Global Eradication Research Articles

Modelling flock heterogeneity in the transmission of peste des petits ruminants virus and its impact on the effectiveness of vaccination for eradication

Peste des petits ruminants (PPR) is an acute infectious disease of small ruminants targeted for global eradication by 2030. The Global Strategy for Control and Eradication (GSCE) recommends mass vaccination targeting 70% coverage of small ruminant populations in PPR-endemic regions. These small ruminant populations are diverse with heterogeneous mixing patterns that may influence PPR virus (PPRV) transmission dynamics. This paper evaluates the impact of heterogeneous mixing on (i) PPRV transmission and (ii) the likelihood of different vaccination strategies achieving PPRV elimination, including the GSCE recommended strategy. We develop models simulating heterogeneous transmission between hosts, including a metapopulation model of PPRV transmission between villages in lowland Ethiopia fitted to serological data. Our results demonstrate that although heterogeneous mixing of small ruminant populations increases the instability of PPRV transmission—increasing the chance of fadeout in the absence of intervention—a vaccination coverage of 70% may be insufficient to achieve elimination if high-risk populations are not targeted. Transmission may persist despite very high vaccination coverage (>90% small ruminants) if vaccination is biased towards more accessible but lower-risk populations such as sedentary small ruminant flocks. These results highlight the importance of characterizing small ruminant mobility patterns and identifying high-risk populations for vaccination and support a move towards targeted, risk-based vaccination programmes in the next phase of the PPRV eradication programme. Our modelling approach also illustrates a general framework for incorporating heterogeneous mixing patterns into models of directly transmitted infectious diseases where detailed contact data are limited. This study improves understanding of PPRV transmission and elimination in heterogeneous small ruminant populations and should be used to inform and optimize the design of PPRV vaccination programmes.

Modeling for Smart Vaccination against Peste des Petits Ruminants (PPR) in the Emirate of Abu Dhabi, United Arab Emirates.

Peste des petits ruminants (PPR) is a contagious and economically important transboundary viral disease of small ruminants. The United Arab Emirates (UAE) national animal health plan aimed to control and eradicate PPR from the country by following the global PPR control and eradication strategy which adopts small ruminants' mass vaccination to eradicate the disease from the globe by 2030. A smart vaccination approach, which is less expensive and has longer-term sustainable benefits, is needed to accelerate the eradication of PPR. In this study, a mathematical algorithm was developed based on animals' identification and registration data, belonging to the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA), and other different parameters related to PPR risk occurrence. The latter included animal holding vaccination history, the number of animals per holding, forecasting of the number of animals and newborns per holding, the proximity of an animal holding to a PPR outbreak and the historical animal holding owner vaccination rejection attitude. The developed algorithm successfully prioritized animal holdings at risk of PPR infection within Abu Dhabi Emirate to be targeted by vaccination. This in turn facilitated the mobilization of field vaccination teams to target specific sheep and goat holdings to ensure the generation of immunity against the disease on a risk-based approach. The vaccination coverage of the targeted livestock population was increased to 86% and the vaccination rejection attitude was reduced by 35%. The duration of the vaccination campaign was reduced to 30 compared to 70 working days and hence can alleviate the depletion of human and logistic resources commonly used in classical mass vaccination campaigns. The results obtained from implementing the algorithm-based PPR vaccination campaign will reduce the negative impact of PPR on the UAE livestock sector and accelerate the achievement of the national PPR eradication plan requirements.

Ultimate Dynamics of the Two-Phenotype Cancer Model: Attracting Sets and Global Cancer Eradication Conditions

In this paper we consider the ultimate dynamics of one 4D cancer model which was created for studying the immune response to the two-phenotype tumors. Our approach is based on the localization method of compact invariant sets. The existence of a positively invariant polytope is shown and its size is calculated depending on the parameters of this cancer model. Various convergence conditions to the tumor free equilibrium point were proposed. This property has the biological meaning of global asymptotic tumor eradication (GATE). Further, the case in which local asymptotic tumor eradication (LATE) conditions entail GATE conditions was found. Our theoretical studies of ultimate dynamics are complemented by numerical simulation results.

Comparative study of HA and HNB staining RT-LAMP assays for peste des petits ruminants virus detection in West African Dwarf goats.

Peste des petits ruminants (PPR) cause severe economic losses to many countries of the world where the disease is endemic. It has been targeted for global eradication by 2030 following the successful eradication of rinderpest in 2011. The proposed eradication program would benefit from efficient and relatively reliable diagnostic tools for early PPR virus (PPRV) detection. A total of 33 eight to 12 months old West African Dwarf (WAD) goats were used. Nineteen goats infected by commingling with two PPR virus-positive animals formed the infected group (PPRV-infected goats) while 14 non-infected goats formed the control group (CTG). The suitability of hydroxyl naphthol blue (HNB) staining of reverse transcription loop-mediated isothermal amplification (RT-LAMP) and haemagglutination (HA) assays was compared for their sensitivity to detect the PPRV in PPRV-infected goats and non-infected CTG. PPR disease severity in WAD goats at different days post infection (dpi) was evaluated by clinical scoring and haemagglutination titre (HAT). HNB staining RT-LAMP reaction and HA showed sensitivities of 100% and 73.68%, respectively, for PPRV detection. Expression of PPR clinical signs began from 3 dpi, attained peak at 5 dpi, thereafter showed irregular patterns till 24 dpi. Evaluation of HAT in PPRV-infected goats at 12 dpi ranged from 2 to 64 haemagglutination units (HAU), while CTG goats had 0 HAU. In conclusion, HA could be a good tool for rapid diagnosis of PPRV in a developing country setting. However, HNB staining RT-LAMP assay demonstrated high sensitivity for accurate diagnoses of PPRV and as an important diagnostic tool when precise phenotyping is desired.

A human monoclonal antibody binds within the poliovirus receptor-binding site to neutralize all three serotypes

Global eradication of poliovirus remains elusive, and it is critical to develop next generation vaccines and antivirals. In support of this goal, we map the epitope of human monoclonal antibody 9H2 which is able to neutralize the three serotypes of poliovirus. Using cryo-EM we solve the near-atomic structures of 9H2 fragments (Fab) bound to capsids of poliovirus serotypes 1, 2, and 3. The Fab-virus complexes show that Fab interacts with the same binding mode for each serotype and at the same angle of interaction relative to the capsid surface. For each of the Fab-virus complexes, we find that the binding site overlaps with the poliovirus receptor (PVR) binding site and maps across and into a depression in the capsid called the canyon. No conformational changes to the capsid are induced by Fab binding for any complex. Competition binding experiments between 9H2 and PVR reveal that 9H2 impedes receptor binding. Thus, 9H2 outcompetes the receptor to neutralize poliovirus. The ability to neutralize all three serotypes, coupled with the critical importance of the conserved receptor binding site make 9H2 an attractive antiviral candidate for future development.

Global health trends of human papillomavirus‐associated oral cancer: A review

AbstractOral cancer is a malignant neoplastic disease, it constitutes the most common cancer in the head‐and‐neck region, and it is the 16th most common and 15th deadliest cancer type affecting humans. Despite the global efforts channelled towards global cancer control, the burden of oral cancer is still increasing. Every year, several thousands of people across 195 countries/territories die of oral cancer, and only about 40%–50% of the victims of oral cancer barely survive for 5 years after diagnosis. Within the past few decades, there has been a paradigm shift in the epidemiological trend of oral cancer risk factors. Oral sex – a major route of transmission of human papillomavirus (HPV) – was found to be increasing at an alarming rate, whereas tobacco and alcohol use had been on the decline. This narrative review critically discussed the contemporary challenges facing the global eradication of HPV‐associated oral cancer, with reasonable recommendations. The challenges discussed in this review are major, ranging from clinical to public health policy issues, which include the lack of validated and inexpensive oral HPV screening and diagnostic tools, high global public illiteracy on oral HPV infection, diverse sociocultural factors, weak global research capacity on oral HPV infection and HPV‐associated oral cancer and the absence of policies across different countries on national preventive programmes on HPV‐associated oral cancer. This review also identified the need for more attention towards the prevention and control oral HPV infection and HPV‐associated oral cancers globally.

The Biggest Global Issues Facing Humankind: A Meta-Analysis of Poverty Alleviation and Poverty Eradication

ABSTRACT This study conducted a comprehensive literature review on global poverty alleviation and eradication. A structured literature review (SLR) was employed, collecting 955 articles from the Scopus database spanning from 1990 to 2022. The data was analyzed using bibliometric analysis tools and Excel. The paper explores the significant and conceptual aspects of the published literature on poverty alleviation and eradication. Additionally, it highlights the global issues faced by humanity, such as poverty alleviation and eradication, their origins, and implications. The study also provides potential directions for future research in this field by examining the poverty alleviation and eradication strategies employed by China and the USA. The significance of this study lies in the need for further research on the factors limiting efforts toward poverty alleviation and eradication from a global perspective. These findings can serve as a foundation for global anti-poverty initiatives and offer insights into reducing poverty in underdeveloped and developing nations worldwide.

Analysis of the Income Enhancement Potential of the Terrestrial Carbon Sink in China Based on Remotely Sensed Data

A key focus of international climate action is achieving a terrestrial carbon sink within the framework of carbon neutrality. For certain regions with vital ecological functions and high poverty rates, the generation of surplus ecological carbon income is crucial for mitigating global inequality. While the evaluation of the economic benefits of carbon income still faces limitations in terms of inadequacy and inaccuracy, enhancing green carbon poverty alleviation schemes is urgently needed. This project introduces an analysis framework for assessing the land-based ecological carbon sink and poverty alleviation potential based on a per capita ideal carbon sink income evaluation, which compares the regional economic benefits of a carbon sink under different carbon price benchmarks and explores tailored green poverty alleviation strategies. It indicates that the per capita ideal carbon sink income in China exhibits a seasonal variation, ranging from approximately USD 16.50 to USD 261.41 per person per month on average. Its spatial distribution shows a pattern of lower values in the central region and higher values in the north and south, following a “high differentiation, low clustering” distribution pattern. The per capita carbon sink income can reach 30% to 70% of the per capita GDP, with a peak value of USD 19,138.10 per year, meeting the minimum livelihood guarantee for the needs in economically underdeveloped areas. Simultaneously, the per capita carbon sequestration income within the Chinese carbon market is expected to demonstrate a yearly ascending trajectory, with an approximate growth rate of USD 23.6 per individual annually. The southwest, northeast, and north China regions can be prioritized as key areas for carbon market development, facilitating more comprehensive inter-regional and sustainable carbon trading. This study plays a significant role in disclosing the regional ecological function and economic benefits, promoting the use of “carbon neutrality” as a driving force to alleviate global inequality and contributing to global climate action and poverty eradication strategies.

Review on Lumpy Skin Disease Virus Characteristics and its Diagnosis in Cattle

Lumpy skin disease is characterized by its signs including eruptive, infectious and occasionally causing death to affected animals. It is caused by the family Poxviridea and genus Capripox with a strain of Neethling virus, a double stranded DNA virus. LSD clinical signs are mainly observed on skin as nodules (0.5 to 5 cm in diameter) throughout the skin surface or subcutaneous tissue involving superficial lymph nodes. Diagnosis of CaPV is based upon clinical signs with laboratory confirmation by virus isolation, polymerase chain reaction (PCR) and electron microscopy. Field diagnosis of LSD is often based on characteristic clinical signs of the disease. However, mild and subclinical forms require rapid and reliable laboratory testing to confirm diagnosis. Isolation of virus can be made from collected biopsy or at post-mortem from skin nodules, lung lesions or lymph nodes within the first week of the occurrence of clinical signs, before the development of neutralizing antibodies. There are different methods to detect LSD virus antibody from blood samples. These are serum neutralization test (SNT), indirect fluorescent antibody test (IFAT) and enzyme-linked immune-sorbent assay. LSD as a member of CaPVs, it has a single serotype, do not cause persistent infection, have a limited host range and vaccines are available that may provide long term immunity. These attributes increase the prospect of successfully implementing regional control programs, leading to the elimination of the virus and conceivably global eradication.

The relationship between dominant Western discourse and personal narratives of female genital cutting: exploring storytelling among Swedish-Somali girls and women.

A dominant narrative, referred to as "the standard tale," prevails in popular representations about female genital cutting (FGC) that often contrast with how cut women traditionally narrate their FGC experience as meaningful in contexts where FGC is customary. However, scholarship has increasingly highlighted how global eradication campaigns and migration to countries where FGC is stigmatized provide women with new frames of understanding which may lead to a reformulation of previous experiences. This article subjects the storytelling itself to analysis and explores how participants narrate and make sense of their FGC experience in a post-migration setting where FGC is stigmatized. Semi-structured focus groups (9) and individual interviews (12) with Swedish-Somali girls and women (53) were conducted. The article highlights how the participants navigate their storying in relation to "the standard tale" of FGC in their efforts to make sense of their experiences. Navigation was conducted both at an intrapersonal level through continuous identity work, and in relation to the social context in interpersonal encounters, i.e., with service providers and others, among whom the standard tale has become a truth. The article places the analysis within broader discussions about anti-FGC work and considers the implications in relation to efforts to end FGC.

Assessment of Peste Des Petits Ruminants (PPR) in Turkey Between 2017-2019

Peste des petits ruminants (PPR) is a viral disease affecting small ruminants and causes significant agricultural damage. The World Organization for Animal Health (OIE) has classified PPR as an animal disease that must be reported immediately. In this study was aimed to understand of spatial and seasonal epidemiology of PPR in Turkey and provide information by using Geographical Information Systems (GIS). Descriptive and analytical statistics were used in the study, logistic regression analysis was applied to assess the effect of season and species factors on PPR outbreaks occurring in Turkey. Data were obtained from the World Animal Health Information System (WAHIS) database of OIE. Between 2017-2019, 337 outbreaks, 18.467 cases and 11.526 deaths were reported 57 provinces of Turkey and the highest number of PPR outbreaks, cases and deaths were reported in The Central Anatolia Region. On time-wise examination, the PPR risk-areas revealed changes with different levels of endemicity. The Central Anatolia Region were the top outbreaks reported region during 2017-2018, whereas The Marmara Region reported more outbreaks during 2019. PPR outbreaks occurred throughout the year in all seasons, but were most frequently encountered during the winter season (December to February) and the results showed that seasonal and species factors are important in the spread of the disease. PPR has widely distributed throughout the country, and the epidemiological picture suggests that the disease has become an endemic infection in the country. The spatial and seasonal distribution of PPR in Turkey gives useful information on hotspot areas, allowing managers to make informed decisions about prevention and control in different parts of the country. In accordance with the PPR Global Control and Eradication Strategy, the study also outlines when and where extensive surveillance, vaccination, and biosecurity measures are required for the control and eradication of the disease in Turkey.

Ex-ante impact of pest des petits ruminant control on micro and macro socioeconomic indicators in Senegal: A system dynamics modelling approach.

Vaccination is considered as the main tool for the Global Control and Eradication Strategy for peste des petits ruminants (PPR), and the efficacity of the PPR-vaccine in conferring long-life immunity has been established. Despite this, previous studies asserted that vaccination can be expensive and consequently, the effectiveness of disease control may not necessarily translate to overall profit for farmers. Also, the consequences of PPR control on socioeconomic indicators like food and nutrition security at a macro-national level have not been explored thoroughly. Therefore, this study seeks to assess ex-ante the impact of PPR control strategies on farm-level profitability and the socioeconomic consequences concerning food and nutrition security at a national level in Senegal. A bi-level system dynamics model, compartmentalised into five modules consisting of integrated production-epidemiological, economics, disease control, marketing, and policy modules, was developed with the STELLA Architect software, validated, and simulated for 30 years at a weekly timestep. The model was parameterised with data from household surveys from pastoral areas in Northern Senegal and relevant existing data. Nine vaccination scenarios were examined considering different vaccination parameters (vaccination coverage, vaccine wastage, and the provision of government subsidies). The findings indicate that compared to a no-vaccination scenario, all the vaccination scenarios for both 26.5% (actual vaccination coverage) and 70% (expected vaccination coverage) resulted in statistically significant differences in the gross margin earnings and the potential per capita consumption for the supply of mutton and goat meat. At the prevailing vaccination coverage (with or without the provision of government subsidies), farm households will earn an average gross margin of $69.43 (annually) more than without vaccination, and the average per capita consumption for mutton and goat meat will increase by 1.13kg/person/year. When the vaccination coverage is increased to the prescribed threshold for PPR eradication (i.e., 70%), with or without the provision of government subsidies, the average gross margin earnings would be $72.23 annually and the per capita consumption will increase by 1.23kg/person/year compared to the baseline (without vaccination). This study's findings offer an empirical justification for a sustainable approach to PPR eradication. The information on the socioeconomic benefits of vaccination can be promoted via sensitization campaigns to stimulate farmers' uptake of the practice. This study can inform investment in PPR control.

Vaccine Refusal: A Major, Underestimated Obstacle for the Poliomyelitis Eradication Initiative.

In 1988, the WHO launched the Global Poliomyelitis Eradication Initiative with the goal of eradication by 2000. Not only has this goal, which has been repeatedly postponed, still not been achieved, but while the wild polio virus is still endemic in two Asian countries, a new epidemic caused by a vaccine-derived virus is spreading and is now affecting numerous developing and industrialized countries, including the United Kingdom and the United States. In addition to biological explanations for the failure of eradication, vaccination refusal by communities in mainly two regions of Africa and Asia has prevented mass vaccination campaigns from achieving their immunization coverage targets. The way these campaigns have been deployed has contributed to mistrust and hostility. The negative reactions of some communities, expressed from the first vaccination campaigns, were belatedly considered, which gave time for rumors to flourish and settle permanently. This failure underscores the importance of taking into account, before any vaccination campaign begins, the "health culture" of target populations-meaning their representations of the vaccines and the health authorities that promote vaccination, as well as their knowledge, fears, and hopes.

Halting vaccine-derived poliovirus circulation: the novel type 2 oral vaccine might not be enough

Halting vaccine-derived poliovirus circulation: the novel type 2 oral vaccine might not be enough

Progress Toward Poliomyelitis Eradication - Worldwide, January 2021-March 2023.

Since the World Health Assembly established the Global Polio Eradication Initiative (GPEI) in 1988, two of the three wild poliovirus (WPV) serotypes (types 2 and 3) have been eradicated, and global WPV cases have decreased by more than 99.9%. Afghanistan and Pakistan remain the only countries where indigenous WPV type 1 (WPV1) transmission has not been interrupted. This report summarizes progress toward global polio eradication during January 1, 2021-March 31, 2023, and updates previous reports (1,2). In 2022, Afghanistan and Pakistan reported 22 WPV1 cases, compared with five in 2021; as of May 5, 2023, a single WPV1 case was reported in Pakistan in 2023. A WPV1 case was reported on the African continent for the first time since 2016, when officials in Malawi confirmed a WPV1 case in a child with paralysis onset in November 2021; neighboring Mozambique subsequently reported eight genetically linked cases. Outbreaks of polio caused by circulating vaccine-derived polioviruses (cVDPVs) can occur when oral poliovirus vaccine (OPV) strains circulate for a prolonged time in underimmunized populations, allowing reversion to neurovirulence (3). A total of 859 cVDPV cases occurred during 2022, an increase of 23% from 698 cases in 2021. cVDPVs were detected in areas where poliovirus transmission had long been eliminated (including in Canada, Israel, the United Kingdom, and the United States). In addition, cocirculation of multiple poliovirus types occurred in multiple countries globally (including Democratic Republic of the Congo [DRC], Israel, Malawi, Mozambique, Republic of the Congo, and Yemen). The 2022-2026 GPEI strategic plan targeted the goal of detecting the last cases of WPV1 and cVDPV in 2023 (4). The current global epidemiology of poliovirus transmission makes the likelihood of meeting this target date unlikely. The detections of poliovirus (WPV1 and cVDPVs) in areas where it had been previously eliminated underscore the threat of continued poliovirus spread to any area where there is insufficient vaccination to poliovirus (3). Mass vaccination and surveillance should be further enhanced in areas of transmission to interrupt poliovirus transmission and to end the global threat of paralytic polio in children.

Poliovirus surveillance in patients with primary immunodeficiencies, India.

Individuals with primary immunodeficiencies who are infected with vaccine-derived polioviruses may continue to shed poliovirus for months and go undetected by surveillance programmes of acute flaccid paralysis. These patients therefore pose a risk of initiating poliovirus outbreaks that jeopardize efforts towards global polio eradication. To identify these individuals, we designed a study protocol for the establishment of a network for surveillance of immunodeficiency-related vaccine-derived poliovirus in India. In the first step we identified recognized centres in India that could diagnose and enrol patients with primary immunodeficiency disorder into the study. Stool sample collection from study sites, culture, isolation, characterization of enteroviruses and reporting to study sites was carried out at the National Institute of Virology Mumbai Unit, as per the WHO national polio surveillance project protocol. In the first phase of the study from January 2020 to December 2021, we implemented the protocol at seven study sites at different medical institutes to determine the proportion of poliovirus infections in primary immunodeficiency disorder patients of India. We later expanded the study by including an additional 14 medical institutes across the country in the second phase running from January 2022 to December 2023. We believe this study protocol will help other countries to initiate immunodeficiency-related vaccine-derived poliovirus surveillance to identify and follow up patients who are long-term excretors of vaccine-derived poliovirus. Integration of immunodeficiency-related poliovirus surveillance with acute flaccid paralysis surveillance of the existing poliovirus network will enhance continuous screening of patients with primary immunodeficiency disorder in the future.

Prevalence of poliovirus neutralizing antibodies in Italian population: A systematic review and meta-analysis

IntroductionThe introduction of anti-poliomyelitis vaccines has driven progress toward the global eradication of wild polioviruses, a millennium goal of the World Health Organization. With the vaccination campaigns carried out since 1964, in 2002 Italy was certified polio-free, considering that no cases had been recorded since 1983. Nevertheless, it is crucial to guarantee high level of immunization coverage also in low-endemicity countries, considering that sporadic polio cases can be recorded. To evaluate the presence of susceptible subjects in the population, seroepidemiological studies are key actions. MethodsWe conducted a systematic review of the relevant literature to evaluate the prevalence of anti-PV neutralizing antibodies in Italian population. Seven studies, selected among scientific articles available in MEDLINE/PubMed, ISI Web of Knowledge and Scopus and published from January 1, 2012, to November 15, 2022, were included. ResultsThe pooled prevalence of subjects without PV1 neutralizing antibodies was 6.4% (95%CI = 0.5–16.9), for PV2 it was 5.3% (95%CI = 0.4–14.2), and for PV3 it was 13.0% (95%CI = 4.0–25.7; I2 = 98.5%). Levels of neutralizing antibodies appears to decrease with increasing age; this decline is a proxy for the real risk factor, which is the time since the last vaccine dose. ConclusionsPublic health institutions must be aware of the risk of reintroduction of wild PV in polio-free countries and therefore they must keep high level of immunization in population and reinforce the active surveillance systems.

Threat of resurgence or hope for global eradication of poliovirus?

Recent outbreaks of poliomyelitis in countries that have been free of cases for decades highlight the challenges of eradicating polio in a globalized interconnected world beset with a novel viral pandemic. We provide an epidemiological update, advancements in vaccines, and amendments in public health strategy of poliomyelitis in this review. Last year, new cases of wild poliovirus type 1 (WPV1) were documented in regions previously documented to have eradicated WPV1 and reports of circulating vaccine-derived poliovirus type 2 (cVDPV2) and 3 (cVDPV3) in New York and Jerusalem made international headlines. Sequencing of wastewater samples from environmental surveillance revealed that the WPV1 strains were related to WPV1 lineages from endemic countries and the cVDPV2 strains from New York and Jerusalem were not only related to each other but also to environmental isolates found in London. The evidence of importation of WPV1 cases from endemic countries, and global transmission of cVDPVs justifies renewed efforts in routine vaccination programs and outbreak control measures that were interrupted by the COVID-19 pandemic. After the novel oral poliovirus vaccine type 2 (nOPV2) received emergency authorization for containment of cVDPV2 outbreaks in 2021, subsequent reduced incidence, transmission rates, and vaccine adverse events, alongside increased genetic stability of viral isolates substantiates the safety and efficacy of nOPV2. The nOPV1 and nOPV3 vaccines, against type 1 and 3 cVDPVs, and measures to increase accessibility and efficacy of inactivated poliovirus vaccine (IPV) are in development. A revised strategy utilizing more genetically stable vaccine formulations, with uninterrupted vaccination programs and continued active surveillance optimizes the prospect of global poliomyelitis eradication.

Real-time prediction model of cVDPV2 outbreaks to aid outbreak response vaccination strategies.

Circulating vaccine-derived poliovirus outbreaks are spreading more widely than anticipated, which has generated a crisis for the global polio eradication initiative. Effectively responding with vaccination activities requires a rapid risk assessment. This assessment is made difficult by the low case-to-infection ratio of type 2 poliovirus, variable transmissibility, changing population immunity, surveillance delays, and limited vaccine supply from the global stockpile. The geographical extent of responses have been highly variable between countries. We develop a statistical spatio-temporal model of short-term, district-level poliovirus spread that incorporates known risk factors, including historical wild poliovirus transmission risk, routine immunization coverage, population immunity, and exposure to the outbreak virus. We find that proximity to recent cVDPV2 cases is the strongest risk factor for spread of an outbreak, and find significant associations between population immunity, historical risk, routine immunization, and environmental surveillance (p<0.05). We examine the fit of the model to type 2 vaccine derived poliovirus spread since 2016 and find that our model predicts the location of cVDPV2 cases well (AUC=0.96). We demonstrate use of the model to estimate appropriate scope of outbreak response activities to current outbreaks. As type 2 immunity continues to decline following the cessation of tOPV in 2016, outbreak responses to new cVDPV2 detections will need to be faster and larger in scope. We provide a framework that can be used to support decisions on the appropriate size of a vaccination response when new detections are identified. While the model does not account for all relevant local factors that must be considered in the overall vaccination response, it enables a quantitative basis for outbreak response size.

Characterization of Anti-Poliovirus Compounds Isolated from Edible Plants.

Poliovirus (PV) is the causative agent of poliomyelitis and is a target of the global eradication programs of the World Health Organization (WHO). After eradication of type 2 and 3 wild-type PVs, vaccine-derived PV remains a substantial threat against the eradication as well as type 1 wild-type PV. Antivirals could serve as an effective means to suppress the outbreak; however, no anti-PV drugs have been approved at present. Here, we screened for effective anti-PV compounds in a library of edible plant extracts (a total of 6032 extracts). We found anti-PV activity in the extracts of seven different plant species. We isolated chrysophanol and vanicoside B (VCB) as the identities of the anti-PV activities of the extracts of Rheum rhaponticum and Fallopia sachalinensis, respectively. VCB targeted the host PI4KB/OSBP pathway for its anti-PV activity (EC50 = 9.2 μM) with an inhibitory effect on in vitro PI4KB activity (IC50 = 5.0 μM). This work offers new insights into the anti-PV activity in edible plants that may serve as potent antivirals for PV infection.