Epidemiology of astrovirus infection in children

Abstract

Human astrovirus (HAstV) is a major cause of acute diarrhea among children, resulting in outbreaks of diarrhea and occasionally hospitalization. Improved surveillance and application of sensitive molecular diagnostics have further defined the impact of HAstV infections in children. These studies have shown that HAstV infections are clinically milder (diarrhea, vomiting, fever) than infections with other enteric agents. Among the 8 serotypes of HAstV identified, serotype 1 is the predominant strain worldwide. In addition to serotype 1, the detection rate of HAstV types 2 to 8 has increased by using newly developed assays. HAstV is less common compared with other major gastroenteritis viruses, including norovirus and rotavirus; however, it is a potentially important viral etiological agent with a significant role in acute gastroenteritis. A better understanding of the molecular epidemiology and characteristics of HAstV strains may be valuable to develop specific prevention strategies.

Keywords: Acute gastroenteritis; Diarrhea; Epidemiology; Human astrovirus; Serotype.

Fig. 1

Phylogram including human astrovirus (HAstV) serotypes 1 to 8, feline AstV, porcine AstV, ovine AstV, turkey AstV, and avian nephritis virus. Neighbor-joining phylogenetic tree was constructed on the basis of nucleotide sequences of the capsid region of the HAstV genome. The numbers in the branches indicate the bootstrap values. Reference strains of HAstV selected from GenBank are indicated by accession numbers. The scale indicates nucleotide substitutions per position.

Fig. 2

Regional variation in the distribution of human astrovirus (HAstV) serotypes (n=436) ascertained by analysis of strains in Asia.