Acute Flaccid Paralysis Surveillance Research Articles

Recent Molecular Epidemiology of Echovirus 11 Throughout North and West Africa Resulted in the First Identification of a Recombinant Strain from an Acute Flaccid Paralysis Case in West Africa

Echovirus 11 has emerged as a major public health concern, causing sepsis in neonates in many European countries in recent years. In Africa, especially West Africa, where resources and diagnostic capacities are limited, only sporadic cases have been reported. To better understand the recent molecular epidemiology of E11 in West Africa, we characterized twenty-three echovirus 11 strains isolated through the acute flaccid paralysis and environmental surveillance systems for polio from 2013 to 2023, using high-throughput sequencing. Our data are noteworthy due to identifying for the first time a recombinant strain from an acute flaccid paralysis case and represent the first focus to date on molecular characterization of echovirus 11 in West Africa. Moreover, our data show that echovirus 11 diverged from 1970 (95% HPD range, 1961–1979) and evolved into four distinct clades, with the virus spread from West Africa to Europe, exhibiting two introductions in France around 2017, from Senegal and Guinea. Furthermore, the in silico analysis reveals four non-conservative amino acid substitutions in the VP1 sequences of the European strains associated with neonatal sepsis in newborns and a conserved amino acid motif in the VP1 protein toward enterovirus genotypes. Our data provide new insights into the epidemiology of echovirus 11 and point to the crucial need to implement specific surveillance programs targeting non-polio enteroviruses for the rapid identification of emerging or re-emerging enterovirus species, particularly in Africa.

Evaluation of the Intensive Acute Flaccid Paralysis Surveillance System in Ghana: Post the Switch from tOPV to bOPV

The Global Polio Eradication Initiative was adopted by Ghana in 1996, and through robust AFP surveillance was able to interrupt the circulation of wild poliovirus in 2008. However, the country suffered vaccine-derived poliovirus type 2 outbreaks in 2019 and 2022. We conducted a retrospective analysis of all AFP surveillance data received by the polio program in Ghana from 2018 to 2022. An analysis of the WHO performance indicators for evaluating a surveillance system was conducted using Epi Info 3.5.4 and Microsoft Excel. Of the 4832 cases investigated, 56.3% were males, 71.1% comprised children aged 5 years and below, and more than half (65.2%) had received a maximum of three doses of OPV. Over 77% (3028) had a fever at the onset of paralysis, and 67.8% had paralysis progression within 3 days. The non-polio AFP rate of ≥2 and the stool adequacy rate exceeded the target of ≥80% in nearly every study year. The proportion of non-polio enteroviruses isolated surpassed the target of ≥10% in all years except 2018. The AFP surveillance system in Ghana is sensitive and representative. Though the surveillance became more intensive and proactive during the outbreak, the system needs to focus on improving the completeness of the data as well as the timeliness of the arrival of stool specimens within 3 days of collection.

Identification of the Emerging C1-like Lineage of Enterovirus A71 in Two Uruguayan Children with Hand-Foot-and-Mouth Disease and Neurological Complications

Enterovirus A71 (EV-A71) is a major cause of hand-foot-and-mouth disease (HFMD), particularly in cases that involve complications affecting the nervous system or cardiopulmonary function. In South America, EV-A71 has primarily been identified through studies of acute flaccid paralysis (AFP) and other neurological disorders. In September 2022, two children from a small city in Uruguay were hospitalized with presumptive rhombencephalitis, exhibiting symptoms of HFMD. EV-A71 was identified through RT-PCR and next-generation sequencing of stool and skin lesion samples. A maximum-likelihood phylogenetic analysis of the P1 coding region classified the Uruguayan strains as part of an emerging lineage, primarily reported in Europe over the past decade, known as the C1-like lineage. The findings presented here represent the first detection of the EV-A71 C1-like lineage in cases of HFMD and encephalitis reported from South America, underscoring the urgent need to enhance surveillance for HFMD, aseptic meningitis, encephalitis, and AFP, in countries facing challenges in establishing effective surveillance programs related to enteroviruses and associated diseases.

Enhancing Global Poliomyelitis Surveillance Performance is Crucial for Eradication Efforts

Background: Poliomyelitis remains a significant public health challenge, with global efforts focused on its eradication. One critical strategy in this endeavor is the implementation of an acute flaccid paralysis (AFP) surveillance system, which is essential for early detection and response to poliovirus transmission. Specific Background: Despite the system's importance, there is limited evaluation of its performance, particularly in regions like Diyala province, Iraq. Knowledge Gap: Previous studies have not adequately assessed the AFP surveillance performance indicators specific to this region, necessitating a comprehensive analysis. Aims: This study aimed to evaluate the performance indicators of the AFP surveillance system in Diyala province during 2021, utilizing established World Health Organization (WHO) standards. Results: The cross-sectional study analyzed data from seven primary health care centers. Key findings revealed a Non-Polio Acute Flaccid Paralysis rate of 5.11 per 100,000 children under 15 years. Performance indicators included 100% reporting completeness, 95% timeliness of notification and investigation, and 97% stool quality for laboratory analysis. Furthermore, 97.3% of specimens reached the national laboratory within three days, demonstrating high operational efficiency. Novelty: This study is one of the first to provide a detailed evaluation of the AFP surveillance system in Diyala province, highlighting areas of strength and compliance with WHO targets. Implications: The findings underscore the effectiveness of the AFP surveillance system in this region, suggesting that its continued implementation can significantly contribute to the global eradication efforts of poliomyelitis while also serving as a model for similar evaluations in other regions. Highlights: High reporting completeness and timeliness in AFP surveillance. Non-Polio AFP rate exceeds WHO targets, indicating effective monitoring. Study supports global efforts toward poliomyelitis eradication. Keywords: Poliomyelitis, Acute Flaccid Paralysis, Surveillance System, Performance Indicators, Iraq

Evaluation of WHO indicators for surveillance of acute flaccid paralysis in children: The case of Kenitra province, Morocco; from 1994 to 2018

Background Polio has not been detected in Morocco since 1989. The aim of this study was to examine the surveillance system for acute flaccid paralysis (AFP) in the province of Kenitra, assess its strengths and weaknesses, and suggest ways to improve it. Method & materials A qualitative and quantitative evaluation was carried out within the Kenitra Provincial Epidemiology Unit. The AFP case database was analyzed using the standards for evaluation of public health surveillance systems defined by the Centers for Disease Control and Prevention (CDC) in 2001 and WHO indicators. The surveillance system was found to be flexible and effective. Result The sensitivity of the system reached 50%, with an average notification rate of 3.04 cases. More than 40% of patients were reported within 7 days of onset of paralysis. Investigation time was approximately 70% within 48 hours of notification. 80% of stool samples were sent to the laboratory within 72 hours of collection. Conclusion: The AFP surveillance system in Kenitra is effective, adaptable and highly vigilant, allowing a rapid response. Maintaining AFP surveillance is essential until polio is eradicated worldwide. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 1185-1196

EVALUATION OF POLIO IMMUNIZATION COVERAGE AND ACUTE FLACCID PARALYSIS SURVEILLANCE IN EAST JAVA, INDONESIA, 2018-2022

Background: Indonesia has successfully eradicated wild poliovirus since 2005 using robust immunization and AFP surveillance programs. However, circulating vaccine-derived poliovirus type 2 has challenged these commitments, followed by the 2024 outbreak in East Java. Purpose: The study aims to analyze the polio eradication initiative by assessing polio immunization coverage and AFP surveillance in East Java. Methods: A descriptive, quantitative study design and retrospective analysis of polio immunization coverage and AFP surveillance indicators from the Provincial Health Office, East Java, from 2018–2022. The data was collected and analyzed using Excel, EpiInfo7, and Health Mapper software. Results: OPV4 coverage ranged from 89.95% to 100.76%, while IPV coverage ranged from 73.98 % to 94.18% from 2018 to 2020; the proportion of districts and cities for IPV coverage increased from 0% in 2018 to 44.74% in 2022, below the 95% WHO target. Of the 826 cases of AFP reported, 820 (99.27%) were actual AFP cases <15 years of age, with most (49.02%) being <5 years of age. Non-polio AFP rates ranged from 0.80 in 2020 to 2.59 in 2022 per 100,1000 <15 years of age, with the proportion of districts and cities slightly declining from 55.26% in 2018 to 50% in 2022. The annual mean percentage of AFP-adequate specimens is 61.15%, with the proportion of districts and cities significantly declining from 31.58% in 2018 to 10.53% in 2022, below the 80% target. Conclusion: IPV immunization coverage and AFP surveillance indicators are below the WHO-recommended targets across districts and cities in East Java.

Strengthening of Vaccine-Preventable Disease (VPD) Surveillance to Enhance National Health Capacity and Security: Perspective from India.

The Government of India, in collaboration with the World Health Organization (WHO), established the National Polio Surveillance Project (NPSP) in 1997 and initiated acute flaccid paralysis (AFP) surveillance to achieve the goal of polio eradication. The WHO South-East Asia Region, comprising of 11 countries, including India, was certified as polio-free in March 2014. India was also validated to have eliminated maternal and neonatal tetanus in May 2015. Over the years, the surveillance of other vaccine-preventable diseases (VPDs) was integrated with AFP surveillance in the country. Outbreak-based measles-rubella (MR) surveillance was initiated in 2005 using AFP surveillance as a platform, case-based fever-rash (FR) surveillance started in 2021 as one of the strategies to achieve measles and rubella elimination in the country. The surveillance of diphtheria, pertussis, and neonatal tetanus was integrated with AFP surveillance in a phased manner during 2015-2022. The surveillance system for VPDs in India, supported by a laboratory network of 10 polio laboratories, 28 measles-rubella laboratories, and 20 diphtheria-pertussis laboratories, has enhanced the national health capacity and security. The setting up and expansion of the surveillance system in the country involved the important component of capacity building of personnel on various components of surveillance, including case identification, case investigation, sample collection and shipment, data analysis and public health response. These capacities have been used effectively during other emergencies, such as the recent COVID-19 pandemic, as well as during outbreaks of other diseases and natural calamities.

Retrospective, cross-sectional study of the determinants of acute flaccid paralysis among children in Pakistan

Background: Timely diagnosis of acute flaccid paralysis is very crucial in developing countries like Pakistan, because this will have significant impact on management. Aim: To assess the surveillance, aetiology and epidemiology of acute flaccid paralysis in a tertiary care hospital in Peshawar, Pakistan. Methods: This retrospective, observational study was conducted at the Paediatric Department of Lady Reading Hospital, Peshawar, in 2022. Data on all children aged 1 month to 15 years and diagnosed with acute flaccid paralysis were retrieved from the electronic medical records and patient files of the hospital. The data were analysed using SPSS version 27. Results: Eighty-eight (1.34%) of the 6544 patients admitted to the paediatric ward met the inclusion criteria for acute flaccid paralysis; 63 (71.6%) of them were male, 25 (28.4%) female, mean age 6.68 ± 3.86 (mean ±SD) years. Guillain Barre Syndrome was diagnosed in 36 (40.9%) of them, meningoencephalitis in 26 (29.5%), septic arthritis in 6 (6.8%), and hypokalaemia paralysis and cerebrovascular accidents in 5 (5.7%). Three (3.4%) of the patients had post-diphtheria neuropathy and 1 (1.1%) had poliomyelitis. In-hospital mortality was 2.3% (2). Conclusion: Although acute flaccid paralysis is vaccine-preventable and its infectious aetiology is low, its surveillance in Pakistan should be continued to reduce occurrence and progress towards polio eradication.

Molecular epidemiology of enteroviruses from Guatemalan wastewater isolated from human lung fibroblasts.

The Global Specialized Polio Laboratory at CDC supports the Global Poliovirus Laboratory Network with environmental surveillance (ES) to detect the presence of vaccine strain polioviruses, vaccine-derived polioviruses, and wild polioviruses in high-risk countries. Environmental sampling provides valuable supplementary information, particularly in areas with gaps in surveillance of acute flaccid paralysis (AFP) mainly in children less than 15 years. In collaboration with Guatemala's National Health Laboratory (Laboratorio Nacional de Salud Guatemala), monthly sewage collections allowed screening enterovirus (EV) presence without incurring additional costs for sample collection, transport, or concentration. Murine recombinant fibroblast L-cells (L20B) and human rhabdomyosarcoma (RD) cells are used for the isolation of polioviruses following a standard detection algorithm. Though non-polio-Enteroviruses (NPEV) can be isolated, the algorithm is optimized for the detection of polioviruses. To explore if other EV's are present in sewage not found through standard methods, five additional cell lines were piloted in a small-scale experiment, and next-generation sequencing (NGS) was used for the identification of any EV types. Human lung fibroblast cells (HLF) were selected based on their ability to isolate EV-A genus. Sewage concentrates collected between 2020-2021 were isolated in HLF cells and any cytopathic effect positive isolates used for NGS. A large variety of EVs, including echoviruses 1, 3, 6, 7, 11, 13, 18, 19, 25, 29; coxsackievirus A13, B2, and B5, EV-C99, EVB, and polioviruses (Sabin 1 and 3) were identified through genomic typing in NGS. When the EV genotypes were compared by phylogenetic analysis, it showed many EV's were genomically like viruses previously isolated from ES collected in Haiti. Enterovirus occurrence did not follow a seasonality, but more diverse EV types were found in ES collection sites with lower populations. Using the additional cell line in the existing poliovirus ES algorithm may add value by providing data about EV circulation, without additional sample collection or processing. Next-generation sequencing closed gaps in knowledge providing molecular epidemiological information on multiple EV types and full genome sequences of EVs present in wastewater in Guatemala.

The evolution, facilitators, barriers, and additional activities of acute flaccid paralysis surveillance platform in polio eradication programme Bangladesh: a mixed-method study

ABSTRACT Background The Global Polio Eradication Initiative (GPEI) helped develop the standard acute flaccid paralysis surveillance (AFP) system worldwide, including, knowledge, expertise, technical assistance, and trained personnel. AFP surveillance can complement any disease surveillance system. Objective This study outlines AFP surveillance evolution in Bangladesh, its success and challenging factors, and its potential to facilitate other health goals. Methods This mixed-method study includes a grey literature review, survey, and key informant interviews (KIIs). We collected grey literature from online websites and paper documentation from GPEI stakeholders. Online and in-person surveys were conducted in six divisions of Bangladesh, including Dhaka, Rajshahi, Rangpur, Chittagong, Sylhet, and Khulna, to map tacit knowledge ideas, approaches, and experiences. We also conducted KIIs, and Data were then combined on focused emerging themes, including the history, challenges, and successes of AFP surveillance programme. Results According to the grey literature review, survey, and KII, AFP surveillance successfully contributed to decreasing polio in Bangladesh. The major facilitating factors were multi-sectoral collaboration, Surveillance Immunization Medical Officer (SIMO) network activities, social environment, community-based surveillance, and promising political commitment. On the other hand, high population growth, hard-to-reach areas, people residing in risky zones, and polio transition planning were significant challenges. Bangladesh is also utilizing these polio surveillance assets for other vaccine-preventable diseases. Conclusion As the world is so close to eradicating polio, the knowledge, and other assets of the AFP surveillance, could be used for other health programmes. In addition, its strengths can be leveraged for combating new and emerging diseases.

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 1 644 cases were received for AFP surveillance from Sri Lanka (93.61%), Maldives (1.52%), and immunodeficient VDPV (4.86%) surveillance. Both polioviruses (19/1 644, 1.15%) and non-polio enteroviruses (73/1 644, 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 >1/100 000 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.

Thirteen-year surveillance results of acute flaccid paralysis cases in Southeast Turkey and the effect of refugee movements on surveillance results.

Acute flaccid paralysis (AFP) is a major neurological problem. Turkey has accepted over 4 million refugees since 2011 due to the wars in neighbouring countries. In the long term, refugees can have adverse effects on the limited resources of health, sanitation, water supply, foodstuff, and shelter services of host countries, precipitating the transmission and spread of enteroviruses causing AFP. This study examines the 13-year surveillance and incidence of AFP cases in southeast Turkey, and questions possible impact of refugee movements on these parameters, comparing the periods before (2007-2010) and after (2011-2019) 2011, when the refugee movements emerged. The records of cases reported from southeast part of Turkey with suspected AFP between January 2007 and December 2019 were reviewed retrospectively. Of the patients, 121 (58.5%) were male. Mean age was 80.36 ± 46.67 months. Eighty-five (41.1%) were aged 60 months or younger. The number of patients under 60 months increased significantly after 2011. Mean incidence was calculated as 0.88 cases/100,000 person years versus 1.58 cases/100,000 person years in the period before and after 2011, respectively. Guillain-Barré syndrome (GBS) was the most common cause of AFP in both periods. As of 2011, however, the incidence of acute transverse myelitis increased approximately 4 times and GBS decreased proportionally. Non-polio enteroviruses were the most frequent isolates, detected from 9.1% of stool samples. Although refugee movements appear to may have adverse effects on AFP incidence and surveillance outcomes, larger studies involving the whole country, particularly at places where no refugees settled, are needed to achieve more conclusive evidence.

Validation of improved automated nucleic acid extraction methods for direct detection of polioviruses for global polio eradication

Polioviruses (PV), the main causative agent of acute flaccid paralysis (AFP), are positive-sense single-stranded RNA viruses of the family Picornaviridae. As we approach polio eradication, accurate and timely detection of poliovirus in stool from AFP cases becomes vital to success for the eradication efforts. Direct detection of PV from clinical diagnostic samples using nucleic acid (NA) extraction and real-time reverse transcriptase polymerase chain reaction (rRT-PCR) instead of the current standard method of virus isolation in culture, eliminates the long turn-around time to diagnosis and the need for high viral titer amplification in laboratories. An essential component of direct detection of PV from AFP surveillance samples is the efficient extraction of NA. Potential supply chain issues and lack of vendor presence in certain areas of the world necessitates the validation of multiple NA extraction methods. Using retrospective PV-positive surveillance samples (n=104), two extraction kits were compared to the previously validated Zymo Research Quick-RNA™ Viral Kit. The Roche High Pure Viral RNA Kit, a column-based manual extraction method, and the MagMaX™ Pathogen RNA/DNA kit used in the automated Kingfisher Flex system were both non-inferior to the Zymo kit, with similar rates of PV detection in pivotal rRT-PCR assays, such as pan-poliovirus (PanPV), poliovirus serotype 2 (PV2), and wild poliovirus serotype 1 (WPV1). These important assays allow the identification and differentiation of PV genotypes and serotypes and are fundamental to the GPLN program. Validation of two additional kits provides feasible alternatives to the current piloted method of NA extraction for poliovirus rRT-PCR assays.

Evaluation of the environmental polio surveillance system-Northern Region, Ghana, 2021.

Acute Flaccid Paralysis (AFP) surveillance is the gold standard in the polio eradication initiative. The environmental component of polio surveillance can detect circulating Polioviruses from sewage without relying on clinical presentation. The effectiveness of the Environmental Surveillance (ES) is crucial to global polio eradication. We assessed the usefulness and attributes of the ES system in the Northern region and determined if the system is meeting its objectives. We conducted a descriptive cross-sectional evaluation in the Northern region from 2019 to 2020 using the updated US Centers for Disease Control and Prevention guideline. We interviewed stakeholders, reviewed records, and observed surveillance activities from 29th March to 7th May, 2021. Quantitative data were analyzed manually as frequencies and proportions whiles thematic analysis was used for the qualitative data. One of 48 (2.1%) samples collected tested positive for circulating vaccine-derived Poliovirus (cVDPV). The cVDPV detection triggered enhanced AFP surveillance that resulted in the identification of a case of AFP. Three rounds of polio vaccination campaigns were organized. All surveillance officers interviewed were willing to continue providing their services for the ES. Reporting form has few variables and is easy to complete. The completeness of forms was 97.9% (47/48). Samples collected were dispatched on the same day to the testing laboratory. The system's data was managed manually. The system was useful in detecting polio outbreaks. Data quality was good, the system was simple, flexible, acceptable, representative, and fairly stable. Sensitivity was high but predictive value positive was low. Timeliness in reporting was good but feedback from the national level could not be assessed. There is a need to improve on the feedback system and ensure that, the surveillance data is managed electronically.

Re-emergence of polio in Pakistan: Can the nation achieve the WPV1 eradication goal?

Poliomyelitis is an acute neurologic condition that causes muscle weakness, permanent flaccid paralysis, and even death. The world has seen a drastic fall in the number of poliovirus cases owing to effective immunization programs and preventive measures. Pakistan and Afghanistan still remain the two endemic countries for poliovirus, particularly, the WPV1 strain. Global Polio Eradication Initiative (GPEI) has set a target to eradicate all WPV1 cases by the end of 2023. However, the re-emergence of WPV1 cases has posed a serious setback for the achievement of this target. This article aims to discuss the public health challenges that contribute to resurgence of poliovirus cases. A comprehensive literature search was conducted using various databases including Cochrane, Google Scholar, PubMed, Science Direct, MEDLINE. Only articles written in English were considered. All the articles reporting the incidence of poliovirus and WPV1 cases in Pakistan, surveillance data and global context of poliovirus outbreak were evaluated to write this correspondence. In addition, references from the selected articles were also examined to ensure a comprehensive review of the literature. This article highlights the factors contributing to the re-emergence of WPV1 cases in Pakistan. Low vaccine coverage, attacks on frontline polio health workers, misinformation, and reluctance to vaccine acceptance pose a daunting challenge for polio eradication. Further, gaps in AFP surveillance and sensitivity may underestimate the true extent of the emerging genetic clusters. The Covid-19 pandemic and subsequent flooding in the affected area have further worsened the underdeveloped public health infrastructure. Despite the challenges, the country has observed a significant decline in the number of cases in the past 2 years. It is high time to capitalize on the decrease in WPV1 cases by intensifying the efforts to mitigate and limit the spread of the disease.

Effectiveness of poliovirus vaccines against circulating vaccine-derived type 2 poliomyelitis in Nigeria between 2017 and 2022: a case-control study

Between 2018 and 2022, Nigeria experienced continuous transmission of circulating vaccine-derived type 2 poliovirus (cVDPV2), with 526 cases of cVDPV2 poliomyelitis detected in total and approximately 180 million doses of monovalent type 2 oral poliovirus vaccine (mOPV2) and 450 million doses of novel type 2 oral poliovirus vaccine (nOPV2) delivered in outbreak response campaigns. Inactivated poliovirus vaccine (IPV) was introduced into routine immunisation in 2015, with a second dose added in 2021. We aimed to estimate the effectiveness of nOPV2 against cVDPV2 paralysis and compare nOPV2 effectiveness with that of mOPV2 and IPV. In this retrospective case-control study, we used acute flaccid paralysis (AFP) surveillance data in Nigeria from Jan 1, 2017, to Dec 31, 2022, using age-matched, onset-matched, and location-matched cVDPV2-negative AFP cases as test-negative controls. We also did a parallel prospective study from March, 2021, using age-matched community controls from the same settlement as the cases. We included children born after May, 2016, younger than 60 months, for whom polio immunisation history (doses of OPV from campaigns and IPV) was reported. We estimated the per-dose effectiveness of nOPV2 against cVDPV2 paralysis using conditional logistic regression and compared nOPV2 effectiveness with that of mOPV2 and IPV. In the retrospective case-control study, we identified 509 cVDPV2 poliomyelitis cases in Nigeria with case verification and paralysis onset between Jan 1, 2017, and Dec 31, 2022. Of these, 82 children were excluded for not meeting inclusion criteria, and 363 (85%) of 427 eligible cases were matched to 1303 test-negative controls. Cases reported fewer OPV and IPV doses than test-negative controls (mean number of OPV doses 5·9 [SD 4·2] in cases vs 6·7 [4·3] in controls; one or more IPV doses reported in 95 [26%] of 363 cases vs 513 [39%] of 1303 controls). We found low per-dose effectiveness of nOPV2 (12%, 95% CI -2 to 25) and mOPV2 (17%, 3 to 29), but no significant difference between the two vaccines (p=0·67). The estimated effectiveness of one IPV dose was 43% (23 to 58). In the prospective study, 181 (46%) of 392 eligible cases were matched to 1557 community controls. Using community controls, we found a high effectiveness of IPV (89%, 95% CI 83 to 93, for one dose), a low per-dose effectiveness of nOPV2 (-23%, -45 to -5) and mOPV2 (1%, -23 to 20), and no significant difference between the per-dose effectiveness of nOPV2 and mOPV2 (p=0·12). We found no significant difference in estimated effectiveness of the two oral vaccines, supporting the recommendation that the more genetically stable nOPV2 should be preferred in cVDPV2 outbreak response. Our findings highlight the role of IPV and the necessity of strengthening routine immunisation, the primary route through which IPV is delivered. Bill & Melinda Gates Foundation and UK Medical Research Council.

Non-Polio Enteroviruses Isolated by Acute Flaccid Paralysis Surveillance Laboratories in the Russian Federation in 1998-2021: Distinct Epidemiological Features of Types.

More than 100 types of non-polio enteroviruses (NPEVs) are ubiquitous in the human population and cause a variety of symptoms ranging from very mild to meningitis and acute flaccid paralysis (AFP). Much of the information regarding diverse pathogenic properties of NPEVs comes from the surveillance of poliovirus, which also yields NPEV. The analysis of 265 NPEV isolations from 10,433 AFP cases over 24 years of surveillance and more than 2500 NPEV findings in patients without severe neurological lesions suggests that types EV-A71, E13, and E25 were significantly associated with AFP. EV-A71 was also significantly more common among AFP patients who had fever at the onset and residual paralysis compared to all AFP cases. In addition, a significant disparity was noticed between types that were common in humans (CV-A2, CVA9, EV-A71, E9, and E30) or in sewage (CVA7, E3, E7, E11, E12, and E19). Therefore, there is significant evidence of non-polio viruses being implicated in severe neurological lesions, but further multicenter studies using uniform methodology are needed for a definitive conclusion.

Analysis of the complete genome characterization of 11 human astrovirus strains in Shandong Province

Objective: To study the complete genome characterization of Human Astrovirus (HAstV) in Shandong Province. Methods: Stool samples from acute flaccid paralysis (AFP) surveillance in Shandong Province from 2020 to 2022 were collected, and HAstV nucleic acid was examined by real-time quantitative PCR (qPCR). Next-generation sequencing (NGS) was conducted for the positive samples to obtain complete genome sequences and identify the genotype. Homology comparison and phylogenetic analysis were performed by using BioEdit and Mega software. Results: A total of 667 samples were examined by qPCR, of which 14 were HAstV-positive (2.1%), including HAstV-1 (n=6), MLB1 (n=6), MLB2 (n=1), and VA2 (n=1). The complete genome sequences were obtained from 11 samples. The six HAstV-1 sequences of this study had 98.2% to 99.9% nt similarities with each other and 87.6% to 98.6% with those from other regions. The four MLB1 sequences of this study had 99.1% to 99.9% nt similarities with each other and 92.2% to 99.4% with those from other regions. The VA2 sequence of this study had 96.0% to 96.3% nt similarities with those from other regions. Phylogenetic analysis based on ORF2 region showed that the local HAstV-1 sequences were most closely related to Japanese strains, and had distinct topology with phylogenies based on ORF1a and ORF1b regions. Conclusion: The complete genome sequences of 11 HAstV strains are obtained, and the VA2 complete genome is found.

Thirty Years of Experience of Acute Flaccid Paralysis Surveillance for Polio - China, 1993-2022.

Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential, highlighting the crucial importance of effective detection methods in the context of polio eradication efforts. In many countries, including China, the primary approach for identifying polio outbreaks has been through acute flaccid paralysis (AFP) surveillance. In this study, we conducted an evaluation spanning three decades (1993-2022) to assess the effectiveness of AFP surveillance in China. Data on all AFP cases identified since 1993 and national-level AFP surveillance system quality indicators aligned with the World Health Organization (WHO) standards were collected for analysis. The quality indicators assess surveillance sensitivity, completeness, timeliness of detection notification, case investigation, and laboratory workup. Surveillance sensitivity is determined by the non-polio AFP (NPAFP) detection rate among children under 15 years of age. Between 1993 and 2022, a total of 150,779 AFP cases were identified and reported. Within this pool, surveillance identified 95 cases of wild poliovirus (WPV) and 24 cases due to vaccine-derived poliovirus. From 1995 onwards, the detection rate of NPAFP cases consistently adhered to the WHO and national standards of ≥1 case per 100,000, falling between 1.38 and 2.76. Starting in 1997, all timeliness indicators consistently achieved the criteria of 80%, apart from the consistency in meeting standards set for the rate of positive specimens sent to the national laboratory. AFP surveillance has been instrumental in China's accomplishment of maintaining a polio-free status. The ongoing adherence to key performance indicators, ensuring sensitivity and prompt specimen collection, demonstrates that AFP surveillance is proficient in detecting poliovirus in China. As we move into the post-eradication phase, AFP surveillance remains crucial for the sustained absence of polioviruses in the long term.

Monitoring the evolution of vaccine-derived poliovirus in East and Southern African countries, 2010 - 2021.

the Africa region was certified indigenous wild poliovirus-free in August 2020. Countries in East and Southern Africa have, during acute flaccid paralysis (AFP) and environmental surveillance (ES), detected equally concerning vaccine-derived polioviruses (VDPVs) that have not been systematically documented to guide programming in the sub-region. The study documents trends and salient observations of the VDPVs by country of detection, for 11 years from 2010 to 2021. we conducted secondary data analysis, a descriptive study design, by deploying field and laboratory of AFP and environmental surveillance databases of the 20 East and Southern African countries from 2010 to 2021. a total of 318 VDPVs were reported over the study period. The majority were from AFP cases (58.8%) and the rest equally distributed between healthy community children and environmental surveillance sources. More polioviruses were detected after 2016 than during the period before. We observed that more boys were affected by VDPVs compared to girls. Children under 5 years were more affected than other age groups, with a mean age of 3.6 years. Delay of samples in the field seemed to increase the likelihood of not reporting VDPVs and not mounting timely public health detailed investigations and vaccination responses. the study provides useful evolutional trends of VDPVs for surveillance and vaccination programming. We also noted that the VDPV2s have been increasing after the 2016 tOPV to oral polio vaccine (bOPV) switch. The COVID-19 pandemic emergence in 2020, led to a decline in AFP, ES surveillance, and immunization activities. Our findings point to the need to implement enhanced tailored childhood immunization recovery strategies and to speed up the use of inactivated polio vaccine (IPV) to boost population immunity.