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

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P. Silal

Abstract Background This paper investigates the impact of malaria preventive interventions in Ghana and the prospects of achieving programme goals using mathematical models based on regionally diverse climatic zones of the country. Methods Using data from the District Health Information Management System of the Ghana Health Service from 2008 to 2017, and historical intervention coverage levels, ordinary non-linear differential equations models were developed. These models incorporated transitions amongst various disease compartments for the three main ecological zones in Ghana. The Approximate Bayesian Computational sampling approach, with a distance based rejection criteria, was adopted for calibration. A leave-one-out approach was used to validate model parameters and the most sensitive parameters were evaluated using a multivariate regression analysis. The impact of insecticide-treated bed nets and their usage, and indoor residual spraying, as well as their protective efficacy on the incidence of malaria, was simulated at various levels of coverage and protective effectiveness in each ecological zone to investigate the prospects of achieving goals of the Ghana malaria control strategy for 2014–2020. Results Increasing the coverage levels of both long-lasting insecticide-treated bed nets and indoor residual spraying activities, without a corresponding increase in their recommended utilization, does not impact highly on averting predicted incidence of malaria. Improving proper usage of long-lasting insecticide-treated bed nets could lead to substantial reductions in the predicted incidence of malaria. Similar results were obtained with indoor residual spraying across all ecological zones of Ghana. Conclusions Projected goals set in the national strategic plan for malaria control 2014–2020, as well as World Health Organization targets for malaria pre-elimination by 2030, are only likely to be achieved if a substantial improvement in treated bed net usage is achieved, coupled with targeted deployment of indoor residual spraying with high community acceptability and efficacy.

2020 ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P Silal

Abstract Background This paper investigates the impact of malaria preventive interventions in Ghana and the prospects of achieving programme goals using mathematical models based on regionally diverse climatic zones of the country. Methods Using data from the District Health Information Management System of the Ghana Health Service from 2008 to 2017, and historical intervention coverage levels, ordinary non-linear differential equations models were developed. These models incorporated transitions amongst various disease compartments for the three main ecological zones in Ghana. The Approximate Bayesian Computational sampling approach, with a distance based rejection criteria, was adopted for calibration. A leave-one-out approach was used to validate model parameters and the most sensitive parameters were evaluated using a multivariate regression analysis. The impact of insecticide-treated bed nets and their usage, and indoor residual spraying, as well as their protective efficacy on the incidence of malaria, was simulated at various levels of coverage and protective effectiveness in each ecological zone to investigate the prospects of achieving goals of the Ghana malaria control strategy for 2014-2020. Results Increasing the coverage levels of both long-lasting insecticide-treated bed nets and indoor residual spraying activities, without a corresponding increase in their recommended utilization, does not impact highly on averting predicted incidence of malaria. Improving proper usage of long-lasting insecticide-treated bed nets could lead to substantial reductions in the predicted incidence of malaria. Similar results were obtained with indoor residual spraying across all ecological zones of Ghana. Conclusions Projected goals set in the national strategic plan for malaria control 2014-2020, as well as World Health Organization targets for malaria pre-elimination by 2030, are only likely to be achieved if a substantial improvement in treated bed net usage is achieved, coupled with targeted deployment of indoor residual spraying with high community acceptability and efficacy.


2020 ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P Silal

Abstract Background: This paper investigates the impact of malaria preventive interventions in Ghana and the prospects of achieving program goals using mathematical models based on regionally diverse climatic zones of the country. Methods: Using data from the District Health Information Management System of the Ghana Health Service from 2008 to 2017 and historical intervention coverage levels, ordinary non-linear differential equations models were developed incorporating transistions between various disease compartments for the three main ecological zones in Ghana. The Approximate Bayesian Computational sampling approach, with a distance based rejection criteria, was adopted for calibration. A leave-one-out approach was used to validate model parameters and the most sensitive evaluated using a multivariate regression analysis. The impact of insecticide treated bed nets and their usage and indoor residual spraying as well as their protective efficacy on the incidence of malaria were simulated at various levels of coverage and protective effectiveness in each ecological zone to investigate the prospects of achieving goals of the Ghana malaria control strategy for 2014-2020. Results: Increasing the coverage levels of both long lasting insecticide treated bed nets and indoor residual spraying activities without a corresponding increase in their recommended utilisation does not impact highly on averting predicted incidence of malaria. Improving proper usage of long lasting insecticide treated bed nets could lead to substantial reductions in the predicted incidence of malaria. Similar results were obtained with indoor residual spraying across all ecological zones of Ghana. 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 to be achieved if a substantial improvement in treated bed net usage is achieved coupled with targeted deployment of indoor residual spraying with high community acceptability and efficacy.


2020 ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P Silal

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.


2020 ◽  
Author(s):  
Timothy Awine ◽  
Sheetal P Silal

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 were investigated using mathematical models based on regionally diverse climatic zones. Methods An ordinary non-linear differential equation models with their associated rate parameters were developed incorporating the transitions between various disease compartments for three ecological zones in Ghana. Models were fitted using data from the District Health Information Management System in Ghana from 2008 to 2017 and historical intervention coverage levels. To calibrate the models, Approximate Bayesian Computational sampling approach with a distance based rejection criteria was adopted. A leave-one-out approach was used to validate model parameters and the most sensitive evaluated using a multivariate regression sensitivity analysis. The impact of insecticide treated bed nets and their usage and indoor residual spraying as well as their protective efficacy on the incidence of malaria were simulated at various levels of coverage and protective effectiveness in each ecological zone to investigate the prospects of achieving goals of the malaria control strategy for 2014-2020. Results Increasing the coverage levels of both long lasting insecticide treated bed nets and indoor residual spraying activities without a corresponding increase in their recommended usage does not impact highly on averting predicted incidence of malaria. Improving upon 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 to be achieved if a substantial improvement in treated bed net usage is achieved coupled with targeted deployment of indoor residual spraying with high community acceptability and efficacy. Key words: model, malaria, interventions, long lasting insecticide bednets, indoor residual spraying


2019 ◽  
Vol 7 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Amit Kumar Shrivastava ◽  
Laxmi Shrestha ◽  
Shraddha Prakash ◽  
Roshan Kumar Mehta

Malaria control with transgenic mosquitoes will be challenging; however, recent advances suggest that it may be a possibility in the foreseeable future. Progress towards discovering refractory genes for rodent malaria and gene drive systems for Drosophila provide hope that similar advances may be made for human malaria in mosquito vector species. That said, the African malaria burden has proved exceptionally difficult to diminish by all means tried thus far; and it is unlikely that transgenic mosquitoes will provide an all-in-one solution. Transgenic mosquitoes should be considered within the context of an integrated vector management strategy which should also include insecticide-treated bed-nets, indoor residual spraying with insecticides and treatment of infected individuals with antimalarial drugs. Integrated strategies will be a necessity for any successful african malaria control program and transgenic mosquitoes should be considered as a potential ingredient in the future goal of continent-wide disease control.


2014 ◽  
Vol 7 (1) ◽  
pp. 52 ◽  
Author(s):  
Hanako Iwashita ◽  
Gabriel O Dida ◽  
George O Sonye ◽  
Toshihiko Sunahara ◽  
Kyoko Futami ◽  
...  

2022 ◽  
Vol 21 (1) ◽  
Author(s):  
Adama Gansané ◽  
Baltazar Candrinho ◽  
Aimable Mbituyumuremyi ◽  
Perpetua Uhomoibhi ◽  
Sagnon NFalé ◽  
...  

Abstract Background Vector control tools have contributed significantly to a reduction in malaria burden since 2000, primarily through insecticidal-treated bed nets (ITNs) and indoor residual spraying. In the face of increasing insecticide resistance in key malaria vector species, global progress in malaria control has stalled. Innovative tools, such as dual active ingredient (dual-AI) ITNs that are effective at killing insecticide-resistant mosquitoes have recently been introduced. However, large-scale uptake has been slow for several reasons, including higher costs and limited evidence on their incremental effectiveness and cost-effectiveness. The present report describes the design of several observational studies aimed to determine the effectiveness and cost-effectiveness of dual-AI ITNs, compared to standard pyrethroid-only ITNs, at reducing malaria transmission across a variety of transmission settings. Methods Observational pilot studies are ongoing in Burkina Faso, Mozambique, Nigeria, and Rwanda, leveraging dual-AI ITN rollouts nested within the 2019 and 2020 mass distribution campaigns in each country. Enhanced surveillance occurring in select study districts include annual cross-sectional surveys during peak transmission seasons, monthly entomological surveillance, passive case detection using routine health facility surveillance systems, and studies on human behaviour and ITN use patterns. Data will compare changes in malaria transmission and disease burden in districts receiving dual-AI ITNs to similar districts receiving standard pyrethroid-only ITNs over three years. The costs of net distribution will be calculated using the provider perspective including financial and economic costs, and a cost-effectiveness analysis will assess incremental cost-effectiveness ratios for Interceptor® G2, Royal Guard®, and piperonyl butoxide ITNs in comparison to standard pyrethroid-only ITNs, based on incidence rate ratios calculated from routine data. Conclusions Evidence of the effectiveness and cost-effectiveness of the dual-AI ITNs from these pilot studies will complement evidence from two contemporary cluster randomized control trials, one in Benin and one in Tanzania, to provide key information to malaria control programmes, policymakers, and donors to help guide decision-making and planning for local malaria control and elimination strategies. Understanding the breadth of contexts where these dual-AI ITNs are most effective and collecting robust information on factors influencing comparative effectiveness could improve uptake and availability and help maximize their impact.


2020 ◽  
Author(s):  
Julie-Anne Tangena ◽  
Chantal M.J. Hendriks ◽  
Maria Devine ◽  
Meghan Tammaro ◽  
Anna E. Trett ◽  
...  

Abstract Background: Indoor residual spraying (IRS) is a key tool for controlling and eliminating malaria by targeting vectors. To support the development of effective intervention strategies it is important to understand the impact of vector control tools on malaria incidence and on the spread of insecticide resistance. In 2006, the World Health Organization (WHO) stated that countries should report on coverage and impact of IRS, yet IRS coverage data are still sparse and unspecific. Here we estimated the subnational coverage of IRS across sub-Saharan Africa for the four main insecticide classes from 1997 to 2017. Methods: Data on IRS deployment were collated from a variety of sources, including the President’s Malaria Initiative spray reports and National Malaria Control program reports, for all 46 malaria-endemic countries in Sub-Saharan Africa from 1997 to 2017. The data were mapped to the applicable administrative divisions and the proportion of households sprayed for each of the four main insecticide classes; carbamates, organochlorines, organophosphates and pyrethroids was calculated. Results: We found that the number of countries implementing IRS increased considerably over time, although the focal nature of deployment means the number of people protected remains low. From 1997 to 2010, DDT and pyrethroids were commonly used, then partly replaced by carbamates from 2011 and by organophosphates from 2013. IRS deployment since the publication of resistance management guidelines has typically avoided overlap between pyrethroid IRS and ITN use. However, annual rotations of insecticide classes with differing modes of action are not routinely used. Conclusion: This study highlights the gaps between policy and practice, emphasizing the continuing potential of IRS to drive resistance. The data presented here can improve studies on the impact of IRS on malaria incidence and help to guide future malaria control efforts.


2019 ◽  
Author(s):  
Julie-Anne Tangena ◽  
Chantal M.J. Hendriks ◽  
Maria Devine ◽  
Meghan Tammaro ◽  
Anna E. Trett ◽  
...  

Abstract Background: Indoor residual spraying (IRS) is a key tool for controlling and eliminating malaria by targeting vectors. To support the development of effective intervention strategies it is important to understand the impact of vector control tools on malaria incidence and on the spread of insecticide resistance. In 2006, the World Health Organization (WHO) stated that countries should report on coverage and impact of IRS, yet IRS coverage data are still sparse and unspecific. Here we estimated the subnational coverage of IRS across sub-Saharan Africa for the four main insecticide classes from 1997 to 2017. Methods: Data on IRS deployment were collated from a variety of sources, including the President’s Malaria Initiative spray reports and National Malaria Control program reports, for all 46 malaria-endemic countries in Sub-Saharan Africa from 1997 to 2017. The data were mapped to the applicable administrative divisions and the proportion of households sprayed for each of the four main insecticide classes; carbamates, organochlorines, organophosphates and pyrethroids was calculated. Results: We found that the number of countries implementing IRS increased considerably over time, although the focal nature of deployment means the number of people protected remains low. From 1997 to 2010, DDT and pyrethroids were commonly used, then partly replaced by carbamates from 2011 and by organophosphates from 2013. IRS deployment since the publication of resistance management guidelines has typically avoided overlap between pyrethroid IRS and ITN use. However, annual rotations of insecticide classes with differing modes of action are not routinely used. Conclusion: This study highlights the gaps between policy and practice, emphasizing the continuing potential of IRS to drive resistance. The data presented here can improve studies on the impact of IRS on malaria incidence and help to guide future malaria control efforts.


2021 ◽  
Author(s):  
Abebe Asale ◽  
Zewdu Abro ◽  
Bayu Enchalew ◽  
Alayu Tesager ◽  
Aklilu Belay ◽  
...  

Abstract Background: Key program components of malaria control in Ethiopia include community empowerment and mobilization, vector control using long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), prompt diagnosis and treatment, and disease surveillance. However, the effectiveness of these interventions is often undermined by various challenges, including insecticide and drug resistance, the plasticity of malaria vectors feeding and biting behavior, and certain household factors that lead to misuse and poor utilization of LLINs. The primary objective of this study was to document households’ perceptions towards malaria and assess the prevalence of the disease and the constraints related to the ongoing interventions in Ethiopia (LLINs, IRS, community mobilization house screening). Method: The study was conducted in Jabi Tehnan district, Northwestern Ethiopi,a from November 2019 to March 2020. A total of 3,010 households distributed over 38 kebeles (villages) were randomly selected for socio-economic and demographic survey. Focus group discussions (FGDs) were conducted in 11 different health clusters taking into account agro-ecological differences. A total of 1,256 children under 10 years of age were screened for malaria parasites using microscopy in order to determine malaria prevalence. Furthermore, five-year malaria trend analysis was undertaken based on data obtained from the district health office to understand the disease dynamics.Result: Malaria knowledge in the area was high as all FGD participants correctly identified mosquito bites during the night as sources of malaria transmission. Delayed health seeking behavior remains a key behavioral challenge in malaria control as it took patients on average 4 days before reporting the case at the nearby health facility. On average households lost 2.53 working days per person-per malaria episode and theey spent US$ 18 per person perepisode. Out of the 1,256 randomly selected under 10 children tested for malaria parasites, 11 (0.89%) were found to be positive. Malaria disproportionately affected the adult segment of the population more, 50% of the total cases reported from households whose age was 15 and beyond. The second most affected group was the age group between 5 and 14 years followed by children under 10, with 31% and 14% burden,respectively.Conclusion: Despite the achievement of universal coverage in terms of LLINs access, utilization of vector control interventions in the area remained low.Using bed nets for unintended purposes remained a major challenge. Therefore, continued community education and communication work should be prioritised in the study area to bring about the desired behavioral changes.


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