Molecular and clinical epidemiological features of human astrovirus infections in children with acute gastroenteritis in Shandong province, China.

Human astrovirus (HAstV) is one of the most common causative agents of acute gastroenteritis in children with an infection rate estimated to range from 2% to 9% worldwide. This study was aimed at investigating the molecular and clinical epidemiological features of human astrovirus infections in children under 5 years old with acute gastroenteritis in Shandong province, China from July 2017 to June 2018. In total, 376 fecal samples and the corresponding clinical information were collected and analyzed. HAstV infections were detected in all age groups with an overall positive rate of 8.51%. In addition to acute diarrhea, the main clinical manifestations were fever, abdominal pain, vomiting, and dehydration, in which fever was the most common complication. Infections could be seen throughout the year with a peak in the colder season. Four genotypes were detected in which HAstV-1 was the most prevalent genotype with a prevalence of 78.12%, followed by HAstV-5 (9.38%), MLB-1 (9.38%), and MLB-2 (3.12%). HAstV-1 strains were classified as lineage 1a, 1b, and 1d, in which lineage 1a strains were the most prevalent followed by lineage 1b and lineage 1d strains. All HAstV-5 strains were classified as lineage 5b and no other lineages were detected. The results showed that HAstV infection was an important cause of acute gastroenteritis among children under 5 years old in Shandong province. Given that their disease spectrum had been broadened, HAstVs should be paid more attention, not only as a causative agent of acute gastroenteritis but also as a potential pathogen of unexpected diseases.