How is Malaria Treated

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QUESTION

How is malaria treated?

ANSWER

This answer is copied from an earlier question about the various available cures for malaria.

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.

 

Three Attacks of Malaria

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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.

Who introduced malaria in which century?

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QUESTION

Who introduced malaria in which century, how does it cause malaria and what is the virus’ name?

ANSWER

Malaria wasn’t introduced; it has been evolving alongside humans for thousands, if not millions of years. The first known mention of malaria by humans is in an ancient Chinese medical text, from 2700 BCE (before common era). Other ancient people, such as the Romans and the Greeks, knew the symptoms of malaria and described it in writing.

Malaria is actually not caused by a virus, but a single-celled animal called a protozoan. The genus name of the protozoans that cause malaria is Plasmodium, and there are five main species that infect humans: P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi.

The malaria parasites cause the disease by entering into red blood cells and multiplying; when they have reproduced, they burst out of the red blood cell, destroying it. The patient’s blood is therefore rapidly full of malaria parasites, their waste products, plus bits of destroyed red blood cell; this produces an extreme immune reaction which causes many of the symptoms of malaria. In infection with P. falciparum, the most deadly and severe kind, infection with the parasite causes red blood cells to sequester in tiny red blood cells within major organs, causing reduced oxygen flow and complications. When this occurs in the brain, the result is cerebral malaria, which can result in convulsions and even a coma.

Signs of Malaria

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Hello my question is how do I see malaria signs if i haven’t gone to check yet?

 

The key is to recognise whether you have any potential symptoms of malaria, or if you have been bitten a lot by mosquitoes recently and live in an area where malaria is present. 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. 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 you live in a malarial area, you can always visit a clinic and see if they will do a test to screen you for malaria, even if you don’t have the above symptoms. People who live in malarial areas develop partial immunity to the disease, meaning that new infections do not always present themselves as acutely as when they were children, or in people who are being infected for the first time. As such, some people can have low levels of parasite in their blood and while they may feel tired or a bit under the weather, do not have specific symptoms. This is especially the case for the less severe and deadly forms of malaria, such as Plasmodium vivax, P. ovale and P. malariae, so if you live in an area where any of these three are present, it might be worth getting a malaria test even if you don’t have symptoms.

However, it is very important not to accept treatment unless you are confirmed as having a positive diagnosis for malaria; taking treatment without having the disease can lead to resistance to the medication, and you may also experience side effects, which, though usually mild, are still probably better to avoid!

Is it just a cold?

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QUESTION

I came back from a Kenya safari and Mombasa beach holiday 21 days ago.
I took my malaria tablets as prescribed, and only got 5 bites on my last morning.

Since yesterday, I have been feeling hot then cold, though not shivering or overly sweating. A headache which is constantly there. I have also today been sick after eating/drinking. Feeling really tired. Also sore throat and blocked nose which makes me think its more a cold, so don’t want to bother my GP.
Any advice would be appreciated.

ANSWER

Malaria does have an incubation period, which means that the symptoms only show up days or weeks (or in some cases, years) after the patient is bitten by an infected mosquito. Different species of malaria have different incubation times; Plasmodium falciparum, which is the most common form in sub-Saharan Africa, usually has shorter incubation times than P. vivax, a still-acute but less deadly form. P. falciparum incubation is usually between 1 and 3 weeks, although taking anti-malarial medication can extend it. As such, since you began experiencing symptoms within a few weeks of returning, there is definitely a chance it could be malaria, although less likely if you haven’t experienced any fever (this is a key symptom of malaria, and usually goes in cycles of about 48 hours). However, since malaria is a serious issue, and can progress rapidly if not treated, I would suggest you see your GP – if you tell them that you have recently returned from a highly malarial area, they will understand your concern! Alternatively, if you live near London, if you have a fever you can go straight to the A&E department of the Hospital for Tropical Diseases (HTD) in Warren Street, where they have doctors that specialise in traveller’s health and tropical medicine.

Chloroquine Resistant Malaria

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QUESTION

What is chloroquine resistant malaria?

ANSWER

Chloroquine-resistant malaria is exactly what it sounds like—particular types of malaria which are not cured by treatment with chloroquine.

Chloroquine was first discovered in the 1930s in Germany and began to be widely used as an anti-malaria post-World War II, in the late 1940s. However, resistance to the drug also rapidly emerged, with the first cases of Plasmodium falciparum not being cured by administration of chloroquine being reported in the 1950s.

Since then, resistance has spread rapidly (since obviously it is beneficial to the parasite to be resistant, so various mutations conferring this protection have arisen multiple times in different areas in the world and also been passed on preferentially to new generations of malaria parasites), and now chloroquine resistant P. falciparum can be found globally in malaria-endemic areas.

Chloroquine resistance in Plasmodium vivax has also now arisen, though more recently—the first reports came from 1989, in Australia, in travellers returning from Papua New Guinea. Now, chloroquine resistant forms of P. vivax are found in multiple locations in south-east Asia, such as Myanmar and India, as well as from Guyana in South America.

Nowadays, other drugs, and notably ones containing artemisinin-based compounds, are preferentially used to treat uncomplicated malaria and especially in areas where chloroquine resistance is known to occur. However, due to fears of resistance to these compounds also developing, the World Health Organisation recommends that artemisinin-based compounds only be administered in conjunction with other anti-malaria drugs, such as lumefantrine (which in combination with artemether forms the widely-used anti-malarial treatment Coartem). These combinations are known as artemisinin-based combination therapies, or ACTs for short.

Examination of Malaria Parasite

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QUESTION

How can you examine malaria parasites?

ANSWER

Malaria parasites are usually examined under a microscope using a peripheral blood smear method (also called a blood film). Thick blood smears, which use a large unsmeared drop of blood, are sensitive since a large number of red blood cells can be examined, though the parasites, if present, are difficult to distinguish morphologically.

For species-level identification of malaria parasites, a thin blood film is more commonly used, whereby a small volume of blood is smeared thinly across the slide and then stained, usually with Romanowsky stain, in order to see the detailed structures which differentiate the different species of malaria. It is crucial to make the blood films soon after the blood sample has been taken, and to store the blood in an appropriate anti-coagulate.

Characters to look out for include the presence of Maurer’s dots on the surface of red blood cells infected with Plasmodium falciparum. You may also see multi-infected red blood cells with this species, and it is rare to see mature trophozoites or schizonts with this parasite since when this stage is reached the red blood cells are usually sequestered deep within major organs and so are not readily present in the peripheral blood.

These parasites have crescent-shaped gametocytes. Plasmodium vivax, on the other hand, enlarges red blood cells that it infects and seems to show a preference for immature red blood cells. The presence of Schüffner’s dots is also characteristic – these looks like specks or granules on the cell surface of the infected red blood cell. P. ovale is very similar to P. vivax, in that it also enlarges the red blood cells and can have Schüffner’s dots, but fewer merozoites tend to be present per cell and infected red blood cells tend to look elongated. P. malariae does not alter the size or shape of the red blood cell it infects and tends to form rosette-like patterns of 8-10 merozoites. Later on in maturation, its trophozoites may form characteristic band-like patterns across the cell.

Schizont

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QUESTION

What is a schizont?

ANSWER

A schizont is a malaria parasite which has matured and contains many merozoites, which are the parasite stage that infects red blood cells.

Schizonts can be produces during two separate phases of the life cycle within the human host: first in the hepatocytic cells in the liver (when sporozoites mature) during the exo-erythrocytic cycle and then within the red blood cells during the erythrocytic cycle (when trophozoites mature and divide).

When malaria parasites do not immediately mature into schizonts in the liver (as can be the case with Plasmodium vivax and P. ovale infections), the parasite instead becomes a hypnozoite, which can lay dormant in the liver for many weeks or even months (or, in rare case, years), and produce relapse of infection at a much later date.

Paludisme Depuis 5 Mois (Malaria for 5 Months)

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QUESTION:

En fait je souffre d’un palu que le médécin a mal traité après une analyse sanguine. J’aimerais savoir comment faire pour m’en débarrasser car je traine ce palu maitenant depuis 5 mois.

ENGLISH TRANSLATION:

In fact I suffer from malaria which the doctor has treated poorly after a blood test. I would like to know how to clear myself of this because I have been carrying this malaria now for 5 months.

ANSWER:

C’est rare de souffre telle longtemps que 5 mois continuellement avec palu; plus commun c’est de observer plusieurs episodes d’infection en serie, si la traitement n’est-ce pas un succes. Mais tout ca depend un peu du type du palu. Vous devrez tenir un autre test sanguine pour determiner ce type du palu, de preference au hôpital ou dans un clinique de santé. Avec celle information, le médécin peut vous recommender un traitement approprié. Par example, si vous avez un infection de Plasmodium vivax ou P. ovale, le parasite peut rester en repos dans le foie pendant plusieurs semaines ou bien plusieurs mois. Des médicaments qui traitent l’infection dans le sang, comme chloroquine ou ACTs, ne touchent pas cette stages de vie dans le foie. Dans ce cas, vous devez parler avec votre médécin sur un autre médicament, qui s’appelle primaquine, qui tue a les parasites dans le foie et previent encore plus de rechutes.

ENGLISH TRANSLATION: It’s rare to suffer from malaria continuously for five months; it is more common to see multiple infections over and over in series, if the disease is not treated appropriately. But all of this depends on the type of malaria that you have. You need to have another blood test to determine the type of malaria, and based on this information, the doctor can give you appropriate treatment. For example, if you have Plasmodium vivax or P. ovale, the parasite can rest dormant in the liver for several weeks or even months. The drugs which treat the initial infection in the blood, such as chloroquine or ACTs, don’t affect these liver stages. In this case, you must talk to your doctor about taking another medication, called primaquine, which kills the liver stages of the malaria parasite and prevents further relapses of the disease.

Pathophysiology of Malaria

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QUESTION

What is the pathophysiology of malaria?

ANSWER

Malaria causes disease through a number of pathways, which depend to a certain extent on the species. Malaria is caused by a single-celled parasite of the genus Plasmodium; there are five species which infect humans, being Plasmodium falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi.

All these species are introduced into the human blood stream through the bite of an infected mosquito; the life stage of malaria at this point is called a “sporozoite”, and they pass first to the liver, where they undergo an initial stage of replication (called “exo-erythrocytic replication”), before passing back into the blood and invading red blood cells (called “erythrocytes”, hence this is the “erythrocytic” part of the cycle). The malaria parasites that invade red blood cells are known as merozoites, and within the cell they replicate again, bursting out once they have completed a set number of divisions. It is this periodic rupturing of the red blood cells that causes most of the symptoms associated with malaria, as the host’s immune system responds to the waste products produced by the malaria parasites and the debris from the destroyed red blood cells. Different species of malaria rupture the red blood cells at different intervals, which leads to the diagnostic cycles of fever which characterise malaria; P. vivax, for example, tends to produce cycles of fever every two days, whereas P. malaria produces fever every three.

In addition, Plasmodium falciparum produces unique pathological effects, due to its manipulation of the host’s physiology. When it infects red blood cells, it makes them stick to the walls of tiny blood vessels deep within major organs, such as the kidneys, lungs, heart and brain. This is called “sequestration”, and results in reduced blood flow to these organs, causing the severe clinical symptoms associated with this infection, such as cerebral malaria.

More details on the exact biochemical mechanisms for sequestration and its effect on the pathology of the infection can be found on the Tulane University website.