Malaria Stratification and Climate in Madagascar Challenges in Fighting the Disease and Policy Recommendations

• Published in: Consilience no. 10; pp. 28 - 58
• Main Author: Smith, Rebecca R.
• Format: Journal Article
• Language: English
• Published: Columbia University 01.01.2013
• Subjects: SCHOLARLY ARTICLES
• ISSN: 1948-3074

Malaria is a treatable infectious disease that is intensely studied but still an important cause of mortality. As a vector-borne disease, malaria transmission is highly dependent on climatic conditions crucial for the development of its vector, Anopheles mosquitoes. Madagascar is a very large island with a great variety of climatic conditions. In many regions, malaria has low and epidemic transmission, for which it is particularly important to understand the relationship between climatic factors and malaria incidence in order to both better understand past epidemics and better anticipate and prepare for future epidemics. A stratification map of monthly malaria incidence by district between January 2008 and April 2012 was created using clustering analysis, which illustrated the current state of malaria, highlights high-risk and outstanding districts such as the islands of Nosy Be and Nosy Boraha, and establishes a new epidemic threshold. Correlation analysis of malaria incidence anomalies and climate anomalies was conducted for a case study district in the semi-arid part of the country, which had a malaria epidemic in March-April 2012. Although correlation results are low and sometimes negative, time series observations reveal a close relationship between malaria and climatic factors. A comparison between presumed and confirmed cases illustrates that presumed cases are an over-estimate of real malaria cases and provide inadequate risk assessment and response. Confirmed diagnosis of malaria is thus crucial for successful implementations of malaria control measures. A better understanding of the relationship between malaria and climate could lead to the creation of an early warning system, to combat the disease more efficiently.