High-Resolution Geospatial Mapping of Zero-Dose and Underimmunized Children Following Nigeria's 2021 Multiple Indicator Cluster Survey/National Immunization Coverage Survey.

BACKGROUND: "Zero-dose" children are those who are without any routine vaccination or are lacking the first dose of the diphtheria, tetanus, and pertussis-containing vaccine. Based on global estimates from the World Health Organization/United Nations Children's Fund in 2022, Nigeria has the highest number of zero-dose children, with >2.3 million unvaccinated. METHODS: We used data from the 2021 Nigeria Multiple Indicator Cluster Survey/National Immunization Coverage Survey to identify zero-dose and underimmunized children. Geospatial modeling techniques were employed to determine the prevalence of zero-dose children and predict risk areas with underimmunized children at a high resolution (1 × 1 km). RESULTS: Zero-dose and underimmunized children are more prevalent in socially deprived groups. Univariate and multivariate bayesian analyses showed positive correlations between the prevalence of zero-dose and underimmunized children and factors such as stunting, contraceptive prevalence, and literacy. The prevalence of zero-dose and underimmunized children varies significantly by region and ethnicity, with higher rates observed in the country's northern parts. Significant heterogeneity in the distribution of undervaccinated children was observed. CONCLUSIONS: Nigeria needs to enhance its immunization system and coverage. Geospatial modeling can help deliver vaccines effectively to underserved communities. By adopting this approach, countries can ensure equitable vaccine access and contribute to global vaccination objectives.

High-resolution geospatial mapping of zero-dose and under-immunized children following Nigeria's 2021 multiple indicator cluster survey/national immunization coverage survey (MICS/NICS).

BACKGROUND: The "zero-dose" children are those without any routine vaccination or lacking the first dose of the diphtheria-tetanus-pertussis-containing vaccine. As per 2022 WHO/UNICEF estimates, globally, Nigeria has the highest number of zero-dose with over 2.3 million unvaccinated. METHODS: We used data from the 2021 Nigeria Multiple Indicator Cluster Survey - National Immunisation Coverage Survey to identify zero-dose and under-immunized children. Geospatial modelling techniques were employed to determine the prevalence of zero-dose children and predict risk areas with under-immunized at a high resolution of 1x1 km. RESULTS: Both zero-dose and under-immunized children are more prevalent in socially deprived groups. Univariate and multivariate Bayesian analyses showed positive correlations between the prevalence of zero-dose and under-immunized children with factors like stunting, contraceptive prevalence, and literacy. The prevalence of zero-dose and under-immunized children varies significantly by region and ethnicity, with higher rates observed in the country's northern parts. Significant heterogeneity in the distribution of under-vaccinated children was observed. CONCLUSIONS: Nigeria needs to enhance its immunization system and coverage. Geospatial modelling can help deliver vaccines effectively to underserved communities. By adopting this approach, countries can ensure equitable vaccine access and contribute to global vaccination objectives.

The global switch from trivalent oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV): facts, experiences and lessons learned from the south-south zone; Nigeria, April 2016.

BACKGROUND: The globally synchronized switch from trivalent Oral Polio Vaccine (tOPV) to bivalent Oral Polio Vaccine (bOPV) took place in Nigeria on April 18th 2016. The country is divided into six geopolitical zones. This study reports the experiences and lessons learned from the switch process in the six states that make up Nigeria's south-south geopolitical zone. METHODS: This was a descriptive retrospective review of Nigeria's switch plan and structures used for implementing the tOPV-bOPV switch in the south-south zone. Nigeria's National Polio Emergency Operation Centre (NPEOC) protocols, global guidelines and reports from switch supervisors during the switch were used to provide background information for this study. Quantitative data were derived from reviewing switch monitoring and validation documents as submitted to the NPEOC RESULTS: The switch process took place in all 3078 Health Facilities (HFs) and 123 Local Government Areas (LGAs) that make up the six states in the zone. A total of $139,430 was used for this process. The 'healthcare personnel' component received the highest budgetary allocation (59%) followed by the 'logistics' component (18%). Akwa Ibom state was allocated the highest number of healthcare personnel and hence received the most budgetary allocation compared to the six states (total healthcare personnel = 458, total budgetary allocation = $17,428). Validation of the switch process revealed that eight HFs in Bayelsa, Cross-River, Edo and Rivers states still possessed tOPV in cold-chain while six HFs in Cross-River and Rivers states had tOPV out of cold-chain but without the 'do not use' sticker. Akwa-Ibom was the only state in the zone to have bOPV and Inactivated Polio Vaccine (IPV) available in all its HFs monitored. CONCLUSION: The Nigerian tOPV-bOPV switch was successful. For future Oral Polio Vaccine (OPV) withdrawals, implementation of the switch plan would be more feasible with an earlier dissemination of funds from global donor organizations, which would greatly aid timely planning and preparations. Increased budgetary allocation to the 'logistics' component to accommodate unexpected hikes in transportation prices and the general inefficiencies with power supply in the country is also advised.

Clinical profile and containment of the Ebola virus disease outbreak in two large West African cities, Nigeria, July-September 2014.

INTRODUCTION: The Ebola virus disease (EVD) outbreak in Nigeria began when an infected diplomat from Liberia arrived in Lagos, the most populous city in Africa, with subsequent transmission to another large city. METHODS: First-, second-, and third-generation contacts were traced, monitored, and classified. Symptomatic contacts were managed at Ebola treatment centers as suspected, probable, and confirmed EVD cases using standard operating procedures adapted from the World Health Organization EVD guidelines. Reverse transcription PCR tests confirmed EVD. Socio-demographic, clinical, hospitalization, and outcome data of the July-September 2014 Nigeria EVD cohort were analyzed. RESULTS: The median age of the 20 EVD cases was 33 years (interquartile range 26-62 years). More females (55%), health workers (65%), and persons <40 years old (60%) were infected than males, non-health workers, and persons aged ≥40 years. No EVD case management worker contracted the disease. Presenting symptoms were fever (85%), fatigue (70%), and diarrhea (65%). Clinical syndromes were gastroenteritis (45%), hemorrhage (30%), and encephalopathy (15%). The case-fatality rate was 40% and there was one mental health complication. The average duration from symptom onset to presentation was 3±2 days among survivors and 5±2 days for non-survivors. The mean duration from symptom onset to discharge was 15±5 days for survivors and 11±2 days for non-survivors. Mortality was higher in the older age group, males, and those presenting late. CONCLUSION: The EVD outbreak in Nigeria was characterized by the severe febrile gastroenteritis syndrome typical of the West African outbreak, better outcomes, rapid containment, and no infection among EVD care-providers. Early case detection, an effective incident management system, and prompt case management with on-site mobilization and training of local professionals were key to the outcome.