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Rotavirus diarrhoea mechanism — MRCPCH TAS MCQ

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HardMicrobiologyRotavirus diarrhoea mechanismMRCPCH TAS

A 10-month-old has profuse watery diarrhoea and vomiting. Stool PCR confirms rotavirus. There is no blood in the stool and bicarbonate is low. What mechanism best explains the diarrhoea?

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Correct answer: A — Enterocyte injury with NSP4-mediated secretion

Rotavirus damages mature enterocytes and the NSP4 enterotoxin contributes to secretory diarrhoea. Invasive colitis would be more likely to cause blood and inflammatory features. The pearl is that bicarbonate loss in diarrhoea can produce metabolic acidosis in infants.

Reference: Nelson Textbook of Pediatrics; UKHSA Green Book; RCPCH Theory examination syllabi