Molecular epidemiology of hepatitis A virus in patients in the ahwaz region of Iran

Detection and Phylogenetic Analysis of Hepatitis A Virus in the Wastewater Treatment Plant of Ekbatan Town in Tehran, Iran

Background: Limited sources of fresh water necessitate the application of health policies for treatment and decontamination of human sewage for further use. A wide variety of infectious agents, including bacteria, fungi, parasites, and viruses, can be found in sewage. Enteric viruses such as hepatitis A virus (HAV) can survive the current treatments and infect susceptible hosts. Objectives: This study aimed to evaluate HAV contamination in human sewage before and after treatment in the wastewater treatment plant of Ekbatan town in Tehran, Iran, and analyze the phylogenetic properties of the identified viruses. Methods: Over a 12-month period, we collected the wastewater samples including influent, before chlorination, and effluent, from the wastewater treatment plant of Ekbatan town in Tehran, Iran. Ribonucleic acid (RNA) extraction, complementary deoxyribonucleic acid (cDNA) synthesis, and semi-nested polymerase chain reaction (PCR) were performed to identify HAV contamination. Phylogenetic analysis was performed to investigate subgenotypes of the virus. Results: HAV was detected in all influents and samples before chlorination, while the virus was detected in 50% of the effluent samples. All detected viruses belonged to subgenotype IB. Conclusions: Investigating the presence of HAV in sewage provides a general picture of the virus spread in the population of interest. HAV was detected in all influent samples, indicating that the infection is endemic in this area all year round. This also indicates the inability of the current treatment protocols in virus removal, which can be a threat to the public health.

Classification and Genomic Diversity of Enterically Transmitted Hepatitis Viruses

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are significant human pathogens and are responsible for a substantial proportion of cases of severe acute hepatitis worldwide. Genetically, both viruses are heterogeneous and are classified into several genotypes that differ in their geographical distribution and risk group association. There is, however, little evidence that variants of HAV or HEV differ antigenically or in their propensity to cause severe disease. Genetically more divergent but primarily hepatotropic variants of both HAV and HEV have been found in several mammalian species, those of HAV being classified into eight species within the genus Hepatovirus in the virus family Picornaviridae. HEV is classified as a member of the species Orthohepevirus A in the virus family Hepeviridae, a species that additionally contains viruses infecting pigs, rabbits, and a variety of other mammalian species. Other species (Orthohepevirus B-D) infect a wide range of other mammalian species including rodents and bats.

Hepatitis A among refugees, asylum seekers and migrants living in hosting facilities, Greece, April to December 2016

An increased number of hepatitis A cases among refugees, asylum seekers and migrants residing in hosting facilities in Greece were recorded between April and December 2016. In total, 177 laboratory-confirmed symptomatic cases were reported; of these, 149 (84%) occurred in hosting camps mostly among Syrian children under 15 years. All cases reported symptom onset after their entry into the country. Public health interventions focused on hygiene measures and vaccination.

Hepatitis A virus: host interactions, molecular epidemiology and evolution

Infection with hepatitis A virus (HAV) is the commonest viral cause of liver disease and presents an important public health problem worldwide. Several unique HAV properties and molecular mechanisms of its interaction with host were recently discovered and should aid in clarifying the pathogenesis of hepatitis A. Genetic characterization of HAV strains have resulted in the identification of different genotypes and subtypes, which exhibit a characteristic worldwide distribution. Shifts in HAV endemicity occurring in different parts of the world, introduction of genetically diverse strains from geographically distant regions, genotype displacement observed in some countries and population expansion detected in the last decades of the 20th century using phylogenetic analysis are important factors contributing to the complex dynamics of HAV infections worldwide. Strong selection pressures, some of which, like usage of deoptimized codons, are unique to HAV, limit genetic variability of the virus. Analysis of subgenomic regions has been proven useful for outbreak investigations. However, sharing short sequences among epidemiologically unrelated strains indicates that specific identification of HAV strains for molecular surveillance can be achieved only using whole-genome sequences. Here, we present up-to-date information on the HAV molecular epidemiology and evolution, and highlight the most relevant features of the HAV-host interactions.