How serious is malaria as a disease?

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QUESTION:

(In conclusion to an earlier question regarding the seriousness of the disease and the way it is likely to affect population vigour if not controlled) –  What can the community, the government, individuals (school children, parent, and teachers) do to improve the situation?

ANSWER:

The best way to improve the impact that malaria has upon populations afflicted by malaria is to prevent the disease in the first place.

At a community level, this can be done through the use of long-lasting insecticide treated bednets, which have been shown to be extremely effective in preventing exposure to malaria-carrying mosquitoes. The nets are furthermore cheap and easy to use; the problem is distributing them, and ensuring that the highest-risk groups of people (pregnant women and children under 5 years old) have priority access to the bednets.

In some places, bednets are given out for free at antenatal clinics to target pregnant women; in other places, bednets have been sold at subsidised prices as a way of maintaining the sustainability of the delivery program.

For more information about bednet distribution and the debate surrounding whether they should be free or paid for, please see the post “Malaria – Free Bednets?”

These high risk groups may also benefit from intermittent preventive therapy (IPT) whereby individuals are given treatment for malaria at set intervals, to reduce the risk of suffering from a full-on malaria infection. More information on IPT can be seen in the comments to the question “Reduce risk of P. falciparum.”

If bednet coverage is not thorough an thus prevention not complete, the next stage in reducing the burden of the disease on endemic communities is through accurate, effective diagnosis followed by appropriate treatment. This requires a functional and efficient health services system as well as a well developed transportation network, to ensure that people are encouraged to seek assistance at a clinic or hospital if they develop malaria symptoms, and that they can easily and quickly reach these facilities.

Advanced health systems and transportation networks are the goal of many developing countries, and many regions in the world have made huge amounts of progress in these areas recently. However, momentum must be maintained, and governments throughout the regions of the world where malaria continues to be a huge public health burden need to continue their efforts to strengthen the availability of malaria diagnostics and treatment, in order to remove malaria as an obstacle to people’s well-being and development.

What is Malaria?

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QUESTION:

What is malaria?

ANSWER:

Malaria is a disease caused by parasites of the genus Plasmodium. Transmitted by mosquitoes, there are several different kinds of malaria distributed throughout the tropical and sub-tropical regions of the world, causing somewhere between 300-500 million cases of disease each year, and as many as 1 million deaths. In fact, malaria is one of the biggest killers of children under the age of five in sub-Saharan Africa, one of the regions of the world where the burden from malaria is the highest. Malaria is usually an acute disease, manifesting itself with severe fever, chills, headache and often nausea as well. Some types of malaria can have relapsing episodes over a time period of many years.

Having said this, malaria is easily preventable, through avoiding mosquito bites by wearing appropriate clothing and sleeping under insecticide-treated bednets, or through taking preventative medication (called prophylaxis). Malaria is also treatable once symptoms appear, through ingesting safe, effective and relatively cheap drugs. With such control measures at hand, you may ask why malaria is still such a huge problem in our world; the answer is that delivering control strategies and treatment to populations most at risk is difficult, and often countries with high malaria burdens don’t have efficient and effective health systems in place to coordinate control efforts.

International non-governmental organisations such as the World Health Organisation, as well as a multitude of non-profit organisations such as the Malaria Consortium and Malaria No More, work tirelessly to bring malaria control and treatment to the places that need it most, with the aim to eradicate malaria as a disease of public health importance.

NetGuarantee: Financing Speeds Delivery of Mosquito Nets

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NetGuarantee, a new innovative finance facility, announces its first transaction with Zurich in North America, part of the Zurich Financial Services Group, to celebrate World Malaria Day today, April 25. This collaboration will help accelerate access to and advance the delivery of vital malaria prevention tools in Africa by six to 10 months, and shows how core business competencies and best practices can improve efficiencies in global health and save lives.

[Read more…]

Safety of Bed Net Insecticides

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QUESTION:

Are the insecticides used on the bed nets safe? What are the brand names and chemical names of those insecticides, and can you point me to any studies that have been done to determine their safety?

ANSWER:

The short answer is yes, the insecticides used in bednets are safe under the conditions in which people are exposed to them through using bednets.

Most standard bednets are treated with a chemical known as a pyrethroid, and usually permethrin or deltramethrin. Both of these chemicals have low toxicity to most mammals and are poorly absorbed by the skin, making them safe for treating bednets. There are some studies on mice which suggest that pyrethroids such as permethrin can be carcinogens when ingested, though once bound to the fibre of a bednet the chemical is not ingested by the person sleeping under the net so this is not a danger.

The World Health Organisation maintains a comprehensive set of specifications (PDF) for maintaining quality and safety in insecticide treated bednets.

There is another WHO report on the safety of pyrethroids (PDF) for public health use, which gives more details about conditions under which these compounds are considered toxic and the risk of exposure through bednet use.

How to Prevent Malaria

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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.

 

Malaria – Free Bednets?

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QUESTION:

Why do people have to pay for the bed nets?  I think that is mean to the people and they should get them for free.

ANSWER:

You have hit on a very important and on-going debate in the malaria control community. In many places around the world, organisations such as UNICEF have distributed free, insecticide-treated bednets, and especially to mothers—pregnant women and children under five are the groups most at risk from dying from malaria.

In 2010, UNICEF reported that together with its partners (WHO, the EU and the World Bank, to name a few) 5.5 million free bednets have been distributed in DR Congo alone. Similarly, in Mozambique, the Malaria Consortium has been working in a partnership with DFID and the public sector to distribute 400,000 bednets to pregnant women as part of an ante-natal service, again targeting some of the most at-risk people.

However, you are right to say that in some cases, people have to pay for bednets; in some of the poorest countries in the world, this can seem like an unjustifiable expense. However, there are some arguments in favor of having people buy their bednets.

For example, some people argue that a purely public donation initiative is unsustainable, and in order to have an on-going distribution campaign, the private sector has to be involved at some level, and this usually means charging a fee for each bednet. Moreover, forcing people to buy their own nets would free up donor funds for other purposes. Similarly, it is thought in some circles that having payment encourages suppliers to continue producing and selling nets. Finally, there are suggestions that purchasing a bednet increases their value to the recipient, who subsequently uses their net more frequently and more reliably in the manner in which it is intended (and not, for example, as a spare fishing net, as I’ve seen in parts of Uganda!).

I believe a study in Malawi showed that by asking people in urban areas, who have a bit more disposable income, to purchase full-price bednets, the program was able to generate sufficient funds to offer bednets at a highly subsidized cost in rural, poorer areas of the country; by asking people to purchase the nets, the program believed bednet usage among its recipients was higher overall, than if the nets had been given out for free.

I think the organization that tried this approach was called PSI (Population Services International)—they also offered nurses a small monetary incentive to sell bed nets (at the small sum of 50 cents each) to the rural women who attended pre-natal clinics, thus encouraging them to offer the nets widely to pregnant women.

As the final word, a study in Kenya recently showed that as costs for services such as bednets increased, demand for the service among the poorest sectors of the population declined sharply. Instead, it seemed most economical and efficient to target high-risk groups with free bednets, who are also incentivized to use the product properly and value the protection it confers, such as pregnant women in ante-natal settings, rather than doling them out to the community at large.

So we’re back to where I started with this response; the great job that many organizations out there are doing in distribution insecticide-treated bednets to the people who need it the most, and who can’t afford to buy them themselves, although it is worth bearing in mind that alternative models of bednet funding and distribution might prove equally beneficial and potentially more sustainable, at least in certain areas.

I’m also going to ask Hugo Gouvras to weigh in on this one—he works for Malaria No More, an organization that has recently launched an innovative mechanism for accelerating funding provision for bednet distribution to Africa. Hopefully he can update anything that I have said which is old news, and provide additional information!

Insecticide-Treated Mosquito Nets (ITMNs) Helps Prevent Japanese Encephalitis

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A new study reveals that using treated mosquito nets could drastically reduce the transmission of Japanese Encephalitis (JE) to humans.

The study, conducted by the Regional Medical Research Centre (RMRC), Dibrugarh, North East Region (NE), Indian Council of Medical Research and released in the March issue of the American Journal of Tropical Medicine and Hygiene, showed that the use of insecticide-treated mosquito nets (ITMNs) on humans and pigs reduced transmission of JE 72 percent in humans.

The study looked at the effectiveness of using ITMNs to protect both pig and human populations. It evaluated the efficacy of reducing the transmission of JE in areas where high virus activity has been reported. The JE virus multiplies rapidly in pigs, considered by experts to be a key element in the natural cycle of the virus and its transmission to humans.

Sharp drops in infection rates were found in three locations following the use of ITMNs. In one location, the nets were used to protect both humans and pigs which resulted in the greatest drop in infection rates (72 percent), compared with areas where treated mosquito nets protected only humans (67 percent) or pigs (56 percent).

“We are pleased that the results of this study show that ITMNs are extremely effective against JE,” said Prafulla Dutta, Scientist, RMRC, NE, “Educating people in JE-prone areas that using ITMNs will help reduce the transmission of the disease without disturbing social customs in these communities. We believe that this will, in turn, reduce mortality associated with JE while keeping communities healthy and productive, further improving the global economy.”

JE is a viral disease transmitted by mosquitoes that infects both animals and humans. It is the leading cause of viral encephalitis (infection of the brain) in Asia and is estimated to be fatal in 30 percent of cases. Death as a result of JE is particularly high among children, killing approximately 8,000 children yearly.

“Increasingly, ITMNs have been shown to be an easy-to-use and effective tool in preventing mosquito-borne diseases such as JE, lymphatic filariasis and malaria,” said Peter J. Hotez, MD, PhD, President, American Society of Tropical Medicine and Hygiene. “This simplicity of action, combined with its low cost, drives the absolute necessity for distribution of these life-saving devices on a much larger scale.”

The researchers note that insecticide components, particularly pyrethroids, are gaining importance in mosquito control because of their low toxicity towards mammals and the strong repellant impact on mosquitoes.

Source: American Society of Tropical Medicine and Hygiene (ASTMH)