It has been estimated that wildlife is responsible for 72% of emergent infectious diseases in humans [
1,
2]. In order to limit the spill over of zoonotic agents, improved wildlife pathogen surveillance is required. It is also necessary to gain better insight into viral factors for species specificity. This is true also for Hepatitis E virus (HEV) a pathogen that is present in wildlife, domestic animals and humans [
3,
4]. In developing countries, it causes large scale disease outbreaks in humans as well as endemic infections related to poor sanitary conditions. In countries with good sanitary standards the disease in humans, Hepatitis E, occurs sporadically. Such infections are either acquired during travelling to endemic areas or from a domestic source in the infected person’s home country [
3,
4]. Wild-boars or pigs may constitute such a reservoir [
3,
4] but other species can also play a role. HEV infecting humans only or humans and other mammals are taxonomically divided in four genotypes [
5]. While the large scale epidemics and endemic infections in third world countries as well as cases imported from these countries are caused by hepatitis E of genotype 1 or 2, infecting humans only, the domestically acquired infections in industrialized countries are caused by genotype 3 in Europe and North America or 4 in East Asia. It is widely believed that pigs and wild boars constitute a reservoir for genotype 3 or 4 for human infections and humans may acquire these infections through consumption of undercooked pig, wild boar or deer meat. In France the prevalence of anti-HEV antibodies in the general population was determined to be 3.2%, a figure similar to other industrializes countries [
6]. A survey performed on French pig farms demonstrated a 65% prevalence of anti-HEV antibodies [
7]. Another survey on wild boar demonstrated a prevalence of anti-HEV antibodies between 7.2 and 22.7% in different geographical regions [
8]. No figures for Lyon were available but the highest value came from Aveyron that is relatively close to Lyon. The transmission of HEV between different animal species has not yet been clarified. Furthermore it is not known what determines the pathogenicity and the host range. The current taxonomy is based on a study by Lu et al. [
5] but has been challenged and additional genotypes have been proposed [
9]. HEV has been detected in several species like for example pig, wild boar, deer, moose, rabbit, ferret, mink, rat, poultry and cutthroat trout [
3,
4,
10‐
15]. HEV from pig and wild boar belong to genotype 3 or 4 and are related. HEV from deer belong to genotype 3 [
4] and HEV from rabbits is closely related to genotype 3 [
9] while HEV from moose does not belong to genotype 1-4 [
10]. Avian HEV share only 50% nucleotide identity with genotype 1-4 and cutthroat trout HEV is very distantly related to the others [
14,
15]. Rats can be infected with seemingly rat specific HEV or with genotype 3 [
13,
16]. The zoonotic potential of rat specific HEV is controversial [
17,
18]. Serological investigations have suggested that humans may be infected by rat specific HEV [
19]. It is likely that genotype 1-4 infecting rats can also infect humans. Because
R. norvegicus is a synanthropic species, humans and rats live in close proximity. Rats are well known to transmit pathogens to humans and other animals. Their high prevalence and propensity to carry pathogens make them a potential reservoir for human pathogens including HEV. Indeed, according to previous surveys, antibodies against HEV are highly prevalent in rats [
17] and HEV RNA has been detected in rats (
R. norvegicus and other rat species) in Germany, USA, Vietnam, Denmark, China and Indonesia [
13,
16,
20‐
23]. Differentiation of rat specific HEV from HEV genotype 3 by serology has been published [
19] but is not generally available. Most HEV strains found in rats were of the rat specific type but genotype 3 RNA has also been detected in rats [
16]. It is therefore important to further clarify the role rats may have as a reservoir for human HEV infections. The objectives of this study were to investigate if HEV could be detected in French rats in an urban environment, to determine the type HEV that was present in order to better judge the risk for zoonotic infections and finally to determine the relationship to other previously detected HEV strains order to create a more complete picture of HEV infecting rats.