Molecular detection and characterization of Aichivirus A in adult patients with diarrhea in Thailand.

Viral gastroenteritis is a common public health problem that causes morbidity and mortality worldwide. Recently, new viruses causing gastroenteritis have been identified. Among these, Aichivirus has also been proposed as a causative agent of gastroenteritis in human. Most studies have been conducted in infants and children, the information in adults is limited. Therefore, the purpose of this study was to investigate the epidemiology and molecular characterization of Aichivirus in adult patients with diarrhea. A total of 332 fecal specimens collected from January to December 2008 were screened for the presence of Aichivirus by reverse transcription-PCR (RT-PCR) method. Out of 332 fecal specimens tested, Aichivirus was detected with the prevalence of 0.9% (3/332). The data indicate that the prevalence of Aichivirus in adults was as low as those reported in children in Thailand. Phylogenetic analysis of the VP1 sequence revealed that one Aichivirus belonged to genotype A, while other two Aichiviruses were genotype B. In conclusion, this study provided the molecular epidemiological data of Aichivirus circulating in adult patients with diarrhea at low prevalence and the viruses were genetically variable as both genotypes A and B were found in this population.