Only two interventions aimed at the mosquitoes that transmit malaria and other vector borne diseases are operationally proven to dramatically reduce disease transmission, and to reduce malaria morbidity and mortality, in the majority of epidemiological settings. These are indoor residual spraying (IRS) of insecticides and distribution and use of long lasting pyrethroid impregnated bed nets (LLINs). Used effectively these methods are capable of spectacular results. The malaria eradication campaigns of the mid 1900s eliminated malaria in much of the world. It was driven out of the USA, most of Europe, Latin America and parts of Asia, and the disease burden was substantially reduced in much of Sub-Saharan Africa.

The eradication campaigns were discontinued for a variety of reasons, including concerns about drug and insecticide resistance and problems with sustainability. Vector control, as conducted in the 1960s, relied on intensive, short-term efforts, without a long term vision or strategy for maintenance. Over the last two decades there has been a shift, in Africa, away from the original vector control paradigm of IRS towards large scale distribution of insecticide treated bednets (LLINs).

The RBM Global Malaria Action Plan forecasts that the cost of control and elimination is dominated by the preventive costs (LLINs and IRS) although the cost of the insecticide is only a small proportion of the total cost of executing the intervention, and is currently estimated at only $400M in an overall vector control commodity market of $800M.

Vector control addresses many diseases

In many parts of the world malaria, dengue, and other globally important vector borne diseases, such as Chagas, filariasis, and leishmaniasis, are all transmitted principally in the home, which is the most important point of contact between the vector, the pathogen, and the human host.

For example, dengue is the most important arthropod-borne viral infection of humans with more than three billion people living in dengue endemic areas. Worldwide, 50-100 million cases of dengue fever (DF) and 500,000 cases of the more severe dengue hemorrhagic fever (DHF) occur each year, and the incidence of life threatening disease is exploding throughout much of the tropical world.

Control of all of the main vectors of these diseases is currently predicated upon the efficacy of pyrethroid insecticides. New products to control malaria vectors will be efficacious for  control of the vectors of dengue and other globally important vector-borne diseases.

Vector control and the malaria eradication agenda

The current push to eliminate malaria from many countries, and the longer term goal of eradicating malaria globally, will rely heavily on IRS and LLINs, particularly in hyper-endemic areas where appropriate drugs and vaccines will only be effective at driving the disease towards elimination when transmission levels and parasite loads in the human populations have been depressed by coordinated large scale mosquito control campaigns.

As countries move towards elimination, mosquito control efforts will need to concentrate on remaining foci of disease, and once elimination has been achieved capacity will need to be maintained to cost-effectively and efficiently monitor for outbreaks occurring through infected human or mosquito migration and then rapidly respond to these. Neither of the current interventions is ideally suited to this end game activity, and our current monitoring tools are woefully inadequate for this task.

The IVCC Product Development Partnership has a leading role in optimising and stabilising the role of mosquito control within the elimination agenda. It aims to: