Etiologic investigation in an acute diarrhea outbreak and genetic analysis of human adenovirus serotype 41 strains

Abstract

Objective To identify the causative agent of an acute diarrhea outbreak in a school in Taian, Shandong, and to analyze the genetic characteristics of the pathogenic virus. Methods A total of nineteen samples including anal swabs from the diarrheal patients and related staff in the school canteen and environmental samples were collected. These samples were tested for common pathogens causing viral diarrhea by quantitative real-time PCR (qPCR), followed by high-throughput sequencing to obtain the viral genome sequences of the qPCR positive samples. Genetic characterizations of the causative agent were further studied including nucleotide and amino acid sequence identity and phylogenetic analysis. Results Seven of the 19 samples tested positive for adenovirus by qPCR, with the positive rate of 36.8%. Whole-genome sequences of human adenovirus serotype 41 (HAdV-F41) were obtained from the anal swab of Patient 10 and the tableware of Patient 4, with the nucleotide and amino acid identity of 100% between them. Phylogenetic analyses of the full-length genome, hexon gene, and fiber gene sequences showed that the HAdV-F41 strain discovered in this study had high homology with strains previously described from China, the United States, Japan, Iraq, and other countries. Conclusion Our findings indicated that HAdV-F41 was the causative agent responsible for the acute diarrhea outbreak in Taian, which shared high homology with previously reported HAdV-F41 strains worldwide. These results enriched the genetic resource of HAdV-F41 in Shandong and provided a theoretical basis for the prevention and control of acute diarrhea in children caused by adenoviruses.

Keywords

• human adenovirus f41
• diarrhea
• high-throughput sequencing
• genetic analysis