Respiratory syncytial virus in lower respiratory tract infections

ABSTRACT

Acute lower respiratory infections lead to high morbidity and mortality rates in children from developing countries. The aim of this study was to look into the extent of respiratory syncytial virus infections in children with special reference to the role of specific immunoglobulins in protection against infection as well as the association with bacterial pathogens. Nasopharyngeal aspirates were tested for respiratory syncytial virus antigen by enzyme immunoassay and IgA antibodies by single radio immunodiffusion test. Viral culture on HEP-2 cell system and bacterial culture was done. Sera were tested for detection of antibodies to respiratory syncytial virus by indirect fluorescent antibody test. Antigens of streptococcus pneumoniae and haemophilus influenzae were detected in serum and urine by latex agglutination assay. Incidence rates of acute lower respiratory infections were highest in infants; bronchiolitis and bronchopneumonia being the main contributors. Respiratory syncytial virus infection was found in 27.08% of the cases. Secretory IgA antibodies level was found to be a good indicator of respiratory syncytial virus infection as seen by the significantly higher levels in cases as compared to both non respiratory syncytial virus cases and controls