Date Published: June 19, 2018
Publisher: Public Library of Science
Author(s): Assad Hassan, G. U. Mustapha, Bola B. Lawal, Aliyu M. Na’uzo, Raji Ismail, Eteng Womi-Eteng Oboma, Oyeronke Oyebanji, Jeremiah Agenyi, Chima Thomas, Muhammad Shakir Balogun, Mahmood M. Dalhat, Patrick Nguku, Chikwe Ihekweazu, Caroline L. Trotter.
Nigeria reports high rates of mortality linked with recurring meningococcal meningitis outbreaks within the African meningitis belt. Few studies have thoroughly described the response to these outbreaks to provide strong and actionable public health messages. We describe how time delays affected the response to the 2016/2017 meningococcal meningitis outbreak in Nigeria.
Using data from Nigeria Centre for Disease Control (NCDC), National Primary Health Care Development Agency (NPHCDA), World Health Organisation (WHO), and situation reports of rapid response teams, we calculated attack and death rates of reported suspected meningococcal meningitis cases per week in Zamfara, Sokoto and Yobe states respectively, between epidemiological week 49 in 2016 and epidemiological week 25 in 2017. We identified when alert and epidemic thresholds were crossed and determined when the outbreak was detected and notified in each state. We examined response activities to the outbreak.
There were 12,535 suspected meningococcal meningitis cases and 877 deaths (CFR: 7.0%) in the three states. It took an average time of three weeks before the outbreaks were detected and notified to NCDC. Four weeks after receiving notification, an integrated response coordinating centre was set up by NCDC and requests for vaccines were sent to International Coordinating Group (ICG) on vaccine provision. While it took ICG one week to approve the requests, it took an average of two weeks for approximately 41% of requested vaccines to arrive. On the average, it took nine weeks from the date the epidemic threshold was crossed to commencement of reactive vaccination in the three states.
There were delays in detection and notification of the outbreak, in coordinating response activities, in requesting for vaccines and their arrival from ICG, and in initiating reactive vaccination. Reducing these delays in future outbreaks could help decrease the morbidity and mortality linked with meningococcal meningitis outbreaks.
Meningococcal meningitis outbreaks in Africa are frequently detected too late to enable appropriate control and preventive actions to limit their impact . High mortality rates often characterise the onset of outbreaks before appropriate measures are taken , leading to high attack rates of up to 100 to 800 per 100,000 populations, and case fatality ratios (CFR) of between 5 and 10% . The age group mostly affected by outbreaks of meningococcal meningitis are the 5–15 year olds , and about 10–20% of patients develop neurological sequalae such as deafness, learning disabilities and epilepsy . These figures are likely to be higher due to the sub-optimal reporting system to record cases [3, 6]. Given that outbreaks occur frequently in the 26 contiguous countries that make up the African meningitis belt , questions have been asked on why outbreaks cannot be detected earlier to enable a more rapid public health response.
For Zamfara, Sokoto and Yobe states, case counts and deaths were determined against time-lines for surveillance, treatment and care; and reactive vaccination in response to the outbreak through the following activities:
This study on the response to the 2016/2017 regional outbreak of meningococcal meningitis in Sokoto, Yobe and Zamfara states has shown that there were delays at different stages in the response to the outbreak which might have aggravated this public health emergency. If these delays had been minimised, it is likely that fewer cases and deaths would have been recorded during the outbreak. We found delays in four major areas: detection and notification of the outbreak by the states, initiating an integrated national response to the outbreak by the NCDC, request for vaccines and response from ICG, and initiating reactive vaccination campaigns. We also found that various factors might have contributed to these delays.
Timely detection and reporting of meningococcal outbreaks is an important control strategy. Good surveillance is the prerequisite for subsequent control measures such as timely standard treatment and care as well as reactive vaccination campaigns. Coordination of response activities also minimizes delays and wastage of scarce resources. Moving forward, improvements in response to meningococcal meningitis outbreaks should focus on reducing the delays in these four stages of response i.e. detection and notification of the outbreak by the states, initiating an integrated national response to the outbreak by the NCDC, request for vaccines and response from ICG, and initiating reactive vaccination campaigns.