Examining Recent Climate Changes in Ghana in the Context of Developing New Perspectives on Local Malaria Case Rates

This study investigated recent climate changes in Ghana and the relationships between climate and malaria case rates. for 2008–2022. These were analysed at three spatial scales: national; regional; and ‘climate zone’ (i.e., coastal, savannah and forest zones that are roughly horizontal zones that move south to north across Ghana). Descriptive statistics and qualitative discussion were used to identify possible relationships between the climate variability and the malaria case rates. A correlation analysis was used to provide a quantitative framing for the discussion of the results. The climate analysis identified a general warming over the period with a mid-2010s maximum temperature peak in the forest and savannah zones, also associated with changes in the annual temperature cycle. Malaria case rates increased between 2008 and 2013, decreased sharply in 2014, and then decreased steadily from 2015 to 2022 for all spatial scales. The sharp decline was broadly coincident with a change in the temperature regime that would provide a less favourable environment for the malaria vectors. This was particularly so for an increase in maximum temperatures in the savannah and coastal climate zones in the key months for malaria transmission after 2014. The correlation analysis showed statistically significant (p<0.05) relationships between malaria case rates and mean and maximum temperatures at the national scale, and malaria case rates and mean, maximum and minimum temperatures for the coastal climate zone.