According to the World Health Organization (WHO), viruses spread by mosquitos kill an estimated 700,000 people a year. Out of the mosquito-spread viruses, dengue, Zika and chikungunya are considered some of the most dangerous due to the quickness and severity of their infection rates. Although disease prevention has proven to be expensive for developed and developing countries alike, Wolbachia is increasingly being explored as a new tool in the fight against mosquitos.
Wolbachia, a word most of us are not familiar with, is, in fact, a safe and naturally developed bacteria that is present in 60 percent of all insect species. However, Wolbachia is not found in the Aedes aegypti species of mosquito that are the primary transmitters of dengue, Zika and chikungunya to humans.
The bacteria prevent the spread and outbreak of viruses by acting as a natural competitor in the mosquito. First, Wolbachia boosts the immune systems of Aedes aegypti mosquitos and prevents viruses from being able to spread to and survive on the species. Secondly, Wolbachia effectively consumes molecules, such as cholesterol, which viruses need in order to thrive.
In other words, viruses are being prevented from spreading viruses mosquito-to-mosquito and mosquito-to-human. This bacteria has proven to be very efficient in reducing the threat of mosquitos.
The World Mosquito Program
The leader in utilizing Wolbachia against mosquito-spread viruses is the nonprofit World Mosquito Program (WMP). The WMP conducts research, works with communities, governments and other nonprofit organizations and implements the release and studying of Wolbachia bacteria in mosquito populations.
Currently, the WMP operates in 12 at-risk countries with a primary interest in economically disenfranchised countries and populations. These 12 countries are Vietnam, India, Sri Lanka, Indonesia, Australia, Kiribati, Vanuatu, New Caledonia, Fiji, Mexico, Colombia and Brazil. According to the U.N. Development Programme, viruses such as Zika pose tremendous economic, health care and tourism risks to countries while simultaneously hurting people in poverty who have a reduced access to health and sanitation facilities.
Support in Reducing the Threat of Mosquitos
Throughout the countries mentioned above, the WMP has gained countless support from communities, governments and nonprofits. For instance, the Australian and New Zealand have worked closely together to fund the WMP projects in Fiji and Vanuatu. In Fiji, these additional funds have allowed the WMP to reach an additional 120,000 people.
A well-known U.S. nonprofit organization, the Bill and Melinda Gates Foundation, has become an important funder for the WMP projects and for developing new technology for research and operations. The U.S. Agency for International Development has proven to be a lead contributor to financing projects against Zika in Colombia, where 25 million people are at-risk to an outbreak.
Other important actors that participate in WMP programs include the U.K. and Brazilian governments, the Candeo Fund, the Wellcome Trust, local rotary clubs and many health ministries and local governments.
Results are just as vital as gaining support for reducing mosquito-spread viruses. While the WMP has not moved onto phase two by analyzing the reduction of viruses, they have collected data for the spread and sustainability of Wolbachia in mosquito populations.
Tri Nguyen Island, Vietnam, Queensland and Australia have witnessed the spread of Wolbachia to nearly 100 percent of their mosquito populations since the projects began.
Doubts about Wolbachia
While initial results look promising, there have been reasonable doubts expressed about using Wolbachia bacteria. Some studies suggest that Wolbachia enhances the ability of West Nile Virus to spread in the Culex tarsalis mosquito and that temperatures play a large role in the effectiveness of the bacteria. However, the WMP has discounted the temperature claim by referencing the success rates in Vietnam, Australia, Brazil and Colombia in reducing the threat of mosquitos.
Despite the possible consequences, the WMP has maintained its belief in the ability of Wolbachia and continuing to research and study the results as much as possible. Looking at their sponsors, the WMP has become a popular potential solution to actors affected by and interested in mosquito-spread viruses.
These sponsors are not the only ones, however, as the WHO has labeled Wolbachia as a viable tool going forward. In 2016, the organization recommended that Wolbachia should be tested in pilot programs in order to gain more beneficial evidence. In fact, their laboratory tests confirmed that Zika, Dengue and Chikungunya were reduced in mosquitos introduced to Wolbachia.
The WMP’s program is meant to be a long-term, low-cost and sustainable virus reduction solution, not the one to be used just in emergency circumstances. With that being said, Wolbachia should be part of a greater toolbox in reducing mosquito-spread viruses through prevention, containment and reduction.
To reiterate, the entomology coordinator for the WMP operations in Brazil stated to the U.N. that Wolbachia bacteria is not a silver bullet, but it is really promising.
– Tanner Helem