Genetic analysis of hepatitis A virus variants circulating among children presenting with acute diarrhea in Cameroon

Area of Science:

• Virology
• Molecular Epidemiology
• Public Health

Background:

• Hepatitis A virus (HAV) is a significant cause of acute gastroenteritis globally.
• Understanding the molecular epidemiology of HAV is crucial for effective control strategies, especially in resource-limited settings.
• Acute diarrhea in young children is a major public health concern in many African regions.

Purpose of the Study:

• To investigate the molecular characteristics of circulating hepatitis A virus (HAV) strains associated with acute diarrhea in children under 5 years in Kumba, Cameroon.
• To identify the specific HAV genotypes and subgenotypes prevalent in the study population.
• To assess the genetic relatedness and potential common source of HAV infections.

Main Methods:

• Molecular investigation of stool samples from children with acute diarrhea.
• Reverse transcription PCR (RT-PCR) for viral RNA detection.
• Sequencing and phylogenetic analysis of the VP1/P2A junction region (371 bp) of HAV isolates.
• Tajima's neutralization tests to assess population dynamics.

Main Results:

• Six HAV isolates were obtained, all belonging to subgenotype IA.
• The Cameroonian HAV isolates formed a distinct cluster with 99.5% nucleotide identity, suggesting a common source.
• Phylogenetic analysis indicated that these isolates did not cluster with HAV strains from other global regions.
• Tajima's neutralization tests suggested population expansion of HAV/IA (D = -1.37; P = 0.016).

Conclusions:

• This study provides the first description of indigenous HAV genotypes circulating in Cameroon, specifically subgenotype IA.
• Findings reveal a community-wide spread and predominance of HAV/1A infection in the Kumba area.
• The results underscore the importance of routine molecular tracking of HAV as a cause of acute diarrhea in Cameroonian children.