Isolation of hepatitis E virus genotype 4 from patients with acute cryptogenic hepatitis in Korea

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Autochthonous hepatitis E occurs sporadically in developed countries. The consumption of undercooked pork containing hepatitis E virus genotype 3 (HEV-3) or 4 (HEV-4) is the major risk factor for infection. The serological diagnostic kits currently used in hospitals sometimes produce false-negative or −positive results. Therefore, detection of both HEV RNA and antibodies to the virus is required for confirmative diagnosis of hepatitis E.</P> <P><B>Objectives</B></P> <P>We aimed to detect HEV in serum samples from patients with cryptogenic hepatitis and to determine the origin of HEV.</P> <P><B>Study design</B></P> <P>A nested polymerase chain reaction (PCR) method was developed for detection of HEV-3 and HEV-4 in patients with hepatitis. A total of 23 serum samples, deposited in 2006–2012, from patients with acute cryptogenic hepatitis who were serologically negative for hepatitis A, B, C, and E were examined using this method. The amplified PCR products were genetically analyzed.</P> <P><B>Results</B></P> <P>Four HEV-4 isolates were detected from the 23 serum samples. Phylogenetic analysis indicated that three of the four isolates were closely related to HEV-4 isolates found in pigs in Korea and in patients with hepatitis E in Japan.</P> <P><B>Conclusions</B></P> <P>The newly developed nested PCR method was useful for detection of HEV in patients with cryptogenic hepatitis. The close relationship between the human HEV-4 isolates identified in this study and swine isolates implied that zoonotic transmission of HEV might be a source of infection in patients with hepatitis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A nested PCR method was developed for detection of HEV-3 and HEV-4. </LI> <LI> HEV-4 isolates were identified in serum of patients with cryptogenic hepatitis. </LI> <LI> These isolates were closely related to swine and Japanese HEV-4 strains. </LI> </UL> </P>