1Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
2Comprehensive rural health service project Ballabhgarh, All India Institute of Medical Sciences, New Delhi, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
Acute lower respiratory infections (ALRI) are one of the major causes of morbidity and mortality in young children worldwide especially in developing countries. A prospective longitudinal study, for the prevalence of seven respiratory viruses viz: Respiratory syncytial virus (RSV), Influenza A/B viruses, Parainfluenza (PIV) 1–3 viruses and human metapneumovirus (hMPV) was carried out in children below 3 years of age from four rural villages near Delhi to define their role using direct fluorescence assay (DFA) and multiplex-PCR (mPCR). A total of 245 NPAs were collected from October 2007 to September 2008. Samples were processed; supernatant was aliquoted, one was kept for m-PCR and another was kept at −70°C until use, with cell pellet spots were made on Teflon coated slides for DFA. Primary detection for all the 7 respiratory viruses was done by Simafluor Assay and confirmation for the specific viruses was done by DFA. RNA was isolated from clinical samples with RNeasy kits and reverse-transcribed into cDNA using random hexamer and AMV-RT. Previously Standardized m-PCR developed in our lab, was applied on the clinical samples for the detection of above said 7 respiratory viruses. Of the 245 NPAs, 37 samples (15.1%) were positive by DFA and 43 (17.5%) were positive by m-PCR for one or more pathogens. m-PCR detected 6 (15%) additional samples positive for respiratory viruses as compare to DFA. Of the total 43 positive children infected with viruses, RSV infection was detected in 20 (9.7%) samples, INF A in 11 (4.4%), PIV 3 in 6 (2.4%), PIV-1 in 3 (1.2%). Co-infections were detected by m-PCR assay of RSV with PIV in 1 sample, INF-A with RSV in 1 and PIV1, PIV3 & INF A in 1. M-PCR is a very sensitive technique for the detection of respiratory viruses. The above said seven viruses account for 20% of ALRI infections in rural community near Delhi of which RSV was the most commonly identified pathogen.
