Antigenic and genetic characterization of Influenza viruses circulating in Chennai during 2002 to 2007

Abstract

Acute Respiratory Diseases (ARD) cause enormous morbidity and mortality, particularly in infants and children in developing countries. ARD is responsible for about 4 million deaths and 500- 900 million episodes per annum in children globally. In India, studies indicate that 600,000 children under the age of 5 die every year from ARD. There is considerable variation in the severity of illness caused by Influenza in different individuals. This is partly due to the age of those affected, general health, and immunistation status relative to previous Influenza infections. Infections may be subclinical or may produce symptoms ranging from minor respiratory illness to fatal viral pneumonia. The classic symptoms of Influenza are rapid onset of malaise, feverishness and myalgia, usually with a non productive cough or sore throat. In children, nausea, vomiting and diarrhea are often observed. Blood samples for serosurveillance were collected from normal healthy children attending ICDS units in Chennai and from adults for attending hospitals for reasons other than acute respiratory tract infections. 200 samples were collected during the year; 50 samples from each age group in four age groups (0-5, 6-15, 16-45, 46-60). The results of MIC were in total concurrence with RT-PCR RFLP, therefore MIC can be used to screen large number of samples and the positives can be subjected to RT-PCR RFLP to study where the mutations have occurred and about the amino acid change. There is a need for continued surveillance for Amantadine resistance. Antiviral screening of two herbs The results of antiviral evaluation of two herbs showed that the aqueous and ethanolic extracts of herbs Ocimum sanctum and Glycyrrhiza glabra showed anti Influenza B activity. The extracts of both were virucidal and inhibitory to viral replication.The virucidal effect of the all the three extracts were concentration dependent. newline