Epidemiological description of and response to a large yellow fever outbreak in Edo state Nigeria, September 2018 - January 2019.

BACKGROUND: Edo State Surveillance Unit observed the emergence of a disease with "no clear-cut-diagnosis", which affected peri-urban Local Government Areas (LGAs) from September 6 to November 1, 2018. On notification, the Nigeria Centre for Disease Control deployed a Rapid Response Team (RRT) to support outbreak investigation and response activities in the State. This study describes the epidemiology of and response to a large yellow fever (YF) outbreak in Edo State. METHODS: A cross-sectional descriptive outbreak investigation of YF outbreak in Edo State. A suspected case of YF was defined as "Any person residing in Edo State with acute onset of fever and jaundice appearing within 14 days of onset of the first symptoms from September 2018 to January 2019". Our response involved active case search in health facilities and communities, retrospective review of patients' records, rapid risk assessment, entomological survey, rapid YF vaccination coverage assessment, blood sample collection, case management and risk communication. Descriptive data analysis using percentages, proportions, frequencies were made. RESULTS: A total of 209 suspected cases were line-listed. Sixty-seven (67) confirmed in 12 LGAs with 15 deaths [Case fatality rate (CFR 22.4%)]. Among confirmed cases, median age was 24.8, (range 64 (1-64) years; Fifty-one (76.1%) were males; and only 13 (19.4%) had a history of YF vaccination. Vaccination coverage survey involving 241 children revealed low YF vaccine uptake, with 44.6% providing routine immunisation cards for sighting. Risk of YF transmission was 71.4%. Presence of Aedes with high-larval indices (House Index ≥5% and/or Breteau Index ≥20) were established in all the seven locations visited. YF reactive mass vaccination campaign was implemented. CONCLUSION: Edo State is one of the states in Nigeria with the highest burden of yellow fever. More males were affected among the confirmed. Major symptoms include fever, jaundice, weakness, and bleeding. Majority of surveillance performance indicators were above target. There is a high risk of transmission of the disease in the state. Low yellow fever vaccination coverage, and presence of yellow fever vectors (Ae.aegypti, Ae.albopictus and Ae.simpsoni) are responsible for cases in affected communities. Enhanced surveillance, improved laboratory sample management, reactive vaccination campaign, improved yellow fever case management and increased risk communication/awareness are very important mitigation strategies to be sustained in Edo state to prevent further spread and mortality from yellow fever.

Establishing event-based surveillance system in Nigeria: a complementary information generating platform for improved public health performance, 2016.

Introduction: event-based surveillance (EBS) is a surveillance method involving systematic and prompt data collection on incidents of public health importance, and complements the current indicator-based surveillance system and the Integrated Disease Surveillance and Response System (IDSR). It also promotes a rapid assessment and response to public health emergencies in Nigeria, although there is a lack of information regarding the status of EBS among Public Health Stakeholders in Nigeria; hence our study aimed to assess the awareness, availability, and utility of EBS among Nigerian public health stakeholders. Methods: we conducted a cross-sectional study to assess the awareness, availability, functionality, and utilization of EBS in the 36 States in Nigeria, plus the Federal Capital Territory (FCT). We interviewed 53 stakeholders in disease surveillance and response using a self-administered, semi-structured questionnaire to obtain responses on the awareness of the event-based surveillance system, availability, and functionality. We also assessed the common structures used to report health-related events and the availability of minimum requirements for an event-based surveillance system. We performed descriptive statistics for the data obtained. Results: the majority of respondents were males and 37.7% were disease surveillance and notification officers (DSNOs). Awareness of EBS was poor with about half, 49% of the respondents reported hearing of EBS, but only 17% described it correctly. The overall level of availability of the EBS reporting structure was inadequate, 28.2% and poorly utilised in the States. Conclusion: the awareness, availability, and utilization of event-based surveillance systems are low in Nigeria. The government should improve the feasibility and utility of EBS in the States to enhance early disease detection and response.

Reviewing Health Security Capacities in Nigeria Using the Updated WHO Joint External Evaluation and WHO Benchmarks Tool: Experience from a Country-Led Self-Assessment Exercise.

Across the world, the level of pandemic preparedness varies and no country is fully prepared to respond to all public health events. The International Health Regulations 2005 require state parties to develop core capacities to prevent, detect, and respond to public health events of international concern. In addition to annual self-assessment, these capacities are peer reviewed once every 5 years through the voluntary Joint External Evaluation (JEE). In this article, we share Nigeria's experience of conducting a country-led midterm self-assessment using a slightly modified application of the second edition of the World Health Organization (WHO) JEE and the new WHO benchmarks tool. Despite more stringent scoring criteria in the revised JEE tool, average scoring showed modest capacity improvements in 2019 compared with 2017. Of the 19 technical areas assessed, 11 improved, 5 did not change, and 3 had lower scores. No technical area attained the highest-level scoring of 5. Understanding the level of, and gaps in, pandemic preparedness enables state parties to develop plans to improve health security; the outcome of the assessment included the development of a 12-month operational plan. Countries need to intentionally invest in preparedness by using existing frameworks (eg, JEE) to better understand the status of their preparedness. This will ensure ownership of developed plans with shared responsibilities by all key stakeholders across all levels of government.

Electronic reporting of integrated disease surveillance and response: lessons learned from northeast, Nigeria, 2019.

BACKGROUND: Electronic reporting of integrated disease surveillance and response (eIDSR) was implemented in Adamawa and Yobe states, Northeastern Nigeria, as an innovative strategy to improve disease reporting. Its objectives were to improve the timeliness and completeness of IDSR reporting by health facilities, prompt identification of public health events, timely information sharing, and public health action. We evaluated the project to determine whether it met its set objectives. METHOD: We conducted a cross-sectional study to assess and document the lessons learned from the project. We reviewed the performance of the local government areas (LGAs) on timeliness and completeness of reporting, rumors identification, and reporting on the eIDSR and the traditional paper-based system using a checklist. Respondents were interviewed online on the relevance, efficiency, sustainability, project progress and effectiveness, the effectiveness of management, and potential impact and scalability of the strategy using structured questionnaires. Data were cleaned, analyzed, and presented as proportions using an MS Excel spreadsheet. Responses were also presented as direct quotes. RESULTS: The number of health facilities reporting IDSR increased from 103 to 228 (117%) before and after implementation of the eIDSR respectively. The timeliness of reporting was 43% in the LGA compared to 73% in health facilities implementing eIDSR. The completeness of IDSR reports in the last 6 months before the evaluation was ≥85%. Of the 201 rumors identified and verified, 161 (80%) were from the eIDSR pilot sites. The majority of the stakeholders interviewed believed that eIDSR met its predetermined objectives for public health surveillance. The benefits of eIDSR included timely reporting and response to alerts and disease outbreaks, improved timeliness, and completeness of reporting, and supportive supervision to the operational levels. The strategy helped stakeholders to appreciate their roles in public health surveillance. CONCLUSION: The eIDSR has increased the number of health facilities reporting IDSR, enabled early identification, reporting, and verification of alerts, improved timeliness and completeness of reports, and supportive supervision of staff at the operational levels. It was well accepted by the stakeholder as a system that made reporting easy with the potential to improve the public health surveillance system in Nigeria.

The reactive vaccination campaign against cholera emergency in camps for internally displaced persons, Borno, Nigeria, 2017: a two-stage cluster survey.

INTRODUCTION: In 2017, amidst insecurity and displacements posed by Boko Haram armed insurgency, cholera outbreak started in the Muna Garage camp for Internally Displaced Persons (IDPs) in Borno State, Nigeria. In response, the Borno Ministry of Health and partners determined to provide oral cholera vaccine (OCV) to about 1 million people in IDP camps and surrounding communities in six Local Government Areas (LGAs) including Maiduguri, Jere, Konduga, Mafa, Dikwa, and Monguno. As part of Monitoring and Evaluation, we described the coverage achieved, adverse events following immunisation (AEFI), non-vaccination reasons, vaccination decisions as well as campaign information sources. METHODS: We conducted two-stage probability cluster surveys with clusters selected without replacement according to probability-proportionate-to-population-size in the six LGAs targeted by the campaign. Individuals aged ≥1 years were the eligible study population. Data sources were household interviews with vaccine card verification and memory recall, if no card, as well as multiple choice questions with an open-ended option. RESULTS: Overall, 12 931 respondents participated in the survey. Overall, 90% (95% CI: 88 to 92) of the target population received at least one dose of OCV, range 87% (95% CI: 75 to 94) in Maiduguri to 94% (95% CI: 88 to 97) in Monguno. The weighted two-dose coverage was 73% (95% CI: 68 to 77) with a low of 68% (95% CI: 46 to 86) in Maiduguri to a high of 87% (95% CI: 74 to 95) in Dikwa. The coverage was lower during first round (76%, 95% CI: 71 to 80) than second round (87%, 95% CI: 84 to 89) and ranged from 72% (95% CI: 42 to 89) and 82% (95% CI: 82 to 91) in Maiduguri to 87% (95% CI: 75 to 95) and 94% (95% CI: 88 to 97) in Dikwa for the respective first and second rounds. Also, coverage was higher among females of age 5 to 14 and ≥15 years than males of same age groups. There were mild AEFI with the most common symptoms being fever, headache and diarrhoea occurring up to 48 hours after ingesting the vaccine. The most common actions taken after AEFI symptoms included 'did nothing' and 'self-medicated at home'. The top reason for taking vaccine was to protect from cholera while top reason for non-vaccination was travel/work. The main source of campaign information was a neighbour. An overwhelming majority (96%, 95% CI: 95% to 98%) felt the campaign team treated them with respect. While 43% (95% CI: 36% to 50%) asked no questions, 37% (95% CI: 31% to 44%) felt the team addressed all their concerns. CONCLUSION: The campaign achieved high coverage using door-to-door and fixed sites strategies amidst insecurity posed by Boko Haram. Additional studies are needed to improve how to reduce non-vaccination, especially for the first round. While OCV provides protection for a few years, additional actions will be needed to make investments in water, sanitation and hygiene infrastructure.

A rapid assessment of the implementation of integrated disease surveillance and response system in Northeast Nigeria, 2017.

BACKGROUND: Integrated disease surveillance and response (IDSR) is the strategy adopted for public health surveillance in Nigeria. IDSR has been operational in Nigeria since 2001 but the functionality varies from state to state. The outbreaks of cerebrospinal meningitis and cholera in 2017 indicated weakness in the functionality of the system. A rapid assessment of the IDSR was conducted in three northeastern states to identify and address gaps to strengthen the system. METHOD: The survey was conducted at the state and local government areas using standard IDSR assessment tools which were adapted to the Nigerian context. Checklists were used to extract data from reports and records on resources and tools for implementation of IDSR. Questionnaires were used to interview respondents on their capacities to implement IDSR. Quantitative data were entered into an MS Excel spreadsheet, analysed and presented in proportions. Qualitative data were summarised and reported by thematic area. RESULTS: A total of 34 respondents participated in the rapid survey from six health facilities and six local government areas (LGAs). Of the 2598 health facilities in the three states, only 606 (23%) were involved in reporting IDSR. The standard case definitions were available in all state and LGA offices and health facilities visited. Only 41 (63%) and 31 (47.7%) of the LGAs in the three states had rapid response teams and epidemic preparedness and response committees respectively. The Disease Surveillance and Notification Officers (DSNOs) and clinicians' knowledge were limited to only timeliness and completeness among over 10 core indicators for IDSR. Review of the facility registers revealed many missing variables; the commonly missed variables were patients' age, sex, diagnosis and laboratory results. CONCLUSIONS: The major gaps were poor documentation of patients' data in the facility registers, inadequate reporting tools, limited participation of health facilities in IDSR and limited capacities of personnel to identify, report IDSR priority diseases, analyze and interpret IDSR data for decision making. Training of surveillance focal persons, provision of IDSR reporting tools and effective supportive supervisions will strengthen the system in the country.

What are the drivers of recurrent cholera transmission in Nigeria? Evidence from a scoping review.

BACKGROUND: The 2018 cholera outbreak in Nigeria affected over half of the states in the country, and was characterised by high attack and case fatality rates. The country continues to record cholera cases and related deaths to date. However, there is a dearth of evidence on context-specific drivers and their operational mechanisms in mediating recurrent cholera transmission in Nigeria. This study therefore aimed to fill this important research gap, with a view to informing the design and implementation of appropriate preventive and control measures. METHODS: Four bibliographic literature sources (CINAHL (Plus with full text), Web of Science, Google Scholar and PubMed), and one journal (African Journals Online) were searched to retrieve documents relating to cholera transmission in Nigeria. Titles and abstracts of the identified documents were screened according to a predefined study protocol. Data extraction and bibliometric analysis of all eligible documents were conducted, which was followed by thematic and systematic analyses. RESULTS: Forty-five documents met the inclusion criteria and were included in the final analysis. The majority of the documents were peer-reviewed journal articles (89%) and conducted predominantly in the context of cholera epidemics (64%). The narrative analysis indicates that social, biological, environmental and climatic, health systems, and a combination of two or more factors appear to drive cholera transmission in Nigeria. Regarding operational dynamics, a substantial number of the identified drivers appear to be functionally interdependent of each other. CONCLUSION: The drivers of recurring cholera transmission in Nigeria are diverse but functionally interdependent; thus, underlining the importance of adopting a multi-sectoral approach for cholera prevention and control.

The multi-sectorial emergency response to a cholera outbreak in Internally Displaced Persons camps in Borno State, Nigeria, 2017.

Introduction: In August 2017, a cholera outbreak started in Muna Garage Internally Displaced Persons camp, Borno state, Nigeria and >5000 cases occurred in six local government areas. This qualitative study evaluated perspectives about the emergency response to this outbreak. Methods: We conducted 39 key informant interviews and focus group discussions, and reviewed 21 documents with participants involved with surveillance, water, sanitation, hygiene, case management, oral cholera vaccine (OCV), communications, logistics and coordination. Qualitative data analysis used thematic techniques comprising key words in context, word repetition and key sector terms. Results: Authorities were alerted quickly, but outbreak declaration took 12 days due to a 10-day delay waiting for culture confirmation. Outbreak investigation revealed several potential transmission channels, but a leaking latrine around the index cases' house was not repaired for more than 7 days. Chlorine was initially not accepted by the community due to rumours that it would sterilise women. Key messages were in Hausa, although Kanuri was the primary local language; later this was corrected. Planning would have benefited using exercise drills to identify weaknesses, and inventory sharing to avoid stock outs. The response by the Rural Water Supply and Sanitation Agency was perceived to be slow and an increased risk from a religious festival was not recognised. Case management was provided at treatment centres, but some partners were concerned that their work was not recognised asking, 'Who gets the glory and the data?' Nearly one million people received OCV and its distribution benefited from a robust infrastructure for polio vaccination. There was initial anxiety, rumour and reluctance about OCV, attributed by many to lack of formative research prior to vaccine implementation. Coordination was slow initially, but improved with activation of an emergency operations centre (EOC) that enabled implementation of incident management system to coordinate multisectoral activities and meetings held at 16:00 hours daily. The synergy between partners and government improved when each recognised the government's leadership role. Conclusion: Despite a timely alert of the outbreak, delayed laboratory confirmation slowed initial response. Initial responses to the outbreak were not well coordinated but improved with the EOC. Understanding behaviours and community norms through rapid formative research should improve the effectiveness of the emergency response to a cholera outbreak. OCV distribution was efficient and benefited from the polio vaccine infrastructure.

Identifying and quantifying the factors associated with cholera-related death during the 2018 outbreak in Nigeria.

INTRODUCTION: cholera outbreaks in Nigeria are often associated with high case fatality rates; however, there is a dearth of evidence on context-specific factors associated with the trend. This study therefore aimed to identify and quantify the factors associated with cholera-related deaths in Nigeria. METHODS: using a cross-sectional design, we analysed surveillance data from all the States that reported cholera cases during the 2018 outbreak, and defined cholera-related death as death of an individual classified as having cholera according to the Nigeria Centre for Disease Control case definition. Factors associated with cholera-related death were assessed using multivariable logistic regression and findings presented as adjusted odds ratios (ORs) with 95% Confidence Intervals (95% CIs). RESULTS: between January 1 and November 19, 2018, 41,394 cholera cases were reported across 20 States, including 815 cholera-related deaths. In the adjusted multivariable model, older age, male gender, living in peri-urban areas or in flooded states, infection during the rainy season, and delay in seeking health care by >2 days were positively associated with cholera-related death; whereas living in urban areas, hospitalisation in the course of illness, and presentation to a secondary hospital were negatively associated with cholera-related death. CONCLUSION: cholera-related deaths during the 2018 outbreak in Nigeria appeared to be driven by multiple factors, which further reemphasises the importance of adopting a multisectoral approach to the design and implementation of context-specific interventions in Nigeria.

Research as a pillar of Lassa fever emergency response: lessons from Nigeria.

Emerging and re-emerging infectious diseases are becoming more frequent and developing countries are especially at increased risk. A recurring infectious disease outbreak in Nigeria has been that of Lassa fever (LF), a disease that is endemic in Nigeria and other West African countries. Nigeria, between 1st January and 27th October 2019, reported 743 confirmed cases of LF and 157 deaths in confirmed cases. Lassa fever outbreaks continue to be recurrent after fifty years of its identification. The true burden of the disease in Nigeria is unknown while gaps in knowledge about the infection still persist. Based on the Nigeria national Lassa fever research agenda and the World Health Organisation's roadmap initiative for accelerating research and product development which enables effective and timely emergency response to LF disease epidemics among other infectious diseases; a research pillar was added to the seven existing LF emergency operations centre response pillars in 2019. We describe lessons learnt from the integration of a research pillar into the LF national emergency response.

Descriptive epidemiology of cholera outbreak in Nigeria, January-November, 2018: implications for the global roadmap strategy.

BACKGROUND: The cholera outbreak in 2018 in Nigeria reaffirms its public health threat to the country. Evidence on the current epidemiology of cholera required for the design and implementation of appropriate interventions towards attaining the global roadmap strategic goals for cholera elimination however seems lacking. Thus, this study aimed at addressing this gap by describing the epidemiology of the 2018 cholera outbreak in Nigeria. METHODS: This was a retrospective analysis of surveillance data collected between January 1st and November 19th, 2018. A cholera case was defined as an individual aged 2 years or older presenting with acute watery diarrhoea and severe dehydration or dying from acute watery diarrhoea. Descriptive analyses were performed and presented with respect to person, time and place using appropriate statistics. RESULTS: There were 43,996 cholera cases and 836 cholera deaths across 20 states in Nigeria during the outbreak period, with an attack rate (AR) of 127.43/100,000 population and a case fatality rate (CFR) of 1.90%. Individuals aged 15 years or older (47.76%) were the most affected age group, but the proportion of affected males and females was about the same (49.00 and 51.00% respectively). The outbreak was characterised by four distinct epidemic waves, with higher number of deaths recorded in the third and fourth waves. States from the north-west and north-east regions of the country recorded the highest ARs while those from the north-central recorded the highest CFRs. CONCLUSION: The severity and wide-geographical distribution of cholera cases and deaths during the 2018 outbreak are indicative of an elevated burden, which was more notable in the northern region of the country. Overall, the findings reaffirm the strategic role of a multi-sectoral approach in the design and implementation of public health interventions aimed at preventing and controlling cholera in Nigeria.

Measures to control protracted large Lassa fever outbreak in Nigeria, 1 January to 28 April 2019.

Lassa fever cases have increased in Nigeria since 2016 with the highest number, 633 cases, reported in 2018. From 1 January to 28 April 2019, 554 laboratory-confirmed cases including 124 deaths were reported in 21 states in Nigeria. A public health emergency was declared on 22 January by the Nigeria Centre for Disease Control. We describe the various outbreak responses that have been implemented, including establishment of emergency thresholds and guidelines for case management.

Meningococcus serogroup C clonal complex ST-10217 outbreak in Zamfara State, Northern Nigeria.

After the successful roll out of MenAfriVac, Nigeria has experienced sequential meningitis outbreaks attributed to meningococcus serogroup C (NmC). Zamfara State in North-western Nigeria recently was at the epicentre of the largest NmC outbreak in the 21st Century with 7,140 suspected meningitis cases and 553 deaths reported between December 2016 and May 2017. The overall attack rate was 155 per 100,000 population and children 5-14 years accounted for 47% (3,369/7,140) of suspected cases. The case fatality rate (CFR) among children 5-9 years was 10%, double that reported among adults ≥ 30 years (5%). NmC and pneumococcus accounted for 94% (172/184) and 5% (9/184) of the laboratory-confirmed cases, respectively. The sequenced NmC belonged to the ST-10217 clonal complex (CC). All serotyped pneumococci were PCV10 serotypes. The emergence of NmC ST-10217 CC outbreaks threatens the public health gains made by MenAfriVac, which calls for an urgent strategic action against meningitis outbreaks.

Large Outbreak of Neisseria meningitidis Serogroup C - Nigeria, December 2016-June 2017.

On February 16, 2017, the Ministry of Health in Zamfara State, in northwestern Nigeria, notified the Nigeria Centre for Disease Control (NCDC) of an increased number of suspected cerebrospinal meningitis (meningitis) cases reported from four local government areas (LGAs). Meningitis cases were subsequently also reported from Katsina, Kebbi, Niger, and Sokoto states, all of which share borders with Zamfara State, and from Yobe State in northeastern Nigeria. On April 3, 2017, NCDC activated an Emergency Operations Center (EOC) to coordinate rapid development and implementation of a national meningitis emergency outbreak response plan. After the outbreak was reported, surveillance activities for meningitis cases were enhanced, including retrospective searches for previously unreported cases, implementation of intensified new case finding, and strengthened laboratory confirmation. A total of 14,518 suspected meningitis cases were reported for the period December 13, 2016-June 15, 2017. Among 1,339 cases with laboratory testing, 433 (32%) were positive for bacterial pathogens, including 358 (82.7%) confirmed cases of Neisseria meningitidis serogroup C. In response, approximately 2.1 million persons aged 2-29 years were vaccinated with meningococcal serogroup C-containing vaccines in Katsina, Sokoto, Yobe, and Zamfara states during April-May 2017. The outbreak was declared over on June 15, 2017, after high-quality surveillance yielded no evidence of outbreak-linked cases for 2 consecutive weeks. Routine high-quality surveillance, including a strong laboratory system to test specimens from persons with suspected meningitis, is critical to rapidly detect and confirm future outbreaks and inform decisions regarding response vaccination.