Epidemiology of Aichi virus in fecal samples from outpatients with acute gastroenteritis in Northwestern Spain.

• Prevalence of Aichi virus was determined in outpatients from NW Spain. • The virus was detected in 5.0% of the samples among all age groups. • Monoinfections (58.1%) were more abundant than mixed infections (41.9%). • Genotypes A and B were detected in all age groups. In recent years, Aichi virus (AiV) has been involved in acute viral gastroenteritis outbreaks. However, the common pathogenesis of AiV releases more in subclinical infections underestimating the impact of AiV in human health. The present study describes the presence and genetic diversity of AiV in patients with gastroenteritis in Northwestern Spain. Study design: A total of 2667 stool samples, obtained between July 2010 and June 2011, from diarrheic outpatients were studied for detection and molecular characterization of AiV using PCR techniques followed by sequencing and phylogenetic analyses. The virus was detected in 124 (5.0%) of the samples among all age groups. Coinfections were also detected, from the 124 positive samples, 72 (58.1%) were positive only for AiV, whereas mixed contaminations with Norovirus genogroup I or genogroup II, Sapovirus, or other enteric pathogens were detected in 52 (41.9%) samples. A total of 70 positive samples could be genotyped, being characterized as genotype A (58.6%) or B (41.4%). AiV was detected from August to April, being the highest number of AiV positive samples detected during autumn and winter seasons. This survey remarks the importance of emerging enteric viruses in patients who require medical assistance, and offers more information about the real importance of AiV as gastroenteritis agent. [ABSTRACT FROM AUTHOR]