Evaluation of acute flaccid paralysis surveillance indicators in Sokoto state, Nigeria, 2012–2019: a secondary data analysis

Background Nigeria, the last endemic country in the WHO African Region, was certified free of Wild Polio Virus (WPV) in 2020. However, due to low immunity in some communities in Sokoto, outbreaks of the circulating Vaccine Derived Polio Virus (cVDPV) occur. The aim of this study is to evaluate the Acute Flaccid Paralysis (AFP) surveillance indicators in Sokoto state, Nigeria. Methods This retrospective study was an analysis of routinely collected AFP surveillance data between 2012 and 2019 by the Sokoto state surveillance network. We assessed the Sokoto state AFP surveillance system using the AFP surveillance performance indicators. We performed all analyses using Microsoft Excel 2019. Results Cumulatively, 3001 Acute Flaccid Paralysis (AFP) cases were reported over the evaluation period, out of which 1692 (56.4%) were males, and 2478 (82.4%) were below five years. More than half, 1773 (59.1%), had a fever at the beginning of the disease, and 1911 (63.7%) had asymmetric paralysis. The non-polio AFP rate (9.1 to 23.5% per 100,000 children < 15 years old) and stool adequacy rate (92.5 to 100%) indicate high sensitivity. The proportion of cases that had stool samples collected early, timely transported to the laboratory and arrived at the laboratory in optimal condition were all above the World Health Organization (WHO) minimum standard of 80%. There was inadequate profile documentation of some suspected cases. Conclusions Sokoto State has exceeded the WHO minimum standards in most of the AFP surveillance indicators. The performance of the system is sufficient enough to detect any reintroduction of WPV into the state. However, there is a need for improvement in data quality.

Some lessons for malaria from the Global Polio Eradication Initiative

The Global Polio Eradication Initiative (GPEI) was launched in 1988 with the aim of completely clearing wild polio viruses by 2000. More than three decades later, the goal has not been achieved, although spectacular advances have been made, with wild polio virus reported in only 2 countries in 2019. In spite of such progress, novel challenges have been added to the equation, most importantly outbreaks of vaccine-derived polio cases resulting from reversion to neurovirulence of attenuated vaccine virus, and insufficient coverage of vaccination. In the context of the latest discussions on malaria eradication, the GPEI experience provides more than a few lessons to the malaria field when considering a coordinated eradication campaign. The WHO Strategic Advisory Committee on Malaria Eradication (SAGme) stated in 2020 that in the context of more than 200 million malaria cases reported, eradication was far from reach in the near future and, therefore, efforts should remain focused on getting back on track to achieve the objectives set by the Global Technical Strategy against Malaria (2016–2030). Acknowledging the deep differences between both diseases and the stages they are in their path towards eradication, this paper draws from the history of GPEI and highlights relevant insights into what it takes to eradicate a pathogen in fields as varied as priority setting, global governance, strategy, community engagement, surveillance systems, and research. Above all, it shows the critical need for openness to change and adaptation as the biological, social and political contexts vary throughout the time an eradication campaign is ongoing.

Lessons Learnt from Interregional and Interagency Collaboration in Polio Outbreak Response in the Horn of Africa

Following the outbreak of poliovirus in the countries in the Horn of Africa, Somalia, Kenya and Ethiopia, in two WHO regions, an outbreak response involving the WHO Africa and WHO East and Mediterranean Regions and partner agencies like the UNICEF in East and Southern African was developed. This paper documents response to polio virus outbreak in the Horn of Africa and the lessons learnt for the interregional and inter-agency collaboration on the response. This collaboration led to speedy interruption of the outbreak and within a period of one year the total virus load of 217 in 2013 was brought down to mere six. This resulted from collaborative planning and implementation of activities to boost the hitherto low immunity in the countries andimprove surveillance among others. A number of lesson were generated from the process. Some of the lessons is critical role such collaboration plays in ensuring simultaneous immunity boosting, information and resources sharing, among other. Some challenges were equally encountered, chiefly in the appropriation of authorities. In conclusion, however, one is safe to note that the collaboration was very fruitful given the timely interruption of transmission.

Detection of non-polio and polio enteroviruses in Acute Flaccid Paralysis surveillance in Turkey

Poliomyelitis was a disease feared worldwide, striking suddenly and paralysing mainly children for life. Monitoring of suspected cases of poliomyelitis is carried out with Acute Flaccid Paralysis (AFP) surveillance in Turkey. This study examines national data of AFP surveillance and the epidemiology of enteroviruses (EV) in Turkey from 2000 to 2019 and gives an overview of the detected serotypes of EVs. A total of 13,640 samples collected from patients with 5216 AFP pre-diagnosed cases (2 samples from each patient) and 3,208 contacts, during a 20-year period (2000–2019) were investigated. All isolated polioviruses were tested for their wild or vaccine origin according to the WHO recommended protocol by PCR and sequencing analysis were performed. Enterovirus positivity was detected in a total of 915 cases, which were identified as 204 Sabin-like polio virus (SLPV) and 711 non-polio enterovirus (NPEV). Of the 204 SLPV, 141 (69.1%) AFP were detected in patients and 63 (30.9%) were detected in samples taken from their contacts. Of the 711 NPEVs, 516 (72.5%) were from AFP cases and 195 (27.5%) were detected in samples taken from their contacts. It is concluded that the reason for the higher detection rate of NPEV in samples from AFP pre-diagnosed cases is attributed to the polio vaccination rates reaching 97% between 2008 and 2019 in Turkey. The most frequently detected NPEV serotypes were Coxackie A24, B3, and Echo 30. This retrospective study is the first comprehensive study in Turkey to evaluate the results of the AFP surveillance in the last 20 years.

ACUTE FLACCID PARALYSIS REGISTERED FOR THE PERIOD 2012-2020, IN STARA ZAGORA REGION

Acute Flaccid Paralysis (AFP) is a clinical syndrome. There are many infectious and non-infectious causes of AFP. Poliomyelitis caused by the wild polio virus (the natural circulating strain of polio) is one of the causes of AFP. As a part of the worldwide campaign to eradicate polio, all countries do surveillance for polio by looking for clinical cases of AFP. The purpose of the study is to describe the cases of Acute Flaccid Paralysis, without Paresis Nervi facialis, in the Stara Zagora region for the period 2012-2020. Methods: A retrospective, descriptive analysis was performed on the parameters: diagnosis, seasonality, sex, residence, age, clinical data, and comorbidities, results of follow-up examinations, polio vaccine administration, and timeliness of studies. Results: There were 9 cases of AFP, without Paresis nervi facialis, registered and reported for the Stara Zagora region, for the period 2012 – 2020. The children in 3 years old were more affected- 4 patients. About the coverage with polio vaccine: 7 of the patients had 4 doses, 1- had 6 doses, 1 child had 5 doses, and + 1 zero dose. 100% of children are covered, according to their age, with IPV. Follow-up in 6 of the patients is without residual paresis and complications. Residual paresis was found in 1 of the cases. In 2 patients no control examination was performed due to migration. Conclusion: The correct epidemiological diagnosis is the way to timely and corrects clinical diagnosis. AFP Surveillance is of particular importance as well as fecal sampling up to 48 hours, from the onset of paralysis, and follow-up after the 60th day in children <15 years.

An Efficient Numerical Method for the Solution of the Polio Virus (Poliomyelitis) Epidemic Model with the Role of Vaccination

Mathematical modeling of a communicable disease is an effective way to describe the behavior and dynamics of the disease. It builds on our understanding of the transmission of a contagion in a population. In this paper, we explore the transmission dynamics of the polio virus (poliomyelitis) with vaccination using standard methods. We formulate an unconditionally stable Non-Standard Finite Difference (NSFD) scheme for a continuous system of the epidemic polio virus. The designed scheme to approximate the solution is bounded, consistent with the underlying model. The proposed numerical scheme preserves the positivity of the stated variables which is necessary for any population dynamical system. It is used to calculate the numerical solutions of the epidemic model for different step sizes “h”. Two other numerical schemes are enforced to find the solution of the proposed system. Finally, the comparison of the NSFD technique with these methods proves its validity and effectiveness.

Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis

Background: Nigeria and indeed, entire Africa has been certified free of Wild Polio Virus (WPV) in 2020. However, the continent is still at risk of importation of WPV, especially in states like Sokoto in Nigeria, which has an international border. Furthermore, due to low immunity in some communities in Sokoto, outbreaks of the circulating Vaccine Derived Polio Virus (cVDPV) occur. Therefore, this paper evaluates the Acute Flaccid Paralysis (AFP) surveillance indicators in Sokoto state, Nigeria. Methods: This retrospective study was an analysis of routinely collected AFP surveillance data between 2012 and 2019 by the Sokoto state surveillance network. We assessed the Sokoto state AFP surveillance system using the AFP surveillance performance indicators. We performed all analyses using Microsoft Excel 2019.Results: Cumulatively, 3001 Acute Flaccid Paralysis (AFP) cases were reported over the evaluation period, out of which 1692 (56.4%) were males, and 2478 (82.4%) were below five years. More than half, 1773 (59.1%) had a fever at the beginning of the disease, and 1911 (63.7%) had asymmetric paralysis. The non-polio AFP rate (9.1 to 23.5%) and stool adequacy rate (92.5 to 100%) indicate high sensitivity. The proportion of cases that had stool samples collected early, timely transported to the laboratory and arrived at the laboratory in optimal condition were all above the World Health Organization (WHO) minimum standard of 80%. There was inadequate profile documentation of some suspected cases.Conclusions: Sokoto State has exceeded the WHO minimum standards in most of the AFP surveillance indicators. The performance of the system is sufficient enough to detect any reintroduction of WPV into the state. However, there is a need for improvement in data quality.