Etiology of Severe Pneumonia in Intubated Children: A Case-Control Study in Children 1-24 Months of Age in a Tertiary Hospital in South India.

Identification of the etiological agent in severe pneumonia is limited by factors such as the poor yield from blood samples and the presence of colonizers in the respiratory tract. Samples from the lower respiratory tract could be more representative of the etiological agent causing pneumonia. We conducted a case-control study to determine the etiology of community-acquired severe pneumonia requiring intubation. This case-control study was conducted from 2017 to 2019 at Christian Medical College, Vellore. The cases included children between 1 and 24 months of age who were intubated for community-acquired severe pneumonia. The controls included children undergoing intubation for elective surgeries. Tracheal aspirates and nasopharyngeal swabs were obtained from all cases and controls. Additionally, a nonbronchoscopic bronchoalveolar lavage was obtained from all cases. The total nucleic acid extracted from all samples was tested for multiple respiratory pathogens using CDC-developed TaqMan Array Cards (Thermo Fisher Scientific, Waltham, MA) on the QuantStudio 12K Flex platform (Thermo Fisher Scientific). A total of 100 samples were collected from the 34 cases, and 64 samples were collected from the 32 controls. Respiratory syncytial virus and Streptococcus pneumoniae (S. pneumoniae) were the most commonly isolated pathogens. Respiratory syncytial virus detection rates were significantly higher in cases compared with controls in nasopharyngeal (odds ratio: 10.45; 95% CI: 1.25-88.25) samples. Streptococcus pneumoniae was more frequently detected in nasopharyngeal samples in cases than controls; however, this difference was not statistically significant. Respiratory syncytial virus and S. pneumoniae were the most commonly isolated pathogens in cases of severe pneumonia that required intubation in children between 1 and 24 months of age in Vellore, India.