Related Experiment Video
Updated: Jun 25, 2025
Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
Modelling control strategies for pneumococcal meningitis outbreaks in the African meningitis belt
Liza Hadley1, Heidi M Soeters2, Laura V Cooper3
1Disease Dynamics Unit, University of Cambridge, Cambridge, UK.
Introduction:
Pneumococcal meningitis outbreaks occur sporadically in the African meningitis belt. Outbreak control guidelines and interventions are well established for meningococcal but not pneumococcal meningitis. Mathematical modelling is a useful tool for assessing the potential impact of different pneumococcal control strategies. This work aimed to estimate the impact of reactive vaccination with pneumococcal conjugate vaccine (PCV) had it been implemented in past African meningitis belt outbreaks and assess their efficiency relative to existing routine infant immunisation with PCV.
Methods & Results:
Using recent pneumococcal meningitis outbreaks in Burkina Faso, Chad, and Ghana as case studies, we investigated the potential impact of reactive vaccination. We calculated the number needed to vaccinate to avert one case (NNV) in each outbreak setting and over all outbreaks and compared this to the NNV for existing routine infant vaccination. We extended previous analyses of reactive vaccination by considering longer-term protection in vaccinees over five years, incorporating a proxy for indirect effects. We found that implementing reactive vaccination in previous pneumococcal meningitis outbreaks could have averted up to 10-20 % of outbreak cases, with the biggest potential impact in Brong Ahafo, Ghana (2015-2016) and Goundi, Chad (2009). The NNV, and hence the value of reactive vaccination, varied greatly. 'Large' (80 + cumulative modelled cases per 100,000 population) and/or 'prolonged' (exceeding a response threshold of 10 suspected cases per 100,000 per week for four weeks or more) outbreaks had NNV estimates under 10,000. For routine infant vaccination with PCV, the estimated NNV ranged from 3,100-5,600 in Burkina Faso and 1,500-2,600 in Ghana.
Implications:
This analysis provides evidence to inform the design of pneumococcal meningitis outbreak response guidelines. Countries should consider reactive vaccination in each outbreak event, together with maintaining routine infant vaccination as the primary intervention to reduce pneumococcal disease burden and outbreak risk.
Insights
Reactive vaccination with pneumococcal conjugate vaccine (PCV) could have averted 10-20% of past pneumococcal meningitis outbreaks in Africa. This strategy, alongside routine infant immunization, is recommended for reducing disease burden and outbreak risk.
Area of Science:
- Epidemiology
- Mathematical Modeling
- Public Health Interventions
Background:
- Pneumococcal meningitis outbreaks are a recurring threat in the African meningitis belt.
- Existing control strategies are established for meningococcal but not pneumococcal meningitis.
- Mathematical modeling offers a valuable approach to evaluate pneumococcal meningitis control strategies.
Purpose of the Study:
- To estimate the impact of reactive vaccination using pneumococcal conjugate vaccine (PCV) during past outbreaks in the African meningitis belt.
- To compare the efficiency of reactive vaccination with current routine infant immunization programs.
Main Methods:
- Utilized Burkina Faso, Chad, and Ghana outbreak data as case studies.
- Calculated the number needed to vaccinate (NNV) to avert one case for both reactive and routine vaccination strategies.
- Incorporated longer-term protection and indirect effects into the analysis.
Main Results:
- Reactive vaccination could have potentially averted 10-20% of outbreak cases, particularly in large or prolonged outbreaks (NNV < 10,000).
- The NNV for reactive vaccination varied significantly across different outbreak scenarios.
- Routine infant vaccination showed NNVs ranging from 1,500-5,600 depending on the region.
Conclusions:
- Findings support the development of guidelines for pneumococcal meningitis outbreak response.
- Reactive vaccination should be considered for each outbreak event.
- Maintaining routine infant vaccination remains crucial for long-term disease burden reduction and outbreak prevention.
More Related Videos
Related Concept Videos
01:18Steps in Outbreak Investigation
01:28Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include: