Effect of pneumococcal conjugate vaccination on radiological findings of chest in infants hospitalized with community acquired pneumonia in northern India: a case-control study

Abstract

Background: Burden of community acquired pneumonia (CAP) in infants is high in India. Streptococcus pneumoniae is stated to be an common etiological agent for it. Hence Pneumococcal Conjugate Vaccination(PCV) has been introduced in India since 2017(phased-wise). Objective: To study effect of PCV on radiological findings of chest in infants hospitalized with WHO-defined CAP. Methods: Prospective hospital-based pneumonia surveillance is ongoing since 2015 in Lucknow & Etawah districts, Uttar Pradesh and Patna & Darbhanga districts, Bihar, India. Recruitments were done from a network of hospitals formed for project. Infants(2-11months)hospitalized with WHO-defined CAP from index districts with Results: From May2017-October2018, 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 in3(13.6%) and normal7(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.