Antibody seropositivity and endemicity of chikungunya and Zika viruses in Nigeria

Mosquito-borne infections are of global health concern because of their rapid spread and upsurge,which creates a risk for coinfections.chikungunya virus(CHIKV),an arbovirus disease transmitted by Aedes aegypti or A.albopictus,and malaria,a parasitic disease transmitted by Anopheles gambiae,are prevalent in Nigeria and neighbouring countries,but their burden and possible coinfections are poorly understood.In this study,we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses(ZIKV)in three regions of Nigeria.A cross-sectional serosurvey was conducted on 871 participants.Samples were collected from outpatients by simple random sampling.Analyses of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP(virus like particle),ZIKV NS1 and ZIKV Equad according to manufacturers’instructions and malaria RDT for malaria parasite.There was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions(69.5%,291/419),while ZIKV-seropositivity(22.4%,34/152)and CHIKV-ZIKV co-circulating antibody seropositivity(17.8%,27/152)were notably higher in the southern region than in the central and northern regions.This investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian regions.The seropositivity of detectable antibodies differed among the three geographical locations.

Supporting and strengthening research on urban health interventions for the prevention and control of vector-borne and other infectious diseases of poverty:scoping reviews and research gap analysis

Background:More than half of the world’s population currently lives in urban settlements that grow both in size and number.By 2050,approximately 70%of the global population will be living in urban conglomerations,mainly in low-and middle-income countries.Mobility,poverty,different layers of inequalities as well as climate variability and change are some of the social and environmental factors that influence the exposure of human populations in urban settings to vector-borne diseases,which pose eminent public health threats.Accurate,consistent,and evidencebased interventions for prevention and control of vector-borne and other infectious diseases of poverty in urban settings are needed to implement innovative and cost-effective public policy and to promote inclusive and equitable urban health services.Main body:While there is growing awareness of vector-borne diseases epidemiology at the urban level,there is still a paucity of research and action being undertaken in this area,hindering evidence-based public health policy decisions and practice and strategies for active community engagement.This paper describes the collaboration and partnership of the Special Programme for Research and Training in Tropical Diseases(TDR)hosted by the World Health Organization(WHO)and the“VEctor boRne DiseAses Scoping reviews”(VERDAS)Research Consortium as they joined efforts in response to filling this gap in knowledge and evidence by supporting the development of a series of scoping reviews that highlight priority research gaps and policy implications to address vector-borne and other infectious diseases at the urban level.Conclusions:The set of scoping reviews proposed in this special issue presents a critical analysis of the state-of-the-art of research on urban health interventions for the prevention and control of vector-borne and other infectious diseases of poverty.The authors of the 6 reviews highlighted severe gaps in knowledge and identified organizational and theoretical limitations that need to be urgently tackled to improve cities preparedness and vector control response.The more pressing need at present is to ensure that more implementation research on vector-borne diseases in urban settings is conducted,addressing policy and practice implications and calling for more political commitment and social mobilization through adequate citizen engagement strategies.

Support for research towards understanding the population health vulnerabilities to vector-borne diseases:increasing resilience under climate change conditions in Africa

Background:Diseases transmitted to humans by vectors account for 17%of all infectious diseases and remain significant public health problems.Through the years,great strides have been taken towards combatting vectorborne diseases(VBDs),most notably through large scale and coordinated control programmes,which have contributed to the decline of the global mortality attributed to VBDs.However,with environmental changes,including climate change,the impact on VBDs is anticipated to be significant,in terms of VBD-related hazards,vulnerabilities and exposure.While there is growing awareness on the vulnerability of the African continent to VBDs in the context of climate change,there is still a paucity of research being undertaken in this area,and impeding the formulation of evidence-based health policy change.Main body:One way in which the gap in knowledge and evidence can be filled is for donor institutions to support research in this area.The collaboration between the WHO Special Programme for Research and Training in Tropical Diseases(TDR)and the International Centre for Research and Development(IDRC)builds on more than 10 years of partnership in research capacity-building in the field of tropical diseases.From this partnership was born yet another research initiative on VBDs and the impact of climate change in the Sahel and sub-Saharan Africa.This paper lists the projects supported under this research initiative and provides a brief on some of the policy and good practice recommendations emerging from the ongoing implementation of the research projects.Conclusion:Data generated from the research initiative are expected to be uptaken by stakeholders(including communities,policy makers,public health practitioners and other relevant partners)to contribute to a better understanding of the impacts of social,environmental and climate change on VBDs(i.e.the nature of the hazard,vulnerabilities,exposure),and improve the ability of African countries to adapt to and reduce the effects of these changes in ways that benefit their most vulnerable populations.

Global burden, distribution, and interventions for infectious diseases of poverty

Infectious diseases of poverty(IDoP)disproportionately affect the poorest population in the world and contribute to a cycle of poverty as a result of decreased productivity ensuing from long-term illness,disability,and social stigma.In 2010,the global deaths from HIV/AIDS have increased to 1.5 million and malaria mortality rose to 1.17 million.Mortality from neglected tropical diseases rose to 152,000,while tuberculosis killed 1.2 million people that same year.Substantial regional variations exist in the distribution of these diseases as they are primarily concentrated in rural areas of Sub-Saharan Africa,Asia,and Latin America,with geographic overlap and high levels of co-infection.Evidence-based interventions exist to prevent and control these diseases,however,the coverage still remains low with an emerging challenge of antimicrobial resistance.Therefore,community-based delivery platforms are increasingly being advocated to ensure sustainability and combat co-infections.Because of the high morbidity and mortality burden of these diseases,especially in resource-poor settings,it is imperative to conduct a systematic review to identify strategies to prevent and control these diseases.Therefore,we attempted to evaluate the effectiveness of one of these strategies,that is community-based delivery for the prevention and treatment of IDoP.In this paper,we describe the burden,epidemiology,and potential interventions for IDoP.In subsequent papers of this series,we describe the analytical framework and the methodology used to guide the systematic reviews,and report the findings and interpretations of our analyses of the impact of community-based strategies on individual IDoPs.

Establishing research priorities in prevention and control of vector-borne diseases in urban areas:a collaborative process

Background:In 2015,following a call for proposals from the Special Programme for Research and Training in Tropical Diseases(TDR),six scoping reviews on the prevention and control of vector-borne diseases in urban areas were conducted.Those reviews provided a clear picture of the available knowledge and highlighted knowledge gaps,as well as needs and opportunities for future research.Based on the research findings of the scoping reviews,a concept mapping exercise was undertaken to produce a list of priority research needs to be addressed.Methods:Members of the six research teams responsible for the“VEctor boRne DiseAses Scoping reviews”(VERDAS)consortium’s scoping reviews met for 2 days with decision-makers from Colombia,Brazil,Peru,Pan-American Health Organization,and World Health Organization.A total of 11 researchers and seven decision-makers(from ministries of health,city and regional vector control departments,and vector control programs)completed the concept mapping,answering the question:“In view of the knowledge synthesis and your own expertise,what do we still need to know about vector-borne diseases and other infectious diseases of poverty in urban areas?”Participants rated each statement on two scales from 1 to 5,one relative to‘priority’and the other to‘policy relevance’,and grouped statements into clusters based on their own individual criteria and expertise.Results:The final map consisted of 12 clusters.Participants considered those entitled“Equity”,“Technology”,and“Surveillance”to have the highest priority.The cluster considered the most important concerns equity issues,confirming that these issues are rarely addressed in research on vector-borne diseases.On the other hand,the“Population mobility”and“Collaboration”clusters were considered to be the lowest priority but remained identified by participants as research priorities.The average policy relevance scores for each of the 12 clusters were roughly the same as the priority scores for all clusters.Some issues were not addressed during the brain-storming.This is the case for governance and for access and quality of care.Conclusions:Based on this work,and adopting a participatory approach,the concept mapping exercise conducted collaboratively with researchers from these teams and high-level decision-makers identified research themes for which studies should be carried out as a priority.

China’s 1-3-7 surveillance and response strategy for malaria elimination: Is case reporting, investigation and foci response happening according to plan?

Background:The China’s 1-3-7 strategy was initiated and extensively adopted in different types of counties(geographic regions)for reporting of malaria cases within 1 day,their confirmation and investigation within 3 days,and the appropriate public health response to prevent further transmission within 7 days.Assessing the level of compliance to the 1-3-7 strategy at the county level is a first step towards determining whether the surveillance and response strategy is happening according to plan.This study assessed if the time-bound targets of the 1-3-7 strategy were being sustained over time.Such information would be useful to improve implementation of the 1-3-7 strategy in China.Methods:This cross-sectional study involved country-wide programmatic data for the period January 1st 2013 to June 30th 2014.Data variables were extracted from the national malaria information system and included socio-demographic information,type of county,date of diagnosis,date of reporting,date of case investigation,case classification(indigenous,or imported,or unknown),focus investigation,date of reactive case detection(RACD),and date of indoor residual spraying(IRS).Summary statistics and proportions were used and comparisons between groups were assessed using the chi-square test.Level of significance was set at a P-value≤0.05.Results:Of a total of 5,688 malaria cases from 731 counties,there were 55(1%)indigenous cases(only in Type 1 and Type 2 counties)and 5,633(99%)imported cases from all types of counties.There was no delay in reporting malaria cases by type of county.In terms of case investigation,97.5%cases were investigated within 3 days with the proportion of delays(1.5%)in type 2 counties,being significantly lower than type 1 counties(4.1%).Regarding active foci,96.4%were treated by RACD and/or IRS.Conclusions:The performance of 1-3-7 strategy was encouraging but identified some challenges that if addressed can further improve implementation.

Infestation risk of the intermediate snail host of Schistosomajaponicum in the Yangtze River Basin: improved results by spatial reassessment and a random forest approach

Background:Oncomelania hupensis is only intermediate snail host of Schistosomajaponicum,and distribution of 0.hupensis is an important indicator for the surveillance of schistosomiasis.This study explored the feasibility of a random forest algorithm weighted by spatial distance for risk prediction of schistosomiasis distribution in the Yangtze River Basin in China,with the aim to produce an improved precision reference for the national schistosomiasis control programme by reducing the number of snail survey sites without losing predictive accuracy.Methods:The snail presence and absence records were collected from Anhui,Hunan,Hubei,Jiangxi and Jiangsu provinces in 2018.A machine learning of random forest algorithm based on a set of environmental and climatic variables was developed to predict the breeding sites of the 0.hupensis intermediated snail host of S.japonicum.Different spatial sizes of a hexagonal grid system were compared to estimate the need for required snail sampling sites.The predictive accuracy related to geographic distances between snail sampling sites was estimated by calculating Kappa and the area under the curve(AUC).Results:The highest accuracy(AUC=0.889 and Kappa=0.618)was achieved at the 5 km distance weight.The five factors with the strongest correlation to 0.hupensis infestation probability were:(1)distance to lake(48.9%),(2)distance to river(36.6%),(3)isothermality(29.5%),(4)mean daily difference in temperature(28.1%),and(5)altitude(26.0%).The risk map showed that areas characterized by snail infestation were mainly located along the Yangtze River,with the highest probability in the dividing,slow-flowing river arms in the middle and lower reaches of the Yangtze River in Anhui,followed by areas near the shores of China's two main lakes,the Dongting Lake in Hunan and Hubei and the Poyang Lake in Jiangxi.Conelusions:Applying the machine learning of random forest algorithm made it feasible to precisely predict snail infestation probability,an approach that could improve the sensitivity of the Chinese schistosome surveillance.system.Redesign of the snail surveillance system by spatial bias correction of 0.hupensis infestation in the Yangtze River Basin to reduce the number of sites required to investigate from 2369 to 1747.

Data and tools to integrate climate and environmental information into public health

Background:During the last 30 years,the development of geographical information systems and satellites for Earth observation has made important progress in the monitoring of the weather,climate,environmental and anthropogenic factors that influence the reduction or the reemergence of vector-borne diseases.Analyses resulting from the combination of geographical information systems(GIS)and remote sensing have improved knowledge of climatic,environmental,and biodiversity factors influencing vector-borne diseases(VBDs)such as malaria,visceral leishmaniasis,dengue,Rift Valley fever,schistosomiasis,Chagas disease and leptospirosis.These knowledge and products developed using remotely sensed data helped and continue to help decision makers to better allocate limited resources in the fight against VBDs.Main body:Because VBDs are linked to climate and environment,we present here our experience during the last four years working with the projects under the,World Health Organization(WHO)/The Special Programme for Research and Training in Tropical Diseases(TDR)-International Development Research Centre(IDRC)Research Initiative on VBDs and Climate Change to integrate climate and environmental information into research and decision-making processes.The following sections present the methodology we have developed,which uses remote sensing to monitor climate variability,environmental conditions,and their impacts on the dynamics of infectious diseases.We then show how remotely sensed data can be accessed and evaluated and how they can be integrated into research and decision-making processes for mapping risks,and creating Early Warning Systems,using two examples from the WHO TDR projects based on schistosomiasis analysis in South Africa and Trypanosomiasis in Tanzania.Conclusions:The tools presented in this article have been successfully used by the projects under the WHO/TDRIDRC Research Initiative on VBDs and Climate Change.Combined with capacity building,they are an important piece of work which can significantly contribute to the goals of WHO Global Vector Control Response and to the Sustainable Development Goals especially those on health and climate action.

Impact of past and on-going changes on climate and weather on vector-borne diseases transmission:a look at the evidence

Background:The climate variables that directly influence vector-borne diseases'ecosystems are mainly temperature and rainfall.This is not only because the vectors bionomics are strongly dependent upon these variables,but also because most of the elements of the systems are impacted,such as the host behavior and development and the pathogen amplification.The impact of the climate changes on the transmission patterns of these diseases is not easily understood,since many confounding faaors are acting together.Consequently,knowledge of these impacts is often based on hypothesis derived from mathematical models.Nevertheless,some direct evidences can be found for several vector-borne diseases.Main body:Evidences of the impact of climate change are available for malaria,arbovirus diseases such as dengue,and many other parasitic and viral diseases such as Rift Valley Fever,Japanese encephalitis,human African trypanosomiasis and leishmaniasis.The effect of temperature and rainfall change as well as extreme events,were found to be the main cause for outbreaks and are alarming the global community.Among the main driving factors,climate strongly influences the geographical distribution of insect veaors,which is rapidly changing due to climate change.Further,in both models and direct evidences,climate change is seen to be affecting veaor-borne diseases more strikingly in fringe of different climatic areas often in the border of transmission zones,which were once free of these diseases with human populations less immune and more receptive.The impact of climate change is also more devastating because of the unpreparedness of Public Health systems to provide adequate response to the events,even when climatic warning is available.Although evidences are strong at the regional and local levels,the studies on impact of climate change on vector-borne diseases and health are producing contradictory results at the global level.Conclusions:In this paper we discuss the current state of the results and draw on evidences from malaria,dengue and other vector-borne diseases to illustrate the state of current thinking and outline the need for further research to inform our predictions and response.

The role of multilateral organizations and governments in advancing social innovation in health care delivery

Background:Despite great medical advances and scientific progress over the past century,one billion people globally still lack access to basic health care services.In the context of the 2030 Agenda for Sustainable Development social innovation models aim to provide effective solutions that bridge the health care delivery gap,address equity and create social value.This commentary highlights the roles of multilateral organizations and governments in creating an enabling environment where social innovations can more effectively integrate into health systems to maximize their impact on beneficiaries.Main text:The integration of social innovations into health systems is essential to ensure their sustainability and the wide dissemination of their impact.Effective partnerships,strong engagement with and endorsement by governments and communities,regulations,trust and sometimes willingness are key factors to enhance system integration,replication and dissemination of the models.Three examples of social innovations selected by the Social Innovation in Health Initiative illustrate the importance of engaging with governments and communities in order to link,integrate and synergize their efforts.Key challenges that they encountered,and lessons learnt are highlighted.Multilateral organizations and governments increasingly engage in promoting and supporting the development,testing and dissemination of social innovations to address the health care delivery gap.They play an important role in creating an enabling environment.This includes promoting the concept of social innovation in health care delivery,spreading social innovation approach and lessons learnt,fostering partnerships and leveraging resources,convening communities,health system actors and various stakeholders to work together across disciplines and sectors,and nurturing capacity in countries.Conclusions:Multilateral organizations and local and national governments have a critical role to play in creating an enabling environment where social innovations can flourish.In supporting and disseminating social innovation approach,multilateral organizations and governments have a great opportunity to accelerate Universal Health Coverage and the achievement of the Sustainable Development Goals.

免疫诊断在控制血吸虫病中的作用

前言 尽管在本世纪早期已经具备了血吸虫病的免疫诊断技术,但由于难于阐明针对寄生虫抗原的免疫应答,它们一直未被用于控制规划,而这些控制规划一直依赖于感染病原的直接证明,尽管这个方法在很大一部分轻感染病人中不很成功。原因是每天排卵量变化很大,以及通常粪检只能检出不低于每日虫卵排出量的2％。因此假阴性结果的偏差导致对实际情况过分乐观的局面,这在反复治疗感染程度急剧下降而传播仍在继续的地区尤其如此。

在肺结核诊断中应用系列痰涂片的结果:系统综述

目前的国际结核病(TB)指南推荐在对肺结核可疑患者评价时应用3次痰涂片镜检以寻找结核菌。我们对符合3次痰标本结果标准的研究进行了系统的评价。通过对多个数据库和资源的检索,我们确定了共37个合格的研究。第3份标本中涂阳结果的增加(所有培阳病例作为分母的研究)和敏感性的增高(所有培阳病例作为分母的研究)是我们关注的主要结果。虽然各研究的方法和结果不同对数据综合构成了挑战,但亚组的分析提示对第3份标本的检查使结果和/或敏感性平均增加了2%～ 5%。把推荐的标本检查数量从3份减至2份(特别是在同一天收集的2份标本)对结核控制项目有利。有很多理由可潜在增加病例检出;许多实施性研究问题需要强调。如果按照国际间协调和标准化的方法,在痰标本镜检时应用现行技术检验哪种方法最有效,这样的研究会是最有用的,既可以增加本国的数据,又可进行研究之间的对比。

A look at the ASEAN-NDI: building a regional health R&D innovation network

Globally,there are growing efforts to address diseases through the advancement in health research and development(R&D),strengthening of regional cooperation in science and technology(particularly on product discovery and development),and implementation of the World Health Assembly Resolution 61.21(WHA61.21)on the Global Strategy and Plan of Action on Public Health,Innovation,and Intellectual Property(GSPA-PHI).As such,the Association of Southeast Asian Nations(ASEAN)is responding to this through the establishment of the ASEAN-Network for Drugs,Diagnostics,Vaccines,and Traditional Medicines Innovation(ASEAN-NDI).This is important in the ASEAN considering that infectious tropical diseases remain prevalent,emerging,and reemerging in the region.This paper looks into the evolution of the ASEAN-NDI from its inception in 2009,to how it is at present,and its plans to mitigate public health problems regionally and even globally.

What if communities held the solutions for universal health coverage?

This commentary highlights the value of community-engaged social innovations to advance health care delivery in low-and middle-income countries and to accelerate universal health coverage.It emphasizes the importance of research to guide the innovators on what works,what does not work to make their innovations sustainable and to replicate and scale them up as relevant.It also helps to demonstrate impact and to enhance uptake within the health systems.