The Eliminate Dengue Program is developing an approach to fighting mosquito-transmitted diseases by using naturally occurring bacteria that reduce the ability of mosquitoes to transmit harmful human viruses such as dengue fever.

The bacterium, called Wolbachia, is a natural bacterium that is present in several different insect species and is safe for humans, animals and the environment. However, when the bacterium is introduced to the Aedes aegypti mosquito, it stops viruses from growing inside the mosquito and from transmitting to people. Mosquitoes cause millions of deaths every year. The Aedes aegypti mosquito is responsible for the spread of several diseases such as dengue fever, chikungunya, yellow fever and Zika.

Since 2011, the Eliminate Dengue Program has been conducting trials in dengue-affected areas such as Australia, Vietnam, Indonesia, Brazil, Columbia and India. The trails include the release of Wolbachia-infected mosquitoes that breed with wild mosquitoes, establishing the bacteria in the wild mosquito population. Wolbachia can sustain itself in mosquito populations, making this method sustainable and cost-effective in the long-term. The program is targeted to cost U.S. $1 per person. This distinguishes the program from other similar initiatives like the Oxitec program.

Oxitec developed genetically modified male mosquitoes that have a gene preventing offspring from surviving to maturity. The aim is to reduce the mosquito population. This is a more expensive approach because a huge number of mosquitoes have to be released continuously.

In 2016, the Eliminate Dengue Program received additional funding to roll out the program in large areas of Brazil and Colombia to stop the spread of the Zika outbreak. The program is funded by the Wellcome Trust, the Bill and Melinda Gates Foundation, and the Brazilian, U.K. and U.S. governments. The World Health Organization also called for large-scale pilot studies of the Wolbachia mosquito-control method to establish its effectiveness in fighting mosquito-transmitted diseases in humans.

The possibility exists that this approach might provide a similar result in the Anopheles mosquitoes that spread malaria.

Helena Kamper

Photo: Flickr

Diseases in Costa RicaOne of the many struggles that accompany poverty in developing countries is the risk of disease. A greater understanding of the types of threats that face individual countries enables nonprofit and governmental organizations to better cater to their aid towards the needs of a community.

Costa Rica is best known for its beautiful beaches and mountains, which make it a tourist hot spot for much of the year. However, poverty impacts 21.7% of the population and this poverty brings a heightened risk of disease.

As a tropical country, tourists and locals alike are at risk of contracting illnesses related to insect and mosquito bites. Diseases in Costa Rica like dengue fever and chikungunya are especially of note considering their prevalence. Both are transmitted through mosquito bites and have similar symptoms including fever, headaches and joint pain.

Dengue fever, which is now present in 73 of Costa Rica’s 81 cantons, is usually an unpleasant but not fatal illness so long as it does not develop into severe dengue, which has more severe effects. Chikungunya is also typically not fatal, although the symptoms can be debilitating.

The Zika virus has recently been the subject of much study and media attention. Zika is another disease in Costa Rica that threatens the population. Like chikungunya and dengue, it is spread through mosquito bites. A June 15 report confirmed 107 cases of Zika in the country.

Costa Rica’s year is divided into two seasons, the rainy and the dry, and during the rainy season, mosquito populations increase due to the increase in still water. Costa Rica is taking the risk of disease seriously and has begun several important steps in the prevention of these illnesses.

Their efforts include fumigation campaigns across the country as well as attempts to rid communities of objects that collect still water and create additional breeding grounds for disease-carrying mosquitos. Another disease-fighting strategy rests in Spinosad, a product of bacterial fermentation.

This chemical is non-toxic to humans and yet has a deadly effect on insect larvae making it a perfect solution to the problem of mosquito breeding grounds. The Spinosad pills can be used in swimming pools, ponds and fountains.

While mosquitos are a significant cause of diseases in Costa Rica, there are many ways to prevent these types of illness. Costa Rica shows impressive self-sufficiency in their fight to end Zika, dengue and chikungunya.

Jordan Little
Photo: Flickr

Throughout the course of history, there has never been a deadlier disease than malaria. Every year, an average of 300 million people are diagnosed with the disease, and on average, around 500,000 of those patients die. Infected mosquitos carry the disease, transmitting it to humans through a bite. This phenomenon—the origin of this disease—seems to stretch back to the earliest humans.

In light of the continuing deaths due to malaria, there is a cure. In fact, Jesuit missionaries in Peru discovered the cure to malaria over 400 years ago, in the early 1600s. Within the cinchona tree existed a substance called quinine, a treatment that is still used effectively in malaria cases today.

Since 1897, we have known how to prevent the disease. At that time, the British army surgeon Ronald Ross posited that mosquitos were the agents of the disease, a view divergent from previous notions of “bad air.” Simply, to protect against the disease, individuals need to protect themselves from mosquitos, particularly in tropical populations where the disease is rampant.

Yet, despite the quantity and quality of information regarding malaria, the disease continues to persist with vehemence today. In her TED Talk, Sonia Shah conjectured that there are three reasons for the failure to eradicate malaria: the complex science of the parasite that causes the disease, poverty and the challenges of providing adequate medical care in the developing world, and lastly, the lack of a cultural awareness in regards to the disease, much of which exists in the countries most affected by the disease.

Malaria poses a scientific challenge because of the complex parasite that causes the disease, one that lives half its life within a cold-blood mosquito and the other half within a warm-blooded human. Its resilience to attack—to the defenses of the human body—is multifaceted and unknowable. The parasite evades attacks and is constantly undergoing change. Thus, it is quite difficult to create a drug that works in all of the seemingly infinite stages of the parasite’s life cycle.

Malaria also creates an economic challenge for affected communities. The disease occurs most in countries with little resources. In order to protect from mosquitos, individuals need access to proper clothing and housing, resources that struggling communities often lack. Furthermore, beyond an inability to protect from the disease, poor communities often do not have adequate medical care (i.e. access to quinine) after contracting the disease.

Lastly, in these same countries where the disease takes many lives, there is often a failure to appropriately recognize malaria and the grave dangers it poses. Malaria has become a fairly routine part of existence, as its victims are numerous. Therefore, many have become desensitized to its seriousness and take minimal measures to prevent against mosquitos.

There is not an easy solution to eradicate malaria. However, the unnecessary loss of life incited from the disease beckons an international attempt. Governments need to improve basic conditions of life, and in doing so, educate their populations about the deleterious effects of the disease.

By eliminating malaria, our generation would forever change the course of human history, providing a certain medical security to those who need it most.

– Anna Purcell

Sources: National Geographic,, TED
Photo: NANDA