Experience and findings from surveillance peer review in Nigeria, August 2017-May 2019.

Introduction: acute flaccid paralysis (AFP) surveillance is the gold standard of the Global Polio Eradication Initiative (GPEI) for detecting cases of poliomyelitis and tracking poliovirus transmission. Nigeria's AFP surveillance performance indicators are among the highest in countries of the World Health Organization (WHO) African Region. The primary AFP surveillance performance indicators are the rate of non-polio AFP among children and the proportion of timely, adequate specimen collection. The surveillance working group of the National Emergency Operations Centre assessed the quality of AFP surveillance data in some reportedly high-performing states. Methods: we conducted a retrospective review of AFP surveillance performance indicators in Nigeria for 2010-2019. We also reviewed data in reports from four groups of surveillance peer reviews and validation visits (conducted by in-country GPEI partners) during August 2017-May 2019 in 16 states with high primary AFP surveillance indicators; the validation visits reviewed clinical information and the dates of specimen collection and onset of paralysis with caretakers. Results: there were consistently increasing AFP surveillance primary performance indicators during 2010-2016, followed by declines during 2017-2019. From the data for 16 states with peer reviews conducted from August 2017-May 2019, overall concordance of reported and "true" (validated) AFP indicator data in peer review investigations was highly variable. True AFP concordance ranged from 58%-100%, and stool timeliness concordance ranged from 56%-95%. The most common clinical causes of reported AFP cases that were not true AFP were spastic paralysis, malaria, sickle cell disease, and malnutrition. All the states that participated in peer reviews developed surveillance improvement plans based on the gaps identified. Conclusion: Nigeria has highly sensitive AFP surveillance according to reported primary AFP performance indicators. The findings of peer reviews indicate that the AFP surveillance system needs to be strengthened and well-supervised to enhance data quality.

Internal displacement; an impediment to the successful implementation of planned measles supplemental activities in Nigeria, a case study of Benue State.

BACKGROUND: Measles is a highly infectious disease with great burden and implication on a displaced population with low immunity status. The disease can cause up to 140,000 deaths annually. Internal displacement during supplemental immunization activities often affects optimal reach and coverage of the campaign as people move and implementation and logistic plans are usually disrupted with attendant missed children. This study documented the process of extension of the measles vaccination campaign (MVC) 2018 for five internally displaced persons (IDPs) camps in Benue state, not previously in the microplan, to increase population herd immunity. METHODS: We obtained population figures and disease surveillance data for five IDPs camps and used it to conduct detailed microplanning to determine the requirement for the conduct of additional days of measles vaccination. Vaccination teams used fixed posts in the camps and temporary posts strategy in designated locations in the host communities. RESULTS: The estimated total population of the IDPs was 170,000 with MVC target population of 9374 which was not earlier planned for. There was reported measles outbreaks in IDP camps in both Guma and Makurdi Local Government areas (LGAs) during period of displacement. Microplans requirement determined 10,421 bundled measles vaccine, 30 health workers, 5 vehicles and 15 motorcycles. A total of 7679 out of 9374 (81.9%) of the eligible children aged 9-59 months were vaccinated during the 3 days of the campaign. CONCLUSION: Non-inclusion of plans on internally displaced population in supplemental immunization activities (SIAs) microplans have a potential risk of vaccine preventable diseases (VPDs) outbreak. Future Measles Vaccination campaigns should take cognizance of internal displacement due to insecurity and other humanitarian emergencies.

Towards an effective poliovirus laboratory containment strategy in Nigeria.

BACKGROUND: The Global Commission for the Certification of the Eradication of Poliomyelitis will declare the world free of wild poliovirus transmission when no wild virus has been found in at least 3 consecutive years, and all laboratories possessing wild poliovirus materials have adopted appropriate measures of containment. Nigeria has made progress towards poliomyelitis eradication with the latest reported WPV type 1 on 21 Aug 2016 after 2 years without any case. This milestone achievement was followed by an inventory of biomedical laboratories completed in November 2015 with the destruction of all identified infectious materials. This paper seeks to describe the poliovirus laboratory containment process in Nigeria on which an effective containment system has been built to minimize the risk of virus re-introduction into the population from the laboratories. METHODS: A national survey of all biomedical facilities, as well as an inventory of laboratories from various sectors, was conducted from June-November 2015. National Task Force (NTF) members and staff working on polio administered an on-site questionnaire in each facility. Laboratory personnel were sensitized with all un-needed materials destroyed by autoclaving and incineration. All stakeholders were also sensitized to continue the destruction of such materials as a requirement for phase one activities. RESULTS: A total of 20,638 biomedical facilities were surveyed with 9575 having laboratories. Thirty laboratories were found to contain poliovirus or potentially infectious materials. The 30 laboratories belonged to the ministries of health, education, defence and private organizations. CONCLUSIONS: This article is amongst the first in Africa that relates poliovirus laboratory containment in the context of the tOPV-bOPV switch in alignment with the Global Action Plan III. All identified infectious materials were destroyed and personnel trained to continue to destroy subsequent materials, a process that needs meticulous monitoring to mitigate the risk of poliovirus re-introduction to the population.

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.

Profile of polio-compatible cases in Nigeria, 2006-2016.

BACKGROUND: The tremendous progress made by Nigeria towards polio eradication has recently suffered a setback with the isolation of circulating vaccine-derived poliovirus (cVDPV) type 2 from environmental samples and confirmation of four wild poliovirus (WPV) cases from acute flaccid paralysis (AFP) cases, with dates of onset of paralysis in July and August 2016. All these viruses were confirmed from the security-challenged northeastern state of Borno. Polio-compatible cases exist in Nigeria, and they indicate surveillance failure. Surveillance, therefore, has to be strengthened for the country to achieve certification. The objective of this paper is to highlight the epidemiological profile and magnitude of polio-compatible cases in Nigeria during the reporting period, as well as immunization and surveillance response activities conducted to close immunity and surveillance gaps. METHODS: We conducted a retrospective review of AFP surveillance performance and polio-compatible cases in Nigeria between 2006 and 2016 from the AFP database at the World Health Organization Country Office. We also reviewed and compared key epidemiological features of polio-compatible cases with those of wild poliovirus cases during the reporting period. RESULTS: The non-polio AFP rate improved from 6.5 in 2006 to 19.5 in 2016. The corresponding figures for stool adequacy rates were 88 and 98%. The total number of polio-compatible cases reported during the reporting period was 888, with the highest number (194) of cases reported in 2006 and the least (24) in 2016. Clusters of polio-compatible cases were reported every year during the reporting period except in 2015. The highest number (65) of polio-compatible cases in clusters was reported in 2006. The key epidemiological features of polio-compatible and wild poliovirus cases were similar. CONCLUSION: AFP surveillance performance has improved significantly during the reporting period. Surveillance gaps still existed as shown by the presence of orphan viruses and polio-compatible cases, and these gaps need to be identified and closed to achieve certification.

Factors contributing to routine immunization performance in Ethiopia, 2014.

INTRODUCTION: An increasing trend of routine immunization performance has generally been observed over the past decade in Ethiopia. However, the improvement is irregular with wide disparity among and within regions. This study analyzes health facility characteristics contribution to immunization performance in Ethiopia. METHODS: We conducted a cross-sectional study and compared characteristics of health facilities in good and poor performing zones. We used administrative coverage reports and Personal Digital Assisted (PDA) supervisory data collected by WHO EPI field officers using a standardized structured checklist. We selected 48 zones and 302 health facilities based on immunization performance data and supervisory data on potential variables. RESULTS: Logistics regression was used to identify independent contributors to good immunization performance. On logistics regression we found that: actions by higher levels in conducting supervision (Odds Ratio (OR) =4.15. 95% Confidence Interval (CI) = 1.85, 9.32, p value <0.01] and providing written feedback (Odds Ratio (OR) =4.35. 95% Confidence Interval (CI) = 2.27, 8.33, p value <0.01) , and provision of immunization services by the health facility itself for catchment population under each health unit (Odds Ratio (OR) =20.15. 95% Confidence Interval (CI) = 2.24, 181.38, p value =0.01) and absence of stock out of vaccines (Odds Ratio (OR) =0.44. 95% Confidence Interval (CI) = 0.23, 0.83, p value =0.01) are the likely significant factors contributing to good immunization performance in Ethiopia. CONCLUSION: Ensuring availability of immunization services in all health facilities, regular supervision and written feedback and improved stock management are essential factors contributing to good immunization performance.

Effects of polio eradication activities on routine immunization: lessons from the 2013 outbreak response in Somali region of Ethiopia.

INTRODUCTION: Ethiopia experienced several WPV importations with a total of 10 WPV1 cases confirmed during the 2013 outbreak alone before it is closed in 2015. We evaluated supplemental immunization activities (SIAs), including lessons learned for their effect on the routine immunization program during the 2013 polio outbreak in Somali regional state. METHODS: We used descriptive study to review documents and analyse routine health information system reports from the polio outbreak affected Somali regional state. RESULTS: All data and technical reports of the 15 rounds of polio SIAs from June 2013 through June 2015 and routine immunization coverages for DPT-Hib-HepB 3 and measles were observed. More than 93% of the SIAs were having administrative coverage above 95%. The trend of routine immunization for the two antigens, over the five years (2011 through 2015) did not show a consistent pattern against the number of SIAs. Documentations showed qualitative positive impacts of the SIAs strengthening the routine immunization during all courses of the campaigns. CONCLUSION: The quantitative impact of polio SIAs on routine immunization remained not so impressive in this study. Clear planning, data consistencies and completeness issues need to be cleared for the impact assessment in quantitative terms, in polio legacy planning as well as for the introduction of injectable polio vaccine through the routine immunization.

Analysis of acute flaccid paralysis surveillance in Ethiopia, 2005-2015: progress and challenges.

INTRODUCTION: Ethiopia joined the global effort to eradicate polio in 1996, and interrupted indigenous wild poliovirus transmission by December 2001. However, the country experienced numerous separate importations during 2003-2013. Sensitive Acute Flaccid (AFP) surveillance is critical to rule out undetected circulation of WPV and VDPVs. METHODS: In this study described, we used a retrospective descriptive study design to characterize the surveillance performance from 2005 to 2015. RESULTS: The none-polio AFP rate improved from 2.6/100,000 children <15 years old in 2005 to 3.1 in 2015, while stool adequacy has also improved from 78.5% in 2005 to 92 % in 2015. At the national level, most AFP surveillance performance indicators are achieved and maintained over the years, however, AFP surveillance performance at sub-national level varies greatly particularly in pastoralist regions. In addition, the minimum standard for non-polio enterovirus isolation rate (10%) was not achieved except in 2007 and 2009. Nevertheless, the proportion of cases investigated within 2 days of notification and the proportion of specimens arriving in good condition within 3 days to the laboratory were maintained throughout all the years reviewed. CONCLUSION: We found that the AFP surveillance system was efficient and progressively improved over the past 10 years in Ethiopia. However, the subnational AFP surveillance performance varies and were not maintained, particularly in pastoralist regions, and the non-polio enterovirus isolation rate declined since 2010. We recommend the institution of community-based surveillance in pastoralist regions and conduct detail review of the laboratory sensitivity and the reverse cold chain system.