Rotavirus and Enteric Viruses

Which of the following is the primary mechanism by which rotavirus causes acute watery diarrhea in infants and young children?

A 18-month-old boy from rural Madhya Pradesh presents to the pediatric ward with a 3-day history of profuse watery diarrhea, vomiting, and fever (38.5°C). The mother reports the child attends a local anganwadi where several other children have similar symptoms. On examination, the child appears lethargic with sunken eyes and skin turgor loss. Stool is non-bloody, pale yellow, and watery. Serum electrolytes show Na⁺ 128 mEq/L, K⁺ 2.8 mEq/L, and HCO₃⁻ 16 mEq/L. Stool microscopy is negative for RBCs, WBCs, and parasites. Electron microscopy of stool shows wheel-shaped viral particles. Which is the most likely causative agent?

A 3-year-old girl from urban Chennai presents with acute-onset watery diarrhea (8–10 stools/day), vomiting, and abdominal cramping for 2 days. She attends a private daycare center where 5 other children have similar symptoms in the past week. On examination, she is afebrile (37.2°C), has mild dehydration, and a soft, non-distended abdomen. Stool culture is negative for bacterial pathogens. A rapid immunochromatographic test on stool detects rotavirus antigen. The child received her first dose of rotavirus vaccine 6 weeks ago. What is the most likely explanation for the infection despite prior vaccination?

Rotavirus belongs to which family of viruses and possesses which characteristic structural feature that distinguishes it from other enteroviruses?