Epidemiologic Patterns of Wild-Type Hepatitis A Virus Determined by Genetic Variation

Abstract

Hepatitis A virus (HAV) isolates from different parts of the world are a single serotype. However, genetic analysis of the VP1 genome region of published HAV sequences suggested that distinct genotypes of HAV could be defined based upon the geographic source ofthe original isolates. To circumvent the process of cell culture adaptation or animal passage, a 247-bp segment within the VP1 genome region of wild-type HAV was amplified by reverse transcription followed by polymerase chain reaction amplification in the presence of negative- and positive-sense primers. From the sequences obtained from 22 epidemiologically distinct HAV isolates, three genetic groups ofHAV could be delineated. Two of the groups differed by 10%, while the third group differed from other isolates by ∼20%. These investigations indicate that HAV isolates from different parts of the world can be differentiated genetically, which will facilitate studies of epidemiologic transmission.