BT and MT Malaria

QUESTION:

What is MT and BT malaria?

ANSWER:

“MT” stands for “malignant tertian” and “BT” stands for “benign tertian” malaria. Tertian malaria describes fever which occurs every other day, in cycles. Of the main types of human malaria, Plasmodium vivax and Plasmodium ovale are the most stereotypically tertian. P. falciparum can be tertian, but it is more erratic and due to its severity, can result in increased frequency of fever. “Malignant” and “benign” refers to the severity of the disease. Malignant malaria is severe and sometimes fatal, whereas benign malaria is less acute and rarely results in death.

Incubation Period for Malaria

QUESTION:

What is the incubation period of malaria?

ANSWER:

That depends on the species of malaria. Plasmodium falciparum has the shortest incubation time, typically 10 to 14 days. For P. vivax, incubation is usually between 10 to 17 days, but can be much longer (up to a year; the longest incubation time recorded for this species was 30 years!). P. ovale has an incubation period similar to that of P. vivax, and can also be dormant for many months or even years. P. malariae is thought to have an incubatiom time of between 16-59 days.

Will malaria come back?

QUESTION:

As a result of a blood test I have just been informed that at some time I have had malaria. Though I have no idea when this was. I once was ill for 4 days with what I thought was flu and that is the only occasion I can remember. Therefore I have never been treated for malaria. Could you please tell me if there is any chance the disease will come back.

ANSWER:

That will depend on the type of malaria you had. I presume you found out you were infected through a blood test – it is likely a test that looked for antibodies to malaria in your blood. These tests can sometimes differentiate between the different species of malaria, and so it is definitely worth asking the clinic or doctor that performed the test if they can give you this information. Your location, or places where you have travelled in the last 4 years, may also assist in determining which type of malaria you had. Given that you barely registered being sick, I would suspect that you probably didn’t have Plasmodium falciparum, which is usually the most severe kind; it also cannot survive dormant in your system for long periods of time, so if you happened to have this kind, you wouldn’t need to worry about it coming back (though of course you can still be re-infected by all types of malaria, so prevention is still important!).

However, the other three main types of malaria can linger in a patient’s body. P. malariae is the least acute of all the malaria species, and can survive for a long time in the bloodstream, meaning that some people can have the infection for long periods of time without really feeling sick. If the blood test you took looked directly for parasites in your blood, and you tested positive, it is likely you have this kind. Like all uncomplicated cases of malaria, it is easily treatable, and once cured, you won’t have worry about it coming back (again, you do still need to watch out for being bitten by mosquitoes and getting re-infected though!).

The final two types of malaria are P. vivax and P. ovale. These persist in the body in a slightly different way than P. malariae – these have a special life stage which can lie dormant in the liver. Months or even years later, these dormant stages can re-activate and enter the blood stream, causing the patient to feel symptoms again, such as fever and nausea. Therefore, if you find you tested positive for one of these two forms, it is very important to ask your doctor about receiving medication (called primaquine) that will specifically target the liver stages of the parasites, to ensure you don’t get a recurrence of the infection later on.

As I’ve mentioned a couple of times earlier in this response, a key thing to be aware of is that even if you don’t have a recurring form of malaria, or treat it successfully, you will still be susceptible to re-infection if you are bitten by an infected mosquito. As such, if you live in or travel to a region known to have malaria transmission, it is crucial to take steps to prevent infection. For example, sleeping under a long-lasting insecticide treated bednet greatly reduces your risk of being bitten by the mosquitoes that carry malaria; similarly, wearing long-sleeved clothing and insect repellent, especially at night when malaria mosquitoes are most active, is recommended. Finally, medication is available that can be taken to prevent malaria (these are called prophylactics). As they can be expensive and are not recommended to be taken over long periods of time, these tend to be used primarily by people travelling to malarial areas rather than residents. There are several different forms of these prophylactics available commercially; the one to use will depend on several factors, including where you are travelling to.

Why do people die of malaria?

QUESTION:

Why is it that people die of malaria?

ANSWER:

The symptoms of malaria are caused by the malaria parasite reproducing inside the patient’s red blood cells and eventually destroying them. In this process, the malaria parasites also produce toxic waste chemicals and debris which build up in the patient’s blood stream. The body produces a strong immune response as a reaction to these toxic products and debris; most of the systemic symptoms associated with malaria, such as fever, aching muscles and joints and nausea, are related to this immune response. Infected red blood cells can also build up in internal organs, notably the spleen and the liver, causing them to swell.

Despite these nasty-sounding effects, most cases of malaria are relatively benign and don’t lead to death. However, in some cases, the manifestation of the disease can become more severe. Most commonly, this occurs when a patient is infected with Plasmodium falciparum, one of the four main kinds of malaria that infect humans, and by far the most severe. P. falciparum reproduces very rapidly in the human host, causing extremely high fever and a fast onset of symptoms. It also changes the structure of the red blood cells it infects, causing them to become “stuck” deep within tiny blood vessels and especially in major organs such as the brain, intestines, liver, heart and lungs. Stuck within these blood vessels, the infected red blood cells are effectively hidden from the immune system and are not cleared from the body via the spleen. This allows the malaria parasite’s reproduction to go unchecked, resulting in very high numbers of the parasite in the patient’s blood.

If left untreated, the build-up of infected red blood cells can result in severe anaemia, reduced local oxygen flow and the blocking of the immune reaction; the exact mechanisms are not fully understood. When these processes occur in the brain, the result is so-called “cerebral malaria”, characterised by impaired consciousness, and which can lead to convulsions, coma and death. Even if a patient recovers from the disease episode, they may be left with permanent neurological damage. Luckily, malarial comas are often rapidly reversed after treatment is administered, and in many cases, neurological damage is not permanent.

Malaria Schizonts

QUESTION:

What is the difference between schizont of Plasmodium vivax and P. falciparum?

ANSWER:

P. falciparum schizonts tend to fill up to about two-thirds of the host red blood cell, and contain 8-24 merozoites (see image below for development of schizont). However, schizonts of P. falciparum are rarely seen in peripheral blood; instead, multiple, smaller rings are the usual diagnostic sign. Characteristic crescent-shaped gametocytes may also be observed, though usually later on in infection.

 

falciparum schizont CDC

The stages of maturation of a Plasmodium falciparum schizont. Image courtesy of CDC (www.dpd.cdc.gov)

P. vivax schizonts are large and fill up the entirety of the red blood cell with 12-24 merozoites, each containing visible chromatin and cytoplasm (see below). Their size and shape can differentiate them from the more compact P. ovale and P. malariae schizonts, though separating the former can sometimes be difficult.

vivax schizont CDC

The stages of maturation of a Plasmodium vivax schizont. Image courtesy of CDC (www.dpd.cdc.gov)

Can malaria cause kidney failure?

QUESTION:

Can malaria be a cause for kidney failure or brain fever?

ANSWER:

Malaria, and specifically Plasmodium falciparum malaria, the most severe and deadly form of the disease, can certainly cause both renal failure and brain fever. It usually does this by infecting red blood cells, which then become blocked in tiny blood vessels deep within organs. This process is called sequestration. When sequestration happens in the brain, the effect can be so-called “cerebral malaria” or brain fever. In the kidney, this can result in kidney failure. Given these severe consequences, it is crucially important to seek diagnosis and then treatment immediately if you are concerned you might be suffering from malaria.

What is “Pf” and “Pv” in relation to malaria?

QUESTION:

What is pf and pv?

ANSWER:

“Pf” stands for Plasmodium falciparum and “Pv” stands for Plasmodium vivax. These are two different species of the parasite that causes malaria in humans. Pf causes the most acute, severe form of the disease, which can have a cerebral manifestation (“cerebral malaria”) and causes the most deaths worldwide. Pv is still a serious disease, but usually less severe. If diagnosed early, both forms are easily treated and completely curable.

high fever after malaria is cured?

QUESTION:

My dad was infected with malaria,and his blood platelets were depleted to 35000. He was immediately admitted to hospital. Now after 5 days of being admitted, he is getting high fever around 102 degrees every morning and evening. His blood platelets have increased to 3lac and all other reports are normal. According to the doctor, the malaria is cured, but they are not able to detect the reason for periodical high fever…is such fever common after malaria? What might be the reason? Please help.

ANSWER:

One of our collaborating medical doctors has kindly assisted in providing this answer. Fever can be from co-infection with a second strain/type of malaria, or from the drug being used to treat the malaria.  If his platelets were that low, then the likely type of malaria causing the infection would be Plasmodium falciparum, or a particularly heavy P. vivax burden, or infection with both. If he was/is in the hospital, other causes for fever could also be the IV line/another drug being given, complications such as pneumonia from being at bedrest or so ill, cholecystitis from not eating due to illness, DVT or blood clots in legs from immobility….there are many possibilities. More information would be needed to distinguish between these options.

What is malaria?

QUESTION:

What is malaria?

ANSWER:

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.

What pathogenic organisms cause malaria?

QUESTION:

What pathogenic organism causes the disease?

ANSWER:

Malaria is caused by single-celled organisms, called protozoans, of the genus Plasmodium. Different forms of malaria are caused by different species of Plasmodium. The most severe and deadly form is caused by P. falciparum, which is responsible for 90% of the global deaths from malaria, the majority of these in Africa, and mostly in young children. Other species of Plasmodium which commonly infect humans include P. vivax, P. ovale and P. malariae. Recently, a fifth form, P. knowlesi, has been found infecting rural communities in south-east Asia.

The disease is caused when the parasite enters the patient’s red blood cells, reproduces rapidly and then bursts out of the cell, destroying it in the process. The resultant immune response, combined with the chemicals and debris produced by theparasites, induces the fever, nausea, aches and other symptoms of a malaria infection.