Introduction: Rotavirus diarrhea has a worldwide distribution, infecting almost all children by the age of 3-5 years.

Epidemiology: A comparable etiological 2-year survey carried out by the W.H.O Diarrheal Disease control (CDD) Program in 1991, in a multicenter study in 5 developing countries including Pakistan revealed that Rotavirus was found to be the most frequently detected pathogen in diarrheal episodes, during the first year of life, with the highest incidence (20%) occurring among 6-11 months old. Two other studies done in Pakistan, in under five children done in Lahore (between 1985 and 1991) and Rawalpindi (between May 1983 and April 1984) showed that Rotavirus was the second most common Diarrhea causing enteric pathogen following E.Coli

Transmission: Rotaviruses are shed in high concentrations 2 days before and as many as 10 days after onset of symptoms in immunocompetent hosts, thus being an important source of viral transmission.

Clinical course: A multicenter study in 5 developing countries including Pakistan conducted by WHO CDD program revealed that only 1.8 % of cases presented with severe dehydration and these were mostly due to Rotavirus, V. Cholerae and ETEC13.

Diagnostic tests: A study conducted in local hospitals in Pakistan during the period of October 1985-April 1986 compared the different diagnostic modalities for the detection of rotavirus in the faeces of children with acute diarrhea. The study all methods detected Rotavirus to varying degrees but ELISA was found to be the most sensitive method with 72.4% stools being positive. PREVENTIVE STRATEGIES: A study was conducted in Lahore (Pakistan) among 72 infants 6 weeks old in 1991 to assess safety and efficacy of RRV vaccine. It was found that of all infants given RRV with OPV, 50% had a two to four-fold rise in neutralization titers against rotavirus. RRV was found to be safe and not associated with adverse reactions in the 6 weeks old infants.

Conclusion: With regards to Pakistan, there is a great need for defining rotavirus associated disease burden and strain prevalence. We also need to conduct Rotavirus vaccine trials to assess its efficacy and safety in our setting.