Treatment for malaria in Africa

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QUESTION:

What is the treatment for malaria in Africa?

ANSWER:

The appropriate form of treatment for malaria, regardless of where you are, depends on the type of malaria you have. This can be determined through diagnosis; each of the main malaria parasites that ordinarily infect humans (P. falciparum, P. vivax, P. malariae and P. ovale) looks slightly different under the microscope, although you have to be well trained to tell them apart! Rapid diagnostic tests (RDTs) can also sometimes distinguish between malaria species, although many RDTs only test for P. falciparum, he most acute, severe and deadly of the species.

In much of Africa, P. falciparum is the most common and dangerous form of the disease. In some places, it can be treated with chloroquine, though in many places the parasite has developed resistance to this drug, so other treatment is necessary.

The most common drugs given in areas with known chloroquine-resistant strains of P. falciparum are ACTs (artemisinin-based combined therapies). There are some parts of Africa where other forms of malaria, such as P. ovale and P. vivax, can also occur – it is important to know whether a patient is infected with these species as they require an additional form of treatment, the drug primequine, in order to kill dormant liver stages that characterise these species and can lead to a relapse of infection months or even years after the initial exposure.

What is malaria? What Causes Malaria?

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QUESTIONS:

What is malaria?
What causes malaria?

ANSWER:

I have copied below the text from an earlier question, also asking about the causes of malaria and explaining what it is:

Malaria is a disease caused by a parasitic single-celled animal known as Plasmodium. There are different species of Plasmodium, which cause different kinds of malaria. The main types which infect humans are P. falciparum, P. vivax, P. ovale and P. malariae. The parasite is transmitted by certain species of mosquito; the parasite lives in the human blood stream and so goes in to the mosquito when the insect feeds. When the same individual mosquito then feeds on another person, it transmits parasites into a new host.

The symptoms of malaria are caused by the actions that the parasite undertakes while in the human host. For example, part of its reproductive cycle involves invading and then multiplying inside red blood cells. Once several cycles of reproduction have occurred, the new parasites burst out of the red blood cell, destroying it. The cycles are times so that all the new parasites burst out of the red blood cells at the same time; this coordinated destruction of the red blood cells, either every 24, 48 or 72 hours, depending on the malaria species, causes the one day, two day or three day cycles of fevers and chills that characterize malaria infection episodes.


Malaria symptoms

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QUESTION:

When a person is ill he or she will have what symptoms?

ANSWER:

Malaria can have many different symptoms, but the initial signs are similar to a flu-like illness, with high fever, chills, headache and muscle soreness or aches. A characteristic sign of malaria is cyclical fever, with peaks of severity every two or three days. Additionally, some people will experience nausea, coughing, vomiting and/or diarrhea.

Because these symptoms are quite generic of a wide variety of illnesses, if you live in a malaria-endemic region, it is crucial to be tested when you develop such symptoms, rather than assuming it’s just the flu and soldiering on! If you have recently traveled to a malarial area and start to experience these signs of infection, similarly you should inform your doctor of your travel history, as otherwise they might not recognize your symptoms as potentially that of malaria.

If treated rapidly and with the correct medication, malaria is almost always completely treatable; it is only if treatment is delayed that it becomes more serious, with long-lasting and potentially fatal consequences. Similarly, if you take sensible precautions while living or traveling in malarial areas, such as taking prophylaxis (and taking them as per the instructions, for the full required amount of time!), avoiding being bitten by mosquitoes and sleeping under an insecticide-treated bed-net, you vastly reduce your chances of getting infected in the first place.

It’s also worth noting that different species of Plasmodium, the parasite that causes malaria, cause slightly different manifestations of the disease, and also require different forms of treatment. Plasmodium falciparum has a unique way of affecting the red blood cells it infects, which eventually can result in loss of function of internal organs. ‘Cerebral malaria’ is a particularly deadly version of this, whereby the function of the brain is affected. The cycles of fever, mentioned above, are caused by synchronous rupturing of the red blood cells in the body by the malaria parasite; P. falciparum, P. vivax and P. ovale complete this cycle every 48 hours, resulting in fever cycles of roughly two days (though P. falciparum can be unpredictable); P. malariae, on the other hand, has a cycle lasting 72 hours, so three day cycles of fever are expected. Finally, although many types of malaria can be successfully treated with the drug chloroquine, some strains, and notably of P. falciparum, have become resistant to this treatment. In these cases, artemesinin-based treatment is recommended, usually in combination with other therapies (artemesinin-combination therapy, or ACT). P. vivax, in addition, requires an additional drug, called primaquine, which is used to treat lingering liver stages of the parasite, to prevent recurrence of the infection.

Malaria Treatment

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QUESTION:

Is there any treatment for malaria?

ANSWER:

Yes, treatment is available for malaria and most cases can be cured easily if diagnosed accurately and early. There are several different drugs that are used to treat malaria, and different modes of ingestion.

Most cases of malaria can be treated effectively with oral drugs, usually artemisinin-based combination therapies (which contain a drug called artemisinin, long used in Chinese medicine to treat malaria) or chloroquine. The choice between these will depend on the type of malaria you have (hence the need for accurate diagnosis) as well as whether the area you are in is known to have types of malaria that are resistant to chloroquine. In addition, some types of malaria, notably P. vivax and P. ovale, require an additional drug, known as primaquine, to prevent later relapses of malaria from dormant forms of the parasite, that hide in the liver.

Severe malaria may require the administration of drugs directly into the body, usually intravenously. Quinine is often the first-choice drug at this stage, though artemisinin-based compounds have also been shown to be effective. Severe malaria, sometimes manifesting as cerebral malaria, is usually only caused by P. falciparum, the most deadly of the types of malaria found in humans.

How long has malaria existed?

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QUESTION:

How long has malaria been going on?

ANSWER:

The answer to your question depends on the kind of malaria as well as how exactly you define ‘malaria’. The parasites which cause all forms of malaria, in humans as well as other mammals and birds, belong to a group called Plasmodium; scientists believe, based on genetic information, that this genus evolved around 130 million years ago, which is before the dinosaurs went extinct! These ancient ‘malaria’ parasites probably infected lizards; some types of malaria still infect reptiles today.

Plasmodium parasites have since evolved to infect primates, including humans; some scientists argue that this ‘jump’ has probably occurred several times in evolutionary history, whereas other suggest it has only happened once; the debate on this will likely continue for some time!

In terms of when human malaria first evolved, the four main types of malaria that infects humans are P. vivax, P. malariae, P. ovale and P. falciparum; the first three likely either co-evolved with humans or at least first became associated with infecting humans very soon after anatomically modern humans evolved. This dates these types of malaria back to the Middle Stone Age, which started around 300,000 years ago in Africa.

P. falciparum, on the other hand, probably crossed over much more recently, and the most up-to-date genetic evidence suggests that it evolved from a type of malaria which is found in gorillas. Estimates for when this transfer occurred are shaky at best, but it might have only been in the region of 10,000 years ago.

For more reading on the debate regarding the origin and evolutionary histories of Plasmodium as a whole and human forms of malaria more specifically, the following scientific articles may be a good place to start:

Joy, DA; Feng X, Mu J, Furuya T, Chotivanich K, Krettli AU, Ho M, Wang A, White NJ, Suh E, Beerli P & Su XZ, (2003). ‘Early origin and recent expansion of Plasmodium falciparum’, Science 300 (5617): 318–21

Liu, W; Y Li, GH Learn, RS Rudicell, JD Robertson, BF Keele, JN Ndjango, CM Sanz, DB Morgan, S Locatelli, MK Gonder, PJ Kranzusch, PD Walsh, E Delaporte, E Mpoudi-Ngole, AV Georgiev, MN Muller, GM Shaw, M Peeters, PM Sharp, JC Rayner & BH Hahn (2010), ‘Origin of the human malaria parasite Plasmodium falciparum in gorillas’, Nature 467.

Yotoko KSC & Elisei C (2006), ‘Malaria parasites (Apicomplexa, Haematozoea) and their relationships with their hosts: is there an evolutionary cost for the specialization?’, Journal of Zoological Systematics and Evolutionary Research 44 (4): 265–73

How Many Types of Human Malaria?

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QUESTION:

How many types of malaria infect humans?

ANSWER:

There are four main types of malaria which infect humans: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. P. ovale additionally can be split into two sympatric sub-species, P. o. curtisi and P. o. wallikeri. Each of these five kinds has a subtly different life cycle which results in slight variations in symptoms and also in treatment. For more information on this, check out the Q&As on malaria symptoms and malaria treatment; CDC is also a site worth checking out.

Additionally to the four species above, there are observations of a number of other Plasmodium species being able to infect humans, although much less frequently. The most reported of these is P. knowlesi, found in SE Asia, which usually infects macaque monkeys but is capable of crossing over into humans and causing severe quotidien malaria, and may even result in death. The number of cases of P. knowlesi appears to be on the rise in some regions, although the cause of this is not quite clear. For an introduction to P. knowlesi, you should read Christina Faust’s blog.

The list of other species of Plasmodium that have been reported to infect humans (sometimes only experimentally in the lab) includes P. brasilianum, P. cynomolgi, P. eylesi, P. inui, P. rhodiani, P. schwetzi, P. semiovale, P. simium and P. tenue.

A Research Agenda for Malaria Eradication: Drugs

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Abstract: Antimalarial drugs will be essential tools at all stages of malaria elimination along the path towards eradication, including the early control or “attack” phase to drive down transmission and the later stages of maintaining interruption of transmission, preventing reintroduction of malaria, and eliminating the last residual foci of infection.Drugs will continue to be used to treat acute malaria illness and prevent complications in vulnerable groups, but better drugs are needed for elimination-specific indications such as mass treatment, curing asymptomatic infections, curing relapsing liver stages, and preventing transmission. [Read more…]