eradicated diseases — World News, Travel and Social Action

The World Mosquito Program has successfully prevented outbreaks of Dengue and Zika using a unique and effective method.

Mosquito. Gerald Yuvallos. CC BY-ND 2.0.

The World Mosquito Program (WMP) is an Australian-based nonprofit organization working to eradicate several diseases carried and spread by mosquitoes, specifically Dengue and Zika. About 50 million people per year contract Dengue, while there are roughly between 100,000 and 500,000 cases of Zika per year worldwide. Both Dengue and Zika are mosquito-born illnesses, but they have very different effects. Dengue has a wide range of symptoms, and in the worst cases, the disease can end in hospitalization and death. Dengue is primarily a problem in Asia, with 70% of global cases occurring in the continent, though cases have been reported in 129 countries total. There is a vaccine for Dengue, but regardless, Dengue is still a leading cause of death in certain places in Asia and South America.

Zika, on the other hand, rarely causes death, but it is known for causing birth defects if caught by pregnant women. In addition to issues for fetuses, if caught by teens or adults, Zika can cause Guillain-Barré syndrome, in which the body’s immune system attacks its nervous system, leading to nerve damage of differing severity. There is no vaccine for Zika, and thus, the World Mosquito Program’s work is necessary in this area.

The primary strategy for WMP is breeding mosquitoes that carry a specific bacteria—Wolbachia—which prevents the mosquitoes from spreading these diseases. Once WMP has bred the Wolbachia mosquitoes, they work with governments to determine a plan to disperse the mosquitoes. The goal is that eventually, the non-Wolbachia carrying mosquitoes will die out by natural evolutionary processes. This method has produced positive results multiple times. While it takes some time to see results, the Wolbachia method has been praised for the fact that it uses a naturally occurring bacteria. Thus, it has a minimal impact on the ecosystem. Though there are treatments for Zika and Dengue, there are very few prevention methods other than the Dengue vaccine, which makes the Wolbachia method unique in its field. While Dengue and Zika are both serious and dire diseases, the most well-known mosquito-borne disease is malaria. Zika and Dengue are spread by the same type of mosquito, while malaria is transmitted by a different type, which is why the Wolbachia method cannot be used for malaria prevention.

I had the opportunity to interview Christie Hubbard, the Director of Philanthropic Partnerships for WMP. She explained in a bit more detail how the Wolbachia method is carried out. Hubbard explained the function of the bacteria, and the surprising simplicity of the process, saying: “This bacteria, Wolbachia, renders the female unable to transmit disease… Because it naturally occurs we don’t have to modify it, and we literally breed mosquitoes.” These “Wolbachia mosquitoes” are then released (with governmental permission) into areas suffering from Dengue outbreaks, under the assumption that through natural reproduction eventually the disease carrying mosquitoes will die out.

In terms of the tangible impact that WMP has had, Hubbard gave a few examples: “We did a gold standard trial in Indonesia… it resulted in a 77% reduction in Dengue and an 80% reduction in hospitalizations, which is really big… We’ve also seen success in Australia, which is where we’re founded and there’s a lot of Dengue. That’s where the program really first started and where we really… we never say eradicate, but we eliminated Dengue.” The near elimination of Dengue in two countries is an extreme feat, and WMP’s website also lists some other countries in which their method has seen success, such as Mexico and Sri Lanka. In both of these countries, there have not been any Dengue outbreaks in the areas where the Wolbachia mosquitoes were released in the years following their release.

Wolbachia method is launched by Brazil Ministry of Health. Ministério da Saúde. CC BY-NC-SA 2.0.

An obvious complication to WMP’s approach is that they are an Australian-based organization going into other countries. Hubbard addressed this, saying, “Our intervention is really geared towards governments and countries, so that’s who we work with and not so much private individuals. So yeah, we just go in, we release the mosquitoes, but it’s not as simple as that. It takes a long time, you’ve got to get the eggs to the country—we’ve got an insectary in every country—and of course there’s a big piece with community engagement, because you don’t just walk into another country and say, ‘hi, we’re bringing in more mosquitoes’... and working very closely with the ministries of health, and government officials.” WMP works in conjunction with the governments and the health officials of the countries which they work in, trying to eliminate any disruption or possible harm to the local communities. WMP’s website also publicly lists the percentage of the population of each place it works in that supports their intervention.

Get Involved

In terms of getting involved with WMP, there are few volunteer opportunities outside of the places where they are currently working. However, their website does have a page listing the places where they have or are currently working. Another, more accessible way to get involved that doesn’t require money is by simply raising awareness for WMP, and for the issue of mosquito-borne illness in general. Following and promoting their instagram, or even just educating yourself further on the issue through reading articles and sharing them with the people you know is a way to get involved, as this issue is not a high profile one.

Guinea worm disease is on track to be the second disease eradicated from the world, but there is still work left to be done.

Health workers explain how to use water filters. uncultured. CC BY-NC-SA 2.0.

Guinea worm disease, also known as dracunculiasis, is an infection caused by the parasite Dracunculus medinensis. Larvae of the parasite are found in water sources in sub-Saharan Africa, and they can contaminate drinking water. Once consumed, the parasite stays inside the infected individual for up to a year as it grows into a worm until it removes itself from the human host, leaving through the skin.

When the worm emerges from the human, it causes a painful skin blister, possibly resulting in a fever or secondary infection. There have been cases of people becoming crippled by a Guinea worm infection. The worm needs to be pulled out from the human body, several centimeters per day, by winding it around some gauze or a small stick.

Health worker treating an infant with Guinea worm disease. Centers for Disease Control and Prevention. CC0 1.0.

In 1986, the Carter Center, the foundation of former president Jimmy Carter, began to lead the global campaign to eradicate Guinea worm disease. When the campaign started, there were 3.5 million cases of the disease in that one year. In 2021, there were only 15 reported human cases worldwide. This dramatic reduction of cases was the result of several carefully planned interventions.

The program to eradicate Guinea worm disease is community-based and relies on extensive villager volunteers. This approach respects the dignity of the people affected and builds trust between the community members and health professionals. The Carter Center aims to work with ministries of health to provide comprehensive health education and maintain political will.

Surveillance and supervision is instrumental in containing the spread of the disease. In the Gambella region of Ethiopia, village volunteers try to ascertain possible cases among their peers every week. When a suspected case is found, an investigation occurs. A lab test is needed to confirm a case of Guinea worm disease. The infected person’s demographics and symptoms are also tracked, as is information about the water sources that the person used. There are also community meetings to inform them of those infected. This is why gaining the trust of communities is so important. Community participation, especially in light of the stigma associated with the disease, is vital in containing the disease, and it all depends on trust.

As Guinea worm disease is waterborne and is contracted by drinking water contaminated with the larvae, interventions that involve treating water before it is drunk is essential. The Carter Center has distributed pipe filters to affected populations and taught them how to use them to prevent the new cases of the disease. In some places, the pesticide abate is applied to water sources to kill the larvae that cause Guinea worm disease. These interventions have drastically reduced the prevalence of Guinea worm disease, but the fight is not over yet.

While great progress has been made in eliminating Guinea worm disease in much of the world, some challenges have arisen. Civil unrest and political instability in some places where Guinea worm disease is prevalent have prevented efforts to combat the disease. Ethiopia, which had some of the highest rates of the disease, is mired in a civil war, making it hard to reach everyone affected by Guinea worm disease. Recently, cases of Guinea worm disease have also started to appear in animals. Today, most cases of Guinea worm disease occur in other animals, not humans. Complete eradication of Guinea worm disease cannot be completed until the world is free of the disease in both humans and animals.

To Get Involved

While the Carter Center is the leader in the drive to eradicate Guinea worm disease, there are also other partners and stakeholders in the campaign who can be supported through donations and volunteering. Among them include the ministries of health of affected countries, UNICEF, WHO, Ethiopian Public Health Institute and the UNHCR.

Bryan is currently a History and Global Affairs major at the University of Notre Dame. He aims to apply the notion of Integral Human Development as a framework for analyzing global issues. He enjoys hiking and visiting national parks.