HUMAN SAPOVIRUS AMONG OUTPATIENTS WITH ACUTE GASTROENTERITIS IN SPAIN: A ONE YEAR STUDY

Viral agents of human gastroenteritis affect people of all ages across the globe. Most of the epidemiology has no clinical diagnosis as it is mainly a self-limiting disease, and sometimes asymptomatic. Therefore, it is difficult to correctly evaluate the real prevalence of etiological agents circulating in each region. Many of the diagnosed episodes are caused by viruses belonging to the family Caliciviridae, in which genus Sapovirus is included. Nowadays, studies are mainly focused on analyzing other enteric viruses, such as norovirus, leaving sapovirus (SaV) underestimated as an important emerging treat to human health.This one year study analyzed clinical samples from hospital outpatients with acute gastroenteritis in Spain, with the aim of revealing the importance of human SaV as an emerging viral pathogen among the population. A total of 2,667 stools were tested using RT-qPCR methodology to detect and quantify sapovirus, and RT-nested PCR for posterior genotyping of positive samples.General prevalence of SaV was 15.64 % (417 positive samples), being slightly higher in 0-2 and 3-5 years old (19.5 and 17.9 %, respectively), and much lower in 13-18 (9.9 %). Positive samples were detected along all the year, with peaks of detection during some autumn and late winter – spring months. Mean value for quantified samples was 6.5 x 105 SaV genome copies per gram of stool, with the age-group between 0-2 presenting the highest quantitation, and elders (≥60 years old) the lowest.Genetic characterization showed a predominance of GI, with 91 genotype I.1 and 32 genotype I.2 sequences, followed by GII with 21 genotype GII.1 and 21 GII.4 samples, and finally 5 belonging genogroup IV. Sequence similarities between samples from nearby dates were analysed searching for their implication in possible outbreaks or strain circulation.