Genotyping and subtyping are important to understand epidemiology of the hepatitis E virus so as to improve control measures to prevent transmission of virus in the community. Hence, the aim of the current study was to identify the prevalent HEV genotypes in Rajasthan in acute sporadic hepatitis E cases with varying degree of liver failure. We studied hepatitis E virus (HEV) isolates from hospitalized patients in Rajasthan, western India. In a total of seventeen HEV sequences, six acute viral hepatitis, seven acute liver failure, and 4 acute- on-chronic cases were analyzed. Subtypes 1a and 1c of HEV are prevalent in Northwest India. 1. Introduction Hepatitis E is an enterically transmitted disease that spreads through faecal contamination of drinking water. It occurs both in the form of epidemics as well as sporadic infection in developing countries [1, 2]. It is endemic to the Indian subcontinent, where the seroprevalence rate ranges between 4 and 20%. More than 60% of acute viral hepatitis cases are attributed to HEV [3]. Hepatitis E virus affects young to middle aged adults and causes high mortality in pregnant women, 20–30% as compared to 0.2–1% in general population [3]. It has been implicated as an important aetiological agent for sporadic fulminant hepatic failure (FHF) in developing countries [4]. HEV belongs to the genus Hepevirus in the family Hepeviridae and has a 7.2 kb positive-sense single-stranded RNA genome [5]. The HEV genome has three open-reading frames (ORFs). The ORF1, ORF2, and ORF3 encode nonstructural proteins including an RNA-dependent RNA polymerase (RdRp), a capsid protein, and a small protein that possibly induces immune suppression in HEV-infected patients, respectively [6, 7]. Presently, HEV is classified into four major genotypes [8]. Further classification of genotypes into various subtypes was given by Lu et al., 2006 [9]. Genotypes 1 and 2 have been identified exclusively in humans, and genotypes 3 and 4 have been found in humans and several animal species. Genotypes 1 and 2 have been isolated in Asia, Africa, North America; genotype 4 has been identified only in Asia; and genotype 3 has been found in almost every country [10]. All parts of India have been experiencing repeated outbreaks and sporadic cases of HEV since 1955 [11–14] with genotype 1 being prevalent in the human population. With the development of knowledge about the circulation of subtypes of HEV, this study is aimed at the molecular characterization of HEV isolates to determine the most prevalent genotype in Northwest India (Rajasthan). 2. Materials and
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