Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Trends in Invasive Pneumococcal Disease in Nepalese Children: Evaluating the Impact of 10-Valent Pneumococcal Conjugate Vaccine Introduction (2014–2023) (#73)

Meeru Gurung 1 , Ruby Basi 1 , Rusy Shrestha 1 , Shristy Rajkarnikar 1 , Saugat Bhandari 1 , Sanjeev Bijukchhe 1 2 , Bhishma Pokhrel 1 , Merryn Voysey 2 , Stephen Thorson 1 , Michael Carter 2 , Sarah Kelly 2 , Anil Ojha 1 , Maria Knoll 3 , Dominic Kelly 2 4 , David Murdoch 5 , Andrew J Pollard 2 4 , Shrijana Shrestha 1
  1. Department of Paediatrics, Patan Academy of Health Sciences, Lalitpur, Nepal
  2. Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
  3. International Vaccine Access Centre, Department of International Health, Johns Hopkins Bloomberg School of Health, Baltimore, Maryland, United States
  4. NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
  5. Department of Pathology, University of Otago, Christchurch, New Zealand

Background:

We evaluated pneumococcal serotype distribution in microbiologically confirmed invasive pneumococcal disease (IPD) among Nepalese children before (2014–2015) and after (2016–2023) the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) in 2015.

 

Methods:

Children aged 2 months to 14 years admitted to Patan Hospital, Nepal, with Streptococcus pneumoniae detected in blood, cerebrospinal fluid (CSF), or pleural fluid were included. Serotyping was performed using the Quellung method.

 

Results:

Among 87 IPD cases, Streptococcus pneumoniae was cultured in 69 cases (61 blood, 4 CSF, 4 pleural fluid), and 18 were Binax-positive in CSF. In the pre-vaccine period, 33.3% (7/21) of cases were in children under 2 years, declining to 16.7% (8/48) post-vaccine, while cases in children over 2 years increased from 66.7% (14/21) to 83.3% (40/48).

Serotype 1, the most common, accounted for 56.5% (39/69) of culture-confirmed cases. Among children under 2 years, serotype 1 decreased from 9.5% (2/21) pre-vaccine to 2.1% (1/48) post-vaccine, while in children over 2 years, it increased from 47.6% (10/21) to 54.2% (26/48). Of 61 blood isolates, 15 were pre-vaccine (14 vaccine-type [VT], 1 non-vaccine type [NVT]) and 46 post-vaccines (32 VT, 14 NVT). Among 4 CSF isolates, serotypes were 1, 14 and 2 were 6B. Of 4 pleural fluid isolates, 3 were serotype 1 and 1 was 19A.

Conclusion:

PCV10 has reduced IPD among children under 2 years; however, vaccine-type serotypes, particularly serotype 1, remain prevalent. These findings, along with the emergence of non-vaccine serotypes, highlight the need for continued surveillance to guide future vaccine strategies.