV patients identified between 2002 and 2007, 14 were male. Median age was 16 years (interquartile range 13-22). Compared with HAV (n = 68 sex-matched and ±1 year age-matched), HEV patients had higher bilirubin (mean (SD) 10.9 (5.7) uln versus 7.5 (4.4) uln, p 0.05) and aspartate aminotransferase levels (38.6 (27.1) uln versus 18.3 (18.1) uln, p 0.02). Co-infection (hepatitis C virus RNA or hepatitis B surface (HBs) -antigen positive/IgM anti-hepatitis B core (HBc) anitgen negative) was diagnosed in four patients. In univariate matched analysis (17 cases, 68 matched controls), HEV cases were more likely to live in a rural area than HAV controls (matched OR 7.9; 95% CI 2.0-30.4). Of the 16 isolates confirmed as genotype 1, 15 belonged to the same cluster with 94-98.5% identity in the open-reading frame 2 region. Our findings documented the sporadic nature of HEV in Greater Cairo, characterized a large number of Egyptian HEV genotype 1 strains and identified living in a rural area as a potential risk factor for infection.