Which of the following is the most common cause of infectious diarrhea in early childhood?

• A. Norovirus
• B. Rotavirus
• C. Salmonella
• D. Adenovirus

Answer: (B)

Rotavirus infection is the most common cause of infectious diarrhea in young children. It spreads easily from person to person through the fecal-oral route and often leads to watery stools, vomiting, and fever, which can quickly cause dehydration in kids. Even though vaccination has greatly reduced severe disease, rotavirus remains the leading cause of infectious diarrheal illness in early childhood in many populations, especially where vaccination coverage isn’t complete. Norovirus also causes gastroenteritis across ages, but in children under five, rotavirus historically accounts for more cases of severe diarrhea requiring medical care. Salmonella and adenovirus can cause diarrhea as well, but they occur less frequently than rotavirus in this age group. So, rotavirus is the best answer because it is the most common infectious cause of diarrhea in early childhood.