WHO was notified of an outbreak of meningitis by the Government of Nigeria on 20 February 2017. The first case was reported in Zamfara state during epidemiology week 50 (December 12-18, 2016). On 23 June 2017, the Nigeria Federal Ministry of Health officially declared the end of the 2016/2017 meningitis outbreak in the country. This declaration was made almost 8 weeks after the number of new meningitis cases reported each week during this outbreak fell below the epidemic and alert thresholds in all Local Government Areas.
Between December 2016 and 23 June 2017, a total of 14,513 cases with 1,166 deaths (Case Fatality Rate=8.0%) had been reported from 24 States. Of the reported cases, 1,002 (6.9%) were laboratory tested; of which 463 (46.2%) were confirmed positive for bacterial meningitis. Neisseria meningitides serogroup C was the predominant (75.4%) cause of meningitis amongst those who tested positive.
Children between 5-14 year age group were the most affected, accounting for 6,791 (46.8%) cases. The states which were most affected by this outbreak were Zamfara, Sokoto, and Katsina, which accounted for nearly 89% of these cases.
Public health actions
The Nigeria Centre for Disease Control (NCDC) established a National Emergency Operations Centre (EOC) which coordinated the response to this national outbreak in collaboration with the National Primary Health Care Development Agency (NPHCDA). WHO and partners like UNICEF, CDC, University of Maryland, Nigeria Field Epidemiology and Laboratory Training Program (NFELTP), eHealth Africa, Medecins San Frontieres (MSF), and Rotary International were also instrumental in providing support. Rapid Response Teams (RRT) was deployed to the most affected States to strengthen surveillance, case management, laboratory capacity and risk communication. Some of the major interventions were:
Mass vaccination campaigns: Reactive vaccination campaigns were successfully conducted in Zamfara, Sokoto, Yobe and Katsina States. About 2 million were eventually vaccinated during the course of this outbreak. The campaign was monitored by experts who had been deployed by WHO to the field. It had been conducted in Zamfara State for people aged 1 to 29 years using polysaccharide meningococcal A & C vaccine; however, in two wards namely, Gada and Kaffe people aged 2 to 29 years were vaccinated. In the nine LGAs in Sokoto State, it was completed using monosaccharide meningococcal conjugate C vaccine for people aged 1 to 20 years and in Yobe State for people aged 2 to 29 years using polyvalent ACW conjugate vaccine. The state governments ensured the vaccination reached the most at risk population.
Case Management and Laboratory Diagnosis: New cases were successfully investigated and characterized in Sokoto and Zamfara State. Case management protocols had been distributed to health facilities in the most affected States. During the course of this outbreak, WHO deployed 50 health workers in 10 teams to Sokoto and Zamfara States. The first ever meningitis PCR tests were conducted in the National Reference Laboratory in Abuja.
Surveillance and Epidemiology: Daily collection, collation, cleaning and harmonization of newly reported cases from the States to assess the impact of the response activities were undertaken. Monitoring of trends and feedback analysis was carried out. Descriptive epidemiology of cases was being reported weekly to Sokoto, Yobe, Zamfara and Katsina states.
Social mobilization: This was done by sensitizing the communities, faith-based organizations, and traditional leaders. Additionally, there was the production and dissemination of communication materials as well as airing of jingles on local radio stations in the worst affected states