Date Published: April 17, 2007
Publisher: Public Library of Science
Author(s): David C. A Candy
Abstract: Candy discusses a new study inPLoS Medicine that challenges the view that in children with rotavirus diarrhea, the virus is confined to the upper small intestine.
Partial Text: Since the 1950s, rotavirus has been recognized in veterinary circles as an important cause of diarrhoea in young livestock and poultry. In the 1970s, the virus was found to be a cause of infantile diarrhoea in humans , and after this discovery rotavirus rapidly became established as the most prevalent cause of paediatric diarrhoea .
Rotavirus preferentially infects the mature villous enterocytes (intestinal epithelial cells) of the upper small intestine . The microcirculation of jejunal villi responds (by constricting and dilating) to infection in infant mice, but viral particles are not seen by electron microscopy in the tissues of the lamina propria beneath the epithelial layer or within mucosal blood vessels . Inflammatory changes in the jejunal epithelium and lamina propria are not striking compared with those seen with invasive bacterial enteropathogens such as Salmonellae and Shigellae.
A new study published in PLoS Medicine challenges the view that the virus is confined to the upper small intestine in children with rotavirus diarrhoea . In the study, Blutt and colleagues found rotaviral antigens and RNA in blood samples from children with rotavirus diarrhoea .
The authors conclude that the finding of infectious rotavirus in the blood suggests extra-intestinal involvement in rotavirus pathogenesis, though they concede that the impact of rotavirus viraemia on clinical manifestations of infection is unknown. One possibility—which needs further investigation—is that the extra-intestinal manifestations of rotavirus infection, such as respiratory symptoms and seizures, are in fact due to the infection being systemic rather than localised to the jejunal mucosa.