Pneumococcal serotypes and serogroups causing invasive disease in Pakistan, 2005-2013

Area of Science:

• * Microbiology and Immunology
• * Vaccinology
• * Epidemiology

Background:

• * Global implementation of pneumococcal conjugate vaccines (PCV) is widespread, yet Asian regions lag due to insufficient disease burden data.
• * Invasive pneumococcal disease (IPD) remains a significant public health concern, particularly in regions with limited vaccination data.

Purpose of the Study:

• * To characterize pneumococcal serotypes causing invasive pneumococcal disease (IPD) in Pakistan.
• * To assess the proportion of IPD cases preventable by current pneumococcal conjugate vaccines (PCV10 and PCV13).

Main Methods:

• * Retrospective analysis of 111 invasive pneumococcal disease (IPD) episodes from 2005 to 2013 in Pakistan.
• * Serotyping conducted via DNA target amplification from pneumococcal isolates and cerebrospinal fluid (CSF) specimens.
• * Analysis included episodes of meningitis, particularly in children aged 0-15 years.

Main Results:

• * Meningitis accounted for 73% of all IPD episodes (n=81), with 76 cases in children and 5 in adults.
• * Serogroup 18 was the most prevalent serogroup causing meningitis in children under 5 years (21%).
• * PCV10 and related serotypes covered 61% of childhood meningitis cases; PCV13 increased coverage to 63% by including serotype 19A.

Conclusions:

• * A substantial proportion of invasive pneumococcal disease (IPD), especially meningitis in children, in Pakistan is caused by serotypes targeted by current pneumococcal conjugate vaccines (PCV10 and PCV13).
• * The findings underscore the potential impact of PCV implementation in reducing the burden of serious pneumococcal infections in Pakistan.
• * Further data on vaccine-preventable pneumococcal disease in Asia are crucial for informing public health strategies and vaccine policy.