Polio eradication surveillance in Sri Lanka,2019-2023

Objective:To evaluate the polio laboratory surveillance carried out from January,2019 to May,2023 by the Polio Regional Reference Laboratory,Sri Lanka.Methods:This retrospective study analyzed all stool samples received under the acute flaccid paralysis(AFP)and immunodeficient vaccine-derived poliovirus(VDPV)surveillance at Polio Regional Reference Laboratory,Sri Lanka from January,2019 to May,2023.The results of the testing methodologies were extracted from the laboratory data system,i.e.,poliovirus virus isolation,intra-typic differentiation/VDPV real time reverse transcriptase polymerase chain reaction(ITD/VDPV rRTPCR)and sequencing,along with the data on timing of reporting results,stool adequacy and socio-demographics.Data was analyzed using descriptive statistics.Results:A total of 2141 stool samples from 1644 cases were received for AFP surveillance from Sri Lanka(93.61%),Maldives(1.52%),and immunodeficient VDPV(4.86%)surveillance.Both polioviruses(19/1644,1.15%)and non-polio enteroviruses(73/1644,4.44%)were isolated,while Sabin-like 3 virus was detected in majority(12/19,63.15%)among the poliovirus isolated.Wild polioviruses or circulating VDPVs were not detected among the cases.During all years of the study,the non-polio AFP detection rate was>1/100000 in children aged less than 15 years,whereas stool adequacy rate was>80%.All results were reported within 14 days of receipt,ensuring timely reporting as per global guidelines.Conclusions:The Polio Regional Reference Laboratory,Sri Lanka plays a vital role in maintaining the polio-free status in the country through its robust laboratory surveillance,while adhering to the surveillance indicators.Non-detection of wild polioviruses and circulating VDPV during the study period reinforces the polio-free status in the country.

Epidemiology of Polio virus infection in Pakistan and possible risk factors for its transmission

End Polio Pakistan program still has to overcome many hurdles;unfortunately on 8th February2016 first polio case of the year has surfaced in Karachi.It seems that battle against polio demands little bit more conviction and motivation.WHO has set a goal of polio eradication in Pakistan till 2018,in order to evaluate the success of this target;polio eradication campaign in Pakistan has been analyzed in different perspectives.Our analysis indicated that major obstacles in eradication are low literacy rate,poor health infrastructure,lack of planning,natural disaster,economic crisis,counter insurgencies and almost no protection for polio health workers.WHO has allocated new funds to tackle this problem,now there is a need to spend this money more effectively with proper planning and honest deployment of funds.

History of polio vaccination

Poliomyelitis is an acute paralytic disease caused by three poliovirus(PV)serotypes.Less than 1%of PV infections result in acute flaccid paralysis.The disease was controlled using the formalin-inactivated Salk polio vaccine(IPV)and the Sabin oral polio vaccine(OPV).Global poliomyelitis eradication was proposed in 1988by the World Health Organization to its member states.The strategic plan established the activities required for polio eradication,certification for regions,OPV cessation phase and post-OPV phase.OPV is the vaccine of choice for the poliomyelitis eradication program because it induces both a systemic and mucosal immune response.The major risks of OPV vaccination are the appearance of Vaccine-Associated Paralytic Poliomyelitis cases(VAPP)and the emergence of Vaccine Derived Polioviruses strains.The supplementary immunization with monovalent strains of OPV type 1 or type 3 or with a new bivalent oral polio vaccine b OPV(containing type1 and type 3 PV)has been introduced in those regions where the virus has been difficult to control.Most countries have switched the schedule of vaccination by using IPV instead of OPV because it poses no risk of vaccine-related disease.Until 2008,poliomyelitis was controlled in Romania,an Eastern European country,predominantly using OPV.The alternative vaccinationschedule(IPV/OPV)was implemented starting in September 2008,while beginning in 2009,the vaccination was IPV only.The risk of VAPP will disappear worldwide with the cessation of use of OPV.The immunization for polio must be maintained for at least 5 to 10 years using IPV.

Can Non-Polio Enteroviruses Be Tamed with a Vaccine to Minimize Paralysis Caused by Them?

Background: While we are inching towards global eradication of polio, the paralysis due to non-polio viruses (NPEV) poses greater challenge. Factors responsible for causing Acute Flaccid Paralysis (AFP) were studied in 3596 AFP patients in 64 districts of Uttar-Pradesh, India, to observe indirect relationship of AFP with wild polio as well as NPEV. A recent study suggests the need to investigate polio virus negative but NPEV positive AFP cases. Methods: The lab results of the stool samples of these children were line listed and analysed to observe the association of various factors with respect to presence of paralysis on 60 follow-up days. Taking zero OPV dose AFP cases as a biological base, we studied the relationship of presence of paralysis at 60 follow-up days to that of presence of NPEV in stool samples while polio virus was present or absent. Results: 70 of the 86 AFP cases (81%) with zero OPV dose and having only NPEV isolated in stool samples were having paralysis at 60 follow-up days. There were 4.54% (162) AFP cases, which did not carry any polio virus but were having NPEV isolated in the stool samples and paralysis at 60 follow-up days. 79% (75/95) of zero OPV dose children, who were having residual weakness at 60 follow-up days, were carrying both polio virus as well as NPEV in their stool samples. Total AFP cases, having residual weakness at 60 follow-up days and having NPEV in stool samples, decreased with increase in OPV doses;a behavior similar to what wild polio viruses (WPV) have to OPV. Conclusions: Maybe polio like NPEV is active for causing severe paralysis in children and is responding to the OPV. As is evident in the studies by M. Margalith, B. Fattal et al. [1] that there is an antibody response to the enteroviruses, we can think of coming out with a vaccine against the enteroviruses. Therefore, enterovirus vaccine can be produced on similar lines to that of OPV, as now we have enough isolates of NPEV. Effective NPEV surveillance system also needs to be in place.

Treatment of Polio Delayed Epidemic Model via Computer Simulations

Through the study,the nonlinear delayed modelling has vital significance in the different field of allied sciences like computational biology,computational chemistry,computational physics,computational economics and many more.Polio is a contagious viral illness that in its most severe form causes nerve injury leading to paralysis,difficulty breathing and sometimes death.In recent years,developing regions like Asia,Africa and sub-continents facing a dreadful situation of poliovirus.That is the reason we focus on the treatment of the polio epidemic model with different delay strategies in this article.Polio delayed epidemic model is categorized into four compartments like susceptible,exposed,infective and vaccinated classes.The equilibria,positivity,boundedness,and reproduction number are investigated.Also,the sensitivity of the parameters is analyzed.Well,known results like the Routh Hurwitz criterion and Lyapunov function stabilities are investigated for polio delayed epidemic model in the sense of local and global respectively.Furthermore,the computer simulations are presented with different traditions in the support of the analytical analysis of the polio delayed epidemic model.

泰安市POLIO疫情发生原因及控制对策

1995年底实现无脊髓灰质炎(POLIO)野病毒株引起的感染目标,距今仅剩两年,从目前脊灰POLIO疫情看,我国的POLIO发病仍处于较高水平,欲如期实现目标,时间紧、任务重、困难大。因此,如何充分利用今后短暂的两年时机,正确地把握工作重点(尤其基层工作),是当前急需研究解决的问题。本文根据我市近年POLIO疫情和基层工作现状,对其发生因素及下步控制对策进行了探讨。

Evaluation of bacterial pathogens in paediatric polioviruspositive faecal specimens

Objective:To evaluate the in vitro inhibitory potential of commonly available antibiotic(discs) and paediatric suspensions against bacterial species from polio-positive faecal specimens.Methods:Commonly available antibiotic (discs) and oral,paediatric suspensions were screened for in vitro inhibitory activities against bacterial species from infantile polio-positive faecal specimens,using agar disc-diffusion and modified agar well-diffusion methods.Results:Isolated bacteria were Bacillus cereus,B.subtilis,Staphylococcus aureus,Streptococcus pneumoniae,Aeromonas hydrophila,Citrobacter aerogenes,Escherichia coli,Enterobacter aerogenes,Klebsiella pneumoniae,Pseudomonas aeruginosa,Proteus mirabilis,Pr.vulgaris,Shigella dysenteriae,Sh.flexneri,Sh. sonnei and Vibrio parahaemolyticus.Overall phenotypic antibiotic susceptibility rates among Gram-positive bacterial species were between 33.3%(augmentin) and 75.0%(chloramphenicol,erythromycin and gentamicin); higher susceptibility rates(48.6%-100.0%) were recorded among Gram-negative bacterial species, while between7.8%/ 10.1%(metronidazole / ampicillin) and 25.2%/28.1%(cotrimoxazole / septrin) were recorded towards paediatric antibiotics.Conclusions:Bacterial species from polio-positive fecal specimens are minimally susceptible to commonly available oral paediatric antibiotic suspensions in Nigeria.

Socioeconomic factors effecting polio vaccination in Pakistan

Background: Child vaccinations are one of most cost effective health programs that have weakened a number of child morbidity and mortality rate all over the world. Pakistan is considered one of the major country of the world, where people especially children are bound by many harmful infectious diseases like polio, hepatitis, viral infections etc. The effectiveness of routine childhood immunization programs relies on multiple factors. Socio-economic determinants have the potential to affect immunization programs. The purpose of the present study was to determine the association between socio-economic factors and polio vaccination coverage among children inPakistan. Methods: The study used data from the Pakistandemographic health survey (PDHS 2006-07 N 10023). The study focused on respondents who had births in last five years. Descriptive and inferential statistics were used to determine the association between variables. Spss version 20 was used for data analysis. A number of socioeconomic variables were used in chi square & binary logistic regression model to check out their association with polio vaccination coverage. Results: Study shows that most dominant factors associated with polio vaccination coverage were region that is NWFP OR 3.48 (odd ratio) with 95% confidence interval (C-I 2.06 & 3.13) & Punjab OR 2.54 (C-I 2.062 & 3.131), residence urban OR 1.626 (C-I 1.451 & 1.822), sex of child male OR 1.125 (C-I 1.008 & 1.256), age of mother 25 - 34 years OR 1.11 (C-I 0.978 & 1.276), wealth index rich OR 2.98 (C-I 2.55 & 3.48), age of child 4 - 5 years OR 1.17 (C-I 0.899 & 1.538), mother’s education higher OR 2.06 (C-I 1.776 & 2.411), father’s education higher OR 1.399 (C-I 1.221 & 1.203) ,father’s occupation professional OR 1.27 (C-I 0.929 & 1.737). Conclusion: In developing countries like Pakistan most of the children remain unvaccinated because of many socio-economic constraints. Poor marginalized people have a low awareness regarding the importance of polio vaccine. Along with social hierarchies, educational attainment of parents is a strong indicator of defining awareness level regarding vaccination.

关于使用新小儿麻痹(Polio)疫苗的咨询报告

WHO应EPI研究工作组及WHO疫苗开发规划组的要求,于1990年3月12～13日在日内瓦召开了将来可能使用新Polio疫苗的咨询会议。主席为F.Deinhardt。会议目的在于拟从广泛的科学和伦理角度对不同程度衍自Sabin株的减毒株达成共识。由于不断广泛使用Sabin三价减毒Polio疫苗,今日全球Polio发病率持续下降。因此。对有可能采用改进的。

Achieving Polio Eradication: A Need for Innovative Strategies

Objective: The objective of this study was to analyze the current strategies used for eradicating wild polio viruses (WPV) and to propose some innovative strategies that may help to accelerate the progress towards polio eradication. Methods: We assessed the current strategies proposed by the World Health Organization, and the effectiveness of the current trivalent oral polio vaccine types 1, 2 and 3 (tOPV) schedule. Results: With the current schedule, tOPV is given four times to the child during his first year of life. After the four doses, 27%, 10% and 30% of children vaccinated are not immunized against WPV types 1, 2 and 3 respectively. In addition, low access to health care, insufficient funding of the routine immunization activities, and weak health systems hamper the tOPV coverage and the early detection of WPV cases for a rapid outbreak response. All these issues could explain the recurrence of WPV outbreaks, even in countries free of polio for many years. Therefore, we propose for countries of non-polio free regions, a new routine polio vaccination schedule composed of four doses of tOPV, followed by three doses of monovalent OPV type 1, and lastly by three doses of bivalent OPV types 1 and 3. With this schedule, of children fully vaccinated, 100%, 90% and 99% will be immunized against WPV types 1, 2 and 3 respectively. In addition, adequate funding for routine immunization activities and health system strengthening are proposed to accelerate the achievement of the polio eradication goal in a near future. Conclusions: The polio eradication goal is achievable. However, innovative strategies are urgently needed to improve the effectiveness and the efficiency of the routine polio immunization program.

辽宁省1989～1993年polio病毒监测结果及MCAB和PCR分析

１９８９～１９９３年从２２８例急性驰缓性麻痹病例（ＡＦＰ）便、１５９６分正常人群便及８５份城市生活污水中分离出１１０株Ｐｏｌｉｏ病毒，９７株其它病毒。对１１０株Ｐｏｌｉｏ病毒全部用抗Ｐｏｌｉｏ病毒１、２、３型３组单克隆抗体（Ｍｃａｂ）进行中和分析，对其中３０株病毒同时用ＰＣＲ方法对其ＲＮＡ进行了分析。结果１１０株Ｐｏｌｉｏ病毒只有１株９０—３５＋３Ｓ病毒为Ｐ１型野毒株，其它１０９株全为Ｓａｂｉｎ疫苗株。１９９１～１９９３年以来连续３年未发现Ｐｏｌｉｏ野病毒。此结果为辽宁省１９９３年７月消灭由Ｐｏｌｉｏ野病毒引起的麻痹病提供了可靠的病原学依据。

用N—McAb和F—McAb对徐州地区流行PolioⅠ型病毒的抗原分析

1989年徐州市邳县及周围的邻近县发生了脊髓灰质炎的暴发流行。我们用现行的常规方法——中和试验,鉴定出这次流行主要为Ⅰ型脊髓灰质炎病毒。并且用六个中和性单克隆抗体(N—McAb)对在这次流行中分离的91株Polio Ⅰ型病毒进行了抗原分析。

Innovations in the Implementation of Polio Surveillance Enhancement Plan in Oyo State, Nigeria: Key Benefits, Lessons Learned, Challenges and Opportunities

Background: Nigeria attained the milestone of being certified wild poliovirus free in the year 2020. However, a drop in the key performance indicators of polio surveillance system was across various Local Government Areas (LGAs) in Oyo State. This drop highlighted the need for an innovative way of enhancing polio surveillance in Oyo State. Methods: This study was conducted in four phases and each phase utilized a cross-sectional study design and purposive sampling technique to select eligible LGAs and participants. LGAs that met at least two of the set-out criteria (had not reported at least a case of Acute Flaccid Paralysis (AFP) 12 months preceding the survey, with decline in AFP case detection rate, had not met AFP key indicators, are densely populated, and has an international border) were selected. A concurrent mixed method of data collection was utilized, and quantitative data were collected with a semi-structured questionnaire administered using Computer Assisted Personal Interviews (CAPI) during community active case search, health facility retroactive case search (HFRACS). Qualitative data collection was done through Focus Group Discussion (FGD). Surveillance intensification activities were conducted over eight weeks period. Data were analyzed using Microsoft Excel Software;summarization was done using frequencies and percentages while presentation was done using charts and spot maps. Results: A total of 1277, 49, 259 and 632 settlements, households and health facilities respectively were visited across 24 (73%) LGAs in Oyo State. Of the 150 suspected AFP cases identified, 45 (30%) were rejected cases, 33 (22%) were missed cases and 72 (48%) were true AFP cases. Non-Polio AFP Rate (NP-AFP rate) increased from 2.7 to 6.9 (P Conclusions: Innovative strategies implemented in AFP surveillance across Oyo State have resulted in improvement in AFP surveillance performance indicators in the State. There is therefore the need for dynamic and innovative ways of conducting AFP surveillance to prevent poliomyelitis epidemics and to ensure maintenance of Nigeria polio free certification status.

Case report: Effect of immunoglobulin on pain in Post-Polio Syndrome—Three case reports

Study design: Case reports. Setting: University hospital setting. Objective: To analyze the effect of intravenous immunoglobulin on neuropathic and nociceptive pain in three patients with Post-Polio Syndrome (PPS). Materials and Methods: Three patients with PPS and pain who received treatment with 90 g IvIg are described. Results: Before treatment one of the patients had pure neuropathic pain and the other two had a combination of neuropathic and nociceptive pain. There was no effect on pain in the patient with pure neuropathic pain and only effect on the nociceptive pain in the patients with a combination of neuropathic and nociceptive pain. Discussion: Pain is one of the most common symptoms in PPS. Previous studies have shown an effect on pain in PPS patients receiving IvIg. The results of the present study point to that the effect on pain is limited to nociceptive pain and that there is no effect on neuropathic pain which leads to increased knowledge of characterization of responders of IvIg treatment. Conclusion: IvIg treatment treatmentreduces nociceptive but not neuropathic pain in PPS patients.

Distribution Pattern of the Non Polio Enterovirus (NPEV) Rate in Children with Acute Flaccid Paralysis Reported to the Surveillance System in Nigeria 2010-2015

Objective: This study focuses on the reverse cold chain system of stool sample management from cases reported to the AFP surveillance system between 2010 and 2015. Through the distribution of their NPEV isolation rates, we identify lapses in the reverse cold chain management and provide recommendations that should help improve the reverse cold chain system and the AFP surveillance system in general as Nigeria once again matches towards a polio free certification. Methods: A descriptive retrospective study was conducted using AFP surveillance data routinely collected between January 2010 and December 2015 by the Disease Surveillance and Notification Officers (DSNOs) in Nigeria and the WHO accredited Polio Laboratories. All AFP cases reported to the Disease Surveillance network during this period from all the states were included in the study. EPIINFO—veritable customized software was used to run queries on the access database and obtain the specific data sets required. Results: A total of 52,879 AFP cases were reported from 2010-2015, in which 7288 non-polio enteroviruses were isolated. NPEV isolation rate ranged from 10.8% in the southeast to 20.3% in the northeast with the states in the northern geopolitical zones having higher NPEV rates in comparison to the states in the southern geopolitical zones. The WHO Polio laboratory in Ibadan serves twenty-seven states in the country;the average non-polio AFP rate among states served by this laboratory is 11.7% from a total of 4012 AFP cases recorded. The WHO Polio laboratory in Maiduguri recorded 3276 with an average non-polio AFP rate of 19.2%. Conclusion: Though the country’s NPEV isolation rate remain slightly higher above the 10% recommended by WHO, steps should be taken to enhance the reverse cold-chain system particularly in the southern states. This would increase confidence in the AFP surveillance system in Nigeria as she proceeds once again towards complete polio eradication and meeting certification standards.

The influence of gender dynamics on polio eradication efforts at the community,workplace,and organizational level

Background:Globally,gender as a barrier or facilitator in achieving health outcomes is increasingly being documented.However,the role of gender in health programming and organization is frequently ignored.The Global Polio Eradication Initiative,one of the largest globally coordinated public health programs in history,has faced and worked to address gender-based challenges as they emerge.This paper seeks to describe the role of gender power relations in the polio program across global,national,subnational,and front-line levels to offer lessons learned for global programs.Methods:We conducted qualitative key-informant interviews with individuals purposively selected from the polio universe globally and within seven country partners:Afghanistan,Bangladesh,the Democratic Republic of the Congo,Ethiopia,India,Indonesia,and Nigeria.The interview tool was designed to explore nuances of implementation challenges,strategies,and consequences within polio eradication.All interviews were conducted in the local or official language,audio-recorded,and transcribed.We employed a deductive coding approach and used four gender analysis domains to explore data at the household,community,workplace,and organizational levels.Results:We completed 196 interviews globally and within each partner country;74.5%of respondents were male and 25.5%were female.Male polio workers were not allowed to enter many households in conservative communities which created demand for female vaccinators.This changed the dynamics of front-line program teams and workplaces and empowered many women to enter the workplace for the first time.However,some faced challenges with safety and balancing obligations at home.Women were less likely to receive promotions to managerial or supervisory roles;this was also reflected at the global level.Some described how this lack of diverse management and leadership negatively affected the quality of program planning,delivery and limited accountability.Conclusions:Gender power relations play an important role in determining the success of global health programs from global to local levels.Without consideration of gender,large-scale programs may fail to meet targets and/or reinforce gender inequities.Global disease programs should incorporate a gender lens in planning and implementation by engaging men and boys,supporting women in the workplace,and increasing diversity and representation among leadership.

A Pneumonia Case Associated with Type 2 Polio Vaccine Strains

Since the World Health Assembly endorsed a plan to completely eradicate polio in 1988, the large-scale use of the attenuated oral poliovirus vaccine （OPV） has drastically decreased the number of polio cases. However, the OPV vaccine brings rare but serious adverse consequences, especially in the Type 2 vaccine strains.

Why Have cVDPV2 Outbreaks Increased Globally After the Polio Immunization Strategy Switch:Challenges for the Polio Eradication Endgame

Since the World Health Assembly(WHA)set the goal of polio eradication in 1988,the Global Polio Eradication Initiative(GPEI)has reduced the global incidence of polio by more than 99%,and the number of countries with endemic polio decreased from 125 countries to 3.Except for Afghanistan,Pakistan,and Nigeria,wild poliovirus(WPV)transmission has been confirmed to have been interrupted globally.

Another look at silent circulation of poliovirus in small populations

Background:Silent circulation of polioviruses complicates the polio endgame and motivates analyses that explore the probability of undetected circulation for different scenarios.A recent analysis suggested a relatively high probability of unusually long silent circulation of polioviruses in small populations(defined as 10,000 people or smaller).Methods:We independently replicated the simple,hypothetical model by Vallejo et al.(2017)and repeated their analyses to explore the model behavior,interpretation of the results,and implications of simplifying assumptions.Results:We found a similar trend of increasing times between detected cases with increasing basic reproduction number(R0)and population size.However,we found substantially lower estimates of the probability of at least 3 years between successive polio cases than they reported,which appear more consistent with the prior literature.While small and isolated populations may sustain prolonged silent circulation,our reanalysis suggests that the existing rule of thumb of less than a 5%chance of 3 or more years of undetected circulation with perfect surveillance holds for most conditions of the model used by Vallejo et al.and most realistic conditions.Conclusions:Avoiding gaps in surveillance remains critical to declaring wild poliovirus elimination with high confidence as soon as possible after the last detected poliovirus,but concern about transmission in small populations with adequate surveillance should not significantly change the criteria for the certification of wild polioviruses.