Evaluation of response strategies against epidemics due to Neisseria meningitidis C in Niger

Abstract

Abstractobjective To inform public health recommendations, we evaluated the effectiveness and efficiency of current and hypothetical surveillance and vaccine response strategies against Neisseria meningitidis C meningitis epidemics in 2015 in Niger.methods We analysed reports of suspected and confirmed cases of meningitis from the region of Dosso during 2014 and 2015. Based on a definition of epidemic signals, the effectiveness and efficiency of surveillance and vaccine response strategies were evaluated by calculating the number of potentially vaccine-preventable cases and number of vaccine doses needed per epidemic signal.results A total of 4763 weekly health area reports, collected in 90 health areas with 1282 suspected meningitis cases, were included. At a threshold of 10 per 100 000, the total number of estimated vaccine-preventable cases was 29 with district-level surveillance and vaccine response, 141 with health area-level surveillance and vaccination and 339 with health area-level surveillance and district-level vaccination. While being most effective, the latter strategy required the largest number of vaccine doses (1.8 million), similar to the strategy of surveillance and vaccination at district level (1.3 million), whereas the strategy of surveillance and vaccination at health area level would have required only 0.8 million doses. Thus, efficiency was lowest for district-level surveillance and highest for health area-level surveillance with district-level vaccination.conclusion In this analysis, we found that effectiveness and efficiency were higher at health arealevel surveillance and district-level vaccination than for other strategies. Use of N. meningitidis C vaccines in a preventive strategy thus should be considered, in particular as most reactive vaccine response strategies in our analysis had little impact on disease burden.

The association between respiratory tract infection incidence and localised meningitis epidemics: an analysis of high-resolution surveillance data from Burkina Faso

“…The limited number of LME did not allow serogroup-specific analysis, but a strong association between URTI and LME was seen during epidemic waves due to serogroup A and epidemics due to serogroups W or X. The recent epidemic wave due to a new meningococcal serogroup C strain in Nigeria and Niger 9 was constituted of localised epidemics that were spread across the epidemic regions without any systematic pattern 25 . In the light of the present findings, the epidemic emergence could be interpreted as a coincidence between the introduction of a new meningococcal strain and the occurrence of respiratory pathogen outbreaks.…”

Neisseria meningitidis Serogroup W Meningitis Epidemic in Togo, 2016

“…Consequently, in the absence of a multivalent meningococcal vaccine preventive strategy, affected areas must rely on reactive immunization for outbreak control. However, as this epidemic illustrated, even with motivated staff and a well coordinated response, it may take months to detect, confirm, and mobilize vaccine for an effective reactive vaccination program [27], at which point the outbreak may be waning naturally. Implementation of an effective preventive meningococcal vaccination strategy, combined with continued adherence to strong surveillance with rapid laboratory confirmation to monitor disease trends, identify emerging epidemic strains, guide implementation, and evaluate program effectiveness, could minimize future reliance on reactive vaccination campaigns.…”

Spatiotemporal Analysis of Serogroup C Meningococcal Meningitis Spread in Niger and Nigeria and Implications for Epidemic Response

“…However, we note that the majority of districts were larger than 100 000 population, which is not consistent with WHO recommendations. Previous studies have demonstrated that surveillance at finer spatial scales may allow for more efficient and earlier use of vaccine where it is needed [7, 28].…”