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.

High Risk Areas for Malaria

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QUESTION:

Where are the high risk areas of malaria?

ANSWER:

Global malaria incidence rates (courtesy of the World Health Organisation)

Malaria is found in many tropical and sub-tropical parts of the world, although a few areas, through concerted control and prevention efforts, have eliminated the disease locally. Examples of this are the USA, most of the Mediterranean and parts of Central America. The highest burden of the disease is in Africa, although many parts of Asia, particularly India and south-east Asia, also suffer from a large number of cases every year. The map shows the risk of malaria around the world.

Illness from Uganda trip

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QUESTION:

I just came back from a visit to Uganda Africa. I was unable to take Malarone as I had bad side effects. Vomiting. I was only exposed once when we walked into a swampy rain forest. This of-course was the only day I did not have repellent. We were taking the kids on a nature walk and the German volunteer got a little lost. I ran as fast as could out of the area. Started to feel tired and weak 7 days later, getting severe headaches and going from hot to cold. 5 kids ended up with Malaria shortly after our walk. (I found this out after my return).

A missionary on the plain said I must likely had malaria and gave me Lumartem. By the time I got home I was having sever diarrhea and real bad body aches, low grade fever. The doctor here took my blood but reported my results would take 7 days. I started taking the Lumartem, & I felt better, the runs slowed down the boy aches lessened. Now I am finished with my 3 day prescription Feel pretty good compared to how I felt b4. Still have stomach cramps and small runs. What now? Should I go have a blood test to see if its gone or just wait and see???

ANSWER:

Considering you were in Uganda, it is not unlikely that you didn’t also pick up some sort of intestinal bug or parasite, which might be responsible for the residual runs and cramps. However, it is certainly important to take a blood test to ensure that you have completely cured the malaria infection; P. falciparum is common in Uganda, and causes a very severe form of malaria. While it can’t come back directly once it has been cured, if treatment is not entirely successful small numbers can remain in your blood stream and then start reproducing again once you have stopped taking medication, resulting in what is called “recrudescence” of the infection.

If possible, try to find out from the doctor that performs the blood test what type of malaria you had/have, as this will also determine whether you need additional medication (called primaquine) to prevent recurrence or relapse of the infection at a later date. Recurrence is due to a dormant phase of the malaria parasite hiding out in your liver; while P. falciparum cannot produce these dormant phases (and therefore can only relapse if the initial blood infection is not completely cured), two other malaria parasites, called P. vivax and P. ovale, can have liver stages, and so you may need to take primaquine if you are found to have been infected with either of these types.

Malaria Survey in Mumbai, India

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QUESTION:

I want the past year’s malaria survey in Mumbai and other states.

ANSWER:

The Lancet, one of the world’s leading medical journals, recently published an article summarising the mortality of malaria in India. The citation for the article is as follows:

Dhingra, Jha, Sharma, Cohen, Jotkar, Rodriguez, Bassani, Suraweera, Laxminarayan and Peto (2010), ‘Adult and child mortality in India: a nationally representative mortality survey’, The Lancet, 376: 1768-1774.

A slightly older article (from 2007) discusses the burden of malaria in India:

Kumar, Valecha, Jain and Dash (2007), ‘Burden of malaria in India: A retrospective and prospective view’, American Journal of Tropical Medicine and Hygiene, 77: 69-78.

Person to Person Malaria Transmission

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QUESTION:

If someone had malaria but they don’t have it any more can they give it to someone else?

ANSWER:

Regardless of whether a person is still infected with malaria or not, malaria can almost never be transmitted directly from one person to another.

Normally, malaria is only transmitted via infected mosquitoes; so, a mosquito has to bite an infected person, and then bite another person, and the malaria parasites are transmitted via the mosquito’s saliva to the second person. The exception to this is blood transfusions; in area where blood is not thoroughly screened, there have been cases of a person becoming infected with malaria after having received blood from a person with a malaria infection.

Secondly, although the actual disease cannot be transmitted this way, pregnant women who are infected with malaria can pass antigens and antibodies to their unborn child via the placenta, which can cause problems to the baby. For this reason, and others, preventing malaria in pregnant women is a huge priority in global malaria prevention.

Malaria and Loss of Red Blood Cells

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QUESTION:

What is the percentage of red blood cell that is lost at the onset of malaria symptoms?

ANSWER:

This depends entirely on the severity of the malaria infection, and also the type of malaria. Malaria parasites, called Plasmodium, invade red blood cells and use them for rapid, asexual reproduction. After a certain number of multiplications, the parasites burst out from the red blood cell, destroying it. This process leads to the reduction in red blood cells, and causes anaemia in the patient. The most deadly type of malaria, Plasmodium falciparum, takes just 24 hours to complete its cycles of reproduction. Therefore it can very rapidly produce many more parasites, which spread quickly through the blood, reducing the number of red blood cells very quickly.

Malaria Cases in West Bengal

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QUESTION:

What is the number of Malaria patients in West Bengal?

ANSWER:

West Bengal is one of the states considered highly endemic for malaria in India. In 1998, cases in West Bengal comprised approximately 6% of the total number of cases of all malaria in India (corresponding to 129,000 of the total 2.15 million cases reported that year), and approximately 3% of the cases of Plasmodium falciparum malaria, the most acute and deadly form of the disease. However, more recently, there are encouraging signs of decreasing mortality from malaria in West Bengal; in 2007, the number of reported deaths from malaria was 100, down from 203 in 2006 (the total number of cases in 2007 was estimated at 86,132).

White Blood Cells and Malaria

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QUESTION

Does malaria cause loss of white blood cells / antibodies?

ANSWER

The parasites that cause malaria reproduce in the human host by infecting red blood cells, then multiplying asexually and bursting out into the bloodstream, ready to infect more red blood cells.

As such, malaria parasites do not destroy white blood cells. However, patients with malaria may display reduced white blood cell counts during blood tests; this is usually thought to be due to relocalization of the white blood cells from the limbs (where blood is usually taken from during these tests) to the spleen and other internal organs also affected by the malaria infection.

As for antibodies, the malaria parasites contain antigens, which are proteins that cause an antibody response in the patient, thus usually resulting in an increase in antibodies during infection, especially if the patient has been exposed to malaria previously.

Can malaria parasites pass to children through breast milk?

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QUESTION:

Can breast milk transfer malaria parasites from a mother to the child?

ANSWER:

No. Malaria parasites cannot be transferred via breast milk. However, there is evidence that some antimalarial drugs can pass through breast milk, with unknown effects on the infant; as such, it is not recommended that breast feeding mothers take certain antimalarial drugs.

Studies in rats have also shown that antibodies to malaria can pass from a mother to her infant via breast milk although it is unclear what level of protection this confers on the infant; children under five are generally much more susceptible to malaria infection than older children and adults, due to their lower levels of acquired immunity, and so young children should be protected from exposure as much as possible, for example by having them sleep under long-lasting insecticide treated bednets when in high-transmission zones for malaria.

How soon can malaria occur a second time?

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QUESTION:

My son is studying in Tanzania and was diagnosed June 28, 2011 with malaria while taking Malarone. He took Duo-Cotecxin as prescribed for treatment and was feeling much better. He was given a “clear” blood test result. He started taking Malarone July 16, 2011 and on June 18, 2011 was ill again and diagnosed with malaria a second time in less than 6 weeks. Can malaria occur in this way or is there a possibility that the first case of malaria was controlled but not cured with Dus-Cotecxin and then esculated when he started taking Malarone again?

ANSWER:

There are two possibilities in this case; first of all, your son could have had what is called a recrudescence. This is where levels of the parasite in the blood drop to below detectable limits, and the immune system is able to keep the infection at bay. It can occur due to a failure to complete the course of antimalarial drugs, or indeed also due to treatment failure of the medication itself. Although Duo-Cotecxin is one of the recommended artemisinin-based combination therapies (ACTs) on the market for treatment of uncomplicated Plasmodium falciparum malaria, its cure rate is still at 98.7%, meaning that there is still a possibility of the drug not being completely effective in every instance. Moreover, there is a worrying indication that some strains of malaria are actually managing to become resistant even to ACTs.

The other possibility is that your son became re-infected, and it was a separate case of malaria; he was just very unlucky! This is highly unusual while taking Malarone as a prophylaxis, but it is possible. Determining which of these two scenarios occurred is difficult, but some information may be had from the type of blood test he had; clinics in Tanzania regularly use either blood film microscopy or rapid diagnostic tests (RDTs). Microscopy is notoriously insensitive as a diagnostic, and cannot reliably detect malaria parasites below a certain threshold, which depends on the skill and experience of the technician reading the blood slide. Therefore, if your son was declared negative for malaria based on this diagnostic, after the initial treatment, I think there is a good chance he was suffering from a recrudescence or treatment failure. However, if he was diagnosed by RDT, which is very sensitive to even low levels of malaria parasite in the blood, then I would think it might have been re-infection. However, I have concerns about the accuracy of RDTs so soon after infections have been cleared; the tests usually work by binding to malaria antibodies in the blood, which can sometimes persist even after the parasites have all been cleared. As such, you should also check what the diagnostic was the third time he was tested, and if this differed from the other two times; another possibility is that his infection really was cleared through treatment, and then got sick with something other than malaria; if they used an RDT on him at this point to diagnose malaria, they might have got a positive result confounded by his earlier infection. In these cases, you must ensure that the clinician takes a full history and so knows that the patient recently suffered from malaria; it may not be appropriate to use an RDT in this instance.

If your son is still in Tanzania and would like more information on malaria, he can contact us.  I am currently also working in Tanzania and so can perhaps help more if I know the details of his case (where he is based, etc). I would be happy to answer any questions he has.