Conjugate vaccine introduction in the African meningitis belt: meeting surveillance objectives

The epidemiology of bacterial meningitis will change with introduction of meningococcal and pneumococcal conjugate vaccines in the African meningitis belt. The principal objectives of surveillance are to evaluate the impact of vaccination, to detect and investigate epidemics and provide material for research. The capacity of existing surveillance activities in the meningitis belt to meet these objectives varies due to infrastructural and financial constraints. Impact assessment of conjugate vaccine against meningococcal serogroup A will be limited to comparing incidence trends from a few surveillance sites with data obtained before vaccine introduction and to comparing trends in the incidence of suspected cases or localised epidemics in most other settings. The timeliness of detection of epidemics and identification of epidemic meningococcal serogroups could be improved in most countries by analysing suspected case data in health centre level resolution and by investigating outbreaks with mobile teams. For research and impact assessment of pneumococcal conjugate vaccines, several surveillance sites covering at least 0.5 million inhabitants should be maintained which undertake exhaustive case finding and systematic laboratory confirmation of meningitis and pneumonia. Molecular diagnostics will facilitate surveillance in remote areas, but the available techniques should be evaluated for diagnostic performance in the field and long-term sustainability.