Genotypic characterization of symptomatic hepatitis E virus (HEV) infections in Egypt.
BACKGROUND
Hepatitis E virus (HEV) is a common cause of acute viral hepatitis (AVH) in many developing countries. In Egypt, HEV seroprevalence is among the highest in the world; however, only a very limited number of Egyptian HEV sequences are currently available.


OBJECTIVE
The objectives were to determine the HEV genotype(s) currently circulating in Egypt.


METHODS
AVH patients without serologic evidence of hepatitis A, B, and C viruses were evaluated for possible HEV infection using serologic assays for anti-HEV IgM and anti-HEV IgG and real-time PCR for HEV RNA. Stool suspensions from suspected cases were inoculated into rhesus macaques to confirm the presence of HEV. Sequence analysis was utilized to determine HEV genotype.


RESULTS
Of 287 subjects with AVH enrolled, 58 had serologic evidence of acute HEV infection. Stool samples for two of these patients were repeatedly positive for HEV RNA by real-time PCR. Macaques experimentally inoculated with these human stools also developed viremia. Sequence analysis of open reading frame (ORF) 1 demonstrated that these isolates belonged to HEV genotype 1 and were 3.9-9.5% divergent from other genotype 1 isolates. ORF2 was 5.3-8.7% divergent from previously reported Egyptian isolates.


CONCLUSIONS
This study strongly suggests that genotype 1 HEV related to other North African isolates is circulating in acute symptomatic patients in Egypt. Further evaluation of genotypic variability is underway in this highly endemic cohort and is considered an important component of our increased understanding of HEV pathogenesis.
Blackard
Jason T
JT
Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. jason.blackard@uc.edu
Rouster
Susan D
SD
Nady
Soad
S
Galal
Gehan
G
Marzuuk
Naglaa
N
Rafaat
Marwaa M
MM
Daef
Enas
E
El Din
Salwa Seif
SS
Purcell
Robert H
RH
Emerson
Suzanne U
SU
Sherman
Kenneth E
KE
Shata
M Tarek
MT
D000818:Animals; D002648:Child; D004534:Egypt; D005243:Feces / Q000821:virology; D005260:Female; D005838:Genotype; D016751:Hepatitis E / Q000821:virology*; D016752:Hepatitis E virus / Q000235:genetics*; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012367:RNA, Viral