QUESTION:

What is the prevention of malaria?

ANSWER:

Malaria can be prevented in a number of ways, the main three of which are bite reduction, prophylaxis and vector control.

Bite reduction just means steering clear of mosquitoes, and specifically those that transmit malaria. These bite mostly between dusk and dawn, so if walking around at these times of day in a malarial area, it is worth wearing long sleeves and pants, and applying an insect repellant – ones containing DEET are the most effective at keeping off mosquitoes, in my opinion, but they also contain very toxic chemicals so should be used with care.

Specifically, 100% DEET shouldn’t be applied directly to bare skin, since it can be absorbed and cause problems for the liver. Natural insecticides, such as those containing citronella, are also an option. At night, it is advised to sleep under a bednet, which prevents mosquitoes from biting you while you sleep. Nets which are infused with pyrethrin, or other insecticides, are recommended.

Pyrethrin spray can also be used on clothing, to stop mosquitoes biting through light cloth. On a broader scale, bite reduction can also be achieved through better screening of windows and doors, and other ‘environmental’ controls.

Prophylaxis, when referring to malaria, means taking certain medication in order to prevent the onset of the disease. Several different drugs exist, and different ones are recommended depending on the type of malaria you are likely to encounter. Moreover, each has different potential side effects, different schedules of ingestion and come at a range of prices.

Since they do cost money, and are sometimes very expensive, prophylaxis against malaria is usually only used by short term visitors to malarial zones, although since pregnant women are more susceptible to malaria, they may choose to take prophylaxis during their term in order to prevent infection – it should be noted that most of the drugs used for malaria prophylaxis are NOT recommended for pregnant women so it is important to check carefully before starting on any of these medications.

For more info on malaria prevention while pregnant, why not check out the Q&A question about pregnancy and travelling to Belize?

For info on malaria prophylaxis in general, there is a Prophylaxis Forum dedicated to this here on this website, so have a look!

Finally, there is vector control. This means reducing the number of mosquitoes around so that there are less to transmit malaria! Spraying households with insecticides has been very effective in reducing malaria transmission in a number of settings, and although it suffers from a lack of cost-effectiveness and sustainability in the long run, may still be very useful in high-endemicity regions or those where drug-resistant malaria is rife.

Another approach to vector control is to eliminate habitat for the mosquito larvae. The larvae breed in pools of stagnant water, such as ditches or puddles; filling these in can reduce the number of larvae that can mature into biting mosquitoes. Obviously, some water sources, such as wells and irrigation ditches, are required by communities, particularly in rural areas, and so cannot be removed. As such, larval control is probably mostly an effective strategy in urban transmission settings.

Finally, on a slight tangent to traditional vector control, there has long been interest in the idea of controlling malaria through manipulation of mosquito genetics in such a way that populations could be replaced with individuals that cannot transmit the disease. A research article on this subject is available on this website. See: Malaria Control with Transgenic Mosquitos.