What is Malaria?

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.

Malaria in Africa

QUESTION

Why do Africans catch malaria more than others?

ANSWER

There are a number of reasons why malaria is more widespread in Africa than in many other parts of the world. However, it is worth mentioning that other parts of the world, such as India and south-east Asia, also have very high prevalence of malaria, especially in rural areas.

The high transmission of malaria is Africa is predominantly due to two factors: climate and control measures, or rather, the lack of them.

Malaria is spread by mosquitoes of the genus Anopheles, and so in order to persist, an area must have a suitable temperature for the development of both the mosquito as well as the malaria parasite. This limits malaria transmission to the sub-tropics and tropics, primarily. The area must also have sufficient rainfall and areas of standing water, since the malaria mosquitoes lay their eggs in stagnant water, which the larvae live in until they pupate into adults. This means that malaria transmission cannot occur in desert regions.

Unfortunately, a large portion of Africa, and particularly West, Central and East Africa, are climatically very well suited to the development of mosquitoes and thus the transmission of malaria.

In addition, many countries in Africa are not as developed as other tropical countries. This means that health resources have not been as focused on control efforts in Africa—for example, Malaysia very successfully reduced malaria transmission by a huge amount through a combination of vector control (namely spraying households with insecticides and filling up stagnant water pools so larvae couldn’t develop), distribution of bednets (which reduces mosquito biting rate) and better diagnoses and treatment facilities.

All of these efforts are beginning to be developed and rolled out in Africa as well, so hopefully in the near future we will also see a dramatic reduction in malaria transmission in Africa.

Malaria in Thailand: Phrae and Nan

QUESTION

We are traveling in Phrae and Nan (in Thailand) in the period of December-Januar. Is there any risk for malaria. We are travelling with kids (9 months, 6 and 8 year) and want to avoid risky areas. Can we travel safely in that region? Thank you for your reply.

ANSWER

Thanks for your question. Phrae and Nan are two districts in northern Thailand—the latter shares a border with Laos. While most of the very touristy destinations in Thailand (i.e. Bangkok and the coastal regions) are considered to have very low levels of malaria, and perhaps no transmission at all, I’m afraid that the areas bordering Laos, Myanmar and Cambodia do have malaria and so if you visit, you should take appropriate preventative precautions.

It is worth noting that some parts of Thailand are known to have mefloquine (sold as Lariam) and chloroquine resistant strains of malaria, although I have just looked it up and it doesn’t appear that Phrae and Nan are within these regions. However, it would still be worth seeing a physician or visiting a travel clinic to get specific advice for your family, and particularly what anti-malarials are appropriate for your children—a lot of that will depend on personal preference, such as how frequently you are comfortable taking medication and also how much you are prepared to spend.

Some, such as Lariam, are also frequently associated with side effects, which may affect your decision. If you do take anti-malarials on your trip, please take the Malaria Medication Side-effects Survey: Treatment and Prophylaxis. We are trying to collect information from travellers to record people’s experiences with the different types available.

In addition to preventative anti-malaria medication (known as prophylaxis), there are other preventative measures you can take, such as sleeping under a long-lasting insecticide-treated bednet, wearing long-sleeved clothing (especially in the evenings and at night when malarial mosquitoes tend to bite) and using insect-repellent on any exposed skin. You can also spray clothing with permethrin, a chemical which repels insects and prevents them from biting through thin cloth.

Malaria Symptoms, Cures, and Prevention

QUESTION

What is malaria cure, prevention, symptom and course?

ANSWER

I am not sure what you mean by “course” – however, links to information on malaria treatment, prevention and symptoms can be found on the main page of our website. For your convenience, I have provided them here:

As for malaria treatment, I have copied here an earlier answer in response to a question about malaria cures:

Malaria can be cured with a number of different medications, depending on then type of malaria and how far the disease has been progressed.

For standard, non-complicated Plasmodium falciparum malaria, the World Health Organisation recommends use of artemisinin-based combination therapies (ACTs), such as Coartem. This is due to increasing levels of resistance to chloroquine in many parts of the world. Indeed, even though chloroquine is still used in many places as first-line treatment against P. vivax, P. malariae, P. ovale and P. knowlesi uncomplicated malaria, there is some evidence that resistance to this treatment is also emerging, for example in P. vivax in parts of south-east Asia.

In cases where malaria infection has progressed to a stage where oral administration of medication is not possible, or where cerebral symptoms are suspected, the usual treatment option is intravenous quinine.

In addition, P. vivax and P. ovale malaria parasites are able to produce forms (called hypnozoites) which can become dormant in liver hepatocyte cells after the blood stages of the infection have been cleared. These dormant forms can become reactivated weeks or even months or years after the initial infection, which is called a “relapse” of the infection. One drug, called primaquine, is able to kill these liver stages, and so patients with either of these types of malaria should also discuss the possibility of taking primaquine.

Apart from these first-line treatments, there are other medications which are used against malaria, both prophylactically as well as for treatment. These include orally-administered quinine, pyrimethamine, mefloquine, proguanil, atovaquone and sulfonamides.

Blood Test After Child’s Malaria Exposure

QUESTION

Our 2 year old son was exposed and bitten about 10 times on Friday, 21st of Ocober in Malindi, Kenya. This was our last day in Kenya after 3 days on the coast preceded by 4 in Masai Mara. On October 28, our son started vomiting. This lasted a day. He did not have a fever at the time. The doctor diagnosed him with rota virus. Our 2 year old took his last dose of Malarone on the same day the vomiting started.

We believe he did not keep it down. Since the doctor visit our son has developed a cough and has had a low constant 38 C fever for a day and a half. Given the risk of a small child to malaria, is there any reason we should not request a blood test for Malaria?

ANSWER

Generally speaking, coughing is not a common symptom of malaria, and fever more usually comes in cycles, so the clinical presentation suggests that your son may be suffering from another illness.

However, as you say, small children are particularly at risk from malaria, so I would say it is worth getting a blood test for malaria, to be on the safe side. It only requires fingerprick blood, and the results can be available very quickly.

It is also important to remember that Malarone (including Malarone Paediatric, the version marketing for children over 11kg in weight) should be taken for 7 days AFTER leaving a malarial area, to prevent latent stages of malaria developing into a full infection.

With small children, other preventative measures are also especially important, such as sleeping under an insecticide-treated bednet, wearing long sleeved clothing in the evenings and early mornings and using insect repellent on exposed skin.

How to Control Malaria

QUESTION

Suggestions to control malaria?

ANSWER

This answer is copied from an earlier question asking about strategies for controlling malaria in Africa. The methods below are being used by many health ministries, international agencies and non-governmental organisations to combat malaria all over the world (and not just in Africa).

Currently, malaria control is based on a combination of prevention, education, research and treatment. In more detail:

Prevention: This is arguably one of the keys to sustainably reducing malaria burdens and even eliminating infections. Central to this goal has been the distribution of long-lasting insecticide treated bednets, which prevent people from being bitten by infected mosquitoes while they sleep at night. Unfortunately, some recent research has just been published which suggests that bednets might be contributing to insecticide resistance in mosquitoes, as well as increased rates of malaria in adults due to decreasing natural immunity. As such, it may be that more research is needed in order to determine the most effective and efficient ways of using bednets to prevent malaria infection, particularly in high-risk groups like young children and pregnant women. Another arm of prevention is reducing the number of mosquitoes in an area (called vector control), and thus preventing transmission from occurring at all – this can be achieved through insecticide spraying but also filling in the stagnant pools of water that mosquitoes lay their eggs in. Vector control was highly successful in reducing malaria transmission in the United States and Mediterranean in the years after World War II.

Education: Through education, people living in at-risk areas for malaria transmission can learn about ways to prevent the disease, as well as what to do if they suspect they are infected. Similarly, education is important for travellers visiting malarial areas, so they know the best ways in which to avoid being infected.

Research: Understanding the distribution, factors affecting transmission and the development of new strategies for control and treatment is going to be crucial in the fight against malaria, and particularly in high-burden areas such as Africa. Similarly, scientists are busily looking for new compounds to treat malaria, as well as the ever-elusive malaria vaccine. If such a vaccine could be developed, it would be a huge step forward in the fight against malaria; recently, a study was published which reported the results of the first Phase 3 clinical trial of a malaria vaccine, in African children. The vaccine appeared to confer approximately a 50% level of protection against malaria; while this is a start, it perhaps did not live up to many people’s hopes of a new method for controlling malaria.

Treatment: Hand in hand with treatment comes diagnosis; if a person can have their infection easily, accurately and cheaply diagnosed, then they will be able to access effective treatment more rapidly, thus improving their chances of a swift recovery. As such, countries in Africa are working hard to provide health systems capable of local diagnosis and availability of treatment, so that people don’t have to travel far to have their infections cured.

Taken together, these four strategies are having some success even in the world’s poorest and most malaria-endemic regions, especially in decreasing the number of malaria deaths. Decreasing the overall number of infections will be yet a greater challenge, but one which the world, especially through commitment to the Millenium Development Goals, is dedicated to overcoming.

Passing Malaria to Baby

QUESTION

I contracted Malaria 3.5 years ago (either in Uganda or Rwanda). I believe it was the Plasmodium falciparum strain. Upon my diagnosis, I was treated and have been healthy since.

In regards to pregnancy, is it safe for me to have a baby? What are the chances of passing the malaria virus to the baby?

ANSWER

First of all, malaria is caused by a single-celled parasite, not a virus. Secondly, you probably don’t have to worry—malaria is only very rarely transmitted directly between a mother and her unborn baby, via infected red blood cells passing through the placenta. When I say rare, I mean very rare, especially in developed countries without endemic transmission. There are only 48 cases of this occurring in the United States in the last 60 years, for example. Moreover, this can only occur if you actually have malaria during the pregnancy; if you were successfully treated when you had malaria 3.5 years ago, the parasite should no longer be present at all in your body.

P. falciparum does not lay dormant in the body, unlike some other types of malaria. The only thing to consider is if you plan to travel to malarial areas while you are pregnant – pregnancy makes women more vulnerable to malaria infection, and many forms of malaria preventative medication and treatment have not been thoroughly tested for safety in pregnant women. If you are planning on travelling to malarial areas while pregnant, it would be wise to consult with a specialist travel doctor for the most up-to-date recommendations of malaria prevention when pregnant.

Three Attacks of Malaria

QUESTION

I am right now recuperating from a third attack in less than one year’s time. What could have gone wrong ?

I am awaiting to hear your advice.

ANSWER

There are a number of reasons for multiple malaria attacks. One is that although malaria can be easily treated, these treatments often don’t prevent re-infection. There are separate drugs which can be used to prevent malaria (known as malaria prophylactics), but these must be taken all the time to be effective (usually either once a week, once a day or twice a day, depending on the specific drug), and so usually aren’t appropriate (due to the unknown health risks of taking the drugs for that long, plus the prohibitive cost) for people living in areas where malaria occurs.

For people living in malarial areas, other means of prevention are required, of which avoiding being bitten by mosquitoes is paramount. For this, it is recommended to sleep under a long-lasting insecticide treated bednet at night, when many malarial mosquitoes are active. Similarly, wearing long sleeved clothing, especially if it is impregnated with an insecticide such as permethrin, can help avoid the bite of infected mosquitoes.

Second of all, there are some types of malaria which cause repeat episodes of illness, even after only a single infection. Specifically, Plasmodium vivax and Plasmodium ovale (the former is common in many parts of Asia in particular) can form life stages called hypnozoites which rest dormant in liver cells, even after the parasites in the blood have been cleared.

During this time, the patient will have no trace of malaria if they take a blood test, and they will feel fine. However, if these hypnozoites become active again, they will re-invade the blood, and the symptoms of disease will reoccur – at this stage, the parasite will once again be observable in the blood, and so the patient will be diagnosed as positive for malaria. As such, it is very important to find out what type of malaria you have, and if it is one of the above two species, then you can talk to your doctor about taking another type of medication, in addition to that which cures the blood infection, called primaquine—primaquine kills the hypnozoite liver stages of malaria and thus prevent recurrence of the disease.

Thanks for your question—since we think other people may benefit from the questions in this forum, I have removed your name and contact information to preserve your anonymity.

Medicines to Prevent Malaria?

QUESTION

Which medicines are used to prevent malaria?

ANSWER

There are a number of drugs used to prevent malaria infection, known as malaria prophylactic medication. These vary in terms of how they are taken, how long they are taken for, how much they cost and the typical side effects people experience while they are taking them. In addition, some are recommended more highly for certain types of malaria or certain regions of the world, due primarily to the emergence of resistance in certain areas.

The most common forms of malaria prophylaxis used are doxycycline, atovaquone/proguanil (sold under the brand name Malarone), chloroquine (sold as Aralen) and mefloquine (sold as Lariam). More information on these, on other types of prophylaxis and malaria prevention in general can be found on our Malaria Prevention page.

What is Malaria?

QUESTION

What is malaria?

ANSWER