22/07/2016 News / Tackling Zika, Naturally

Tackling Zika, Naturally

Frontline response to the virus threatening the Rio Olympics needn’t be costly, says Swiss biological pest control expert and Right Livelihood Award Laureate Dr Hans R. Herren

Right Livelihood Award Laureate Dr Hans R. Herren, photo by Peter Lüthi

Several high-profile athletes have pulled out of the Olympic Games due to open in Rio de Janeiro, Brazil in just two weeks’ time, citing concerns over Zika virus. How serious is the Zika threat and are there solutions at hand to address it?

Originating from Uganda, Zika was first described in 1947 and has been linked to microcephaly and a range of other dangerous health conditions. The disease has never gained epidemic status in Africa, however it has recently gained prominence in Latin America, particularly in Brazil, and has shown to be as far-reaching as the USA, where a fatal case was registered earlier this month. This shows that no one is immune and that greatest care needs to be taken to avert further spread of this mosquito transmitted disease.

When we look towards Brazil, it is clear that dealing with the vector — in other words, mosquitoes — should be our first line of defense. Eliminating breeding sites is perhaps the easiest and cheapest way to deal with Zika-carrying mosquitoes, as these sites are well defined, easy to spot and can be either removed or treated using non-toxic products for mammals and humans. It costs little, involves the community and is highly effective.

The problem we have with Zika, just as with the ever-lingering yellow fever, malaria, filariasis, dengue and other vector-borne diseases, is that we fail to take action early, before outbreaks occur — most often in poor neighborhoods and slums, which make perfect conditions for mosquitoes. Instead, we rely on emergency interventions once the situation is already out of hand.

Biocontrol measures also hold great promise in our fight against mosquitoes, such as the use of bacteriaBacillus thurigiensis var. israeliensis (Bti), or Bacillus sphaewricus (Bs). Bti and Bs produce toxins that have proven to be effective in killing various species of mosquitoes, fungus gnats and blackflies, while having almost no effect on other organisms. These products are widely used to control mosquito larvae in industrialised countries.

Unfortunately, the relatively simple solutions are often dismissed in favour of more sophisticated, ‘nice to have’ but costly approaches which only treat the ‘symptoms’ of the disease. In this case, the search for a vaccine and other forms of treatments – which, in the case of a malaria vaccine, has been under development for decades, cost hundreds of millions of dollars and is still years away.

Although some solutions such as a vaccine (preventative) or a drug (curative) may come onto the market in due course, the best way to protect oneself is to avoid getting bitten in the first place.

For this, mosquito repellent and protective clothing are essential. On the repellent side, it is best to go for the many effective and safe plant-based products. One such product is “Mozigone”, a low-cost repellent based on African indigenous plants, which was developed 10 years ago in Kenya through local research by the International Centre of Insect Physiology and Ecology and Kenyatta University.

Just like with many other mosquito transmitted diseases, Zika presents a significant danger for local people as well as those visiting outbreak areas. Yet just like with other diseases — from malaria to dengue — effective solutions are not necessarily the costliest or the most technologically advanced. The key to successfully managing Zika and other future outbreaks is to involve communities, learn from nature and tackle the problem efficiently at its source.