Living in Europe, malaria and DDT are a distant worry. People often fail to realise how deadly the disease is and that pesticides are used as one of the most effective tools for destroying the carrier of malaria – the mosquito.

It takes one bite

Malaria was only identified as a cause of death only at the end of the 18th century. People died suddenly and very painfully not knowing what was it that was killing them. It appeared as if they were dying from fever and the only association made at the time was the connection to the “bad air” (MAL – bad, ARIA –air) as the disease hit mainly in hot and humid parts of the world.

In 1897 the link between the mosquito, the parasite that it carries, and the cycle of bite – infection was made. When a person is bitten by a mosquito he is infected with the parasite Plasmodium that finds home in the liver where it multiplies. If not treated it infects red blood cells and prohibits the transmission of blood to vital organs, causing a very painful death. All it takes is just that one bite; once infected, the parasite stays in your body forever.

No cure, only prevention

Understanding the behaviour of malaria paved the way for medical and chemical innovation and modern ways of prevention. Regrettably a cure is yet to be discovered. The most effective management of the disease is prevention; attention is focused on preventing mosquitoes the opportunity to bite humans.

The World Health Organization (WHO) recommends two main approaches for reducing the level of malaria transmission. They are called the vector control measures.

The first is the long lasting insecticide treated bed nets (LLINs) that create a protective barrier against mosquitoes. They play an important role, particularly when you are asleep as the mosquitoes- like burglars – work best at night. How does it work? You hang the net above your bed, tuck it under the mattress so there will be no way in for the mosquito to enter and have a good night sleep. Your work is done. The net is made with holes too small for mosquitoes to pass, but the real magic is an insecticide that coats the material, keeping the mosquitoes away and ensuring the long term effectiveness of the net.

The other suggested way of reducing malaria’s spread is Indoor Residual Spraying. These three letters IRS save the lives of millions. WHO approved 12 insecticides for use in IRS including DDT. Insecticides are sprayed on house walls to prevent settling of the mosquito. The substance repels the insect from a room, irritating it enough to find an alternative location for a feed. However if both of those actions fail and the mosquito is still there flying around like a superman the long-term contact with DDT should result shortly in his death. Once sprayed, DDT remains effective up to 12 months.

Better safe than sorry

The use of DDT is a controversial topic, but what is often forgotten is the fact that IRS involves spraying with very low quantities. To give you an example it’s 2 grams* of the active substance per meter square. That’s how little you need to use to make it 100% effective. The total amount of DDT used for fighting malaria is merely a fraction of what was used once in agriculture sprays.

The indiscriminate spraying of DDT posed unnecessary risk to humans and the environment. However, this mistake of the past should not cost lives today. DDT used in negligible doses saves lives and limits the spread of disease. Continued calls to ban the use of DDT are irresponsible and threaten the health and wellbeing of millions.

DDT causes minimal or close to zero possibility of contaminating the wider environment, because the substance does not escape to the wildlife. Many “green” groups in Africa have recognised that malaria and poverty are far worse than the quantities of DDT in the environment and now they are full supporters of responsible use of the substance for IRS.

Join

There are many ways that one can contribute and help in fighting malaria. You can donate a bed net, you can organise an event, there are tweets you can follow to raise awareness. There are plenty of ways to participate in this important cause. The aim is to eradicate the disease by 2015. Ambitious but not impossible!!!

http://www.malarianomore.org/

http://www.youtube.com/watch?v=pacPN6AW_Yc

http://www.fightingmalaria.org/

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*Correction: on first publication (12:49 CET 21.04.2011) this article incorrectly stated that the active ingredient of DDT is applied at 0.02g/m²

Everyone has heard of Malaria, a disease that is estimated to claim between one and three million lives every year. Young children account for 90% of the deaths, the majority of victims are in sub-Saharan Africa.

Malaria is caused by a tiny single-celled parasite called Plasmodium which is transmitted to humans through the bites of infected mosquitoes. Malaria is not necessarily deadly in every case of infection, but if not treated the disease can quickly become life threatening. There are a number of Malaria medicines available, although in some parts of the world parasites have developed resistance to them (this has been attributed to misuse of malaria drugs), and for the parts of the world most effected by malaria, drugs for treatment are not readily available, or just too expensive.
 

Prevention better than cure

According to the World Health Organisation (WHO) one of the main objectives of malaria control is to significantly reduce the rate and number of cases of both parasite infection and clinical malaria. This is achieved by controlling the malaria-bearing mosquito – basically preventing contact between infected mosquitoes and human beings.

The indoor spraying of insecticide is reported by the WHO to be the most effective means of rapidly reducing mosquito density. A practice known as ‘indoor residual spraying’ can protect a living space for three to six months. The WHO claims that the highly controversial DDT offers a longer term solution, offering up to 12 months of protection – although it’s ongoing effectiveness has been called into question.

Another favoured preventative measure is the use of long-lasting insecticidal nets (mosquito nets). Fine-mesh nets treated with insecticide offer personal or group protection and typically remain effective for three – five years.
 

A closer look at the pesticides

Yes, pesticides – because an insecticide is a type of pesticide. Let’s take a look at those most commonly used in mosquito prevention – permethrin and deltamethrin.

Permethrin is a synthetic chemical and commonly used as both insecticide and insect repellent. It’s effective because it functions as a neurotoxin (it does unpleasant things to insect nerve cells). Permethrin is a favourable deterrent to insects because it is not known to rapidly harm most mammals or birds, and is poorly absorbed by the skin. On the down-side, it is toxic to cats.  Permethrin is an effective agent in the battle against malaria, albeit one perhaps better suited to dog-lovers.

Deltamethrin is also a neurotoxin, and while it is used for insecticidal nets, it is also a widely used household insecticide for dealing with pests including bedbugs, cockroaches, ticks and fleas. Deltamethrin of one of the safest groups of pesticides, with mammalian exposure considered to be safe.

Pesticides save lives

Pesticides save lives, something you won’t read every day, but fact non-the-less. The Red Cross reports growing scientific evidence to demonstrate that combining mosquito net distribution with follow-on support and training at household level increases net usage rates and significantly reduces incidence of malaria.

It’s World Malaria Day on the 25th of April, which means I’m a little early with this post (hey, it’s the weekend… I’ve got plans) but in perfect time to share a few links if you feel like learning more about malaria, World Malaria Day, and how you can help efforts to eradicate a disease that takes a life every 30 seconds.

For your consideration

> World Malaria Day 2010 (coordinating body official site) follow @malariaday2010 on twitter

> World Health Organisation (WHO) hub for malaria

> International Medical Corps (NGO) fact sheet on malaria

> Malaria No More (NGO) follow @MalariaNoMore on twitter

> Office of the United Nations (UN) Special Envoy for Malaria follow @Malaria_Envoy on twitter

This list is not exhaustive, so please feel free to drop links and info in the comments section below.

Actually they don’t, and probably never did. This wonderful question is the result of a German to English Google translation of an article posted at presseportal.de. The story is of Dutch tomato growers who claim their tomatoes taste more like tomatoes when they are grown with biological methods – favouring natural predators to combat pests, over the use of pesticides. The original article can be read here, and the Google translation can be braved here.

Staying with ‘biological’ pest management, an Israeli researcher is developing what is described as an ‘ecologically sound pesticide’ by modifying the venom of scorpions. It is claimed that certain neurotoxins present in the venom have the chemical properties to manage crop damaging pests, while posing no threats to useful pests such as bees, or mammals like you and I.

Pesticides are like medicines, they are used to treat ’sick’ plants, and prevent ’sickness’ in plants. As with medicines, you should always read the label. A well timed news story ‘Pesticides cause impotency if not properly handled‘ (posted on St. Valentines Day), reports on the potential dangers of failing to follow safety instructions. It seems that some farmers in Ghana have taken to tasting pesticides before use in order to reassure themselves of its potency! Without doubt, a practice entirely incompatible with the safe and sustainable use of pesticides. The United States Agency for International Development (USAID) and CropLife Africa Middle East made these revelations during a recent programme of workshops to train farmers and encourage the safe use of plant protection products.

The Food and Agriculture Organisation (FAO) offers a wealth of information on good agricultural practices, including information on the sustainable and safe use of pesticides. Always read the label, and if in doubt, seek expert advice.

Another interview from the Forum for the Future of Agriculture (see previous posts below), this time with James S. Shikwati, an expert in African agriculture and Managing Director of Inter Region Economic Network (IREN), a think-tank based in Kenya that aims to develop strategies to bring prosperity to the African continent.

We asked Mr Shikwati about the prospects for African farming, the role of technology, and the aftermath of the food prices crisis last year, and he gave us some very insightful answers which generally point to a degree of optimism for the future. Highly recommended.