[How to investigate and diagnose autochthonous hepatitis E?]

Seroprevalence of Hepatitis E Virus Infection Among People Living With HIV in the Central African Republic

Background

Hepatitis E virus (HEV) is a waterborne virus that causes acute hepatitis in immunocompromised patients and those who are immunocompetent. Few cases of chronic HEV have been described in industrialized countries. The Central African Republic is 1 of the few countries in the world that is endemic for both HIV and HEV. The prevalence of HIV infection is estimated to be 4.9% among adults aged 15-49 years, and hepatitis E is epidemo-endemic. The aim of this study was to characterize the epidemiology of HEV infection in people living with HIV (PLHIV) in Bangui.

Methods

A cross-sectional study was conducted between April and September 2015 based on answers to a questionnaire, and blood samples were collected for determination of immunological markers by enzyme-linked immunosorbent assay and molecular tests.

Results

Of the 200 PLHIV included, 15 (7.5%) had the IgM that characterizes acute HEV infection; 8.9% were women, and 2.2% were men. The overall seroprevalence of IgG was 68% (48% women and 70.4% men), indicating that men are statistically significantly more exposed to HEV than women. HEV infection had no effect on transaminase or T-CD4+ lymphocyte cell levels. The origin of infection could not be identified.

Conclusions

The seroprevalence of HEV is very high among PLHIV and in the general population of Bangui. This must be taken into account in studies of the risk factors of PLHIV infected with HEV.

Hepatitis E virus in Italy: molecular analysis of travel-related and autochthonous cases

Human hepatitis E virus (HEV) is considered an emerging pathogen in industrialized countries. The aim of the present study was to contribute to the body of knowledge available on the molecular epidemiology of acute hepatitis E in Italy. Three sets of HEV-specific primers targeting the ORF1 and ORF2 were used to examine serum samples collected from acute hepatitis patients positive for anti-HEV IgG and/or IgM, between 2007 and 2010. Seventeen patients (39.5%) tested HEV RNA-positive: 12 infections, due to genotype 1, were associated with travel to endemic areas (Bangladesh, India and Pakistan), while five infections, due to genotype 3, were presumably autochthonous. Risk factors identified in this group included exposure to raw seafood, pork liver sausages and wild boar. Results from the present study confirm that human HEV infection in Italy is caused by different genotypes, depending on whether the infection is travel-related or autochthonous.

Molecular detection of hepatitis E virus in sewage samples

Human hepatitis E virus (HEV) is considered an emerging pathogen in industrialized countries. In Italy, the true burden of HEV infection is unknown. Molecular HEV screening of raw sewage samples from 11 wastewater treatment plants yielded 19 positives (16%; 18 genotype I, 1 genotype III) evenly distributed throughout Italy. Evidence that HEV could be establishing itself in our region is accumulating and may justify more active surveillance to monitor its spread.

Zoonotic hepatitis E: animal reservoirs and emerging risks

Hepatitis E virus (HEV) is responsible for enterically-transmitted acute hepatitis in humans with two distinct epidemiological patterns. In endemic regions, large waterborne epidemics with thousands of people affected have been observed, and, in contrast, in non-endemic regions, sporadic cases have been described. Although contaminated water has been well documented as the source of infection in endemic regions, the modes of transmission in non-endemic regions are much less known. HEV is a single-strand, positive-sense RNA virus which is classified in the Hepeviridae family with at least four known main genotypes (1–4) of mammalian HEV and one avian HEV. HEV is unique among the known hepatitis viruses, in which it has an animal reservoir. In contrast to humans, swine and other mammalian animal species infected by HEV generally remain asymptomatic, whereas chickens infected by avian HEV may develop a disease known as Hepatitis-Splenomegaly syndrome. HEV genotypes 1 and 2 are found exclusively in humans while genotypes 3 and 4 are found both in humans and other mammals. Several lines of evidence indicate that, in some cases involving HEV genotypes 3 and 4, animal to human transmissions occur. Furthermore, individuals with direct contact with animals are at higher risk of HEV infection. Cross-species infections with HEV genotypes 3 and 4 have been demonstrated experimentally. However, not all sources of human infections have been identified thus far and in many cases, the origin of HEV infection in humans remains unknown.