Malaria has always been one of the major health problems for over 90 countries despite being curable. Hundreds of thousands of people die from malaria every year, and about half of the world’s population is at risk of this disease. Many people, including experts, believe that forests are the ideal habitat for mosquitoes and that cutting down trees is the best solution to prevent malaria. But, is that really the right move?
The Link Between Forest Cover and Malaria Incidence
Experts have long confirmed that forest ecosystems are one of the main contributing factors to the widespread transmission of malaria. This has been clearly shown in the latest figures from the World Malaria Report 2021, as the overall number of malaria deaths in regions with enclosed forests is on the rise, again.
Researchers have estimated that the number of global malaria deaths in 2020 is 627,000, 12% higher than the previous year. Of these deaths, 96% occurred in densely forested countries such as the Democratic Republic of the Congo, Angola, Nigeria.
To explain this, you need to understand that the larvae of malaria-carrying mosquitoes need low-acid puddles to develop. In nature, changes in forest cover partly determine the quality of mosquito breeding sites. Each factor such as temperature, rainfall, humidity, flora and fauna of a forest ecosystem has a direct impact on the reproduction and distribution of mosquitoes.
According to a report conducted by the University of California San Francisco, the incidence of malaria fluctuates ‘up and down’ as forest cover changes. Specifically, when an area’s forest cover begins to decrease and population density increases, malaria spreads rapidly and develops into epidemics within the first few years. This sudden spread is the result of habitat interference between mosquitoes and humans combined with the specific environmental conditions of this area.
However, if this decline in forest cover continues for a long time and urbanization takes place, the opposite will happen. Once the landscape changes (in a direction of urbanization), there will be fewer and fewer ideal breeding sites available for mosquitoes. Over time, the malaria incidence will gradually decrease in proportion to the emergence of human settlements. The area would then reach a specific low level of malaria transmission and sustain it depending on environmental conditions.
If that’s the case, tackling malaria sounds like one of the simplest tasks of the health profession, doesn’t it? Just cut down the tree, and the problem is solved. Yes, that’s how it works, in theory. But in practice, the story is much more complicated.
Cutting Trees – A Double-Edged Sword
If our goal is limited to reducing malaria incidence, then there’s not much to argue about. However, deforestation is actually not the absolute solution as you think.
Let’s start with the most basic question: Can deforestation prevent all the mosquitoes that transmit malaria? Unfortunately, it cannot, and this is one of the limitations of this idea. Malaria parasite species such as Plasmodium falciparum or Plasmodium vivax can be found in over 70 different mosquito species. Some mosquito species prefer habitats different from others, therefore cutting down trees may prevent malaria in areas like Asia or South America, but actually make things worse in other areas.
As we dig deeper, it’s also very clear that deforestation can only solve the surface of the problem. It’s true that to some extent, the decline of primary forests indeed leads to the decline of mosquitoes over a period of time. Nevertheless, cutting trees will also leave “scars” for the forests, and the forest’s recovery (or secondary regrowth) will significantly facilitate mosquito breeding. With a faster growth rate and longer survival time, there can be more mosquitoes than initially. The biting rates will therefore increase, resulting in the possibility of malaria outbreaks for the surrounding communities.
Most importantly, we should ask ourselves whether the data we have on the relationship between malaria incidence and urbanization is really promising. While in theory, urbanization will reduce the ideal habitat for mosquitoes in the wild, in reality, some species of mosquitoes unknowingly benefit from it, such as Anopheles darlingi, Aedes aegypti, or Aedes albopictus. These species grow vigorously in urban areas, causing not only malaria, but also other dangerous diseases such as dengue, Zika, and chikungunya.
Long story short, despite the fact that there are examples of deforestation reducing malaria incidence, this in fact does more harm than good. Not only can’t deforestation completely solve global malaria, but it also causes more negative ecological impacts in the long run.
The Forest Isn’t The Problem. It’s Us
You obviously don’t want your arm to disappear just because you accidentally injure your finger, right? Instead, you give first-aid to the wound and let it heal.
Similarly, we don’t destroy forests just because malaria-transmitting mosquitoes live there. The existence of forest ecology is not what holds us back from preventing malaria, it’s the way we deal with it. And therefore, reinforcing the active role of humans in malaria prevention should be a top priority.
It’s necessary to educate communities about the dangers of malaria and how to control it. There are a lot of remote and backward communities that don’t have access to vital health information, thereby unintentionally creating favorable conditions for the spread of malaria. If we want to eradicate malaria, or at least keep it under control, we need cooperation from these communities.
The involvement of government stakeholders, NGOs, and health providers is also very important in raising awareness about malaria and improving malaria control. The quality and availability of health facilities as well as communication infrastructure need to be ensured for easier access to healthcare services.
We need to learn from statistics, research, and real-world examples to understand malaria outbreak trends in different landscapes and forest cover levels. That way, we will have more information to come up with intervention plans and conservation initiatives.
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