Epidemiology of human rotaviruses as determined by electrophoresis of genome RNA

Molecular epidemiology of rotavirus in black infants in South Africa

The molecular epidemiology of rotavirus infections in black infants in Ga-Rankuwa, South Africa, was investigated by polyacrylamide gel electrophoresis. Between 1983 and 1986, 14 different RNA electrophoretic patterns were observed for children with acute gastroenteritis. These electrophoretypes showed a sequential pattern of appearance, with a limited number being present at any one time. In contrast, for neonates only one RNA electrophoretype was detected, which persisted for at least 3 years.

Molecular epidemiology of human rotavirus infections

Recognition of rotaviruses as a major aetiological agent of acute gastroenteritis in infants and young children has prompted the investigation of their epidemiology by molecular techniques. Genome analysis by electrophoretic separation of the RNA segments has been widely used to distinguish virus isolates and to monitor patterns of virus transmission. Examination of virus isolates from different epidemics has clearly demonstrated the existance of extensive genomic variation in viruses circulating in large communities; with the co-circulation of a number of viruses of differing electrophoretype. Preliminary studies using the more advanced techniques of oligonucleotide mapping and hybridization analysis have suggested that variation among the viruses may occur by processes involving both "drift" and "shift". Because of their ease and specificity the new hybridization analysis techniques should greatly facilitate both the rapid diagnosis of rotavirus infections, and the solution of many epidemiological and evolutionary questions. Continued and expanded use of molecular techniques for the study of the epidemiology of rotavirus infections will be required to manage future outbreaks and to effect long term control measures.

Influence of breast milk on nosocomial rotavirus infections in infants

To prevent nosocomial rotavirus infections in hospitalized children with various non-gastrointestinal diseases, 30 children (mean age five months) received 200 ml of fresh human milk per day in addition to the normal diet for their age. A matched group of children on formula diet served as a control. Fecal samples were routinely screened for rotavirus by a commercial ELISA test. In stools containing rotavirus, the virus RNA segments were analysed by gel electrophoresis to identify the different rotavirus strains. Clinical symptoms were recorded daily and quantified by a score system. Human milk had no effect on the frequency of nosocomial rotavirus infections: ten infected children were fed with human milk and seven were not. However, the severity of the clinical symptoms was clearly reduced: the mean score of clinical symptoms was only half as great and the number of mild or asymptomatic infections was doubled in the group receiving fresh human milk.