Assessing the effectiveness of malaria interventions at the regional level in Ghana using a mathematical modelling Application

Abstract Background Supporting malaria control with interfaced applications of mathematical models that enables investigating effectiveness of various interventions as well as their cost implications could be supportive. Through their usage for planning, these applications may improve the chances of attaining various set targets such as those of the National Strategic Plan policy for malaria control 2014-2020 in Ghana. This approach could boost the fight against malaria and accelerate the achievement of pre-elimination in a shorter time Methods A single patch malaria model was adapted and used for simulating the incidence of malaria in all ten administrative regions of Ghana. The model and it’s application were developed by the Modelling and Simulation Hub Africa (MASHA) and calibrated using aggregated district level data captured on the District Health Information Management System (DHIMS) in Ghana from 2012 to 2018. Average monthly rainfall at the zonal level was fitted to trigonometric functions for each zone using least squares approach. These zonal functions were then used as forcing functions for all the regions within their respective zones. Various intervention packages such as increasing insecticide treated bednets coverage and usage, increasing indoor residual spraying coverage and effectiveness, improving the health system effectiveness, increasing seasonal malaria chemotherapy coverage among children were investigated to observe the their impact on averting malaria incidence by 2030. Results Increased usage of bednets but not only coverage levels, predicted to lead to significant proportion of cases of malaria averted in all regions. Whereas, improvements in the health systems by way of health seeking, testing and treatment predicted to lead to a decline in incidence largely in all regions, it allows more incidence cases to be detected in the Upper East, Upper West and Brong-Ahafo regions. With an increased coverage of SMC, to include higher age groups, a modest proportion of cases could be averted in populations of the Guinea savannah. Indoor residual spraying could also benefit populations of the Transitional forest and Coastal savannah as its impact is significant in averting incidence. Conclusions Having achieved relatively high bednet coverage, enhancing bednet usage to at least a doubling of the current usage levels and deployed in combination with various interventions in all the regions predicted a significant reductions, ranging from 44.0% - 97.0%, in malaria incidence. Regions of the Transitional forest and Coastal savannah could also benefit from a drastic decline in incidence following a gradual introduction of indoor residual spraying on a sustained basis. A much improved health system in all regions could potentially cater for all incident cases that were not prevented through vector control activities. The modelling application has shown to be beneficial given the opportunity to be able to study in relatively more detail, the regional differences in malaria morbidity in Ghana.