World Health Organization African Region Research Articles

COVID-19 Vaccination Coverage - World Health Organization African Region, 2021-2023.

With the availability of authorized COVID-19 vaccines in early 2021, vaccination became an effective tool to reduce COVID-19-associated morbidity and mortality. Initially, the World Health Organization (WHO) set an ambitious target to vaccinate 70% of the global population by mid-2022. However, in July 2022, WHO recommended that all countries, including those in the African Region, prioritize COVID-19 vaccination of high-risk groups, including older adults and health care workers, to have the greatest impact on morbidity and mortality. As of December 31, 2023, approximately 860 million doses of COVID-19 vaccine had been delivered to countries in the African Region, and 646 million doses had been administered. Cumulatively, 38% of the African Region's population had received ≥1 dose, 32% had completed a primary series, and 21% had received ≥1 booster dose. Cumulative total population coverage with ≥1 dose ranged by country from 0.3% to 89%. Coverage with the primary series among older age groups was 52% (range among countries=15%-96%); primary series coverage among health care workers was 48% (range=13%-99%). Although the COVID-19 public health emergency of international concern was declared over in May 2023, current WHO recommendations reinforce the need to vaccinate priority populations at highest risk for severe COVID-19 disease and death and build more sustainable programs by integrating COVID-19 vaccination into primary health care, strengthening immunization across the life course, and improving pandemic preparedness.

Low Measles Vaccination Coverage and Spatial Analysis of High Measles Vaccination Dropout in Ethiopia's Underprivileged Areas.

(1) Background: Measles remains a major cause of disease and death worldwide, especially in the World Health Organization African Region. This study aimed to estimate the coverage of measles vaccinations and map the spatial distribution of measles vaccination dropout in Ethiopia; (2) Methods: A cross-sectional survey was conducted in Ethiopia's underprivileged areas. The study included 3646 mothers/caregivers of children. ArcGIS for the spatial analysis, Global Moran's I statistic for spatial autocorrelation, and Getis-Ord Gi* statistics for hot spot analysis were applied; (3) Results: Overall, coverages of measles-containing-vaccine first- and second-doses were 67% and 35%, respectively. Developing regions had the lowest coverages of measles-containing-vaccine first- and second-doses, 46.4% and 21.2%, respectively. On average, the measles vaccination dropout estimate was 48.3%. Refugees had the highest measles vaccination dropout estimate (56.4%). The hot spot analysis detected the highest burden of measles vaccination dropout mainly in the northeastern parts of Ethiopia, such as the Afar Region's zones 1 and 5, the Amhara Region's North Gondar Zone, and peripheral areas in the Benishangul Gumuz Region's Assosa Zone; (4) Conclusions: The overall measles vaccination coverages were relatively low, and measles vaccination dropout estimates were high. Measles vaccination dropout hot spot areas were detected in the northeastern parts of Ethiopia.

Barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of oral health policies in the WHO Africa region: A scoping review protocol.

Evidence-informed oral health policies (OHP) can be instrumental in ending the neglect of oral health globally. When appropriately developed and implemented, OHP can improve the efficiency of healthcare systems and the quality of health outcomes. However, more than half of the countries in the World Health Organization (WHO) African region do not have an oral health policy or even the existence of a policy in need of additional and more national-specific OHP as part of non-communicable diseases and universal health coverage agendas. The objective of this protocol's study is to determine the barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of OHP in the WHO Africa region. We will conduct a systematic search in Global Health, Embase, PubMed, PAIS, ABI/Inform, Web of Science, Academic Search Complete, Scopus, databases that index gray literature, and the WHO policy repositories. We will include qualitative, quantitative, or mixed-methods research studies and OHP documents published since January 1, 2002, which address stakeholders' perceptions and experiences regarding barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of OHP in countries part of the WHO African region. We will produce descriptive statistics (frequencies and proportions) for quantitative data and conduct descriptive content analysis for qualitative data. To effectively establish evidence-based OHP in the WHO African region, it is crucial to recognize existing challenges and opportunities for progress. The findings of this review will be relevant for Chief Dental Officers at ministries of health, administrators of dental schools, or academic institutions in the WHO African region and will inform a stakeholder dialogue meeting in Kenya in November of 2023. Open Science Framework: https://doi.org/10.17605/OSF.IO/9KMWR.

Status of Routine Immunization Coverage in the World Health Organization African Region Three Years into the COVID-19 Pandemic.

Data from the WHO and UNICEF Estimates of National Immunization Coverage (WUENIC) 2022 revision were analyzed to assess the status of routine immunization in the WHO African Region disrupted by the COVID-19 pandemic. In 2022, coverage for the first and third doses of the diphtheria-tetanus-pertussis-containing vaccine (DTP1 and DTP3, respectively) and the first dose of the measles-containing vaccine (MCV1) in the region was estimated at 80%, 72% and 69%, respectively (all below the 2019 level). Only 13 of the 47 countries (28%) achieved the global target coverage of 90% or above with DTP3 in 2022. From 2019 to 2022, 28.7 million zero-dose children were recorded (19.0% of the target population). Ten countries in the region accounted for 80.3% of all zero-dose children, including the four most populated countries. Reported administrative coverage greater than WUENIC-reported coverage was found in 19 countries, highlighting routine immunization data quality issues. The WHO African Region has not yet recovered from COVID-19 disruptions to routine immunization. It is critical for governments to ensure that processes are in place to prioritize investments for restoring immunization services, catching up on the vaccination of zero-dose and under-vaccinated children and improving data quality.

Monitoring progress on Antimicrobial Resistance (AMR) response in the World Health Organization African region: Insights from the Tracking AMR Country Self-Assessment Survey (TrACSS) 2021 results for the human health sector.

Antimicrobial resistance (AMR) is a major 21st century global health challenge. The WHO African Region Member States committed to develop and implement multisectoral national action plans (NAPs) that address AMR, in line with the Global Action Plan on AMR (GAP). The aim of this paper is to present the progress of AMR response in the WHO African Region based on the annual Tracking AMR Country Self-Assessment Survey (TrACSS), with a focus on human health indicators. This was a secondary data analysis of responses from forty-one countries that participated in the 2021 TrACSS. Of the 41 countries that responded to the 2021 TrACSS, 35(85%) have developed NAPs. Fifteen 15(37%) of countries have functional AMR multisector working groups. 55% (21/41) of countries are collating data nationally on AMR surveillance. Forty nine percent of countries conducted small-scale AMR awareness campaigns and 53% (21/41) covered AMR in some pre- and in-service training for human health workers. While 83% of countries reported having laws and regulations on the prescription and sale of antimicrobials, only 32% (13/41) have national systems for monitoring antimicrobial use. Twenty-three (58%, 23/41) reported having Infection Prevention and Control (IPC) programs at select health facilities. Countries have developed and are implementing AMR NAPs. Gaps still exist across key indicators monitored through TrACSS. Effective AMR response requires established functional multisectoral governance mechanisms in the One Health approach; political commitment, sustainable funding, and clear monitoring and reporting is critical.

Investigating Infection Prevention and Control Practices among Healthcare Workers in Kasese District, Uganda: Factors and Implications for Ebola Preparedness

The World Health Organization (WHO) African region often faces numerous public health emergencies, with a significant proportion caused by infectious diseases. Ebola virus disease (EVD) is a high-consequence pathogen of particular concern due to its high mortality rate and potential for global transmission. The study aimed to investigate infection prevention and control (IPC) practices with factors associated with the practice among health care workers (HCWs) in Kasese district, Uganda. The study design was cross-sectional, utilizing both qualitative and quantitative methods. The study population consisted of HCWs working in six selected Health Centre III facilities in sub-counties bordering the Democratic Republic of Congo (DRC). A sample of 106 HCWs was purposively selected and data collection involved structured questionnaires, and then data analysis was done using descriptive statistics and logistic regression. The study reveals that a majority of HCWs were female (55.7%), worked in outpatient departments (49.1%), had 6-10 years of service (43.4%), held certificates as their highest education level (48.1%), and were predominantly nurses (53.8%). IPC practices were found to be low, with 72.6% of participants exhibiting inappropriate IPC practices. Individual factors influencing low IPC practices included the duration of IPC training, knowledge, attitude towards IPC, and education level, all statistically significant (P < 0.05). Similarly, health facility factors such as the accessibility of IPC guidelines and personal protective equipment (PPE), availability of sanitizer/soap, and proper and continuous IPC training/continuing medical education (CME) were associated with low IPC practice (P < 0.05). In conclusion, the study highlights a low level of IPC practice among HCWs in Health Centre Threes in Kasese District, with both individual and health facility factors contributing to this issue. Recommendations include training HCWs in IPC and organizing regular cascade training, providing IPC knowledge as part of their daily duties, ensuring confidence in managing Ebola during outbreaks, maintaining IPC strategies implemented during EVD outbreaks, and supplying IPC materials to healthcare facilities. These efforts, coupled with increased staffing, can significantly enhance protection and performance in public healthcare services.

Обзор актуальных рисков заноса инфекционных болезней на территорию Российской Федерации из стран Африканского континента

The paper presents generalized epidemiological data and analyzes the situation in the countries of the African region on infectious diseases requiring measures for sanitary protection of the territory of the Russian Federation. The epidemiological analysis was carried out on the basis of data from the official website of the African Bureau of the World Health Organization (WHO), the African Center for Disease Prevention and Control (CDC), Ministries of Health of the relevant countries, other international organizations, as well as materials of publications in the public domain. The paper summarizes and systematizes data on the incidence and territorial spread of diseases in the region from the perspective of possible risks for those visiting it. The presented data on infectious diseases make it possible to navigate issues related to the risk of infection with infectious diseases, to determine the factors and seasonality of the increased risk of infection, to predict the possibility of importing diseases to the Russian Federation. Keywords: infectious diseases, WHO African region, ensuring sanitary and epidemiological well-being, risk of drift, sanitary protection of the territory, plague, cholera, malaria, EVD, MVD.

Development of a Consolidated Health Facility Masterlist Using Data From Polio Electronic Surveillance in the World Health Organization African Region (Preprint)

Development of a Consolidated Health Facility Masterlist Using Data From Polio Electronic Surveillance in the World Health Organization African Region (Preprint)

Toward political economy of sustainable financing for immunization in the World Health Organization African Region through a systems thinking lens

There is an urgent need for countries in Africa to allocate more domestic financial resources to immunization so that national immunization programmes can attain self-reliance in line with World Health Organization's Immunization Agenda 2030. However, resource allocation is fundamentally a political process because other competing needs exist. Political economy analysis (PEA) can guide policy influencers in their engagement with decision makers to tilt their interest in support of sustainable immunization financing. PEA can provide a deeper understanding of the potential constraints and facilitators of a policy direction to expand the fiscal space for immunization using domestic resources within the context of a country's socioeconomic and political realities. To further advance the usefulness of PEA for decision making, a systems thinking lens should be applied to account for the inherent complexity of the social systems involved in resource allocation and implementation. Several methods and tools of systems thinking already exist and can be employed. Causal loop diagrams, when incorporated in a PEA of sustainable financing for immunization can aid the identification of feedback loops which can be used as leverage points for intervention.

Barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of oral health policies in the WHO Africa region: A scoping review protocol

Background: Evidence-informed oral health policies (OHP) can be instrumental in ending the neglect of oral health globally. When appropriately developed and implemented, OHP can improve the efficiency of healthcare systems and the quality of health outcomes. However, more than half of the countries in the World Health Organization (WHO) African region did not have an oral health policy or even the existence of a policy in need of additional and more national-specific OHP as part of non-communicable diseases and universal health coverage agendas. The objective of this protocol’s study is to determine the barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of OHP in the WHO Africa region. Methods: We will conduct a systematic search in Global Health, Embase, PubMed, PAIS, ABI/Inform, Web of Science, Academic Search Complete, Scopus, databases that index gray literature, and the WHO policy repositories. We will include qualitative, quantitative, or mixed-methods research studies and OHP documents published since January 1, 2002, which address stakeholders' perceptions and experiences regarding barriers to and facilitators for the creation, dissemination, implementation, monitoring, and evaluation of OHP in countries part of the WHO African region. We will produce descriptive statistics (frequencies and proportions) for quantitative data and conduct descriptive content analysis for qualitative data. Discussion: To effectively establish evidence-based OHP in the WHO African region, it is crucial to recognize existing challenges and opportunities for progress. The findings of this review will be relevant for Chief Dental Officers at ministries of health, administrators of dental schools, or academic institutions in the WHO African region and will inform a stakeholder dialogue meeting in Kenya in November of 2023. Registration: Open Science Framework: https://doi.org/10.17605/OSF.IO/9KMWR

Progress Toward Measles Elimination - African Region, 2017-2021.

Worldwide, measles remains a major cause of disease and death; the highest incidence is in the World Health Organization African Region (AFR). In 2011, the 46 AFR member states established a goal of regional measles elimination by 2020; this report describes progress during 2017-2021. Regional coverage with a first dose of measles-containing vaccine (MCV) decreased from 70% in 2017 to 68% in 2021, and the number of countries with ≥95% coverage decreased from six (13%) to two (4%). The number of countries providing a second MCV dose increased from 27 (57%) to 38 (81%), and second-dose coverage increased from 25% to 41%. Approximately 341 million persons were vaccinated in supplementary immunization activities, and an estimated 4.5 million deaths were averted by vaccination. However, the number of countries meeting measles surveillance performance indicators declined from 26 (62%) to nine (22%). Measles incidence increased from 69.2 per 1 million population in 2017 to 81.9 in 2021. The number of estimated annual measles cases and deaths increased 22% and 8%, respectively. By December 2021, no country in AFR had received verification of measles elimination. To achieve a renewed regional goal of measles elimination in at least 80% of countries by 2030, intensified efforts are needed to recover and surpass levels of surveillance performance and coverage with 2 MCV doses achieved before the COVID-19 pandemic.

Evaluation of Laboratories Supporting Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance in the World Health Organization African Region, through the Performance of Coordinated External Quality Assessment.

(1) Background: Laboratories supporting the invasive bacteria preventable disease (IB-VPD) network are expected to demonstrate the capacity to identify the main etiological agents of pediatric bacterial meningitis (PBM) (Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae) on Gram stains and in phenotypic identification. Individual reports of sentinel site (SSL), national (NL) and regional reference (RRL) laboratories participating in the World Health Organization (WHO)-coordinated external quality assessment, distributed by the United Kingdom National External Quality Assessment (EQA) Services (UK NEQAS) for Microbiology between 2014 and 2019 were analyzed. (2) Methods: The panels consisted of (1) unstained bacterial smears for Gram staining, (2) viable isolates for identification and serotyping/serogrouping (ST/SG) and (3) simulated cerebral spinal fluid (CSF) samples for species detection and ST/SG using polymerase chain reaction (PCR). SSLs and NLs tested for Gram staining and species identification (partial panel). RRLs, plus any SSLs and NLs (optionally) also analyzed the simulated CSF samples (full panel). The passing score was ≥75% for NLs and SSLs, and ≥90% for RRLs and NLs/SSLs testing the full panel. (3) Results: Overall, 63% (5/8) of the SSLs and NLs were able to correctly identify the targeted pathogens, in 2019; but there were challenges to identify Haemophilus influenzae either on Gram stains (35% of the labs failed 2014), or in culture. Individual performance showed inconsistent capacity, with only 39% (13/33) of the SSLs/NLs passing the EQA exercise throughout all surveys in which they participated. RRLs performed well over the study period, but one of the two failed to reach the minimal passing score in 2016 and 2018; while the SSLs/NLs that optionally tested the full panel scored between 75% and 90% (intermediate pass category). (4) Conclusions: We identified a need for implementing a robust quality management system for timely identification of the gaps and then implementing corrective and preventive actions, in addition to continuous refresher training in the SSLs and NLs supporting the IB-VPD surveillance in the World Health Organization, Regional Office for Africa (WHO AFRO).

COVID-19 Vaccination in the WHO African Region: Progress Made in 2022 and Factors Associated.

This study summarizes progress made in rolling out COVID-19 vaccinations in the African region in 2022, and analyzes factors associated with vaccination coverage. Data on vaccine uptake reported to the World Health Organization (WHO) Regional Office for Africa by Member States between January 2021 and December 2022, as well as publicly available health and socio-economic data, were used. A negative binomial regression was performed to analyze factors associated with vaccination coverage in 2022. As of the end of 2022, 308.1 million people had completed the primary vaccination series, representing 26.4% of the region's population, compared to 6.3% at the end of 2021. The percentage of health workers with complete primary series was 40.9%. Having carried out at least one high volume mass vaccination campaign in 2022 was associated with high vaccination coverage (β = 0.91, p < 0.0001), while higher WHO funding spent per person vaccinated in 2022 was correlated with lower vaccination coverage (β = -0.26, p < 0.03). All countries should expand efforts to integrate COVID-19 vaccinations into routine immunization and primary health care, and increase investment in vaccine demand generation during the transition period that follows the acute phase of the pandemic.

Update on Wild Poliovirus Type 1 Outbreak — Southeastern Africa, 2021–2022

Since the Global Polio Eradication Initiative (GPEI) began in 1988, the number of wild poliovirus (WPV) cases has declined by >99.99%. Five of the six World Health Organization (WHO) regions have been certified free of indigenous WPV, and WPV serotypes 2 and 3 have been declared eradicated globally (1). WPV type 1 (WPV1) remains endemic only in Afghanistan and Pakistan (2,3). Before the outbreak described in this report, WPV1 had not been detected in southeastern Africa since the 1990s, and on August 25, 2020, the WHO African Region was certified free of indigenous WPV (4). On February 16, 2022, WPV1 infection was confirmed in one child living in Malawi, with onset of paralysis on November 19, 2021. Genomic sequence analysis of the isolated poliovirus indicated that it originated in Pakistan (5). Cases were subsequently identified in Mozambique. This report summarizes progress in the outbreak response since the initial report (5). During November 2021-December 2022, nine children and adolescents with paralytic polio caused by WPV1 were identified in southeastern Africa: one in Malawi and eight in Mozambique. Malawi, Mozambique, and three neighboring countries at high risk for WPV1 importation (Tanzania, Zambia, and Zimbabwe) responded by increasing surveillance and organizing up to six rounds of national and subnational polio supplementary immunization activities (SIAs).* Although no cases of paralytic WPV1 infection have been reported in Malawi since November 2021 or in Mozambique since August 2022, undetected transmission might be ongoing because of poliovirus surveillance gaps and testing delays. Efforts to further enhance poliovirus surveillance sensitivity, improve SIA quality, and strengthen routine immunization are needed to ensure that WPV1 transmission has been interrupted within 12 months of the first case, thereby preserving the WHO African Region's WPV-free status.

Progress, Gaps, and Tobacco Industry Opposition to Tobacco Advertising, Promotion, and Sponsorship Bans in the World Health Organization African Region.

Although the African Region (AFRO) has the lowest smoking prevalence by World Health Organization region, the prevalence rate is expected to grow from 15.8% in 2010 to 21.9% in 2030 based on 2010 levels, the largest projected increase in the world.1 A key reason for this upsurge is that tobacco companies aggressively market in AFRO to recruit new tobacco users, especially youth.2 To combat this, the WHO Framework Convention on Tobacco Control (FCTC)’s Article 13 and its Guidelines ­recommend prohibiting all forms of tobacco advertising, promotion, and sponsorship (TAPS).3 While there is robust literature on tobacco industry marketing in Africa,4 there is scarce research to date assessing TAPS, including only one 2011 regional analysis of TAPS policies in AFRO.5 Given these gaps and the lack of TAPS implementation data available, the goal of this review was to assess the progress of TAPS policies adopted and to discuss efforts to overcome barriers to pass and implement TAPS bans in AFRO.

Vaccination and surveillance: Two basic tools for a final poliomyelitis eradication

Over the past 3 decades, the Global Polio Eradication Initiative (GPEI) has strived to achieve a poliomyelitis (polio)-free world. Wild poliovirus (WPV) types 2 and 3 were eradicated in 2015 and 2019, respectively. The World Health Organization (WHO) South-East Asia Region was declared free of poliovirus in 2014, and the WHO African Region was certified

Oral Health Workforce in Africa: A Scarce Resource.

The World Health Organization (WHO) African Region (AFR) has 47 countries. The aim of this research was to review the oral health workforce (OHWF) comprising dentists, dental assistants and therapists, and dental prosthetic technicians in the AFR. OHWF data from a survey of all 47 member states were triangulated with the National Health Workforce Accounts and population data. Descriptive analysis of workforce trends and densities per 10,000 population from 2000 to 2019 was performed, and perceived workforce challenges/possible solutions were suggested. Linear regression modelling used the Human Development Index (HDI), years of schooling, dental schools, and levels of urbanization as predictors of dentist density. Despite a growth of 63.6% since 2010, the current workforce density of dentists (per 10,000 population) in the AFR remains very low at 0.44, with marked intra-regional inequity (Seychelles, 4.297; South Sudan 0.003). The stock of dentists just exceeds that of dental assistants/therapists (1:0.91). Workforce density of dentists and the OHWF overall was strongly associated with the HDI and mean years of schooling. The dominant perceived challenge was identified as 'mal-distribution of the workforce (urban/rural)' and 'oral health' being 'considered low priority'. Action to 'strengthen oral health policy' and provide 'incentives to work in underserved areas' were considered important solutions in the region. Whilst utilising workforce skill mix contributes to overall capacity, there is a stark deficit of human resources for oral health in the AFR. There is an urgent need to strengthen policy, health, and education systems to expand the OHWF using innovative workforce models to meet the needs of this region and achieve Universal Health Coverage (UHC).

Epidemiology of Human Mpox — Worldwide, 2018–2021

Monkeypox (mpox) is a zoonotic disease caused by Monkeypox virus (MPXV), an Orthopoxvirus; the wild mammalian reservoir species is not known. There are two genetic clades of MPXV: clade I and clade II (historically found in central and west Africa, respectively), with only Cameroon reporting both clades (1). Human cases have historically been reported from 1) mostly rural, forested areas in some central and west African countries; 2) countries reporting cases related to population migration or travel of infected persons; and 3) exposure to imported infected mammals (2). The annual number of cases in Africa has risen since 2014 and cumulatively surpassed reports from the previous 40 years for most countries. This reemergence of mpox might be due to a combination of environmental and ecological changes, animal or human movement, the cessation of routine smallpox vaccination since its eradication in 1980, improvements in disease detection and diagnosis, and genetic changes in the virus (2). This report describes the epidemiology of mpox since 1970 and during 2018-2021, using data from national surveillance programs, World Health Organization (WHO) bulletins, and case reports, and addresses current diagnostic and treatment challenges in countries with endemic disease. During 2018-2021, human cases were recognized and confirmed in six African countries, with most detected in the Democratic Republic of the Congo (DRC) and Nigeria. The reemergence and increase in cases resulted in its being listed in 2019 as a priority disease for immediate and routine reporting through the Integrated Disease Surveillance and Response strategy in the WHO African region.* In eight instances, patients with mpox were identified in four countries outside of Africa after travel from Nigeria. Since 2018, introductory and intermediate training courses on prevention and control of mpox for public health and health care providers have been available online at OpenWHO.†,§ The global outbreak that began in May 2022¶ has further highlighted the need for improvements in laboratory-based surveillance and access to treatments and vaccines to prevent and contain the infection, including in areas of Africa with endemic mpox.

The WHO African Region Initiative on Engaging Civil Society Organizations in Responding to the COVID-19 Pandemic: Best Practices and Lessons Learned for a More Effective Engagement of Communities in Responding to Public Health Emergencies.

Engaging communities is a key factor in efficient response to public health emergencies (PHE). Previous and recent outbreaks have shown that civil society organizations (CSOs) can mobilize the communities to better prepare and respond to a PHE. Consequently, the World Health Organization (WHO) Regional Office for Africa (AFRO) implemented an initiative to partner with community leaders by engaging CSOs. The Civil Society Organization Initiative (CSO Initiative) aims to work directly with well-established community-based organizations to accelerate whole-of-society preparation and response. Twenty-three CSOs from 12 WHO African Region Member States have been supported financially and technically to implement effective community-based interventions to respond to the coronavirus disease (COVID-19) pandemic. After 1 year of implementation (2021), the successes, challenges, and recommendations for maximizing future engagements with CSOs are outlined. As the COVID-19 outbreak is again underlining, partnering with established CSOs to engage diverse social groups from various communities can help provide a timely and efficient response to a PHE.

Descriptive epidemiology of poliomyelitis cases due to wild poliovirus type 1 and wild poliovirus type 3 in Nigeria, 2000-2020.

in August 2020, the World Health Organization African Region was certified free of wild poliovirus (WPV) when Nigeria became the last African country to interrupt wild poliovirus transmission. The National Polio Emergency Operations Center instituted in 2012 to coordinate and manage Nigerian polio eradication efforts reviewed the epidemiology of WPV cases during 2000-2020 to document lessons learned. we analyzed reported WPV cases by serotype based on age, oral poliovirus vaccine immunization history, month and year of reported cases, and annual geographic distribution based on incidence rates at the Local Government Area level. The observed trends of cases were related to major events and the poliovirus vaccines used during mass vaccination campaigns within the analysis period. a total of 3,579 WPV type 1 and 1,548 WPV type 3 laboratory-confirmed cases were reported with onset during 2000-2020. The highest WPV incidence rates per 100,000 population in Local Government Areas were 19.4, 12.0, and 11.3, all in 2006. Wild poliovirus cases were reported each year during 2000-2014; the endemic transmission went undetected throughout 2015 until the last cases in 2016. Ten events/milestones were highlighted, including insurgency in the northeast which led to a setback in 2016 with four cases from children previously trapped in security-compromised areas. Nigeria interrupted WPV transmission despite the challenges faced because of the emergency management approach, implementation of mass vaccination campaigns, the commitment of the government agencies, support from global polio partners, and special strategies deployed to conduct vaccination and surveillance in the security-compromised areas.