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.