Identification of genotype 4 hepatitis E virus strains from a patient with acute hepatitis E and farm pigs in Bali, Indonesia

Abstract

A previous study revealed that antibodies to hepatitis E virus (HEV) (anti-HEV) are highly prevalent among healthy individuals and farm pigs in Bali, Indonesia, and suggested that HEV infection may occur via zoonosis among Balinese people. However, there were no reports of acute hepatitis E in Bali. To elucidate whether Balinese HEV strains recovered from infected humans and pigs have significant sequence similarity, serum samples obtained from 57 patients (age, mean +/- standard deviation, 31.1 +/- 11.9 years) with sporadic acute hepatitis and from one hundred and one 2- or 3-month-old farm pigs in Bali were tested for anti-HEV and HEV RNA. Among the 57 patients, 2 (3.5%) had high-titer IgM/IgA class anti-HEV antibodies and one of them had detectable HEV RNA (BaliE03-46). Overall, 58 pigs (57.4%) tested positive for anti-HEV, while 5 pigs (5.0%) had detectable HEV RNA. Based on the 412-nucleotide sequence within open reading frame 2, the BaliE03-46 isolate and the 5 swine HEV isolates recovered from the viremic pigs were phylogenetically classified in genotype 4, but were only 77.3-90.8% identical to the genotype 4 HEV isolates reported thus far in China, India, Japan, Taiwan, and Vietnam. The BaliE03-46 isolate of human origin shared high identities of 97.3-98.3% with 4 of the 5 Balinese swine isolates, but differed by 16.1% from the remaining swine isolate. These results suggest that indigenous HEV strains of genotype 4 with marked heterogeneity are circulating in Bali, Indonesia, and that pigs are reservoirs of HEV for Balinese people who have a habit of ingesting uncooked pigs.

The first case of genotype 4 hepatitis E related to wild boar in South Korea

“…[5][6][7][8][16][17][18][19] Moreover, there are many published articles about zoonotic transmission of HEV from wild boar to humans in rural area as well as urban regions. 20,21 Therefore, hepatitis E should be tested in patients with unexplained hepatitis.…”

“…Sporadic cases of genotype 3 or 4 acute hepatitis E have recently been reported in several developed countries such as France, Germany and Japan. [5][6][7][8]16,17 One report from Bali, Indonesia showed the nucleotide sequence homology of genotype 4 HEV within person and animal (pigs), 18 and the nucleotide sequence homology between 2010-BSNU-AYC with BaliE03-46(AB298178), was about 86%.…”

Emergence of Autochthonous Infections with Hepatitis E Virus of Genotype 4 in Europe

“…The HEV molecular epidemiology has been found to be complex in this country, as several HEV-4 subtypes, including subtypes b and d, have been detected, and sequences recovered from humans were found (although inconsistently) to share a high level of nucleotide similarity with those found from swine in the same geographical area [19,20,22]. Otherwise, HEV-4 have been collected in India, Indonesia, South Korea, Taiwan and Vietnam [18,20,23,24,25,26,27], including in autochthonous hepatitis E, and an epidemiological link with pigs or wild boars has been observed in cases diagnosed in Bali and South Korea [14,23,25]. In addition, HEV-4 infection was reported in 2010 in England in a patient who returned from a 2-month stay in India 1 month before presenting jaundice [28].…”

Sources of Hepatitis E Virus Genotype 3 in the Netherlands

“…The fi rst animal in which HEV genotype 3 was identifi ed and characterized was pig in the United States (6). HEV strains of genotypes 3 and 4 have since been detected in pigs in many other countries, and these strains were found to be genetically closely related to HEV strains originating from humans in the same geographic region (7,8). Serologic studies have also indicated a broad host range of HEV.…”