As part of its wider vector control program, Bayer is investing resources in attempting to halt the global spread of Zika virus.
Aedes-type mosquitoes have been the focus of Bayer vector control for decades because they transmit dangerous diseases such as dengue, chikungunya, and yellow fever. Bayer can now leverage this comprehensive expertise to support the international fight against Zika. The disease is suspected to be related to brain damage in newborns (microcephaly) in several South and Central American countries.
As a leader in vector control, Bayer is active worldwide and offers a complete package to control Aedes; larvicides fight the Aedes larvae that live in the many urban water reservoirs; residual sprays impregnate surfaces in the homes; and space sprays help to reduce Aedes populations in the outdoor environment. All of these tools have been approved by the World Health Organization (WHO) to fight the mosquito and Bayer works in close collaboration with regional authorities and municipalities to train implementers and support the distribution of information.
Bayer is a vital player in fighting Zika in Brazil
In the current emergency situation in Brazil, Bayer has stepped up its insecticide production to cope with the unexpected demand. Bayer also supports the national information efforts to help people protect themselves against mosquitoes. Bayer’s research station in Paulinia serves as an education and training hub for Vector Control.
“We are fully aware of the key role that vector control can play to contribute to mitigating the spread of the current Zika epidemic, and we are putting all our effort into supplying sustainable solutions in a fast and flexible manner,” said Frederico Belluco, head of marketing for Latin America.
Educating people, including Bayer employees main picture, above) on good practices to protect themselves against the Zika epidemic is also critical. In Brazil, Bayer has taken a series of measures to support this effort; activities with national media are taking place and give the floor to Bayer experts such as Luis Fernando Macul, head of marketing and innovation for Environmental Science Latin America, who gave an interview about the Aedes aegypti mosquito in the laboratory of Bayer CropScience in Paulinia.
Since December 2015, about 20 interviews on major Brazilian TV channels featured Bayer experts. In parallel, Bayer experts leverage social media, such as YouTube and Facebook, to give guidance on the use of insecticides. On Facebook for example, Bayer spokesman Fernando Bernardini explained how to use insecticides in the right way to repel the mosquito.
What are the signs and symptoms of the Zika disease?
People infected with the Zika virus may experience fever, skin rash and conjunctivitis, muscle and joint pain, malaise and headache, with symptoms lasting for 2-7 days. But all of these symptoms are usually mild and some people do not show any symptoms at all. However, the suspected number of cases of microcephaly, a rare brain defect in babies, has risen in Brazil since the surge of the Zika disease, even though the connection has not been scientifically confirmed. WHO is studying the potential link and we hope their results will soon be available. So far, there is no treatment or vaccination against Zika.
Aedes aegypti in Australia
Luckily Aedes aegypti does not tolerate cold weather, which prevents its establishment in much of Australia, limiting its presence to the Tropics and Sub-tropics of Australia – mainly Far North Queensland. However, there are other disease-carrying mosquitoes, for which control programs are necessary.
Mosquito control options
Effective treatment is very much dependant on the situation at hand. Since mosquitoes live in and around water, you must be particularly careful when using insecticides – most of the available chemistry has very specific limitations when it comes to application around waterways.
Large government programs in Australia exist for treatment of sensitive waterways, that use insecticides based on the bacterium, Bacillus thuringiensis, which is effective at killing the larvae but does not affect other marine organisms.
This work is highly specialised and often requires aerial application by helicopters to treat large breeding areas. This is not usually a professional pest manager activity, but you need to be aware that many government bodies may run these programs in your area.
Space sprays, like Bayer’s Aqua-K-Othrine, are designed to kill adult mosquitoes on the wing and can be very effective at taking out large numbers of adult mosquitoes over very large areas and very quickly. Space sprays are very small micron sized insecticide clouds that will leave no residual chemical in place once they have dispersed. For this reason they must be applied during periods of high insect activity and very low wind conditions in order to be effective. Drift of the insecticide cloud away from your target area will result in poor control and possibly detrimental effects on non-target insects.
Residual barriers take a different approach, by depositing active ingredient loads onto resting surfaces to kill mosquitoes when they land to rest. External and internal walls, furniture, fences, and the underside of vegetation are typical treatment surfaces. They can be very effective at placing a barrier or killing zone between a major breeding source and a residential area. The idea is to reduce the numbers of mosquitoes alive in the immediate surroundings of the dwelling, which should translate into far less nuisance biting and ideally very low disease transmission risk.
Personal repellents are a very effective tool for preventing bites by mosquitoes. They play almost no role in mosquito management, but if you prevent biting you are limiting the chances of disease transmission significantly. You should ensure that all of your staff involved in mosquito work are protected by personal repellent at all times.
For the homeowner, insect screens play a major role in mosquito control. Most modern screens provide very effective control against mosquitoes when they are in good condition but smaller biting insects such as midges may still penetrate the fine mesh. In addition, small holes made in screens can render them ineffective. Treating screens with a residual insecticide can be a potential add on service, to create the extra protection required against smaller biting flies. This treatment can be quite simple if the screens are easily removed, but when treating them in situ be very careful with insecticide treatment around glass surfaces.