Date of Award

12-11-2022

Degree Type

Thesis

Degree Name

MS in Epidemiology & Biostatistics

Department

Community Health Sciences

Abstract

Background: Streptococcus pneumoniae, a natural colonizer in the nasopharynx of healthy individuals, is a precursor to pneumococcal infection. It is responsible for high rates of mortality and morbidity, especially in low- and middle-income countries (LMIC), with 7.1 million episodes of pneumonia reported in Pakistan under 5 years old. Pakistan introduced 10-valent pneumococcal conjugate vaccine (PCV10) in its Federal directorate on Immunization (FDI) in 2012 and replaced with 13- valent pneumococcal conjugate vaccine (PCV13) in early 2021.
Methods: We performed a cross-sectional study in rural region of Matiari, Sindh in children of less than 2 years of age. A total of 200 nasopharyngeal samples were obtained along with questionnaire data. A total of 140 isolated were obtained from 200 samples. We compared the current prevalence (n=200) with the prevalence before PCV13 in the same geographical location (n=810). Cox Proportional Hazard Regression method was used to determine the association between pneumococcal carriage and associated factors.
Results: The overall carriage prevalence was 140/200 (70%, 95% CI 0.63, 0.76).In our univariate analysis, none of the hypothesized predictors of pneumococcal carriage were significantly associated with pneumococcal carriage. . However, prevalence of PCV13 specific serotype (3, 6A and 19A) declined from 12.1 to 5.1%.
Conclusion: Introduction of PCV13 has demonstrated a decline in PCV13 specific serotypes and emergence of NVT serotypes after a switch from PCV10 to PCV13. Hence, these findings can help us guide newer vaccine formulations.

Comments

Advisor's name is not mentioned in the thesis.

First Page

1

Last Page

88

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