Researchers have taken many approaches to combatting malaria over the past century, but all of these approaches have presented significant obstacles.
However, the research must continue: malaria is an urgent public health concern. In 2017, the World Health Organization reported 219 million cases of malaria, affecting 87 countries. Of those cases, 435,000 were fatal. And the vast majority of those who died were children under the age of five.
Since most malaria cases arise from the parasite P. falciparum, which enters the human body through a mosquito bite, much research has gone into how to eradicate the mosquitos themselves.
The two main approaches to eliminating the mosquitoes are (1) to use insecticide in infested areas and (2) to disrupt the mosquitos’ reproductive cycle.
Though it can be temporarily helpful to use insecticide in exceptionally infested areas, the chemicals also have unhealthy effects on the local flora, fauna, and humans. And eventually, insecticide-resistant mosquito populations develop. Some of these populations have cropped up in Central and South America, Africa, and south Asia.
While studying how to curtail mosquito reproduction, scientists have found that the offspring of male mosquitos genetically modified with a “sterile” gene will die before developing to maturity, and therefore never reproduce.
By releasing a constant supply of these modified male mosquitos into the wild, the hypothesis is that the mosquito population will decrease significantly.
However, the long-term consequences of such an approach are unknown. What unintended outcomes might result? What other ecosystems might be impacted? How might it inadvertently harm humans? Until these questions are answered, it would be irresponsible to deploy this tactic on a mass scale.
So, the other target is the parasite itself.
When P. falciparum enters the human body, it first multiplies in the liver cells and then the red blood cells—destroying them. This is what causes malaria.
Then the parasite gets sucked into a mosquito’s body when the mosquito feeds on an infected human. Once inside the mosquito, the parasite reproduces and awaits another trip into the human body.
P. falciparum is a complex organism, which makes it very difficult to fight; and exposure to the parasite doesn’t confer lifelong immunity.
A recent vaccine against P. falciparum —RTS,S—initiates the production of antibodies that resist the parasite. However, it is not effective enough for the World Health Organization to recommend for infants. Further, it hasn’t proved to be effective against severe malaria.
Another developing vaccine, PfSPZ, is made from the irradiated parasite extracted from the mosquito’s salivary glands and then injected into humans. The efficacy of this vaccine is still being investigated.
At the time of this writing, the Center for Disease Control has licensed no malaria vaccines for the market.
Pursuing its mission to cure malaria, the Sweet William Foundation is thinking outside the box. Our approaches include (1) looking at how diet affects the frequency and severity of malarial infections and (2) learning how to stop the parasite from recognizing food sources in the human body, starving it to death before it can cause damage.