Effect of Deforestation and Land Use Changes on Mosquito Productivity and Development in Western Kenya Highlands: Implication for Malaria Risk.

Eliningaya J Kweka,Epiphania E Kimaro,Stephen Munga

doi:10.3389/fpubh.2016.00238

Abstract

African highlands were known to be free of malaria for the past 50 years. However, the ever growing human population in the highlands of Africa has led to the deforestation and land coverage changes to create space for more land for cultivation, grazing, and house construction materials needs. This has lead to the creation of suitable breeding habitats, which are in open places. Decrease of canopy and forest cover has led to increased temperature both in outdoors and indoors in deforested areas. This increased temperature has resulted in the shortening of developmental stages of aquatic stages of mosquitoes and sporogony development in adult mosquitoes. Assessment of the effects of deforestation and land coverage changes (decrease), which leads to temperature changes and subsequently increases survivorship of adults and sporogony development in adult mosquitoes' body was gathered from previous data collected from 2003 to 2012 using different analysis techniques. Habitats productivity, species dynamics and abundance, mosquitoes feeding rates, and sporogony development are presented in relation to temperature changes. The effects of temperature rise due to land cover changes in highlands of western Kenya on larval developmental rates, adult sporogony developments, and malaria risk in human population were derived. Vector species dynamics and abundance in relation to land use changes have been found to change with time. This study found that, land cover changes is a key driver for the temperature rise in African highlands and increases the rate of malaria vectors Anopheles gambiae ssp., An. Funestus, and An. arabiensis colonizing the highlands. It has also significantly enhanced sporogony development rate and adult vector survival and therefore the risk of malaria transmission in the highlands.

Highlights

In the recent past, the African highland sites were known to be malaria-free zones
This study has demonstrated dominance of An. gambiae s.l. over other species for 85 weeks of the larval habitats follow-up in both land use and habitat types
The current study has demonstrated the effect of land cover on larval habitat productivity and survivorship at a highland area in western Kenya

Summary

Introduction

The African highland sites were known to be malaria-free zones. Only sporadic malaria outbreaks were recorded earlier between 1920 and 1950 in the East African highlands [1, 2]. In western Kenya highlands, forests have been cleared to create farmlands, pasture, and homesteads, while swamps have been cultivated to increase agricultural production These environmental degradation processes, which mainly occur as a result of anthropogenic activities, change the ecological balance and context providing suitable habitats for disease vectors to breed, develop, and transmit disease. The ever growing human population in the highlands of Africa has led to the deforestation and land coverage changes to create space for more land for cultivation, grazing, and house construction materials needs. This has lead to the creation of suitable breeding habitats, which are in open places. This increased temperature has resulted in the shortening of developmental stages of aquatic stages of mosquitoes and sporogony development in adult mosquitoes

Methods

Results

Discussion

Conclusion