Rao, Durga C and Jagannath, MR and Varshney, BC and Das, M and Reddy, BSY (2003) Genomic Diversity Through Gene Reassortment and Antigenic Drift and Molecular Epidemiology of Rotaviruses in India. In: Genomic Diversity and Molecular Epidemiology of Rotaviruses . pp. 55-74.Full text not available from this repository. (Request a copy)
A review. Long term epidemiol. studies on both symptomatic and asymptomatic rotavirus infections during the period 1988 to 1999 in Bangalore revealed a consistently high rate (.apprx.60%) of asymptomatic infection of neonates born in hospitals/clinics by unusual PG10 type strains. The prototype neonatal strain I321 was shown to be a reassortant between a PG10 bovine rotavirus and a human rotavirus with all the genes, except for two genes encoding the nonstructural proteins NSP1 and NSP3, derived from the bovine parent. Neonatal infections were totally dominated by I321-like strains. Neonatal infections appear to confer protection against subsequent rotavirus illness as evident from the two-year follow-up study of I321-infected newborn children as well as by the significant reduction in rotavirus illness in Bangalore for the last 8 years. Another reassortant neonatal strain 116E (PG9) was also isolated in New Delhi. G3 type strains were more prevalent in symptomatic infections in Bangalore throughout the study period. The order of prevalence was G3 (36.6) > G2 (22.0%) > G1 (17.1%) > G4 (6.0%). There was no change in the epidemiology situation during this period. In contrast, serotype G1 was found to be more prevalent in other regions of the country. Majority of the G2-like strains were nontypeable in serotyping ELISA due to broad cross-reactivity to serotyping mAbs. This appears to be due to amino acid substitutions in the antigenic regions of VP7 as well as in VP4 and these strains probably represent a G2 subtype. An unusual G2 strain assocd. with diarrhoea, having 'long' e-type and SG1 specificity has been isolated in Manipur and appears to have been evolved by gene reassortment between a PG2 human strain and a porcine strain. Direct transmission of bovine G8 strains from cattle was observed to cause severe diarrhoea in children in Mysore. Serotype G10 was found to dominate infections in cattle in India and represented 55.0% - 85.0% of the isolates in different farms across the country. Serotype G6 was negligible in Indian cattle and G8 strains were detected in all the regions (5.8%). Another surprising observation was the presence of G3 strains in significant nos. (10.7%) in all the regions. The prototype bovine G3 strain G3 was shown to be a reassortant between a bovine G8 strain and an animal G3 strain (simian, canine or equine). A novel rotavirus was isolated from a single farm in Bangalore and was shown to represent the new serotype PG15. The findings from our lab. are of great significance since they provided strong epidemiol. basis for the origin of PG10 and PG9 reassortant asymptomatic neonatal strains in different regions of the country. Age-old Indian traditions, close proximity of majority of the Indian population with cattle, and environmental conditions appear to facilitate inter-species transmission of rotaviruses between humans and cattle and cattle and animals and evolution of novel strains in India.
|Item Type:||Journal Article|
|Additional Information:||The Copyright belongs to Research Signpost.|
|Department/Centre:||Division of Biological Sciences > Microbiology & Cell Biology|
|Date Deposited:||25 Apr 2006|
|Last Modified:||27 Aug 2008 11:54|
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