The Spatio-Temporal Impact of Climate Change on Malaria Transmission, Control and Elimination in Southern Africa

: The Case of Zambia

Abstract

At present malaria causes over 400,000 deaths per annum and an excess of 200 million cases worldwide, with most cases occurring in African countries. In Zambia, as in many other endemic countries, some regions have high malaria prevalence that is highly influenced by climatic and environmental factors. This influence can potentially interfere with intervention program effectiveness and alter distribution and incidence patterns, resulting in poorer health outcomes and higher incidence rates in some countries with associated additional financial costs estimated to be up to US$2.4 billion yearly by 2030. This study aimed to investigate the spatial and temporal impacts of climate change on malaria transmission, control and elimination efforts in Zambia from 2000-2016. The study modelled Zambian malaria incidence data against a range of socio-environmental datasets, to investigate near-term climatic change and evaluate impacts on control interventions. The results highlighted the importance of understanding evident within-country differences in malaria spatial patterns and how this information can be better used to improve and target implementation of expensive control programmes where they are most needed. It was established that climate change negatively impacts malaria control efforts, and if ignored, has the potential to suppress ongoing malaria elimination efforts significantly. The results indicate that near-term climate change is likely to increase malaria incidence, particularly in areas where malaria incidence trends have been either increasing or decreasing. While malaria incidence rates are highest in young children age <5 and have been decreasing in the last 10 years, significant increases in malaria were identified in those aged 5 years and older. These could have serious future economic and social impacts. The study also showed seasonally sensitive diurnal temperature range (DTR), often neglected in climate change research, as a significant environmental variable affecting malaria incidences, with a strong seasonal influence. In addition to a general north-south pattern of spatial variation in incidence rates, some high incidence hotspots for malaria were identified, particularly along border areas with neighbouring high endemic countries. The results suggest the urgent need to forge bilateral cross-border malaria initiatives in the fight against malaria with neighbouring high endemic countries. A key recommendation from the thesis is for an adaptive-scaling approach to the implementation of both malaria monitoring and intervention programmes for control and elimination strategies.

Date of Award	Jul 2020
Original language	English
Sponsors	The Commonwealth Scholarship Commission
Supervisor	Adrian Moore (Supervisor), Sally Cook (Supervisor) & Yaxin Bi (Supervisor)