Identification of sapovirus infection among Japanese infants in a day care center

Abstract

A total of 921 fecal specimens collected from 44 infants in a day care center in Tokyo, Japan during June 1999 to July 2000 were tested for the presence of sapovirus by reverse transcription-polymerase chain reaction (RT-PCR). Of 88 fecal specimens from infants with acute gastroenteritis, 2.3% (2) were found to be positive for sapovirus. Twenty-two of 833 (2.6%) fecal specimens collected from asymptomatic infants were also infected with this virus. Another interesting feature was the demonstration of high incidence of sapovirus infection (95.5%, 21 of 22) identified in a single day care center, which was not due to viral shedding after the latest acute gastroenteritis. Sapovirus was subjected to genetic analysis by sequencing. Up to 4 of 24 sapoviruses (16.7%) were clustered into genogroup IV known as a rare group. Remarkably, majority (79.2%, 19 of 24) of sapovirus isolates detected in this study turned out to present one novel sapovirus genotype tentatively called GI/8. It was noteworthy to point out that the GI/8 sapovirus infection was apparently confined only within the period of 9 weeks (44th through 52nd weeks). This pattern of infection implied the outbreak of asymptomatic GI/8 sapovirus infection in these subjects. The findings clearly indicate genogroup I sapovirus can be classified into eight genotypes. This is the first report to underscore that sapovirus pathogen causes not only clinical manifestations of acute gastroenteritis but also asymptomatic infection in infants in day care centers in Japan.

Comprehensive Review of Human Sapoviruses

“…Subclinical (asymptomatic) sapovirus infection was also detected (4,6,21,134,135,(213)(214)(215)(216). Quantitative PCR analysis revealed that asymptomatic individuals also shed sapovirus in the feces at levels comparable to those shed by individuals with gastroenteritis (182,183).…”

Molecular detection of genogroup I sapovirus in Tunisian children suffering from acute gastroenteritis

“…Noroviruses are a major cause of both sporadic cases and outbreaks of gastroenteritis [4][5][6][7] whereas sapoviruses have been detected in many areas in the word but only infrequently, a few outbreaks of sapovirus have been reported [8][9][10][11][12] and the impact of the sapoviruses has not been fully established. Sapoviruses were primarily associated with cases of pediatric acute gastroenteritis [13][14][15][16][17][18][19][20][21].…”

Prevalence of diarrhea viruses in hospitalized children in Hong Kong in 2008

“…There have been reports of sapovirus outbreaks involving children [Akihara et al, 2005;Phan et al, 2006] and adults [Johansson et al, 2005;Yan et al, 2005] all over the world. Adenovirus and astrovirus has been detected in patients with diarrhea in many countries, including China (2% and 8%, respectively) [Liu et al, 2006], Botswana (2.8% and 2.7%) [Basu et al, 2003], Tunisia (6% and 7%) [Fodha et al, 2006], Argentina (3% and 7.6%) [Giordano et al, 2001;Bereciartu et al, 2002], Italy (6% and 7%) [Galdiero et al, 2005;Colomba et al, 2006], and United Kingdom (7.9% and 2.3%) [Simpson et al, 2003].…”