scholarly journals The decline of malaria in Vietnam, 1991-2014

2017 ◽  
Author(s):  
Sandra M Goldlust ◽  
Phung Duc Thuan ◽  
Dang Duy Hoang Giang ◽  
Ngo Duc Thang ◽  
Guy E Thwaites ◽  
...  
Keyword(s):  
Case Management ◽  
Vector Control ◽  
Malaria Control ◽  
Malaria Incidence ◽  
Population Level ◽  
Control Measures ◽  
Central Component ◽  
Annual Data ◽  
Combination Therapies ◽  
Insecticide Treated Nets

AbstractA central component of malaria control initiatives throughout the world is the use of artemisinin-based combination therapies (ACTs) for treatment of uncomplicated P. falciparium malaria. Despite the well-documented clinical efficacy of ACTs, the population-level effects of ACT case management on malaria transmission have not been studied thoroughly until recently. An ideal case study for the population-level effects of artemisinin use can be found in Vietnam, where a major increase of malaria cases in the 1980s was followed by the gradual adoption of artemisinin-based clinical case management. We assembled annual data from Vietnam’s National Institutes for Malariology, Parasitology, and Entomology showing the degree to which artemisinin therapies were adopted in different provinces, the effort placed on vector control, and the funding available to provincial malaria control programs, from 1991 to 2014. Data on urbanization were also collected for this period. We found that a 10% increase in the artemisinin proportion of treatments procured by a provincial control program corresponded to a 32.8% (95% CI: 27.7 – 37.5%) decline in estimated malaria cases; the association persisted and the effect size was nearly unchanged if confirmed cases or suspected cases were used. There was no consistent effect of vector control on malaria cases in Vietnam as a whole, nor was any effect found when the data were broken up regionally. The association between urbanization and malaria was generally negative and sometimes statistically significant. This was most pronounced in the central region of Vietnam, where a 10% increase in urbanization corresponded to a 43.3% (95% CI: 21.6 – 58.9%) decrease in suspected malaria incidence; this association was not statistically significant if confirmed cases or estimated cases were used. The decline of malaria in Vietnam from 1991 to 2014 can largely be attributed to the rapid adoption of artemisinin-based drugs. Recent analyses of aggregated data from Africa have shown that insecticide-treated nets have had the greatest effect on lowering malaria prevalence over the past fifteen years, suggesting that the success of different types of malaria interventions is region specific. Continuing global efforts on malaria elimination should focus on both vector control measures and increased access to artemisinin-combination therapies.

scholarly journals Selective sweep suggests transcriptional regulation may underlie Plasmodium vivax resilience to malaria control measures in Cambodia

2016 ◽  
Vol 113 (50) ◽  
pp. E8096-E8105 ◽  
Author(s):  
Christian M. Parobek ◽  
Jessica T. Lin ◽  
David L. Saunders ◽  
Eric J. Barnett ◽  
Chanthap Lon ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Malaria Control ◽  
Histone Deacetylases ◽  
Transcriptional Control ◽  
Selective Sweep ◽  
Malaria Incidence ◽  
Population Level ◽  
Control Measures ◽  
Effective Population ◽  
Species Specific

Cambodia, in which both Plasmodium vivax and Plasmodium falciparum are endemic, has been the focus of numerous malaria-control interventions, resulting in a marked decline in overall malaria incidence. Despite this decline, the number of P. vivax cases has actually increased. To understand better the factors underlying this resilience, we compared the genetic responses of the two species to recent selective pressures. We sequenced and studied the genomes of 70 P. vivax and 80 P. falciparum isolates collected between 2009 and 2013. We found that although P. falciparum has undergone population fracturing, the coendemic P. vivax population has grown undisrupted, resulting in a larger effective population size, no discernable population structure, and frequent multiclonal infections. Signatures of selection suggest recent, species-specific evolutionary differences. Particularly, in contrast to P. falciparum, P. vivax transcription factors, chromatin modifiers, and histone deacetylases have undergone strong directional selection, including a particularly strong selective sweep at an AP2 transcription factor. Together, our findings point to different population-level adaptive mechanisms used by P. vivax and P. falciparum parasites. Although population substructuring in P. falciparum has resulted in clonal outgrowths of resistant parasites, P. vivax may use a nuanced transcriptional regulatory approach to population maintenance, enabling it to preserve a larger, more diverse population better suited to facing selective threats. We conclude that transcriptional control may underlie P. vivax’s resilience to malaria control measures. Novel strategies to target such processes are likely required to eradicate P. vivax and achieve malaria elimination.

scholarly journals An integrated malaria control program with community participation on the Pacific Coast of Colombia

2001 ◽  
Vol 17 (suppl) ◽  
pp. S103-S113 ◽  
Author(s):  
William Rojas ◽  
Sonia Botero ◽  
Hector Ivan Garcia
Keyword(s):  
Health Services ◽  
Vector Control ◽  
Community Participation ◽  
Malaria Control ◽  
Pacific Coast ◽  
Malaria Incidence ◽  
Control Program ◽  
Control Measures ◽  
Radio Communications ◽  
The Pacific

The study focuses on integrated malaria control in 23 communities on the Pacific Coast of Colombia, with several elements of an ecosystem approach to human health, including malaria-related sociopolitical, ecological, and economic factors. The program fostered community participation. The program presented here had 2 components: implementation and research. The first was conducted in 23 communities, 21 of which lacked adequate health services in terms of education, community participation, prompt diagnosis and complete treatment, and vector control. Research focused on specific vector control measures and the current national health services decentralization process. The project: 1) created a malaria prevention culture in the community; 2) avoided deaths from malaria (no fatal cases in the 3-year period, compared to 5-8 deaths a year previously); 3) avoided cases of cerebral malaria (no cases, as compared to 90-110 per year previously); 4) reduced malaria incidence by 45.36%; 5) decreased length of sick leave from 7.52 to 3.7 days; 6) established a permanent network of microscope technicians and 2-way radio communications; 7) integrated work by local, regional, and outside institutions; 8) demonstrated efficacy of insecticide-impregnated bednets to reduce malaria transmission.

scholarly journals Earth observation in support of malaria control and epidemiology: MALAREO monitoring approaches

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Jonas Franke ◽  
Michael Gebreslasie ◽  
Ides Bauwens ◽  
Julie Deleu ◽  
Florian Siegert
Keyword(s):  
Environmental Factors ◽  
Vector Control ◽  
Malaria Control ◽  
Malaria Incidence ◽  
Modern Technology ◽  
Earth Observation ◽  
Malaria Vector Control ◽  
Support Vector ◽  
African Countries ◽  
Control Programmes

Malaria affects about half of the world’s population, with the vast majority of cases occuring in Africa. National malaria control programmes aim to reduce the burden of malaria and its negative, socioeconomic effects by using various control strategies (<em>e.g.</em> vector control, environmental management and case tracking). Vector control is the most effective transmission prevention strategy, while environmental factors are the key parameters affecting transmission. Geographic information systems (GIS), earth observation (EO) and spatial modelling are increasingly being recognised as valuable tools for effective management and malaria vector control. Issues previously inhibiting the use of EO in epidemiology and malaria control such as poor satellite sensor performance, high costs and long turnaround times, have since been resolved through modern technology. The core goal of this study was to develop and implement the capabilities of EO data for national malaria control programmes in South Africa, Swaziland and Mozambique. High- and very high resolution (HR and VHR) land cover and wetland maps were generated for the identification of potential vector habitats and human activities, as well as geoinformation on distance to wetlands for malaria risk modelling, population density maps, habitat foci maps and VHR household maps. These products were further used for modelling malaria incidence and the analysis of environmental factors that favour vector breeding. Geoproducts were also transferred to the staff of national malaria control programmes in seven African countries to demonstrate how EO data and GIS can support vector control strategy planning and monitoring. The transferred EO products support better epidemiological understanding of environmental factors related to malaria transmission, and allow for spatio-temporal targeting of malaria control interventions, thereby improving the cost-effectiveness of interventions.

Smart Surveillance and Micromanagement Using Information Technology for Malaria Elimination in Mangaluru, India – an Analysis of Five Years Data

2020 ◽  
Author(s):  
B. Shantharam Baliga ◽  
Shrikala Baliga ◽  
Animesh Jain ◽  
Naveen Kulal ◽  
Manu Kumar ◽  
...  
Keyword(s):  
Information Technology ◽  
Control System ◽  
Active Surveillance ◽  
Malaria Control ◽  
Malaria Elimination ◽  
Malaria Incidence ◽  
Control Measures ◽  
Smart Surveillance ◽  
Field Response ◽  
Complete Treatment

Abstract BackgroundMalaria control system (MCS), an Information technology (IT)-driven surveillance and monitoring intervention is being adopted for elimination of malaria in Mangaluru city, Karnataka, India since October 2015. This facilitated ‘smart surveillance’ followed by required field response within a timeline. The system facilitated data collection of individual case and data driven mapping and strategies for malaria elimination programme. This paper aims to present the analysis of post-digitization data of 5 years, discuss the current operational functionalities of MCS and its impact on the malaria incidence.MethodsIT system developed for robust malaria surveillance and field response is being continued in the 6th year. Protocol for surveillance control was followed as per the national programme guidilines mentioned earlier. Secondary data from the malaria control system is collated and analysed. Incidence of malaria, active surveillance, malariogenic conditions and its management, malariometric indices, shrinking malaria map were also analysed.ResultsSmart surveillance and subsequent response for control was sustained and performance improved in five years with participation of all stakeholders. Overall malaria incidence significantly reduced by 83% at the end of 5 years when compared with year of digitizarion (DY) (p<0.001). Early reporting of new cases (within 48 hrs) was near total followed by complete treatment and vector control. Slide positivity rate (SPR) decreased from 10.36 (DY) to 6.5 (PDY 5). Annual parasite incidence (API) decreased from 16.17 (DY) to 2.64 (PDY 5). There was a negative correlation between contact smears and incidence of malaria. Five-year data analyses indicated declining trends in overall malaria incidence and correlation between closure by 14 days. The best impact on reduction in incidence of malaria was recorded in pre-monsoon months (~85%) compared to lower impact in July-August months (~40%). ConclusionIT System helped to micromanage control activities such as robust reporting, incidence-centric active surveillance, early and complete treatment, documentation of full treatment of each malaria patient, targeted mosquito control measures in houses surrounding reported cases. The learnings and analytical output from the data helped to modify strategies for control of both disease and the vector, heralding the city into the elimination stage.

scholarly journals VACCINATION AGAINST MALARIA: REALITY AND PERSPECTIVES

2017 ◽  
Vol 22 (3) ◽  
pp. 153-156
Author(s):  
S. K Litvinov ◽  
A. M Bronshteyn ◽  
E. N Morozov
Keyword(s):  
Malaria Control ◽  
Public Health Problem ◽  
Control Measures ◽  
World Health ◽  
European Medicines Agency ◽  
Morbidity Rate ◽  
Effective Vaccine ◽  
Protein Vaccine ◽  
Insecticide Treated Nets ◽  
African Countries

Malaria continues to be a major international public health problem. However a significant reduction in the morbidity rate has been achieved over the past decade. The effective vaccine against malaria, caused by P. falciparun, could contribute significantly to the prevention and control of the disease, as tropical malaria is most widely distributed in the world. Nowadays there is the only RTS,S/AS01 vaccine had passed the accomplished phase 3 of clinical trial and received endorsement of certain bodies of World Health Organization and European Medicines Agency. RTS,S/AS01 is a pre-erythrocytic hybrid recombinant protein vaccine. Both immunogenicity and effectiveness of this vaccine particularly in children aged of 5-12 months were demonstrated by the trial at the time for first vaccination. Vaccine should be administered 3 times as the initial series of inoculation with 4 weeks interval and then the 4th dose should be given 15-18 months later. Since there is still a number of issues required certain clarifications, the decision has been taken to undertake another relatively large pilot project in African countries, prior to final recommendations on the vaccine use could be developed and proposed to countries. The implementation of this new trial will definitely take appropriate time. The contribution of vaccine to malaria control might be significant only if used simultaneously with other proved malaria control measures, such as the use of insecticide-treated nets, detection of malaria cases with the use of rapid diagnostic tests and subsequent its treatment, chemoprevention when appropriate and, of course vector control. The consideration of the vaccine use as the mechanism, which should allow achieve the eradication of the disease is not appropriate in principle.

scholarly journals Accounting for regional transmission variability and the impact of malaria control interventions in Ghana: A population level mathematical modelling approach.

2020 ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P Silal
Keyword(s):  
Malaria Control ◽  
Malaria Incidence ◽  
Protective Efficacy ◽  
Indoor Residual Spraying ◽  
Information Management System ◽  
Control Measures ◽  
Bed Nets ◽  
Model Parameters ◽  
Insecticide Treated Bed Nets ◽  
The Impact

Abstract Background Assessing the effectiveness of malaria control measures in Ghana will require taking transmission dynamics of the disease into account given the influence of climate variability in the region of interest. The impact of preventative interventions on malaria incidence and the prospects of meeting program timelines in Ghana have been investigated using mathematical models based on regionally diverse climatic zones. Methods An ordinary non-linear differential equation model with its associated rate parameters was developed incorporating the transitions between various disease compartments for three ecological zones in Ghana. Model parameters were estimated using data captured on the District Health Information Management System in Ghana from 2008 to 2017.The impact of insecticide treated bed nets and indoor residual spraying on the incidence of malaria were simulated at various levels of coverage and protective effectiveness in each ecological zone. To fit the model, Approximate Bayesian Computational sampling approach was adopted. Results Increasing the coverage levels of both long lasting insecticide treated bed nets or indoor residual spraying activities without a corresponding increase in their proper use or patronage does not impact highly on averting predicted incidence of malaria in Ghana. Improving on the protective efficacy of long lasting insecticide treated bed nets through proper usage could lead to substantial reductions in the predicted incidence of malaria. Similar results were obtained with indoor residual spraying across all zones. Conclusions Projected goals set in the National Strategic plan for malaria control 2014-2020 as well as WHO targets for malaria pre-elimination by 2030 are only likely be achieved if a substantial improvement in treated bed net usage is achieved coupled with targeted deployment of indoor residual spraying with high efficacy.

scholarly journals Malaria: Knowledge and prevention practices among school adolescents in a coastal community in Calabar, Nigeria

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Ndifreke E. Udonwa ◽  
Abraham N. Gyuse ◽  
Aniekan J. Etokidem
Keyword(s):  
Secondary Schools ◽  
School Children ◽  
Malaria Control ◽  
Role Models ◽  
Malaria Prevention ◽  
Control Measures ◽  
Insecticide Treated Nets ◽  
African Countries ◽  
Cross Sectional Survey ◽  
Coastal Community

Background: Malaria prevention and treatment constitute an unbearable economic burden to most African countries, especially south of the Sahara, where about 500 million cases occur annually. The problem of malaria among adolescents has largely been overshadowed by the huge burden of the disease among young children. Attention to malaria among adolescents has also been diverted by the huge burden of HIV/AIDS among adolescents. Some surveys reveal a lack of knowledge and many misconceptions about the transmission and treatment of malaria, which could adversely affect malaria control measures and antimalarial therapy. Such a knowledge gap could have an adverse effect on school children, who could be used as change agents and as role models for their siblings and peers in the malaria control strategy.Objectives: To determine the malaria prevention practices of school adolescents in the coastal community of Calabar, Nigeria.Method: This was a cross-sectional survey involving secondary schools in southern Calabar. Four hundred adolescents were randomly selected from the 4565 learners in 5 out of 17 secondary schools in southern Calabar, Cross River State, Nigeria. A self-administered, semi-structured questionnaire was administered to the respondents.Results: Most respondents (77.5%) were aware that the vector transmits the malaria parasite through biting. Fewer respondents would prevent malaria attacks by clearing the vegetation in the peri-domestic environment (13.5%), filling up potholes (16.9%), opening up drainage (11%), using insecticide-treated nets (25.7%) or using antimalarial drugs (11.2%). Less than one-tenth (8%) would use various other methods such as not accepting unscreened blood, while only 11% obtained the information from their teachers.Conclusion: The study identified knowledge gaps among school children. There is a need to empower teachers with information about the cause of malaria and prevention strategies.

scholarly journals Resurgence of malaria infection after mass treatment: a simulation study

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Thomas A. Smith ◽  
Peter Pemberton-Ross ◽  
Melissa A. Penny ◽  
Nakul Chitnis
Keyword(s):  
Case Management ◽  
Vector Control ◽  
Initial Period ◽  
Treatment Strategies ◽  
Stable State ◽  
Control Measures ◽  
High Coverage ◽  
Effective Coverage ◽  
Transmission Potential ◽  
Test And Treat

Abstract Background Field studies are evaluating if mass drug administration (MDA) might shorten the time to elimination of Plasmodium falciparum malaria, when vector control measures and reactive surveillance strategies are scaled-up. A concern with this strategy is that there may be resurgence of transmission following MDA. Methods A conceptual model was developed to classify possible outcomes of an initial period of MDA, followed by continuously implementing other interventions. The classification considered whether elimination or a new endemic stable state is achieved, and whether changes are rapid, transient, or gradual. These categories were informed by stability analyses of simple models of vector control, case management, and test-and-treat interventions. Individual-based stochastic models of malaria transmission (OpenMalaria) were then used to estimate the probability and likely rates of resurgence in realistic settings. Effects of concurrent interventions, including routine case management and test-and-treat strategies were investigated. Results Analysis of the conceptual models suggest resurgence will occur after MDA unless transmission potential is very low, or the post-MDA prevalence falls below a threshold, which depends on both transmission potential and on the induction of bistability. Importation rates are important only when this threshold is very low. In most OpenMalaria simulations the approximately stable state achieved at the end of the simulations was independent of inclusion of MDA and the final state was unaffected by importation of infections at plausible rates. Elimination occurred only with high effective coverage of case management, low initial prevalence, and high intensity test-and-treat. High coverage of case management but not by test-and-treat induced bistability. Where resurgence occurred, its rate depended mainly on transmission potential (not treatment rates). Conclusions A short burst of high impact MDA is likely to be followed by resurgence. To avert resurgence, concomitant interventions need either to substantially reduce average transmission potential or to be differentially effective in averting or clearing infections at low prevalence. Case management at high effective coverage has this differential effect, and should suffice to avert resurgence caused by imported cases at plausible rates of importation. Once resurgence occurs, its rate depends mainly on transmission potential, not on treatment strategies.

scholarly journals Digitized smart surveillance and micromanagement using information technology for malaria elimination in Mangaluru, India: an analysis of five-year post-digitization data

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
B. Shantharam Baliga ◽  
Shrikala Baliga ◽  
Animesh Jain ◽  
Naveen Kulal ◽  
Manu Kumar ◽  
...  
Keyword(s):  
Information Technology ◽  
Control System ◽  
Active Surveillance ◽  
Malaria Control ◽  
Malaria Elimination ◽  
Malaria Incidence ◽  
Control Measures ◽  
Smart Surveillance ◽  
Field Response ◽  
Complete Treatment

Abstract Background Malaria control system (MCS), an Information technology (IT)-driven surveillance and monitoring intervention is being adopted for elimination of malaria in Mangaluru city, Karnataka, India since October 2015. This has facilitated ‘smart surveillance’ followed by required field response within a timeline. The system facilitated data collection of individual case, data driven mapping and strategies for malaria elimination programme. This paper aims to present the analysis of post-digitization data of 5 years, discuss the current operational functionalities of MCS and its impact on the malaria incidence. Methods IT system developed for robust malaria surveillance and field response is being continued in the sixth year. Protocol for surveillance control was followed as per the national programme guidelines mentioned in an earlier publication. Secondary data from the malaria control system was collated and analysed. Incidence of malaria, active surveillance, malariogenic conditions and its management, malariometric indices, shrinking malaria maps were also analysed. Results Smart surveillance and subsequent response for control was sustained and performance improved in five years with participation of all stakeholders. Overall malaria incidence significantly reduced by 83% at the end of 5 years when compared with year of digitization (DY) (p < 0.001). Early reporting of new cases (within 48 h) was near total followed by complete treatment and vector control. Slide positivity rate (SPR) decreased from 10.36 (DY) to 6.5 (PDY 5). Annual parasite incidence (API) decreased from 16.17 (DY) to 2.64 (PDY 5). There was a negative correlation between contact smears and incidence of malaria. Five-year data analyses indicated declining trends in overall malaria incidence and correlation between closures by 14 days. The best impact on reduction in incidence of malaria was recorded in the pre-monsoon months (~ 85%) compared to lower impact in July–August months (~ 40%). Conclusion MCS helped to micromanage control activities, such as robust reporting, incidence-centric active surveillance, early and complete treatment, documentation of full treatment of each malaria patient, targeted mosquito control measures in houses surrounding reported cases. The learnings and analytical output from the data helped to modify strategies for control of both disease and the vector, heralding the city into the elimination stage.

scholarly journals Evaluating the Efficacy, Impact and Feasibility of Community-based House Screening as a Complementary Malaria Control Intervention in Southern Africa: a Study Protocol for a Household Randomized Trial.

2021 ◽  
Author(s):  
Peter Onyango Sangoro ◽  
Ulrike Fillinger ◽  
Kochelani Saili ◽  
Theresia Estomih Nkya ◽  
Rose Marubu ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Malaria Control ◽  
Malaria Incidence ◽  
Indoor Residual Spraying ◽  
Clinical Malaria ◽  
Sub Saharan Africa ◽  
Substantial Impact ◽  
Transmission Season ◽  
The Impact

Abstract Background: Concerted effort to control malaria has had a substantial impact on transmission of the disease in the past two decades. In areas where reduced malaria transmission is being sustained through insecticide-based vector control interventions, primarily long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), non-insecticidal complementary tools will likely be needed to push towards malaria elimination. Once interruption in local disease transmission is achieved, insecticide-based measures can be scaled down gradually and eventually phased out, saving on costs of sustaining control programmes and mitigating any unintended negative health and environmental impacts posed by insecticides. These non-insecticidal methods could eventually replace insecticidal methods of vector control. House screening, a non-insecticidal method, has a long history in malaria control, but is still not widely adopted in sub-Saharan Africa. This study aims to add to the evidence-base for this intervention in low transmission settings by assessing the efficacy, impact and feasibility of house screening in areas where LLINs are conventionally used for malaria control. Methods: A two-armed, household randomized clinical trial will be conducted in Mozambique, Zambia and Zimbabwe to evaluate whether combined use of house screens and LLINs affords better protection against clinical malaria in children between 6 months and 13 years compared to the sole use of LLINs. Eight hundred households will be enrolled in each study area, where 400 households will be randomly assigned the intervention, house screening and LLINs while the control households will be provided with LLINs only. Clinical malaria incidence will be estimated by actively following up one child from each household for 6 months over the malaria transmission season. Cross-sectional parasite prevalence will be estimated by testing all participating children for malaria parasites at the beginning and end of each transmission season using rapid diagnostic tests.CDC light traps and pyrethrum spray catches (PSC) will be used to sample adult mosquitoes and evaluate the impact of house screening on indoor mosquito density, species distribution and sporozoite rates.Discussion: This study will contribute epidemiological data on the impact of house screening on malaria transmission and assess the feasibility of its implementation on a programmatic scale. Trial registration: This trial was retrospectively registered on 11th August 2020. Registration number PACTR202008524310568.

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