Study on actual status of adult rotavirus infections in Southern Asia and Southeastern Asia

点击翻译按钮获取中文摘要

The purpose of this study is to characterize rotaviruses which cause diarrheal diseases in adults in Southern Asian and Southeast Asian regions. This study was performed in collaboration with India, Bangladesh, Thailand, and China. Stool specimens were collected from diarrheal patients in a period between 2003 and 2005. While detection rate of group A rotavirus in children was 25-35%, detection rate in adult ranged from approx. 1% to 10%. In the study in China, most rotavirus strains from children and adults showed identical antigenic types. Group B rotavirus was detected in adult stool specimens in Bangladesh (14 specimens) and China (2 specimens). In India, group B rotavirus was detected by RT-PCR in about 20% of diarrheal stool specimens from children. Phylogenetic analysis of the group B rotaviruses from individual countries indicated that the viruses from India and Bangladesh were genetically closely related but distinct from Chinese viruses. The Indian-Bangladeshi group B rotavir … More uses and Chinese viruses were suggested to be diverged from a common ancestral virus approximately 60-70 years ago based on estimation of mutation rate calculated for Chinese virus strains. In Bangladesh, an unusual rotavirus strain was detected. This virus was genetically different from the known group A, B, and C rotaviruses, and suggested to represent a novel species (group) of rotavirus. As a study on special characteristic of group B rotavirus, i.e., causing diarrhea primarily in adults, nonstructural protein NSP4 was studied for its sequence diversity and presence of enterotoxin activity which is known as one of the mechanisms causing diarrhea in animals. As a result, group B rotavirus NSP4 exhibited high degree of sequence divergence from group A rotavirus NSP4, however, it was demonstrated that sequences near the C-terminal region possess enterotoxin activity in suckling mice. These findings suggested that group B rotavirus may have similar mechanisms for causing diarrhea in human to group A rotavirus. Less