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Prospective study of community-acquired rotavirus infection
Insights
Group A rotavirus (HRV) infection is common in infants, occurring frequently even without overt disease. Antibody levels are similar in infected and non-infected infants until maternal antibodies wane.
Area of Science:
- Pediatrics
- Virology
- Immunology
Background:
- Group A rotavirus (HRV) is a significant cause of infant gastroenteritis.
- Maternal antibodies play a role in protecting infants from viral infections.
Purpose of the Study:
- To determine antibody titers against human rotavirus (HRV) in infants.
- To compare HRV infection incidence and antibody levels between infants with and without HRV diarrhea.
Main Methods:
- Serum samples from 38 infants were collected from birth to 2 years.
- Antibody titers against HRV serotypes 1-4 were measured.
- Infants were grouped based on HRV diarrhea episodes and matched for age and birth weight.
Main Results:
- The estimated incidence of HRV infection was 1.34 episodes per infant per year, 22 times higher than overt disease.
- Infection occurred throughout infancy, while overt disease peaked before 12 months.
- Antibody levels before diarrhea onset varied and were similar between cases and controls, except during the decline of maternal antibodies.
Conclusions:
- HRV infection is common and often subclinical in the first two years of life.
- The peak incidence of overt HRV disease coincides with the decline of maternal antibodies and before infants develop their own protective antibody titers.
Abstract:
We determined titers of group A rotavirus common antibodies and neutralizing antibodies against serotypes 1 to 4 of prototype human rotavirus (HRV) in cord blood and serum specimens obtained from 38 infants at 4-month intervals from birth until 2 years of age. Nineteen of the infants developed one episode of HRV diarrhea each, and they were matched by age and birth weight with the other 19 infants, who did not develop HRV diarrhea during the follow-up period. We estimated the incidence rate of HRV infection for the two groups of infants combined to be a minimum of 1.34 episodes per infant per year, which is 22 times more common than the occurrence of overt disease caused by the virus in this community. The infection occurred constantly throughout the first 2 years of infancy, whereas all but one of the 19 episodes of overt disease occurred before 12 months of age. Seven of these overt episodes were preceded by at least one episode of subclinical infection earlier, and the other seven were probably due to primary HRV infection. The remaining five episodes occurred before 4 months of age, so that we could not ascertain whether they were due to primary infections because of the presence of maternal antibodies. We showed that levels of HRV antibodies in serum specimens obtained before clinical onset of diarrhea varied widely, and, for most infants in the diarrheal group, levels of these antibodies were similar to those in the serum specimens obtained at the same times from the corresponding age- and birth weight-matched control infants. Nevertheless, the age at which overt disease caused by HRV was most prevalent coincided with the time when the maternal antibodies had declined to low levels but the infants had not yet acquired high titers of these antibodies in their sera.