2. Climate variations, urban solid waste management and possible implications for Anopheles mosquito breeding in selected cities of coastal Ghana

Abstract

Climate-induced environmental changes are known to support prevalence of disease vectors and pathogens. Temperature, rainfall, humidity and other environmental variables are considered potential drivers of population dynamics of many vectors and pathogens of health importance, especially in the tropics. This study was conducted to understand the variability and trends in atmospheric temperature and rainfall, as well as how these factors may affect the breeding of Anopheles mosquitoes in the urban areas in the future. Accra and Sekondi-Takoradi Metropolitan Areas (AMA and STMA) of coastal Ghana were the selected study sites. Anopheles larvae were sampled from pre-identified breeding sites in the two cities. Atmospheric temperature and rainfall as measured by synoptic weather stations were collected for the two cities. Again, thirty years climate data on daily minimum and maximum temperature and rainfall for both cities from Ghana Meteorological Agency (Gmet) were employed in the study. Using a statistical downscaling approach, the average of the ENSEMBLE GCM outputs AR4-BCM2 and AR4-CNCM3 scenario A1B were downscaled to match with rainfall and temperature observations of AMA and STMA. Results showed that improper solid waste management in the cities promote the breeding of Anopheles mosquitoes. Climate data analysis showed that past rainfall in the cities were below average; in the future, however, up to year 2050, the cities may experience high rainfalls and temperatures above the average. Notably, significant increases may be observed in the total monthly rainfalls as well as a slight shift of rainfall pattern in the minor season. This implies that Anopheles mosquito breeding may no longer be seasonal in the cities but perennial and malaria transmission may also follow the same trend. Poor urban dwellers who find it difficult to adopt preventative measures will be prone to persistent malaria transmission. This will increase malaria transmission among vulnerable populations in urban areas. This study recommends that city authorities must intentionally work at lowering the surface temperatures in the cities through the growing of trees and also to regularly desilt drains in order to reduce the breeding of Anopheles mosquitoes.