Epidemiological and molecular investigation of a hepatitis A outbreak in Tamil Nadu, Southern India.

Introduction: Hepatitis A virus causes an acute infection mainly in young children. The present study was carried out to characterize the nature of hepatitis A virus (HAV) involved in an outbreak of jaundice in children.

Methodology: Serum and stool samples from five children were sampled from among 26 clinically diagnosed jaundice cases. HAV IgM ELISA and PCR were used for confirmatory diagnosis and molecular characterization by direct amplicon sequencing and analysis.

Results: All the serum samples collected from the symptomatic cases were found to be positive for Anti-HAV IgM ELISA as were all the serum samples and stool samples using semi-nested PCR. Phylogenetic analysis revealed that the HAV involved in the outbreak belonged to genotype IIIA.

Conclusions: The infection was caused by HAV genotype IIIA. Improved access to clean drinking water, sanitation around drinking water sources and routine chlorination of drinking water in poor and developing countries are needed, as well as childhood HAV vaccination under regular immunization programs in endemic countries.