OBJECTIVE: To determine the distribution, social-demographic, clinical and host characteristics and virulence property [Pathogenicity index (PI)] of rotavirus, norovirus, astrovirus, adenovirus and saporovirus associated with moderate-to-severe diarrhea (MSD) and gut colonization of healthy under-5 community children in Mirzapur, rural Bangladesh.
METHOD: Case-control (case-1394 vs. control-2465) study design for the children who were followed from 2 nd December 2007 to 1 st December 2010. Of them, 389 MSD children and 360 healthy controls with gut colonized assocaited with any of the putative viral pathogens.
RESULT: Rotavirus [overall case (16%) vs. control (3%); p<0.001] was the leading pathogen causing MSD with PI of 5.23; whereas, PI of adenovirus (4% vs. 2%; 0.033] and norovirus group II (GII) [3% vs. 2%; 0.021] were 1.50 and 1.70 respectively. However, PI of sapovirus [1% vs. 2%; 0.032], astrovirus [1% vs. 2%; 0.390] and norovirus group I (GI) [5% vs. 5%; 0.800] were less than 1.0 in MSD children compare to control. Among the cases, children aged 0-23 months were more vulnerable to rotavirus and adenovirus; however, norovirus GII was more common among children aged 24-59 months. Fever (76%), abdominal pain (77%) and vomiting (27%) were the commonly reported clinical features of MSD children. About 24% children presented with some dehydration; and only 4% with severe dehydration. MSD children were more underweight (33% vs. 23%; p<0.001) and wasted (21% vs. 10%; <0.001) than controls. Excess rate of isolation ?5 was found only for rotavirus among children of all age groups.
CONCLUSION: Rotavirus, adenovirus, and norovirus GII were the frequently detected pathogens and among them, rotavirus is the most commonly associated viral pathogen in children with diarrhea in rural Bangladesh. Vaccines and nutritional interventions are the priority strategies to reduce disease burden associated with diverse viral etiologies among under-5 children in this rural community.