What is malaria?

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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?

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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.

How quickly should patient take medicine for malaria?

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QUESTION:

My sister has been suffering from malaria for three months. She consulted with doctor in the first symptom of malaria but doctor gave only fever medicine at that time. Blood test was not done at that time. So my question is: “within how many days or months malaria patient has to immediately take medicine?”

ANSWER:

One of our collaborating medical doctors has assisting in providing this answer:

It depends on the type of malaria….with Plasmodium vivax infection she could have a low burden due to concurrent treatment or recent prophylaxis which is breaking through because of low grade resistance. Alternatively, it could be P. malariae or P. ovale, both of which sometimes cause only mild disease that may or may not progress.  P. falciparum shouldn’t act this way; it is usually a much more severe, aggressive infection. Another option is that she might not have malaria at all.  She needs qualitative and quantitative smears to confirm the diagnosis, together with a comprehensive travel/exposure history to support any clinical suspicions.

 

 

Plasmodium Vivax Shows Malaria Infection?

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QUESTION:

If there is Plasmodium Vivax present, then is the patient infected with malaria or not?

ANSWER:

Yes! Plasmodium vivax is one of the several different species of malaria that can infect humans and cause disease. The other main species found in humans are Plasmodium falciparum, P. ovale and P. malariae.

Malaria Fever

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QUESTION:

How many days will the fever last?

ANSWER:

There is no set amount of time for the duration of a malaria fever, and in fact it will depends on several factors, namely the type of malaria the patient has, their level of acquired immunity, whether they were taking preventative medicine for malaria (prophylaxis) at the time of infection and how quickly they receive appropriate treatment.

There are, however, known “cycles” to the progression of fever during a malaria infection. Plasmodium falciparum, P. vivax and P. ovale, three of the types of malaria that normally infect humans, are known as “tertian” malarias, as they produce fevers that peak every two days. P. falciparum, due to its severity and rapid increase in the human host, can sometimes present with more frequent, or even constant, fever. P. malariae, on the other hand, is considered a “quartan” malaria, as it produces fever in approximately three-day cycles.

Do I have malaria?

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QUESTION:

Hi, I went to Ivory Coast August/2003 back March/2004, took some pills to help prevent Malaria on my trip but ran out and did not get more. While I was there I got many mosquito bites.

Around October/03 became very sick, got tested for malaria at the hospital in Quebec but negative. Now May/2011 still have all the same symptoms, flu like symptoms, feeling cold most of the time, chills headaches, tired.

Is there any way I got it? I’ve gone to doctors and doctors and no one can seem to find what is causing this? I am tired of taking tylenols all the time for the body ache. My wife is from there and she’s so sure that I got it from seeing how I am since she’s been around it all her life. Can you help me?

ANSWER:

There are definitely types of malaria that can cause relapses of symptoms many months or even years after an initial infection. These types are not common in the Ivory Coast but if you had many mosquito bites then it is certainly possible that you were exposed. What kind of test did you have for malaria when you returned to Canada?

Often, the test is by looking at a microscope slide of your blood under the microscope—the problem with this test is that it is not very sensitive for low levels of malaria, for example, after the worst of infection, and especially with the types of malaria that cause relapse (these types, P. ovale and P. malariae being the ones you might expect from Ivory Coast, tend to cause less severe illness than the more common type of malaria in Africa, called P. falciparum, doesn’t relapse in the same way, but results in much higher levels of the malaria parasite in the blood, which makes it easier to diagnose on blood slides). Also, since malaria is relatively rare in northern countries like Canada, laboratory technicians are not as experienced at diagnosing the parasite as they are in countries where malaria is endemic.

Having said that, there are of course lots of other illnesses which also cause symptoms similar to that of malaria – fevers, chills, etc. What I would recommend is that you re-visit the doctor, and ask for a more sophisticated test for malaria. Mention that you have had a relapse of symptoms—this should prompt them to use more sensitive tests, such as PCR or a rapid diagnostic test, and to look specifically for P. ovale or P. malariae. Not only will this answer your question about whether you have malaria, but it will allow the doctors to give you the appropriate treatment for your current symptoms (probably chloroquine) as well as treatment to prevent any further relapses (primequine).

Hope this helps!

Causes of malaria

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QUESTION:

What are the causes of malaria?

ANSWER:

Malaria is caused by parasites of the genus Plasmodium. These are single-celled animals known as protozoans (from the Greek ‘protos’ and ‘zoia’ which together mean ‘first animal’) and they are transmitted via mosquitoes that feed on blood; the parasites need both mosquito and human hosts to complete their life cycle (see below a graphic of the complete life cycle, courtesy of CDC). In the process of reproducing, the malaria parasites destroy human red blood cells, which is what causes the clinical symptoms of disease that the patient experiences, such as fever, headaches and nausea.

Malaria life cycle CDC

Generalized malaria life cycle (courtesy of CDC: www.cdc.gov)

There are four main species of Plasmodium that infect humans: P. falciparum, P. vivax, P. malariae and P. ovale. P. falciparum causes the most severe manifestations of the disease and is responsible for the majority of human deaths from malaria. There is a fifth type of malaria, P. knowlesi, which usually infects macaque monkeys but has been known to pass into humans as well.

For more on this, please see Christina Faust’s excellent blog post about her research.

What are the strains of malaria?

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QUESTION:

What are the different strains of malaria?

ANSWER:

Malaria is caused by small, single-celled parasites called protozoans, and specifically ones of the genus Plasmodium. There are many, many species of Plasmodium, which infect a wide variety of different species, from lizards and birds to rodents, bats and primates. Of all the species of malaria, four main ones infect humans – these are P. falciparum, P. vivax, P. ovale and P. malariae. A fifth species, P. knowlesi, usually infects macaque monkeys in South East Asia but has been known to cross over to humans. Each of these species causes slightly different manifestations of the disease in humans, and even within the species, there are regional strains and variations. Probably the most distinct internal division within a malaria species is within P. ovale, where two sub-species are currently recognised: P. ovale curtisi and P. ovale wallikeri. These two forms are identical morphologically (that is, in the way they look under the microscope) but can be differentiated genetically.

Started Late on Anti-malaria Medication

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QUESTION:

I’m in a malarious country and I had no idea about anti-malarials until I got here, so I started taking anti-malaria(doxycicline) two weeks late. It has been three weeks since I started taking the medicine. Do you think it would work or should I stop taking it?

ANSWER:

It depends a bit on where you are, and what types of malaria are in your region. Plasmodium falciparum usually takes between 7 and 14 days for symptoms to develop after exposure; P. vivax and P. ovale take between 9 and 14 days. P. malariae, on the other hand, sometimes doesn’t show symptoms until 30 days after infection. However, the most acute and dangerous form of malaria is that caused by P. falciparum; as such, if you haven’t had any symptoms since you started taking anti-malarials three weeks ago, you should be ok, and it certainly would be advisable that you continue with the preventative medicine while you remain in the malarial area.

It’s also worth mentioning that because of the lag between infection and symptoms, in many cases you need to continue taking antimalarials for some period of time after you leave the malaria zone. Of course, if at any point you start to develop symptoms, such as fever or chills, go to a hospital or see a doctor for prompt diagnosis.

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.