Oral Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Predictors of nasopharyngeal pneumococcal carriage in children <5 years living in rural and urban Nepal following the introduction of PCV10 vaccination (118039)

Sanjeev Bijukchhe 1 2 , Meeru Gurung 1 , Maria Knoll 3 , Bhishma Pokhrel 1 , Merryn Voysey 2 4 , Pratistha Maskey 1 , Sunaina Gurung 1 , Sarah Kelly 2 4 , Madhav Gautam 1 , Sonu Shrestha 2 , Grace Li 2 , Peter O'reilly 2 , Laxmi Lama 1 , Anil Ojha 1 , Stephen Thorson 1 , Ganesh Shah 1 , David Murdoch 5 , Dominic Kelly 2 4 , Andrew Pollard 2 4 , Shrijana Shrestha 1
  1. Department of Paediatrics, Patan Academy of Health Sciences, Lalitpur, Nepal
  2. Department of Paediatrics, University of Oxford, Oxford, United Kingdom
  3. Department of International Health, Johns Hopkins Bloomberg School of Health, Maryland, United States of America
  4. NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
  5. Department of Pathology and Biomedical Science, University of Otago, Otago, New Zealand

Background

Nepal introduced PCV10 vaccine in its immunization schedule in 2015. We examined demographic variables contributing to nasopharyngeal pneumococcal carriage before and after PCV10 introduction in healthy children <5-years.

 

Methods

From 2014 to 2019, we collected 7,279 and 2,266 nasopharyngeal samples with demographic data from healthy children living in urban Kathmandu (6-59 months) and rural Okhaldhunga (6-23 months), respectively. Adjusted prevalence ratios(aPR) with 95% CI determined the associated factors (pneumococcal vaccination, age, gender, birthweight, and household size) in urban and rural settings separately. Only significant variables were retained in the final model.

 

Results

Urban carriage of any serotype was positively associated with birthweight [aPR per kg 1.020, 95% CI 1.019-1.020, p<0.0001] and age in the pre-vaccine period (2014-2015) [aPR per year 1.06, 95% CI 1.03-1.09, p<0.0001], but negatively associated with PCV vaccination [aPR 0.94, 95% CI 0.90-0.98,p=0.004]. For PCV10 serotypes, urban carriage was negatively associated with PCV vaccination [aPR 0.47, 95% CI 0.42-0.54), p<0.0001], and age in the post-vaccine period (2016-2019) [aPR per year 1.25, 95% CI 1.13-1.38, p<0.0001]. Rural PCV10 serotype carriage was positively associated with birthweight [aPR 1.01, 95% CI 1.00-1.01, p=0.027] and negatively with PCV vaccination [aPR 0.33, 95% CI 0.27-0.41, p<0.0001]. For PCV13 serotypes, rural carriage was negatively associated with age [PR 0.63, 95% CI 0.47-0.85, p=0.003].

 

Conclusion

PCV10 vaccination reduced overall carriage only in the urban setting - however, PCV10 serotype carriage was reduced in both settings. Age and birthweight were the demographic predictors of nasopharyngeal carriage, with varying effects for urban and rural settings.