Hepatitis A virus subgenotypes dissemination during a community outbreak in a surrounding region of Rio de Janeiro

High prevalence of hepatitis A in indigenous population in north Brazil

Objectives

Little is known about hepatitis A virus (HAV) prevalence in indigenous communities. This study aims to evaluate the prevalence of HAV in indigenous community compared to urban population located at Western Amazon in Brazil.

Results

A total of 872 serum samples were obtained from 491 indigenous and 381 non indigenous individuals aging 0 to 90 years. Samples were tested for total and IgM anti-HAV and positive IgM samples were tested for HAV RNA. The overall prevalence of total anti-HAV was 87%, increased according age showing 100% of prevalence in those aging more than 30 years (p < 0.0001) and it was similar among indigenous and urban population. Total anti-HAV prevalence varied between tribes (p < 0.0001) and urban sites (p = 0.0014) and spatial distribution showed high prevalence in homes that received up to 100 dollars. IgM anti-HAV prevalence was 1.7% with predominance in males, those aging more than 41 years. No HAV RNA was detected. In conclusion, high overall anti-HAV prevalence was found in indigenous communities in North Brazil demonstrating the importance of universal vaccination in this group.

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.

Genotypic shift of the hepatitis A virus and its clinical impact on acute hepatitis A in Korea: a nationwide multicenter study

BACKGROUND

The genotypic shift of hepatitis A virus (HAV) and its correlation with clinical course has not been evaluated in acute hepatitis A (AHA).

METHODS

From June 2007 to May 2009, we prospectively enrolled 546 AHA patients. We performed a nested reverse transcriptase polymerase chain reaction (RT-PCR) using the serum samples in addition to phylogenetic analysis, then we compared patient clinical features.

RESULTS

Among 351 successfully genotyped patients, we found genotype IIIA in 178 patients (51%) and IA in 173 patients (49%). The sequences of genotype IA are identical to previously reported Korean genotype IA, and the new IIIA genotype is closely related to NOR24/Norway. We retrospectively analyzed 41 AHA samples collected from 2000 to 2006 and found that all of them were genotype IA. Patients with genotype IIIA showed significantly higher levels of aspartate aminotransferase, higher levels of alanine aminotransferase, and lower platelet counts than patients with genotype IA when comparing baseline laboratory data or peak/lowest laboratory data during the disease course. However, there were no differences in duration of hospital stay, incidence of cholestatic hepatitis, acute kidney injury, and acute liver failure, or mortality between them.

CONCLUSIONS

A genotypic shift of the HAV was identified in Korean AHA subjects, and genotype IIIA HAV has become endemic. Although there were significant differences in the biochemical responses of AHA between genotype IA and genotype IIIA patients, we did not detect any differences in clinical outcomes such as complications or mortality.