What would it mean to eradicate the mosquito? – TechCrunch

From "blitzscaling" to "move fast and innovative, "start-ups focus on growth and speed – this is changing on a large scale. I see this focus in the startups of my accelerators and the students of my courses at the USC. However, we rarely talk about what happens when that growth, speed and change affect other parts of an existing system. This is considered to be outside our concerns.

The commercial and social effects of change may be more common, but today I would like to talk about the health effects, both positive and negative, that can come from significant and rapid change.

One of the preventable diseases that still kills a large number of people is malaria, transmitted by mosquitoes. Humans have treated this disease for centuries. Even in the United States, malaria was eradicated only in 1951.

If malaria kills, the number of annual deaths has greatly decreased. While in 2015, there were 212 million cases of malaria and 429,000 deaths, just 20 years ago, their numbers were much higher, with an estimated 300 to 500 million cases and 3 millions of deaths.

The decrease in deaths from malaria is multifactorial but comes mainly from a few initiatives: the distribution of insecticide-treated mosquito nets, better medicines that can be taken temporarily and the reduction of mosquito breeding sites such as stagnant water.

Bed nets and medications have reduced human suffering and the number of deaths from malaria, but it seems clear that we need to move on to the next step and try to eliminate malaria altogether. However, as there is still no effective vaccine against mosquito-borne parasite parasites, malaria elimination plans often call for the eradication of mosquitoes, or more precisely species of Anopheles gambiae that carry human strains. malaria.

This approach – the eradication of a targeted species that is the vector of the disease – is relatively rare. Some who question this approach warn against the unintended consequences of such an effort. They are right to want to understand the most important effects. The next questions are: how are we going to make that decision? And are we cruel not to eradicate mosquitoes if we can? Would this decision be delayed if malaria remained a problem in the United States? Do we even have the power to attempt an intentional eradication of species? How can we even make these decisions?

The comparison which this last question usually establishes is that of the eradication of smallpox. When, in 1980, it was determined that the disease was eliminated from human populations, it was the triumph of decades of vaccination and rapid response to epidemics.

SAO PAULO, BRAZIL – MARCH 04: Aedes aegypti mosquito, the species transmitting the dengue virus, chikungunya fever and zika is photographed on March 4, 2016 in Sao Paulo, Brazil. (Photo by William Volcov / Brazil Photo Press / LatinContent / Getty Images) c

There are several ways to attempt the eradication of Anopheles gambiae. As mosquitoes have gained resistance to many classes of insecticides and as plasmodium parasites also have resistance to antimalarial drugs, other methods are used.

One of the methods is to release a large number of sterilized men. This process was successfully applied to the worm in the United States in the 1950s. A similar approach could also be adopted with mosquitoes. This is a temporary solution, as even a small number of unsterilized mosquitoes that manage to reproduce can rebuild a population. In the framework of the Debug project, this technique is currently being tested on mosquitoes of the genus Aedes aegypti carrying zika, yellow fever and dengue fever.

There is also a program using the CRISPR gene editing to introduce infertility genes into the mosquito population.

The approach taken against smallpox – too much to vaccinate the disease – does not work against malaria, at least not yet. Current versions of the vaccine require four separate inoculations spread over several weeks. Even in this case, the efficiency rate is around 39%. (And vaccines are a technique that would allow mosquitoes to continue to bite humans immunized against malaria.) This brings us back to the idea of ​​eliminating mosquitoes.

A starting point for evaluating this decision is to integrate mosquitoes into a system that will change if they are eliminated. Adopting a global systemic approach does not delay a solution so much, but tries not to create a new problem by the quick actions mentioned above.

The other side of the equation is that mosquito species carrying malaria are not an important source of food for other animals. Non-prickly males are among the many insects that pollinate different types of plants, but are only the main pollinators of any type of orchid. Also note that biologist E. O. Wilson is supportive of eradicating mosquitoes.

But if the eradication of mosquitoes carrying malaria occurs, there are other potential negative consequences. At least one of them could affect more than the current number of people who died of malaria today.

People change their habits. Without the mosquitoes that drive the human population away from preferred mosquito habitats such as swamps and tropical forests, more people may move into these areas. People can then hunt other animals and prepare unoccupied land for logging and logging. In addition, people can hunt and eat more "bush meat", source of other interspecies diseases, including Ebola and AIDS.

Describe the potential disadvantages of eliminating malaria is easy outside of an area infected with malaria. Could we try to estimate potential deaths from both options?