Mapping internal connectivity through human migration in malaria endemic countries.
Ontology highlight
ABSTRACT:
SUBMITTER: Sorichetta A
PROVIDER: S-EPMC5127488 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Experience gained from the Global Malaria Eradication Program (1955-72) identified a set of shared technical and operational factors that enabled some countries to successfully eliminate malaria. Spatial data for these factors were assembled for all malaria-endemic countries and combined to provide an objective, relative ranking of countries by technical, operational, and combined elimination feasibility. The analysis was done separately for Plasmodium falciparum and Plasmodium vivax, and the limitations of the approach were discussed. The relative rankings suggested that malaria elimination would be most feasible in countries in the Americas and Asia, and least feasible in countries in central and west Africa. The results differed when feasibility was measured by technical or operational factors, highlighting the different types of challenge faced by each country. The results are not intended to be prescriptive, predictive, or to provide absolute assessments of feasibility, but they do show that spatial information is available to facilitate evidence-based assessments of the relative feasibility of malaria elimination by country that can be rapidly updated.
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Project description:Neuroglobin (Ngb), a member of the globin superfamily, was found in the brain of vertebrates and is suggested to play a neuroprotective function under hypoxic conditions by scavenging nitrogen monoxide (NO) through a dioxygenase activity. In order for such a reaction to efficiently take place and to minimize the release of reactive intermediates in the cytosol, the cosubstrates O(2) and NO and other unstable reaction intermediates should bind sequentially to docking sites in the protein matrix. We have characterized the accessibility of these sites by analyzing the geminate CO rebinding kinetics to the heme moiety observed upon nanosecond flash photolysis of the Ngb-CO complex encapsulated in silica gels. The geminate rebinding phase showed a remarkable complexity, revealing the presence of a system of secondary docking sites where ligands are stored for hundreds of microseconds. Most kinetics steps display little temperature dependence, demonstrating that ligands can easily migrate through the cavities, except for the slowest reaction intermediate, possibly reflecting a structural conformational change reshaping the system of cavities. This conformational change is unrelated with distal His E7 binding to the heme, as it persists for the HE7L mutant. Overall, data are consistent with the presence of a discrete system of docking sites, possibly acting as reservoirs for the putative cosubstrates and for other reactive species involved in the physiologically relevant reaction.
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Project description:Air travel has expanded at an unprecedented rate and continues to do so. Its effects have been seen on malaria in rates of imported cases, local outbreaks in non-endemic areas and the global spread of drug resistance. With elimination and global eradication back on the agenda, changing levels and compositions of imported malaria in malaria-free countries, and the threat of artemisinin resistance spreading from Southeast Asia, there is a need to better understand how the modern flow of air passengers connects each Plasmodium falciparum- and Plasmodium vivax-endemic region to the rest of the world.Recently constructed global P. falciparum and P.vivax malaria risk maps, along with data on flight schedules and modelled passenger flows across the air network, were combined to describe and quantify global malaria connectivity through air travel. Network analysis approaches were then utilized to describe and quantify the patterns that exist in passenger flows weighted by malaria prevalence. Finally, the connectivity within and to the Southeast Asia region where the threat of imported artemisinin resistance arising is highest, was examined to highlight risk routes for its spread.The analyses demonstrate the substantial connectivity that now exists between and from malaria-endemic regions through air travel. While the air network provides connections to previously isolated malarious regions, it is clear that great variations exist, with significant regional communities of airports connected by higher rates of flow standing out. The structures of these communities are often not geographically coherent, with historical, economic and cultural ties evident, and variations between P. falciparum and P. vivax clear. Moreover, results highlight how well connected the malaria-endemic areas of Africa are now to Southeast Asia, illustrating the many possible routes that artemisinin-resistant strains could take.The continuing growth in air travel is playing an important role in the global epidemiology of malaria, with the endemic world becoming increasingly connected to both malaria-free areas and other endemic regions. The research presented here provides an initial effort to quantify and analyse the connectivity that exists across the malaria-endemic world through air travel, and provide a basic assessment of the risks it results in for movement of infections.
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Project description:BackgroundThe diagnosis of malaria, using microscopy or rapid diagnostic tests (RDTs), requires the collection of capillary blood. This procedure is relatively simple to perform but invasive and poses potential risks to patients and health workers, arising from the manipulation of potentially infectious bodily fluids. Less or non-invasive diagnostic tests, based on urine, saliva or requiring no sampling, have the potential to generate less discomfort for the patient and to offer simpler and less risky testing procedures that could be safely performed by untrained staff or even self-performed. To explore the potential acceptance and perceived value of such non-invasive tests, an online, international survey was conducted to gather feedback from National Malaria Control Programme (NMCP) representatives.MethodsAn online survey comprising nineteen questions, available in English, French or Spanish, was emailed to 300 individuals who work with NMCPs in malaria-endemic countries. Answers were collected between November and December 2017; responses were qualitatively analysed to identify key themes and trends and quantitatively analysed to determine average values stratified by region.ResultsResponses were received from 70 individuals, from 33 countries. Approximately half of the respondents (52 %) considered current blood-based tests for malaria to be minimally invasive and non-problematic in their setting. For these participants, non-invasive tests would only be of interest if they brought additional performance improvements, as compared with the performance of microscopy and RDTs. Most respondents were of the view that saliva-based (80 %) and urine-based (66 %) tests would be more readily acceptable among children than blood-based tests. Potential use-case scenarios of interest for both saliva- and urine-based tests were ease-of-testing by community health workers, additional surveillance, self-testing, and outbreak investigation. Many respondents (41 %) thought that if saliva-based tests retailed at <$0.50 per unit they could largely replace conventional RDTs, whereas only 25 % of respondents thought a similarly priced urine-based test would do so.ConclusionsAlthough limited to NMCP stakeholders, this survey indicated that current tests for malaria, based on capillary blood, are generally perceived to be minimally invasive and non-problematic. Non-invasive tests, especially if saliva-based, would be welcome if they could match or out-perform the price and performance of current blood-based tests.
| S-EPMC8461884 | biostudies-literature
Project description:BackgroundWhile substantial gains have been made in the fight against malaria over the past 20 years, malaria morbidity and mortality are marked by inequality. The equitable elimination of malaria within countries will be determined in part by greater spending on malaria interventions, and how those investments are allocated. This study aims to identify potential drivers of malaria outcome inequality and to demonstrate how spending through different mechanisms might lead to greater health equity.MethodsUsing the Gini index, subnational estimates of malaria incidence and mortality rates from 2010 to 2020 were used to quantify the degree of inequality in malaria burden within countries with incidence rates above 5000 cases per 100,000 people in 2020. Estimates of Gini indices represent within-country distributions of disease burden, with high values corresponding to inequitable distributions of malaria burden within a country. Time series analyses were used to quantify associations of malaria inequality with malaria spending, controlling for country socioeconomic and population characteristics.ResultsBetween 2010 and 2020, varying levels of inequality in malaria burden within malaria-endemic countries was found. In 2020, values of the Gini index ranged from 0.06 to 0.73 for incidence, 0.07 to 0.73 for mortality, and 0.00 to 0.36 for case fatality. Greater total malaria spending, spending on health systems strengthening for malaria, healthcare access and quality, and national malaria incidence were associated with reductions in malaria outcomes inequality within countries. In addition, government expenditure on malaria, aggregated government and donor spending on treatment, and maternal educational attainment were also associated with changes in malaria outcome inequality among countries with the greatest malaria burden.ConclusionsThe findings from this study suggest that prioritizing health systems strengthening in malaria spending and malaria spending in general especially from governments will help to reduce inequality of the malaria burden within countries. Given heterogeneity in outcomes in countries currently fighting to control malaria, and the challenges in increasing both domestic and international funding allocated to control and eliminate malaria, the efficient targeting of limited resources is critical to attain global malaria eradication goals.
| S-EPMC11234708 | biostudies-literature
Project description:Fever is one of the most common reasons for seeking health care globally and most human pathogens are zoonotic. We conducted a systematic review to describe the occurrence and distribution of zoonotic causes of human febrile illness reported in malaria endemic countries. We included data from 53 (48·2%) of 110 malaria endemic countries and 244 articles that described diagnosis of 30 zoonoses in febrile people. The majority (17) of zoonoses were bacterial, with nine viruses, three protozoa, and one helminth also identified. Leptospira species and non-typhoidal salmonella serovars were the most frequently reported pathogens. Despite evidence of profound data gaps, this Review reveals widespread distribution of multiple zoonoses that cause febrile illness. Greater understanding of the epidemiology of zoonoses in different settings is needed to improve awareness about these pathogens and the management of febrile illness.
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Project description:BackgroundMalaria was first reported in Rwanda in the early 1900s with significant heterogeneity and volatility in transmission over subsequent decades. Here, a comprehensive literature review of malaria transmission patterns and control strategies in Rwanda between 1900 and 2018 is presented to provide insight into successes and challenges in the country and to inform the future of malaria control in Rwanda.MethodsA systematic literature search of peer-reviewed publications (Web of Knowledge, PubMed, Google Scholar, and the World Health Organization Library (WHOLIS) and grey literature on malaria control in Rwanda between 1900 and 2019 was conducted with the following search terms: "malaria"", "Rwanda", "epidemiology", "control", "treatment", and/or "prevention." Reports and other relevant documents were also obtained from the Rwanda National Malaria Control Programme (NMCP). To inform this literature review and evidence synthesis, epidemiologic and intervention data were collated from NMCP and partner reports, the national routine surveillance system, and population surveys.ResultsTwo hundred sixty-eight peer-reviewed publications and 56 grey literature items were reviewed, and information was extracted. The history of malaria control in Rwanda is thematically described here according to five phases: 1900 to 1954 before the launch of the Global Malaria Eradication Programme (GMEP); (2) Implementation of the GMEP from 1955 to 1969; (3) Post- GMEP to 1994 Genocide; (4) the re-establishment of malaria control from 1995 to 2005, and (5) current malaria control efforts from 2006 to 2018. The review shows that Rwanda was an early adopter of tools and approaches in the early 2000s, putting the country ahead of the curve and health systems reforms created an enabling environment for an effective malaria control programme. The last two decades have seen unprecedented investments in malaria in Rwanda, resulting in significant declines in disease burden from 2000 to 2011. However, in recent years, these gains appear to have reversed with increasing cases since 2012 although the country is starting to make progress again.ConclusionThe review shows the impact and fragility of gains against malaria, even in the context of sustained health system development. Also, as shown in Rwanda, country malaria control programmes should be dynamic and adaptive to respond and address changing settings.
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Project description:To date, the only robust estimates of severe malaria cases include children who present to the formal healthcare system. It is a challenge to use these data because of varying age ranges of reporting, different diagnosis techniques, surveillance methods, and healthcare utilization. This analysis examined data from 37 Demographic and Health Surveys and Malaria Indicator Surveys across 19 countries in sub-Saharan Africa collected between 2011 and 2018. The outcome of interest is a proxy indicator for severe malaria, defined as a proportion of children aged 6-59 months with at least one self-reported symptom of severe illness including loss of consciousness, rapid breathing, seizures, or severe anemia (hemoglobin < 5 g/dL) among those who were positive for malaria. The study includes a weighted descriptive, country-level analysis and a multilevel mixed-effects logistic regression model to assess the determinants of severe malaria. Among children positive for malaria across all surveys, 4.5% (95% CI: 4.1-4.8) had at least one sign or symptom of severe malaria, which was significantly associated with age, residence, wealth, and year of survey fieldwork at a P-value less than 0.05. This analysis presents a novel and an alternative approach of estimating the fraction of severe malaria cases among malaria-positive children younger than 5 years in malaria-endemic countries. Estimating severe malaria cases through population-based surveys allows countries to estimate severe malaria across time and to compare with other countries. Having a population-level estimate of severe malaria cases helps further our understanding of the burden and epidemiology of severe malaria.
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