Isolation and Molecular Characterization of Aichi Viruses from Fecal Specimens Collected in Japan, Bangladesh, Thailand, and Vietnam

Abstract

Aichi virus is a new member of the family Picornaviridae, genus Kobuvirus, and is associated with human gastroenteritis. This study detected Aichi virus in 28 of 912 fecal specimens which were negative for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus and were collected in Japan, Bangladesh, Thailand, and Vietnam during 2002 to 2005.Aichi virus, a small round virus about 30 nm in diameter, was first recognized in 1989 as the cause of oyster-associated nonbacterial gastroenteritis in humans (8-10). The virus was classified into a new genus named Kobuvirus of the family Picornaviridae (11), which contains nine genera, Aphthovirus, Cardiovirus, Enterovirus, Erbovirus, Hepatovirus, Kobuvirus (which includes Aichi virus and bovine kobuvirus), Parechovirus, Rhinovirus, and Teschovirus. The complete Aichi virus genome was determined in 1998 and proved to be a singlestranded positive-sense RNA molecule with 8,251 bases, excluding a poly(A) tail; it contains a large open reading frame with 7,302 nucleotides that encodes a potential polyprotein precursor of 2,433 amino acids (11). In 2000, a reverse transcription (RT)-PCR method for the detection of Aichi virus was developed and a genetic analysis was performed with the 519-base RNA sequences at the putative junction between the C terminus of 3C and the N terminus of 3D. As a result, Aichi virus isolates have been divided into groups 1 (genotype A) and 2 (genotype B) (12).Studies on Aichi virus were subsequently performed, and it was also detected in Brazil and Germany (2-7). However, there has been limited knowledge about the epidemiology of Aichi virus infection in Asian countries other than Japan and Pakistan. This study was performed to determine the prevalence of Aichi virus in Bangladesh, Thailand, Vietnam, and also in Japan and to provide a better understanding of the epidemiology and genetic relationships between the Aichi virus strains in the present study and the strains previously reported.A total of 912 stored, extracted RNA samples from fecal specimens known to be negative for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus by RT-PCR that were collected from patients with acute gastroenteritis in Japan (215 samples collected

Acute Infantile Gastroenteritis Associated with Human Enteric Viruses in Tunisia

“…The Aichi virus is known as an agent causing gastroenteritis associated with oyster consumption (43). Its involvement in gastroenteritis in children has recently been shown, but this remains a rare event (2,28,35). These recent data and our present results support the idea of a role of Aichi virus in cases of gastroenteritis and suggest that oysters may not be the only vector for transmission of the virus.…”

Bovine Kobuviruses from Cattle with Diarrhea

“…To date, the genus Kobuvirus consists of 2 species, Aichi virus and bovine kobuvirus (2). The Aichi virus is associated with acute gastroenteritis in humans (3)(4)(5); bovine kobuvirus infection has been detected only in cattle (1). Only 1 report has described the discovery and epidemiologic features of bovine kobuvirus (1).…”

Detection and Genomic Characterization of Aichi Viruses in Stool Samples from Children in Monastir, Tunisia

“…Just as in adults, there has been limited knowledge about the epidemiology of Aichi virus infection in children. Its presence in fecal specimens of children suffering from diarrhea has been demonstrated in several Asian countries (5,13), in Brazil (4), and in France (1). Nevertheless, despite the low incidence of Aichi virus encountered in sporadic and epidemic cases, several studies of seroprevalence conducted in Japan (12), Germany (4), Spain (J. Buesa, personal communication, 28 September 2007), and more recently in France (2) indicated that this virus is quite common.…”