AirWolf  

                                                                Research Priorities                                                                                          

By Richard Howe

Africa has 90% of the world's malaria, to put this statistic in perspective 1,250,000 Africans will get malaria today and 7,500 of these people will die from the disease daily. Considering these statistics Africans ought to be world leaders in mosquito vector control; however this is not the case. Instead Africans look to the West for guidance on these matters. Currently advances in state of the art science and application, relative to mosquito control, in the United States, still revolves around the time Elvis was King. This is not good for a country that is viewed as world leaders in everything technical. However, mosquito control in the United States is a luxury, far from being a priority. Malaria is not a problem here.

I would like to propose at this time the establishment of an internationally funded malaria vector control research center in Africa, for the purpose of advancing this science, for the benefit of developing nations.

Mosquito control consists of two elements, physics and chemistry. There is not one institution devoted to training aerial applicator pilots in the art and science of dispensing mosquito control insecticides. I have more experience than anyone in the States and was given no training at all before I was issued a license 27 years ago, for this purpose. The physics of insecticide aerosol cloud propagation is simply not well understood and never will, if someone does not take the lead in researching this most important aspect of the art.

The chemistry fares a little better than the physics of mosquito control. The most famous and most important chemical tool in the fight against malaria is of course DDT. DDT got a bad reputation in the 1960’s, with the publication of Silent Spring, a book written by Rachel Carson. I have read her book and was surprised to find that she was not so much against the use of chemical insecticides, as she was against the abuse of these products. Not much has changed since her day. The mosquito control industry, in spite of a mountain of EPA regulations is stuck in the 50’s. The overuse and abuse of chemistry is still with us to the detriment of the environment. The overuse of chemical insecticides is what induces resistance, not the under use. If used responsibly DDT still has a future in malaria vector control.

I would like to recommend a series of projects for consideration that address the application of insecticides, and the formulation of new compounds, for vector control. In the area of aerosol cloud propagation, there is not much known, except the insecticide cloud floats downwind of the aircraft. However the optimum release height, lane interval spacing, system flow rate variables needed to establish the most equal cloud density and the most optimum droplet spectrum, are all variables, that in my opinion are in need of extensive study. At present what is done to optimize application efficiencies is just educated guesswork. In order to do this properly, someone is going to have to invent a system of remote sensing stations, that in addition to measuring insecticide cloud densities, also has the ability to conduct a mosquito population survey as well. Once this is accomplished, a minimum insecticide aerosol cloud density, necessary to obtain good control, can be established to avoid wasting insecticide.

In addition to studying the physics of aerosol cloud propagation I would like to see a concerted effort in the area of chemistry. The industry has too few tools at its disposal. Once again don't look to the United States for help in this area. The bureaucrat reins supreme in the land of milk and honey. The cost of obtaining EPA approval on a new insecticide is prohibitive. The market is not large enough to recover cost. I urge Africans to take the lead in developing new products that are not only effective but affordable for everyone in the developing world.

There are 4 ways to kill a mosquito that I would like to talk about. First we have the old Fashioned poisons like DDT, Permethrin, Malathion and Naled. These products affect the nervous system of the insect and in effect turn out the lights and cause the mosquito to die. I believe these insecticide could be synergized with addition of a surfactant to reduce surface tension of the droplet, that will allow it to penetrate the surface of the insect and become systemic. These insecticides are effective without the surfactant; the advantage of this method will allow a reduction of insecticide that will be supplemented with a cheaper surfactant.

The next three methods have never been used to my knowledge and should be candidates for research into alternative approaches to mosquito vector control. The first item worthy of a research effort in my opinion is the use of a descant. In essence using a solvent to dissolve the thin wax coating on the insect and allow it to "bleed" to death. The second would be biological insecticide made from plants. I suspect that there is a compound somewhere in the rain forests of Africa that could be used as a cheap and effective insecticide. This proposition is not so far-fetched, about one third of all prescription medicines here in the United States are derived from plants discovered in the rain forests. The third alternative would employ the use of irritants. This would constitute an indirect method, smoking the mosquito into the open to get a clear shot at it. Mosquitoes are not strong fliers, for aerosolized insecticide to work optimally mosquitoes should be flying. Some insecticides like DDT and Permethrin are natural irritants and could be used in conjunction with descants and biological compounds.

The method for dispensing more than one compound at a time is another area of interest. Insecticide compounds should not be dispensed mixed together with the exception of a surfactant used as a synergist. Standalone products could be used as combination drug therapies are used for malaria. They should however be dispensed using independent units for maximum effectiveness in conjunction with independent aerosol generators, the ability to very flow rates with multiple units lend itself to optimization of product usage.

In Summary, it is imperative; we educate ourselves in the Physics and Chemistry of mosquito vector control. To work smarter not harder. We have a worthy adversary, the mosquito.

Every human should not have to suffer from Malaria.  Not with the knowledge and technology that is out there now.