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. 2023 Jul 14;45(Suppl 2):7.
doi: 10.11604/pamj.supp.2023.45.2.39332. eCollection 2023.

Historical reconstruction of inaccessibility status in Local Government Areas (LGAs) of Borno and Yobe States, Nigeria, 2010-2020

Joseph Che Forbi  1 , Melton Sundu Musa  2 , Musa Salawu  3 , Jibrin Manu Idris  2 , Ahmed Ibrahim Ba'aba  2 , Jeff Higgins  4 , Audu Idowu Musa  5 , Bamusa Bashir  5 , Aliyu Shettima  6 , Nnamdi Njeakor  7 , Iheanyichukwu Uzoma  7 , Hyeni Mshelia  6 , Gatei Wa Nganda  1 , Kabiru Ibrahim Mohammed  6 , Idriss Mohammed Bomoi  2 , Umar Chiroma  6 , Stephanie Diane Kovacs  1 , Oladayo Biya  1 , Ndadilnasiya Endie Waziri  2 , Muyi Aina  8 , Usman Saidu Adamu  6 , Faisal Shuaib  6 , Omotayo Bolu  1 , Richard Franka  1 , Eric Wiesen  1
Affiliations

Historical reconstruction of inaccessibility status in Local Government Areas (LGAs) of Borno and Yobe States, Nigeria, 2010-2020

Joseph Che Forbi et al. Pan Afr Med J. .

Abstract

Introduction: ultimately detected in 2016, wild poliovirus (WPV) transmission continued undetected after 2011 in Northeast Nigeria Borno and Yobe States in security-compromised areas, inaccessible due to armed insurgency. Varying inaccessibility prevented children aged <5 years in these areas from polio vaccination interventions and surveillance, while massive population displacements occurred. We examined progress in access over time to provide data supporting a very low probability of undetected WPV circulation within remaining trapped populations after 2016.

Methods: to assess the extent of inaccessibility in security-compromised areas, we obtained empirical historical data in 2020 on a quarterly and annual basis from relevant polio eradication staff for the period 2010-2020. The extent of access to areas for immunization by recall was compared to geospatial data from vaccinator tracking. Population estimates over time in security-compromised areas were extracted from satellite imagery. We compared the historical access data from staff with tracking and population esimates.

Results: access varied during 2010-2020, with inaccessibility peaking during 2014-2016. We observed concurrent patterns between historical recalled data on inaccessibility and contemporaneous satellite imagery on population displacements, which increased confidence in the quality of recalled data.

Conclusion: staff-recalled access was consistent with vaccinator tracking and satellite imagery of population displacments. Despite variability in inaccessibility over time, innovative immunization initiatives were implemented as access allowed and surveillance initiatives were initiated to search for poliovirus transmission. Along with escape and liberation of residents by the military in some geographic areas, these initiatives resulted in a massive reduction in the size of the unvaccinated population remaining resident.

Keywords: Nigeria; Polio; inaccessibility; local government areas.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
map of Borno and Yobe States, Nigeria showing Local Government Areas (LGAs)
Figure 2
Figure 2
simplified Heatmaps of inaccessibility in Borno and Yobe States by Local Government Areas (LGA), 2010-2020
Figure 3
Figure 3
estimated populations of children aged <5 years in Borno State by Local Government Areas (LGAs), 2016-2019
Figure 4
Figure 4
(A, B, C, D) estimated populations of children aged <5 years in Borno State by inaccessibility wards, 2016-2019
Figure 5
Figure 5
(A, B) estimated populations of children aged <5 years in Borno State in populated wards, 2016-2019
See this image and copyright information in PMC

References

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