Effect of pneumococcal conjugate vaccination on radiological findings in infants hospitalized with community acquired pneumonia in northern India

Abstract

Background: The burden of community acquired pneumonia (CAP) in infants is high in India and Streptococcus pneumoniae is stated to be an common etiological agent for it. Hence Pneumococcal Conjugate Vaccination (PCV) has been introduced in India since 2017 in a phased manner. The objective of this study was the effect of PCV on radiological findings of chest in infants hospitalized with WHO-defined CAP. Methods and materials: This prospective hospital-based pneumonia surveillance is ongoing since 2015-2016 in Lucknow and Etawah districts of Uttar Pradesh and Patna and Darbhanga districts of Bihar, India, after institutional ethical approvals. Recruitments were done from a network of hospitals formed especially for the project. Infants (2-11 months) hospitalized with WHO-defined CAP from index districts with < 14 days of symptoms were recruited after parental consent. Clinical data was abstracted. Chest X-rays (CXRs) were digitalized and interpreted by a panel of three independent blinded radiologists. Results: From May 2017 to October 2018, 282 (22.7% females) infants with PCV vaccination (cases) and 570 (29.8% females) without PCV vaccination (controls) with interpretable CXRs were analyzed. Primary end point pneumonia (PEP) + other infiltrate (OI) were found in 43 (15.2%) cases and 140 (24.7%) controls (p = 0.001); OI in 30 (10.6%) cases and 69 (12.1%) controls (p = 0.5) and normal CXR in 209 (74.1%) cases and 361(63.3%) controls (p = 0.001). There was one death among cases whose CXR showed OI. There were 22 deaths among controls whose CXRs showed PEP + OI in 12 (54.6%); OI in 3 (13.6%) and normal 7 (31.8%). Crude odds ratio for death among cases was 0.088 (95%: CI 0.012-0.66). Conclusion: Among hospitalized patients of CAP, radiological findings differ by PCV vaccination status in infants.