The resurgence of yellow fever outbreaks in Nigeria: a 2-year review 2017-2019.

BACKGROUND: Yellow fever outbreaks are documented to have a considerable impact not only on the individuals but on the health system with significant economic implications. Efforts to eliminate yellow fever outbreaks globally through the EYE strategy remains important following outbreaks in Africa, Nigeria included. The outbreaks reported in Nigeria, since 2017 and the response efforts provide an opportunity to document and guide interventions for improving future outbreaks in Nigeria and other countries in Africa. METHODS: We reviewed the available yellow fever surveillance and vaccination response data between September 2017 and September 2019 across the 36 states across Nigeria. We described the epidemiology of the difference outbreaks and the periods for all interventions. We also documented the emergency vaccination responses as well as preventive mass vaccinations implemented towards improving population immunity and limiting epidemic potentials in Nigeria. RESULTS: A total of 7894 suspected cases with 287 laboratory-confirmed cases were reported in Nigeria between September 2017 and September 2019 with a mean age of 19 years and a case fatality of 2.7% amongst all reported cases. Outbreaks were confirmed in 55 LGAs with most of the outbreaks across four major epicentres in Kwara/Kogi, Edo, Ebonyi and Bauchi states. In response to these outbreaks, eight reactive vaccination campaigns, supported through ICG applications, were implemented. The duration for responding to the outbreaks ranged from 15 to 132 days (average 68 days) and a total of 45,648,243 persons aged < 45 years vaccinated through reactive and preventive mass campaigns between September 2017 and September 2019. CONCLUSIONS: Nigeria experienced intermediate outbreaks of yellow fever between September 2017 and 2019 with vaccination responses conducted to control these outbreaks. However, there are delays in the timeliness of responses and more efforts required in improving reporting, response times and preparedness to further prevent morbidity and mortality from the yellow fever disease outbreaks. These efforts, including improving routine yellow fever coverage, contribute towards improving population immunity and other activities related to achieving the goals of the EYE strategy.

Targeting the last polio sanctuaries with Directly Observed Oral Polio Vaccination (DOPV) in northern Nigeria, (2014-2016).

BACKGROUND: The declaration of poliomyelitis eradication as a programmatic emergency for global public health by the 65th World Health Assembly in 2012 necessitated innovations and strategies to achieve results. Review of the confirmed polio cases in 2013 showed that most of the cases were from non-compliant households, where parents connived with vaccinators to finger mark the children without actually vaccinating the children with oral polio vaccine or children were absent from home at the time of the visit of vaccinators. METHODS: We used pre-post design to quantify the outcomes of directly observed vaccination in 90 local government areas from 12 northern Nigeria states at very high risk of polio transmission. The strategy is an intervention, vaccinating children under the direct supervision of an independent supervisor to ensure compliance. Attractive incentives (pluses) were used to make parents willingly submit their children for vaccination or directly attract children to the vaccination teams or post as part of this strategy. RESULTS: There was a steady increase in population immunity in all the 90 DOPV implementing LGAs since the introduction of DOPV in 2013. The number of states in which > 90% of children received > 4 OPV doses increased from 7 in 2013 to 11 states by July 2016. Yobe state reported the highest proportional increase from 75 to 99% by July 2016 (22% increase), while Kano state reported 17% increase, from 82 to 99% by July 2016. CONCLUSION: Directly observed polio vaccination strategy improved uptake of polio vaccines and population immunity in high-risk areas for polio transmission.

Polio eradication in Nigeria: evaluation of the quality of acute flaccid paralysis surveillance documentation in Bauchi state, 2016.

BACKGROUND: Nigeria is the only country in Africa that is yet to be certified as polio free. Surveillance for acute flaccid paralysis (AFP) is the foundation of the polio eradication initiative since it provides information to alert both health managers and clinician that timely actions should be initiated to interrupt transmission of the polio virus. The strategy also provides evidence for the absence of wild poliovirus. This evaluation was performed to assess key quality indicators defined by the polio eradication program and thus to identify gaps to allow planning for corrective measures to achieve a polio-free situation in Bauchi state and in Nigeria at large. We conducted a cross-sectional descriptive study which involved a desk review of documents to authenticate the correctness and completeness of data, and a review of documented evidence for the quality of AFP surveillance. We interviewed Local Government Authority (LGA) surveillance officers and clinicians from focal and non-focal sites, along with caregivers of children with AFP and community leaders. The data were entered and analyzed in a Microsoft Excel spreadsheet. METHODS: We conducted a cross-sectional study of the AFP surveillance and documentation in eighteen of the twenty Local Government Areas (LGAs) of Bauchi State. We assessed the knowledge of the clinician at focal and non-focal sites on case definition of AFP, the number and method of stool specimen collection to investigate a case and types of training received for AFP surveillance. We verified AFP case investigations for the last three years: The caregivers (mothers) were interviewed to authenticate the reported information of AFP cases, the method used for stool specimen collection and feedbacks. Community leaders' knowledge on AFP surveillance was also assessed. Data was entered and analyzed in excel spread sheet. RESULTS: Of the 18 LGA Disease Surveillance and Notification Officers (DSNOs), only 2 (11%) and 5 (28%) had reports of polio outbreak investigations and supervisory visits at the lower levels, respectively. Furthermore, only 6 (33%) and 7 (39%) of the DSNOs had minutes of meetings and surveillance work plans, respectively. Of the 31 AFP cases investigated, only 39, 26, 23, and 23% had correct and complete information for the birth day, birth month, date of onset of paralysis, and date of investigation, respectively. Seventy-one percent of the clinicians at the AFP focal sites knew the correct definition for AFP compared with only 30% at the non-focal sites. Of the 38 caregivers (mothers), 16 (42%) did not remember the day or month the AFP investigation was conducted. However, 95% gave a correct number of stool samples collected and 40% mentioned that the samples were collected 24 h apart. Feedback was not given to 26 (68%) of the caregivers. The majority (79%) of the community leaders knew how to recognize a case of AFP and knew that the stool was the specimen required for the investigation, but 21% did not know to whom they should report a case of AFP in their community. CONCLUSION: This study revealed a gap in the quality indicators for polio eradication in the state, especially regarding knowledge and documentation for AFP surveillance at the operational level. Regular training of the DSNOs and focal persons, regular sensitization of clinicians, community education, supplies of reporting tools, and ensuring their judicious use will improve AFP surveillance in the state.

Mobilizing political support proved critical to a successful switch from tOPV to bOPV in Kano, Nigeria 2016.

BACKGROUND: Kano is one of the high-risk states for polio transmission in Northern Nigeria. The state reported more cases of wild polioviruses (WPVs) than any other state in the country. The Nigeria Demographic and Health Survey of 2013 indicated that OPV3 coverage in the routine immunization (RI) programmewas 57.9%. Additionally, serial polio seroprevalence studies conducted from 2011 to 2015 in the eightmetropolitan LGAs indicated low immunity levels against all three polio serotypes in children below one year. Areas with sub-optimal RI coverage such as Kanothat fail to remove all tOPV during the tOPV-bOPV switchwill be at increased risk of VDPV2 circulation. METHODS: We assessed the impact of political leadership engagement in mobilizing other stakeholders on the outcomes of the bOPV-tOPV switch in Kano State from February to May 2016 using nationally-selected planning and outcome indicators. RESULTS: A total of 670 health facilities that provide RI services were assessed during the pre-switch activities. Health workers were aware of the switch exercise in 520 (95.1%) of the public health facilities assessed. It was found that health workers knew what to do should tOPV be found in any of the 521 (95.2%)public health facilities assessed. However, there was a wide disparity between the public and private health practitioners' knowledge on basic concepts of the switch. There was 100% withdrawal of tOPV from the state and the seven zonal cold stores. Unmarked tOPVwas found in the cold chain system in 2 (4.5%) LGAs. Only one health facility (0.8%) had tOPV in the cold chain. No tOPVwas identified outside the cold chain without the "Do not use" sticker in any of the health facilities. CONCLUSION: The engagement of the political leadership to mobilize other key stakeholders facilitated successful implementation of the tOPV-bOPVswitch exercise and provided opportunity to strengthen partnerships with the private health sector in Kano State.

Conduct of vaccination in hard-to-reach areas to address potential polio reservoir areas, 2014-2015.

BACKGROUND: The Global Vaccine Action Plan (GVAP) seeks to achieve the total realization of its vision through equitable access to immunization as well as utilizing the immunization systems for delivery of other primary healthcare programs. The inequities in accessing hard-to-reach areas have very serious implications for the prevention and control of vaccine-preventable diseases, especially the polio eradication initiative. The Government of Nigeria implemented vaccination in hard-to-reach communities with support from the World Health Organization (WHO) to address the issues of health inequities in the hard-to-reach communities. This paper documents the process of conducting integrated mobile vaccination in these hard-to-reach areas and the impact on immunization outcomes. METHODS: We conducted vaccination using mobile health teams in 2311 hard-to-reach settlements in four states at risk of sustaining polio transmission in Nigeria from July 2014 to September 2015. RESULTS: The oral polio vaccine (OPV)3 coverage among children under 1 year of age improved from 23% at baseline to 61% and OPV coverage among children aged 1-5 years increased from 60 to 90%, while pentavalent vaccine (penta3) coverage increased from 22 to 55%. Vitamin A was administered to 78% of the target population and 9% of children that attended the session were provided with treatment for malaria. CONCLUSIONS: The hard-to-reach project has improved population immunity against polio, as well as other routine vaccinations and delivery of child health survival interventions in the hard-to-reach and underserved communities.

Transboundary nomadic population movement: a potential for import-export of poliovirus.

BACKGROUND: Nomadic populations have a considerably higher risk of contracting a number of diseases but, despite the magnitude of the public health risks involved, they are mostly underserved with few health policies or plans to target them. Nomadic population movements are shown to be a niche for the transmission of diseases, including poliomyelitis. The nomadic routes traverse the northern states of Nigeria to other countries in the Lake Chad subregion. As part of the February 2016 polio supplemental immunization activity (SIA) plans in Bauchi state, a review of nomadic routes and populations identified a nomadic population who originated from outside the international borders of Nigeria. This study describes the engagement process for a transboundary nomadic population and the interventions provided to improve population immunity among them while traversing through Nigeria. METHODS: This was an intervention study which involved a cross-sectional mixed-method (quantitative and qualitative) survey. Information was collected on the nomadic pastoralists entry and exit points, resting points, and health-seeking behavior using key informant interviews and semistructured questionnaire. Transit vaccination teams targeted the groups with oral polio vaccines (OPVs) and other routine antigens along identified routes during the months of February to April 2016. Mobile health teams provided immunization and other child and maternal health survival interventions. RESULTS: A total of 2015 children aged under 5 years were vaccinated with OPV, of which 264 (13.1%) were zero-dose during the February 2016 SIAs while, in the March immunization plus days (IPDs), 1864 were immunized of which 211 (11.0%) were zero-dose. A total of 296 children aged under 1 year old were given the first dose of pentavalent vaccine (penta 1), while 119 received the third dose (penta 3), giving a dropout rate of 59.8%. CONCLUSIONS: Nomadic pastoralists move across international borders and there is a need for transboundary policies among the countries in the Lake Chad region to improve population immunity and disease surveillance through a holistic approach using the One-health concept.

Micro-planning for immunization in Kaduna State, Nigeria: Lessons learnt, 2017.

BACKGROUND: The OPV 3 coverage for Kaduna State, 12-23 months old children was 34.4%. The low OPV 3 coverage, due mainly to weak demand for routine antigens and the need to rapidly boost population immunity against the disabling Wild Polio Virus (WPV), led the Global Polio Eradication Initiatives (GPEI) to increase supplemental OPV campaigns in Kaduna State, despite the huge cost and great burden on personnel. The OPV campaigns, especially in high risk (low vaccine uptake, <80% OPV 3 coverage and high vaccines refusal rate) states of northern Nigeria with poliovirus transmission has resulted in overestimated denominators or target population, as the highest ever vaccinated is used to set OPV campaign targets. METHODS: We utilized a cross-sectional study that assessed the impacts and possible solutions to the challenges of overestimated denominators in immunization services planning, delivery and performance evaluation in Kaduna State, Nigeria. We used both descriptive and quantitative approaches. We enumerated households and obtained the target populations for routine immunization (<1 year), polio campaign (<5 years) and acute flaccid paralysis surveillance (<15 years). RESULTS: We found a significant difference in mean scores between the micro-planning and supplemental vaccination data on a number of <5 years (M = 102967, SD = 62405, micro-planning compared to M = 157716, SD = 72212, supplemental vaccination, p < 0.05). We also found a significant difference in mean scores between the micro-planning and projected census data on a number of <1 year (M = 26128, SD = 16828, micro-planning compared to M = 14154, SD = 4894, census, p < 0.05). CONCLUSION: Periodic household-based micro-planning, aided with the use of technology for validation remains a useful tool in addressing gaps in immunization planning, delivery and performance evaluation in developing countries, such as Nigeria with overestimated denominators.

Enhancing transit polio vaccination in collaboration with targeted stakeholders in Kaduna State, Nigeria: Lessons learnt: 2014-2015.

INTRODUCTION: In Kaduna State of Nigeria, the high influx of people from neighboring states with eligible children for polio vaccination represents a significant proportion of the target population. Many of these children are often missed by the vaccination team. The purpose of the study was to determine the contribution of targeted stakeholders in transit polio vaccination. METHODS: We used the trends of vaccinated children at transit points, motor parks and markets, well as total children vaccinated by transit teams in Chikun, Igabi and Sabon Gari Local Government Areas (LGAs) of Kaduna State, Nigeria, four rounds before and after the introduction of transit polio vaccination with targeted stakeholders in Kaduna State. RESULTS: A total of 87,502 under-5 children were vaccinated by the various transit teams in the three LGAs, which accounted for 3.2% of the total 2,781,162 children vaccinated by the three LGAs. For transit point vaccination, the number of vaccinated children increased from 1026 to 19,289 (302%), while motor park vaccination increased from 1289 to 4106 (318%) and market vaccination increased from 10,488 to 14,511 (138%), four rounds after the introduction of transit polio vaccination with targeted stakeholders. CONCLUSION: Engagement of targeted stakeholders significantly enhanced transit polio vaccination in Kaduna State, Nigeria.