Population and transmission dynamics model to determine WHO targets for eliminating Hepatitis C virus in Thailand.

BACKGROUND: Hepatitis C Virus is endemic to many areas of Thailand, whose population structure is tending towards older age groups as birth rate and mortality decrease. With around 790,000 cases in 2019, prevalence is still relatively high, but the World Health Organisation has called for elimination of HCV by 2030. METHODS: An age structured compartmental transmission model was used to explore the effectiveness of screening strategies with respect to WHO elimination goals, as well as the effect of changing population structure on the success or failure of such strategies. RESULTS: Population structure did not appear to affect the timeline of elimination targets and screening individuals over the age of 30 at a high (50% per year) coverage could bring forward achievement of the incidence elimination target by four years compared to baseline (approximately 6% per year). Achievement of mortality elimination targets was not reached until after the end of the simulation (2040), and intensive screening strategies did not appear to lead to incidence elimination by 2030. CONCLUSION: The model suggested that with age-targeted screening programmes incidence elimination could be brought forward by several years. However, WHO elimination goals may not be met by 2030.

Simulated Malaria Online Tool: an instrument for evaluating healthcare providers' practices and contributing to the evidence base for certifying malaria elimination and preventing its re-establishment.

BACKGROUND: Healthcare providers (HCPs) practice and correct management of suspected malaria (CMSM) are central components of malaria elimination and prevention of re-establishment (POR) in countries in the elimination phase. However, knowledge of malaria surveillance systems and HCPs practices often wanes in countries aiming to eliminate malaria due to the low numbers of cases. The study aimed to implement a valid Simulated Malaria Online Tool (SMOT) for assessment HCP performance in CMSM and POR in a malaria-free area. METHODS: HCPs were evaluated using SMOT tool based on four criteria including presenting a suspected malaria case for detection of HCPs' failures in recognition (a), diagnosis (b), appropriate treatment (c), and urgent reporting (d); and compared with simulated patients (SP). Multiple logistic regression analysis was carried out to estimate adjusted odds ratios (ORs) for the risk of HCPs failures. RESULTS: The overall failure proportion was 237 (83%), and the majority of failures were in recognition (a). There was no significant difference between the SMOT and SP based on all failure criteria (P > 0.05). The private clinic (93%) and the public specialized clinic (70%) had the highest and lowest failure proportions. After passing the recognition stage (a), the overall failure proportions decreased to 47.8% and 25.0% for total HCPs and infectious disease specialists, respectively. In the final analysis, private sector (AOR = 4.36: 1.25-15.2), not-specialist providers (AOR = 2.84: 1.29-6.25) and HCPs with ≥ 5 years' experience (AOR = 2.03: 1.01-6.25) increased the risk of failure. CONCLUSION: Findings confirmed the implementation of SMOT tool in settings where malaria transmission is low or interrupted. The tool is able to identify sub-groups of providers needing strengthening, and contributes to the prevention of malaria re-establishment.

Control and elimination of Schistosoma mansoni infection in adult individuals on Ukerewe island, northwestern Tanzania: baseline results before implementation of intervention measures.

BACKGROUND: Communities living along the shoreline and on the islands of Lake Victoria in northwestern Tanzania remain endemic for schistosomiasis and suffer from the life-threatening morbidities associated with the disease. Nevertheless, the control measures particularly the mass drug administration do not cover the adult population. The current project on Ukerewe island aims to close this gap by involving adult community members in the control program. Here we report the baseline results of S. mansoni infection and associated hepatosplenic morbidities and factors before implementing the project activities. METHODS: A cross-sectional analytical study was conducted with 4,043 participants aged ≥ 18 years living in 20 villages on Ukerewe island, northwestern Tanzania. Individual stool and urine samples were collected and examined using the Kato-Katz (KK) technique and point-of-care circulating cathodic antigen testing(POC-CCA) to identify S. mansoni eggs and antigens, respectively. All study participants underwent ultrasound evaluation of S. mansoni hepatosplenic morbidities using the Niamey protocol. Rapid diagnostic tests were used to diagnose HIV infection, hepatitis C and chronic hepatitis B. A questionnaire was used to collect demographic data and reported clinical symptoms of study participants. RESULTS: A total of 4,043 participants took part in the study, of which 49.7% (n = 2,009) and 50.3% (n = 2,035) were male and female, respectively. The overall prevalence of S. mansoni infection was 30.4% (95%CI:29.0-31.9%) and 84.7% (95%CI:83.3-85.9%), respectively, based on the KK technique and the POC-CCA test. The geometrical mean eggs per gram of faeces (GMepg) was 105.3 (95%CI:98.7-112.3% GMepg) with 53.9%, 32.4% and 13.7% of the participants having mild, had moderate and severe intensity of infection. The prevalence of hepatitis C, HIV, and hepatitis B was 0.4%, 2.2% and 4.7%, with 0.2%, 2.2% and 5.4% of the infected individuals coexisting with S. mansoni infection. The prevalence of splenomegaly, periportal fibrosis, hepatomegaly, and portal vein dilatation was 40.5%(95%CI: 38.8-42.1%), 48.1%(95%CI:64.4-49.7%), 66.2%(95%CI:4.6-67.7%) and 67.7%(95%CI:66.2-69.2%), with their prevalence varying depending on the demographic information and infection status of the participants. Other detectable ultrasound-related morbidities included ascites (1.7%), collateral veins (18.3%) and gall bladder wall thickness (40.4%). Age groups, gender, reported clinical characteristics, reported non-use of the drug praziquantel, liver imaging pattern, and place of residence remained independently associated with hepatosplenic morbidities. CONCLUSION: The current study setting is endemic for S. mansoni infection and the population has a high prevalence of the disease associated hepatosplenic morbidities characterized by hepatomegaly, splenomegaly, ascites, gall bladder wall thickening, periportal fibrosis and portal vein dilatation. Several demographic, clinical and epidemiological circumstances remained independently associated with S. mansoni infection and associated morbidities. These findings call for integrative intervention efforts, starting with whole community MDA that includes all out of schools community members.

Benchmarking of an Intervention Aiming at the Micro-Elimination of Hepatitis C in Vulnerable Populations in Perpignan, France, to Inform Scale-Up and Elimination on the French Territory.

Hepatitis C virus (HCV) is an important cause of chronic liver disease. Among at-risk populations, access to care is challenging. The French Ministry of Health has supported a seek-and-treat pilot intervention aiming at micro-elimination in Perpignan, France, to inform scale-up of elimination efforts across the whole territory. University College Dublin (UCD) led a successful EU funded project, called HepCare, focusing on the micro-elimination of HCV. UCD was contracted to evaluate and benchmark the Perpignan results against results from HepCare. Using mixed-method approaches including qualitative interviews with patients, a focus group with healthcare professionals, and quantitative analyses of the cascade of care against results obtained at other European sites, we analyse the acceptability, reproducibility, replicability, and effectiveness of the Perpignan intervention. A total of 960 participants were recruited in the Perpignan area. HCV antibody test results were obtained for 928 (96.6%), of which 150 (15.6%) were antibody-positive. Of the antibody-positive participants, 68 (45.3%) tested positive for HCV-RNA, 141 (94%) were linked to care, and of the HCV-RNA-positive participants, 60 (88%) started treatment. Of those who underwent treatment, 34 (56.7%) completed treatment and achieved a sustained viral response (SVR) at dataset closure, 18 (30%) were still in treatment, 5 (8.3%) defaulted from treatment, and 3 (5%) had a virologic failure or died. The intervention in Perpignan was acceptable to patients, but had limitations in effectiveness, as shown in comparisons with HepCare results. To engage harder-to-reach cohorts in France, future models of care in the territory should incorporate peer support.

Hepatitis C elimination: amplifying the role of primary care nurses in Australia.

Background Australia's commitment to eliminate hepatitis C by 2030 is underpinned by the mobilisation of the primary care sector. Primary care nurses are well placed to contribute to achieving elimination given their unique access to people with/at risk of hepatitis C and their person-centred approach to care delivery. This study examines the enablers to primary care nurse involvement in elimination efforts. Methods Primary care nurses involved in the care of people with/at risk of hepatitis C were recruited through two national nursing organisations. Participants provided verbal consent to participate in an electronically recorded, semi-structured interview. Interview data were transcribed verbatim, coded and analysed using a thematic analysis. Results Sixteen interviews were conducted with nurses working in general practice, community health, alcohol and other drug services, and custodial settings, with the findings framed using a social-ecological model. The study identified individual attributes, such as empathy and advocacy for clients deemed 'too hard for everyone else'. Interpersonal enablers included participants' ability to effectively communicate with clients and colleagues, and using trusted professional relationships to improve client access to care. Public policy that addressed community factors, including stigma and confidentiality, were seen as supportive. Conclusions This study identified the critical and varied role primary care nurses play in hepatitis C elimination. Effective scale up of hepatitis C care involves recognising the pivotal role of primary care nurses, which will help to create an enabling environment that supports nurses to work to their full scope of practice and enhance their contribution to the elimination response.

Investigation of P. vivax elimination via mass drug administration: A simulation study.

Plasmodium vivax is the most geographically widespread malaria parasite. P. vivax has the ability to remain dormant (as a hypnozoite) in the human liver and subsequently reactivate, which makes control efforts more difficult. Given the majority of P. vivax infections are due to hypnozoite reactivation, targeting the hypnozoite reservoir with a radical cure is crucial for achieving P. vivax elimination. Stochastic effects can strongly influence dynamics when disease prevalence is low or when the population size is small. Hence, it is important to account for this when modelling malaria elimination. We use a stochastic multiscale model of P. vivax transmission to study the impacts of multiple rounds of mass drug administration (MDA) with a radical cure, accounting for superinfection and hypnozoite dynamics. Our results indicate multiple rounds of MDA with a high-efficacy drug are needed to achieve a substantial probability of elimination. This work has the potential to help guide P. vivax elimination strategies by quantifying elimination probabilities for an MDA approach.

CUREMA project: a further step towards malaria elimination among hard-to-reach and mobile populations.

BACKGROUND: In most countries engaged on the last mile towards malaria elimination, residual transmission mainly persists among vulnerable populations represented by isolated and mobile (often cross-border) communities. These populations are sometimes involved in informal or even illegal activities. In regions with Plasmodium vivax transmission, the specific biology of this parasite poses additional difficulties related to the need for a radical treatment against hypnozoites to prevent relapses. Among hard-to-reach communities, case management, a pillar of elimination strategy, is deficient: acute malaria attacks often occur in remote areas, where there is limited access to care, and drugs acquired outside formal healthcare are often inadequately used for treatment, which typically does not include radical treatment against P. vivax. For these reasons, P. vivax circulation among these communities represents one of the main challenges for malaria elimination in many non-African countries. The objective of this article is to describe the protocol of the CUREMA study, which aims to meet the challenge of targeting malaria in hard-to-reach populations with a focus on P. vivax. RESULTS: CUREMA is a multi-centre, international public health intervention research project. The study population is represented by persons involved in artisanal and small-scale gold mining who are active and mobile in the Guiana Shield, deep inside the Amazon Forest. The CUREMA project includes a complex intervention composed of a package of actions: (1) health education activities; (2) targeted administration of treatment against P. vivax after screening against G6PD deficiency to asymptomatic persons considered at risk of silently carrying the parasite; (3) distribution of a self-testing and self-treatment kit (malakit) associated with user training for self-management of malaria symptoms occurring while in extreme isolation. These actions are offered by community health workers at settlements and neighbourhoods (often cross-border) that represent transit and logistic bases of gold miners. The study relies on hybrid design, aiming to evaluate both the effectiveness of the intervention on malaria transmission with a pre/post quasi-experimental design, and its implementation with a mixed methods approach. CONCLUSIONS: The purpose of this study is to experiment an intervention that addresses both Plasmodium falciparum and P. vivax malaria elimination in a mobile and isolated population and to produce results that can be transferred to many contexts facing the same challenges around the world.

Comprehensive evaluation of malaria reactive surveillance and response strategies in Lao People's Democratic Republic: a mixed-methods study.

OBJECTIVES: To achieve malaria elimination by 2030, the Lao People's Democratic Republic (PDR) adopted a reactive surveillance and response (RASR) strategy of malaria case notification within 1 day, case investigation and classification within 3 days and foci investigation and response within 7 days. It is important to evaluate the performance and feasibility of RASR implementation in Lao PDR so that the strategy may be optimised and better contribute towards the goal of malaria elimination. DESIGN: A mixed-methods study comprising of secondary data analysis of routinely collected malaria surveillance data, quantitative surveys and qualitative consultations was conducted in 2022. SETTING: Primary data collections for quantitative surveys and qualitative consultations were conducted in Huaphan, Khammouane, Luangprabang and Savannakhet Provinces of Lao PDR. PARTICIPANTS: Quantitative surveys were conducted among malaria programme stakeholders and service providers. Qualitative interviews were conducted with malaria programme stakeholders, and focus group discussions with malaria programme stakeholders, service providers and mobile and migrant populations (MMPs). OUTCOME MEASURES: Outcomes of interests were awareness and acceptability of current RASR activities by different group of participants, implementation, performance and feasibility of RASR activities including enablers and barriers. RESULTS: In Lao PDR, malaria programme stakeholders and service providers were aware of RASR; however, these activities were not well known in MMPs. Respectively, the timeliness of case notification and case investigation was 0.0% and 15.6% in 2018 but increased to 98.0% and 98.6% in 2022. Implementation of RASR was acceptable to the malaria programme stakeholders and service providers, and continued implementation was perceived as feasible. Nevertheless, issues such as low level of community awareness, high level of migration and limitations in health system capacity were identified. CONCLUSION: Overall, the timeliness of case notification and investigation in Lao PDR was high, and malaria programme stakeholders and service providers had positive opinions on RASR. However, some operational and health system-related barriers were identified, which need to be addressed to improve the performance of RASR in Lao PDR.

Bridging Hepatitis C Care Gaps: A Modeling Approach for Achieving the WHO's Targets in Ontario, Canada.

BACKGROUND: The World Health Organization (WHO) has set hepatitis C (HCV) elimination targets for 2030. Understanding existing gaps in the "HCV care-cascade" is essential for meeting these targets. We aimed to identify the level of service scale-up needed along the "HCV care-cascade" to achieve the WHO's HCV elimination targets in Ontario, Canada. METHODS: By employing a decision analytic model, we projected the quality-adjusted life years (QALYs) and healthcare costs for individuals with HCV in Ontario. We increased RNA testing and treatment rates to 98%, followed by increasing antibody testing uptake until we achieved the WHO's mortality target (i.e., a 65% reduction in liver-related mortality by 2030 vs. 2015). RESULTS: Without scaling up by 2030, the expected QALYs and costs per person were 9.156 and CAD 48,996, respectively. Improved RNA testing and treatment rates reduced liver-related deaths to 3.3/100,000, a 57% reduction from 2015. Further doubling the antibody testing rates can achieve the WHO's mortality target in 2035, but not in 2030. Compared to the status quo, such program would be cost-effective considering a 50,000 CAD/QALY gained threshold if annual implementation costs stayed under 2.3 M CAD/100,000 people. CONCLUSIONS: Doubling the antibody testing rates, along with increased RNA testing and treatment rates, showed promise in meeting the WHO's goals by 2035.

Geographic information system and information visualization capacity building: Successful polio eradication and current and future challenges in the COVID-19 era for the World Health Organization's African region.

Despite a half-century-long global eradication effort, polio continues to have a devastating impact on individuals and communities worldwide, especially in low-income countries affected by conflict or geographic barriers to immunization programs. In response, the World Health Organization (WHO) Global Polio Eradication Initiative (GPEI) employs disease surveillance and vaccination campaigns coordinated through the WHO Regional Office for Africa (AFRO) Geographic Information System (GIS) Centre. Established in 2017, the AFRO GIS Centre played a key role in the eradication of wild-type polioviruses (WPVs) in 2020, but the COVID-19 pandemic, emergence of circulating vaccine-derived polioviruses, and transmission of WPV1 from Central Asia have led to a resurgence of polio in Sub-Saharan Africa. The AFRO GIS comprises a set of mobile device or cloud-based tools for geospatial data collection, analysis, and visualization. Using tools such as Auto-Visual Acute Flaccid Paralysis Detection and Reporting, electronic surveillance, and Integrated Supportive Supervision, GIS personnel collect polio case numbers and locations, track field worker activities, follow the movements of nomadic populations vulnerable to polio and other diseases, and determine needs for further healthcare deployments. The system is location specific and operates in real time, enabling the AFRO GIS to promptly target its responses to polio, COVID-19, Ebola virus disease, and other public health crises and natural disasters. The present review describes the components of the AFRO GIS and how the AFRO GIS Centre coordinated on-the-ground polio eradication efforts to help secure Africa's certification as WPV free. It also examines current and prospective challenges regarding other disease outbreaks in the COVID-19 era and how the AFRO GIS Centre is addressing these ongoing public health needs.

The impact of the National Programme to Eliminate Lymphatic Filariasis on filariasis morbidity in Sri Lanka: Comparison of current status with retrospective data following the elimination of lymphatic filariasis as a public health problem.

INTRODUCTION: Sri Lanka implemented the National Programme for Elimination of Lymphatic Filariasis (NPELF) in its endemic regions in 2002. Five annual rounds of mass drug administration using the two-drug combination diethylcarbamazine (DEC) and albendazole led to sustained reductions in infection rates below threshold levels. In 2016, WHO validated that Sri Lanka eliminated lymphatic filariasis as a public health problem. OBJECTIVE: To explore the impact of the NPELF on lymphatic filariasis morbidity in Sri Lanka. METHODS: Passive Case Detection (PCD) data maintained in filaria clinic registries from 2006-2022 for lymphoedema and hospital admission data for managing hydroceles/spermatoceles from 2007-2022 were analyzed. The morbidity status in 2022 and trends in overall and district-wise PCD rates were assessed. Poisson log-linear models were used to assess the trends in PCD for endemic regions, including district-wise trends and hospital admissions for the management of hydroceles/spermatoceles. RESULTS: In 2022, there were 566 new lymphoedema case visits. The mean (SD) age was 53.9 (16.0) years. The staging was done for 94% of cases, of which 79% were in the early stages (57.3% and 21.4% in stages two and one, respectively). Western Province had the highest caseload (52%), followed by the Southern (32%) and Northwestern (16%) Provinces, respectively. The reported lymphoedema PCD rate in 2022 was 0.61 per 10,000 endemic population. The overall PCD rate showed a decline of 7.6% (95%CI: 4.9% - 10.3%) per year (P < 0.0001) from 2007 to 2022. A steady decline was observed in Colombo, Gampaha and Kurunegala districts, while Kalutara remained static and other districts showed a decline in recent years. Further, admissions for inpatient management of hydroceles/spermatoceles showed a declining trend after 2015. CONCLUSIONS: The PCD rates of lymphoedema and hydroceles/spermatoceles showed a declining trend in Sri Lanka after the implementation of the NPELF.

Coverage, delays and implementation challenges of 'Direct Benefit Transfer' in the National Tuberculosis Elimination Programme - A mixed methods study.

INTRODUCTION: Food insecurity and undernutrition both contribute to the large tuberculosis burden in India. Indian government rolled out the direct benefit transfer (DBT) programme "Nikshay Poshan Yojana" on a national scale on April 1, 2018 largely to provide nutritional support. Hence, it was proposed to take up this study in Western Maharashtra (Pune district) to study the coverage, delays and implementation challenges of 'Direct Benefit Transfer' in the National Tuberculosis Elimination Programme as there have only been a limited number of studies conducted regarding the same. METHODOLOGY: This mixed methods study was conducted at Tuberculosis Units (TUs) under District Tuberculosis Officer (DTO) in Western Maharashtra (Pune district) for the duration August 2020 to September 2022. A total of 3373 participants were included for the quantitative component. For qualitative component In-depth interviews of key informants (healthcare providers involved in the implementation of Direct Benefit Transfer) and Focus Group Discussion (FGD) for patients and care givers was done and explored using thematic analysis. RESULTS: The total coverage was found to be 76.81%. The health providers reported staff related challenges (overburden and non-cooperative staff), bank related issues (local and cooperate banks not involved in the Public Financial Management System (PFMS) loop and lack of bank account), patient related issues (fear of being scammed), the DBT process (lengthy and complex) and software related issues as major hurdles involved in the scheme's implementation. The challenges to the implementation of DBT reported by the beneficiaries (TB patients) were lack of awareness and disbelief about the scheme, bank related issues (lack of bank account and necessary documents to open account), financial challenges (job insecurity, loans), physical challenges (weakness) and delays in delivering the benefit due to software errors. CONCLUSION: In the present study the DBT coverage was very encouraging. The common challenges identified by the staff members and patients in the implementation of the scheme were lack of awareness about the scheme, bank related issues and software issues. To increase the coverage of DBT, it is vital that these issues be resolved.

Eliminating a gut microbe could slash gastric cancers.

Mammoth study in Chinese villages shows antibiotics that kill Helicobacter pylori reduced cancer risk.

Empirical and model-based evidence for a negligible role of cattle in peste des petits ruminants virus transmission and eradication.

Peste des petits ruminants virus (PPRV) is a multi-host pathogen with sheep and goats as main hosts. To investigate the role of cattle in the epidemiology of PPR, we simulated conditions similar to East African zero-grazing husbandry practices in a series of trials with local Zebu cattle (Bos taurus indicus) co-housed with goats (Capra aegagrus hircus). Furthermore, we developed a mathematical model to assess the impact of PPRV-transmission from cattle to goats. Of the 32 cattle intranasally infected with the locally endemic lineage IV strain PPRV/Ethiopia/Habru/2014 none transmitted PPRV to 32 co-housed goats. However, these cattle or cattle co-housed with PPRV-infected goats seroconverted. The results confirm previous studies that cattle currently play a negligible role in PPRV-transmission and small ruminant vaccination is sufficient for eradication. However, the possible emergence of PPRV strains more virulent for cattle may impact eradication. Therefore, continued monitoring of PPRV circulation and evolution is recommended.

Operational research to inform post-validation surveillance of lymphatic filariasis in Tonga study protocol: History of lymphatic filariasis elimination, rational, objectives, and design.

BACKGROUND: Lymphatic filariasis (LF), a mosquito-borne helminth infection, is an important cause of chronic disability globally. The World Health Organization has validated eight Pacific Island countries as having eliminated lymphatic filariasis (LF) as a public health problem, but there are limited data to support an evidence-based approach to post-validation surveillance (PVS). Tonga was validated as having eliminated LF in 2017 but no surveillance has been conducted since 2015. This paper describes a protocol for an operational research project investigating different PVS methods in Tonga to provide an evidence base for national and regional PVS strategies. METHODS: Programmatic baseline surveys and Transmission Assessment Surveys conducted between 2000-2015 were reviewed to identify historically 'high-risk' and 'low-risk' schools and communities. 'High-risk' were those with LF antigen (Ag)-positive individuals recorded in more than one survey, whilst 'low-risk' were those with no recorded Ag-positives. The outcome measure for ongoing LF transmission will be Ag-positivity, diagnosed using Alere™ Filariasis Test Strips. A targeted study will be conducted in May-July 2024 including: (i) high and low-risk schools and communities, (ii) boarding schools, and (iii) patients attending a chronic-disease clinic. We estimate a total sample size of 2,010 participants. CONCLUSIONS: Our methodology for targeted surveillance of suspected 'high-risk' populations using historical survey data can be adopted by countries when designing their PVS strategies. The results of this study will allow us to understand the current status of LF in Tonga and will be used to develop the next phase of activities.

Could a ring treatment approach be proposed to control Taenia solium transmission in a post elimination setting? A pilot study in Zambia.

BACKGROUND: Geographically targeted Taenia solium ring approaches consisting of treating individuals within a radius of 100-meter of a cysticercosis positive pig have been trialled in Peru. This study explored if a similar approach could be proposed to control T. solium transmission in a post elimination setting in Zambia, focussing on community members' willingness to be sampled and treated. METHODOLOGY AND PRINCIPAL FINDINGS: The study was conducted in a community where elimination of active T. solium transmission was achieved. All eligible pigs and people were sampled, at 4- to 6-monthly intervals, followed by implementation of the ring treatment approach. This implied that whenever a pig was seropositive for cysticercosis during sampling, every human and pig residing in a radius of 50-meters of the seropositive pig would be treated. The results of the positive human stool samples were used to create the rings, whenever no pigs were positive. From June 2018 to October 2019, four samplings, followed by ring treatments were conducted. Between 84% and 91% of the willing people provided a stool sample, covering 46% to 59% of the total population living in the study area. Between 78% and 100% of the eligible pigs got sampled. Three ring treatments were based on porcine seropositivity and one on taeniosis results. Two to four rings were opened per sampling. During the ring treatments, between 89% and 100% of the eligible human and pig population living within a ring was treated. CONCLUSIONS: Participants were willing to participate and get treatment, once the rings were opened. However, the utility of ring treatment approaches in a post elimination setting needs further evaluation, given the lack of highly accurate diagnostic tools for porcine cysticercosis and the challenges in obtaining stool samples. The ring treatment approach adopted should be further improved before recommendations to public health authorities can be given.

Estimation of the poliovirus type 2 immunity gap in South Africa.

In the context of polio eradication efforts, accurate assessment of vaccination programme effectiveness is essential to public health planning and decision making. Such assessments are often based on zero-dose children, estimated using the number of children who did not receive the first dose of the Diphtheria-Tetanus-Pertussis containing vaccine as a proxy. Our study introduces a novel approach to directly estimate the number of children susceptible to poliovirus type 2 (PV2) and uses this approach to provide district-level estimates for South Africa of susceptible children born between 2017 and 2022. We used district-level data on annual doses of inactivated poliovirus vaccine (IPV) administered, live births, and population sizes, from 2017 through 2022. We imputed missing vaccination data, implemented flexible assumptions regarding dose distribution in the eligible population, and used estimated efficacy values for one, two, three, and four doses of IPV, to compute the number of susceptible and immune children by birth year. We validated our approach by comparing an intermediary output with zero-dose children (ZDC) estimated using data reported by WHO/UNICEF Estimates of National Immunization Coverage (WUENIC). Our results indicate high heterogeneity in susceptibility to PV2 across South Africa's 52 districts as of the end of 2022. In children under 5 years, PV2 susceptibility ranged from approximately 30 % in districts including Xhariep (31.9 %), Ekurhuleni (30.1 %), and Central Karoo (29.8 %), to less than 4 % in Sarah Baartman (1.9 %), Buffalo City (2.1 %), and eThekwini (3.2 %). Our susceptibility estimates were consistently higher than ZDC over the timeframe. We estimated that ZDC decreased nationally from 155,168 (152,737-158,523) in 2017 to 108,593 in 2021, and increased to 127,102 in 2022, a trend consistent with ZDC derived from data reported by WUENIC. While our approach provides a more comprehensive profile of PV2 susceptibility, our susceptibility and ZDC estimates generally agree in the ranking of districts according to risk.

Slaying the Serpent: A Research Agenda to Expand Intervention Development and Accelerate Guinea Worm Eradication Efforts.

Dracunculiasis, also known as Guinea worm disease, is targeted to become the second human disease and first parasitic infection to be eradicated. The global Guinea Worm Eradication Program (GWEP), through community-based interventions, reduced the burden of disease from an estimated 3.5 million cases per year in 1986 to only 13 human cases in 2022. Despite progress, in 2012 Guinea worm disease was detected in domesticated dogs and later in domesticated cats and baboons. Without previous development of any Guinea worm therapeutics, diagnostic tests to detect pre-patent Guinea worm infection, or environmental surveillance tools, the emergence of Guinea worm disease in animal hosts-a threat to eradication-motivated an assessment of evidence gaps and research opportunities. This gap analysis informed the refinement of a robust research agenda intended to generate new evidence and identify additional tools for national GWEPs and to better align the global GWEP with a 2030 Guinea worm eradication certification target. This paper outlines the rationale for the development and expansion of the global GWEP Research Agenda and summarizes the results of the gap analysis that was conducted to identify Guinea worm-related research needs and opportunities. We describe five work streams informed by the research gap analysis that underpin the GWEP Research Agenda and address eradication endgame challenges through the employment of a systems-informed One Health approach. We also discuss the infrastructure in place to disseminate new evidence and monitor research results as well as plans for the continual review of evidence and research priorities.

Progress Toward Onchocerciasis Elimination in Brazil.

The single onchocerciasis-endemic focus in the remote Amazon rainforest is shared by Brazil and Venezuela and affects primarily the indigenous Yanomami people. Regional elimination of onchocerciasis is challenged by the magnitude and inaccessibility of this area. In Brazil, 272 onchocerciasis-endemic communities are operationally organized through 21 health centers ("polos bases"). Mass drug administration of ivermectin began in 1995, with 36 effective biannual rounds (≥85% coverage of the eligible population) through 2022. The national on chocerciasis program maintains community-level monitoring to prioritize treatment activities and epidemiological surveys. The Onchocerciasis Elimination Program for the Americas and the WHO onchocerciasis elimination guidelines have helped Brazil move toward its goal of stopping ivermectin treatment by 2025 and verifying transmission elimination by 2030. Additional challenges to the Brazilian onchocerciasis program include cross-border movements and insecurity due to illegal mining and inter-community conflicts. The new government in Brazil offers hope given its commitment to the equity of indigenous people and preservation of the Amazon environment.

Factors Influencing Community Engagement during Guinea Worm and Polio Eradication Endgames in Chad: Recommendations for "Last Mile" Programming.

Community engagement is a strategy commonly used in health and development programming. Many disease eradication programs engage with communities through different structures and mechanisms to detect, report, contain, and respond to the diseases they target. Qualitative operational research was conducted in a district of Chad co-endemic for both dracunculiasis (i.e., Guinea worm disease) and circulating vaccine-derived poliovirus to reveal factors influencing community engagement behavior in the context of eradication-related programming. Women and men from six communities and stakeholders from the local, district, and central levels were recruited to participate in focus group discussions and semi-structured in-depth interviews. A thematic analysis was performed to identify barriers and facilitators of community engagement. Barriers to community engagement included mistrust in exogenously established health program initiatives (i.e., initiatives designed by partners external to targeted program communities) resulting from negative past experiences with external entities and community groups and the lure of profit-motivating community engagement. Subgroup and intersectionality analyses revealed that gender and other identities influence whether and to what extent certain members of the community engage in a meaningful way. Facilitators of community engagement included leadership and the influence of authorities and leaders in community participation, perceived benefits of being engaged with community-based initiatives, and use of incentives to enhance community participation. Study findings may be used to inform the refinement of community engagement approaches in Chad and learning agendas for other "last mile" disease eradication programs.