Previous studies have shown that deforestation and disturbance of tropical forests lead to increased transmission of malaria. The destruction of the jungle generates new environmental and ecological conditions in which mosquitoes thrive better. A new study links global demand for goods with deforestation and the risk of malaria.
The work is the first to directly relate global consumption to the increase in malaria cases in some regions. It is estimated that in these regions where cases are increasing, a fifth of deforestation is driven by international trade. Coffee, wood, soy, cocoa, palm oil, tobacco, calf meat and cotton are the main products demanded globally that stimulate deforestation.
Despite the fact that globally it seems that the number of cases has been decreasing since 2000, its increase is worrying in some regions. In 2018 there were 228 million cases worldwide and 405,000 deaths, of which seven out of ten were children under the age of five.
7 out of 10 deaths from malaria worldwide are children under the age of 5
90% of malaria cases occur in three tropical forest regions: the Congo Basin, the Amazon Basin, and the Greater Mekong Basin in Asia (Fig. 1). In these regions, the main mosquitoes that transmit malaria are: Anopheles gambiae, Anopheles funestus, Anopheles dirus, Anopheles minimus and Nyssorhynchus darlingi. All of them associated with deforestation, land use changes and human migration.
Demand for basic products from rich countries increases the risk of malaria in other countries
The link between deforestation and the increase in malaria cases has been demonstrated in Indonesia, Nigeria and the Amazon. A work carried out in 795 municipalities of the Amazon during 13 years, concluded that clearing the forests by 10% leads to a 3.3% increase in malaria cases.
The new study reconnects the incidence of malaria with deforestation, but also establish a relationship between deforestation with the consumption of products globally. For this they used a detailed international database with the entry and exit of products by country. With it they were able to establish the global network of supplies, from the deforested area to produce, to the countries that consume the product.
Countries with an increased risk of malaria associated with deforestation are Nigeria, Tanzania, Cameroon, Uganda, the Democratic Republic of the Congo, India, Zambia, Burma, the Central African Republic and Burundi. Part of the increased risk in these areas is due to the demand for products from the richest countries, with Germany, the United States, Japan, China, the United Kingdom, France, Italy, Spain, the Netherlands and Belgium leading the list. The demand for wood, cocoa, tobacco and cotton are among the main causes of deforestation.
Populations most exposed to malaria are those that benefit the least economically from forest exploitation
The work is new evidence of the close relationship between the health of human populations and the environment, and shows, with numbers, that the problem is global. The authors hope that their results can be used to mitigate malaria cases, either by regulating supply chains or by labeling and certifying products.
Communities that are facing a greater transformation of their landscape to meet international demands are at the same time the most at risk as they are more exposed to mosquitoes that transmit malaria. In addition, the populations most exposed to the disease are those that benefit least from the exploitation of forests.
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