Combating malaria and other so-called vector diseases with chemical controls is increasingly ineffective, besides being hazardous for humans and the environment. These chemical controls must therefore be eliminated. In order to combat the diseases that insects and ticks transmit, all possible strategies must be united.
Only then can we successfully combat these stubborn and escalating disease threats. Prof. Willem Takken made this proposal during his inaugural address as Professor of Medical and Veterinary Entomology at Wageningen University (the Netherlands).
Even now, says Prof. Takken, the many human and animal diseases transmitted by insects and ticks (the so-called vector diseases) claim countless lives in the world, not only in developing countries but also increasingly in the West. Government agencies and public bodies should make combating these diseases a top priority.
Due to the intensification of international commerce and tourism, more tropical and sub-tropical diseases find their way to Europe. In addition, changes in climate mean that these diseases can more often thrive in moderate climate zones. Examples include Bluetongue virus, which recently appeared in the Netherlands, and the increase in Lyme disease, but also West Nile virus, dengue and chikungunya.
Every year, 4 billion people are exposed to malaria worldwide and 500 to 600 million of them become infected. Initially, in the 1940s and 1950s, the disease was combated very successfully with DDT. However, it gradually became apparent that the insects were becoming resistant to DDT and that this pesticide had very detrimental effects on human health and the environment. This led to DDT being banned in many countries, which in turn meant that the control of the disease virtually stopped between 1969 and 1999.
Prof. Takken is alarmed that some countries have again started using DDT. It has been shown that chemical control measures only work for a limited time and are not sustainable. Therefore an entirely different strategy must be developed which will provide a lasting solution to the malaria problem. He draws attention to the biological crop protection agents used for controlling pests and diseases in greenhouse horticulture. Currently, 95% of all vegetables from greenhouse horticulture in Western Europe are grown without insecticides. Prof. Takken wondered why this approach was not being used with vector diseases. Therefore he set the goal of controlling malaria without the use of chemical pesticides.