Analysis of Aichi virus and Saffold virus association with pediatric acute gastroenteritis

Background: Aichi virus (AiV) and Saffold virus (SAFV) have been reported in children with acute gastroenteritis and respiratory disease worldwide; however, their causative role in acute gastroenteritis remains ambiguous.

Objectives: To assess the clinical association of AiV and SAFV with acute gastroenteritis in the pediatric population.

Study design: A case-control study involving 461 paired stool samples from pediatric cases with diarrhea and healthy controls was conducted in China. Quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) was used to screen AiV and SAFV.

Results: In the 461 paired samples, AiV and SAFV were more prevalent among asymptomatic children than children with acute gastroenteritis (0.87% vs. 0.43% and 2.8% vs. 1.5%, respectively), with no significant differences between groups (p=0.142 and p=0.478, respectively). Cox regression model analysis revealed no correlation between AiV (odds ratio, OR=2.24; 95% confidence interval, CI, 0.76-6.54) or SAFV infection (OR=1.36; 95% CI, 0.86-2.15) and diarrhea. High viral loads were found in both AiV- and SAFV-positive groups, with no significant difference in viral load between the groups (p=0.507 and p=0.677, respectively). No other known enteric pathogens were found in the AiV-positive samples but common in SAFV-positive cases. Phylogenetic analysis revealed that all 6 AiV subjects clustered with genotype B. All 7 SAFV-positive cases and 8 of 13 SAFV-positive controls were genotyped successfully; the genotypes identified included SAFV-1, SAFV-2 SAFV-3, and SAFV-6.

Conclusion: Our study revealed no association of these viruses in acute gastroenteritis in children. These viruses may have the ability to replicate in humans; however, the infections are usually asymptomatic.