Rotavirus: the first five years.

We found a human reovirus-like agent in the stools of 42 per cent of 143 infants and young children hospitalized with acute gastroenteritis between January, 1974, and June, 1975. Half the patients studied by electron microscopy and serologic technics had evidence of infection with the agent. The infection had a seasonal pattern: 59 per cent of those admitted during the cooler months (November to April) shed the agent, with a peak of 78 per cent in December, 1974, and January, 1975, combined. None of the patients admitted during the warmer months (May to October) shed the agent. None of 275 Escherichia coli isolates from 32 patients with diarrhea produced heat-labile enterotoxin, whereas 17 of the 32 had evidence of infection with the reovirus-like agent. In addition, 14 of 40 parents of 37 patients with diarrhea associated with the reovirus-like agent were also infected, but most infectious were inapparent. This agent appears to be the major cause of diarrheal illness in the young during the cooler months.

In a year-long survey of children admitted with acute enteritis to hospital in Melbourne, Australia, an aetiological agent was found in approximately 75% of patients. During most months of the year a newly described virus belonging to the family Reoviridae was detected by electron microscopy of faecal extracts from more than 50% of patients. Recovery of this virus reached a peak (73%) during the winter. All age-group up to five years of age were susceptible to infection, which was occasionally fatal. Duration of infection was brief, with a probable incubation period of less than two days. Infections acquired in hospital were not uncommon. The name of this new virus is not decided. The name "duovirus" is proposed rather than "rotavirus" as previously suggested. There is already convincing evidence that this new virus will prove to be the most important aetiological agent of sporadic acute enteritis in young children.