Recurrence of Malaria

QUESTION

If a person treated for malaria after being infected from a malaria endemic country of West Africa and cured then he travel back to his country which does not known for malaria endemic region of the world. Question is: Is there any chance of re-occurrence even he is not being exposed to malaria spreading mosquito for some time may be year?
Is it true Malaria parasites stays in liver as hibernation for a long period and attack after many months or year?
If so what treatment can prevent it?

Please advise.

ANSWER

There are several different types of malaria which are found in West Africa, and the most common and deadly form, Plasmodium falciparum, is not able to hibernate in the liver. However, two other types of malaria are able to lay dormant in the liver – these two kinds are called Plasmodium vivax and P. ovale. Both are not nearly as common as P. falciparum in West Africa, though P. ovale has been reported at prevalences of over 10% in some areas, which is double its usual prevalence elsewhere in the world. Weeks, months or even years after an initial infection with P. vivax or P. ovale, the patient may experience what is known as a relapse, which is when the dormant liver forms become active again and re-invade the blood stream, causing a renewal of malaria symptoms. These relapses can be treated with normal anti-malarial drugs (even chloroquine, in many cases), but a different drug is required to kill the dormant liver forms and prevent future relapse. This drug is called primaquine, and may not be suitable for people with certain types of G6DP deficiencies, so you should talk to your doctor about having a test for this condition before taking primaquine.

Dormant Malaria

QUESTION

I was bitten by mosquitoes many years ago and I was wondering can the symptoms lie dormant for as long as 40 years? The reason I am asking is that every summer I am ill with several of these symptoms. I do not have a good immune system.

ANSWER

There are a couple of types of malaria, namely Plasmodium vivax and Plasmodium ovale, which can lie dormant for many years, and often cause relapses at regular intervals.

Next time you suffer from these symptoms, you should go to your doctor and have a blood test to check for malaria; while you are experiencing symptoms, if you have malaria, the parasites will be visible in your blood.

Once positively diagnosed, your doctor can provide you with treatment. If you do have malaria, you will need one medication to clear the infection from your blood (which kind depends on where you were when you got those mosquito bites; malaria has become resistant to certain types of medication in some areas), plus another type of medication to kill the dormant forms which are responsible for the yearly relapses. This latter medication is called primaquine, and is not recommended for people with G6DP deficiency, so you should be tested for this prior to taking the medication.

Having said all of that, it is very important to get the blood test if you suspect you have malaria, because the symptoms of malaria are very general (fever, chills, nausea, aches) and can be mistaken for many other illnesses. If your blood test is negative for malaria, then you should talk to your doctor about other possible infections.

Malaria Fever

QUESTION

My Father aged 65 years was diagnosed with 2 types of malaria almost a week back. he has been given medicines but temperature is fluctuating and not coming down. all other organs are functionining properly except platelet count which is little less.

Now he has been suggested new medicines for a duration of 14 days.
How fast can he recover from this malaria and when will the fever come down?

ANSWER

When patients are given the appropriate treatment against malaria, the fever is usually reduced very quickly and the patient will start to recover after a few days. The right kind of treatment depends on the severity of the infection and the type (or, in your father’s case, types) of malaria the patient is infected with.

If your father was infected with P. falciparum alongside another type of malaria (probably P. vivax, P. malariae or P. ovale), then he should have first received an artemisinin-based combination therapy (ACT) drug first. These drugs combine artemisinin or a derivative (such as artemether, artesunate or dihydroartemisinin) with another anti-malarial, such as lumefantrine. Common brand names of these ACTs include Coartem, Alu and Duo-Cotecxin.

There are no reported cases of resistance to these combination therapies at present, so if your father continued to feel sick after completing this treatment, he should be re-tested for malaria; it is possible that the malaria parasites were killed, and his continuing fever was an after effect either of the medication or just an indication that the body was recovering from the infection.

If he was re-tested and found positive, then other second-line drugs can be prescribed. However, it is important to note that malaria is resistant to chloroquine in many areas, and so this drug is not suitable for treatment in these places. Similarly, resistance is widespread to sulfadoxine-pyrimethamines, such as Fansidar, and in south-east Asia, P. falciparum is also resistant to mefloquine (Lariam) in some cases. As such, your father’s doctor should be careful to prescribe him an appropriate treatment for the area in which he is living.

In addition, if your father was found to be co-infected with either P. vivax or P. ovale, then there is a chance of later relapse into malaria again, weeks or even months after the initial infection has been treated. This is because the parasites in these types of malaria can form dormant stages in the liver, where they escape being killed by the normal forms of treatment. In this case, your father should ask about the possibility of being treated with primaquine; the course is normally 14 days, so it may be that this is what his doctors have currently given him. If so, this will kill the dormant liver stages and prevent relapse. Prior to taking primaquine, patients should be tested for G6DP deficiency, as patients with this condition may become dangerously anaemic when they take primaquine.

Malaria Recurrence

QUESTION

I had malaria 5 months back it has again reoccurred. this time there has been increase in the size of the spleen. As of now it is being treated but I fear of getting it again. Is it true the malaria which i am down with reoccurs every 6- 8 months ??? Local people call it as registered malaria.. .

ANSWER

There certainly are types of malaria that can reoccur relatively regularly, at various intervals. This malaria is caused by one of two species, either Plasmodium vivax or Plasmodium ovale.

With both, it is important to get it diagnosed via a blood test with a doctor before getting treated again, to make sure it is indeed a relapse of the same malaria, and not a new infection with a different kind, or indeed some other disease (the symptoms of malaria can often be confused with other infections).

There is also medication that can be taken to prevent future relapses and re-occurrences—it is called primaquine, so you should talk to your doctor about the possibility of taking this medication. Please note it is not suitable for people who have G6DP deficiency, so you should be tested for that before taking it.

Repeated Malaria Cases, New Guinea

QUESTION

Hello, I live in Papua New Guinea. Myself, my wife and my 2 kids (both under 4 years old), get diagnosed with malaria approximately 3-4 times a year, usually vivax or falciparum. Our GP uses a prick of blood and examines under a microscope. Is it that easy/obvious to diagnose under this method and is it common to get this many attacks in a year? I also fear the affects of taking malaria tabs (eg Fansidar, Primaquin, Artemeter, Amodiaquine) this many times, especially for my young kids. Please help!

ANSWER

In high transmission areas, particularly in rural areas in sub-Saharan Africa, it certainly isn’t unusual for children to get as many a 5 or 6 malaria attacks in a year; adults tend to present with fewer clinical episodes, usually because they were heavily exposed as children and thus developed a significant level of immunity against malaria.

If you and your wife didn’t grow up in a malarial area, then you would not have that acquired immunity, and so you would be expected to get sick almost as often as your young children. Papua New Guinea certainly is a high transmission zone, and I think one thing which might help your family is to focus more on malaria prevention. Since malaria is transmitted by mosquitoes, the best way to avoid getting malaria is to avoid getting bitten by mosquitoes. You should all be sleeping under log-lasting insecticide-treated bednets, which kill and/or repel mosquitoes that try to bite you while you sleep (the mosquitoes that transmit malaria, of the genus Anopheles, are most active at dusk, at night, and at dawn—during the heat of the day they usually don’t feed, but may be found in cooler, heavily shaded areas).

You could also try spraying the walls of your house with a long-lasting insecticide like permethrin, which will also kill adult mosquitoes. Making sure your house is well-screened will also prevent mosquitoes from getting in and biting you at night and in the evenings, and if you are going out during these times, you and your family should wear long-sleeved clothing, and exposed skin should be covered with insect repellent. A DEET-based insect repellent is best, but you may not be comfortable using these regularly on young children, since it can have some potentially dangerous long-term effects, particularly on the liver.

In terms of your other questions, looking at your blood under the microscope is the normal way to diagnose malaria in many places, so it sounds like your GP is doing a good job. There is no indication of adverse effects from taking multiple, repeated doses of anti-malarials, but as I mention above, taking additional preventive measures may further help in reducing your family’s malaria incidence.

One thing you might want to talk to your doctor about is the fact that in some cases, Plasmodium vivax can cause relapses of infection weeks or even months after the initial infection. The reason is that P. vivax can form dormant life stages, which can hide out in the liver, and cannot be killed by the normal anti-malarial treatment. However, there is a medication, called primaquine, which can kill these liver forms, and prevent future relapse. People with a deficiency in a particular enzyme, called G6DP, may not be able to take this medication, as it may cause severe anaemia, so prior to taking the drug you might have to be tested for this deficiency. However, it is definitely something you should talk to your GP about.

Please take a moment to complete our Malaria Survey, as it will help us better understand the effects of malaria medications.

P.vivax Malaria Treatment

QUESTION

Which drug should be given to a p.vivax malaria patient with deficient glucose 6-phosphate for prevention of relapse?

ANSWER

Unfortunately, primaquine is the only drug that is known to kill the latent liver stages of P. vivax and P. ovale. Since it can induce haemolysis in people with G6DP deficiency, this drug is usually not recommended for people with this deficiency. However, there are actually gradations of severity of G6DP deficiency, and so in some cases, primaquine at therapeutic doses may be tolerated by people with only mild G6DP deficiency, if they are carefully monitored for anaemia throughout the process. This may be preferable to no treatment, since no other known medication can prevent relapse.

Malaria Treatments

QUESTION

What are the of different types of antimalaria drugs?

ANSWER

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

  • chloroquine
  • atovaquone-proguanil (Malarone®)
  • artemether-lumefantrine (Coartem®)
  • artesunate-pyronaridine (Pyramax®)
  • dihydroartemisinin-piperaquine (Duo-Cotecxin®)
  • mefloquine (Lariam®)
  • quinine (given intravenously, this is recommended first-line treatment for severe, complicated malaria)
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)

All of the treatments above which combine an artemisinin-derivative (such as artemether, artesunate or dihydroartemisinin) in combination with another anti-malarial are called the artemisinin-based combination therapies (ACTs) and are collectively recommended by the World Health Organisation as the first line medication against uncomplicated malaria.

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

Malaria Prophylaxis in Ghana, Africa

QUESTION

My husband will be traveling to Ghana soon. We have Mefloquine and Primaquine. Which one do you think is best for prophylaxis in Ghana? He also has Fansidar, but we understand it’s best not to use this for prophylaxis. Thank you for your help!

ANSWER

There are positives and negatives associated with both of these medications. Mefloquine is recommended for travelers in Ghana (whereas the Centers for Disease Control does not explicitly recommend primaquine for this area, since primaquine is particularly effective against Plasmodium vivax malaria, which is almost completely absent from West Africa), and only has to be taken once a week (primaquine must be taken daily).

A disadvantage with mefloquine is that you must start taking it 2 weeks before your trip, whereas primaquine can be started as little as 1-2 days before travel; mefloquine is also not recommended for people with a history of psychiatric or mental problems, as it can cause severe side effects. Even healthy individuals often report disturbing dreams or increased agression/anxiety while taking mefloquine. However, one major disadvantage to primaquine is that you must be tested for G6DP deficiency prior to taking it – your husband may have already done this, prior to being prescribed the drug. People with G6DP deficiency should not take primaquine.

Overall, the decision comes down to personal preference, though from a disease perspective, mefloquine would probably be the better choice for travel to Ghana, given the higher prevalence of P. falciparum malaria in this region, as opposed to P. vivax. Other options to consider would be atovaquone-proguanil (Malarone – expensive, taken daily, but very effective and very well tolerated by most people, with very low side effects) or doxycycline (very cheap, taken daily, is an antibiotic so can prevent some other infections but often results in sun sensitivity, which can be a problem in the tropics). Both of these can be started 1-2 days before arriving in the malarial area.

After you come back, I would be very grateful if you could take our malaria medication side effects survey, as we are very interested in hearing from our readers what their experiences with malaria prophylaxis and treatment have been.

Reoccurring Malaria

QUESTION

Can malaria reoccur year after year from a single infection? I have been told that it comes back every year by many people. I have had malaria once and it never came back after successful treatment. My thinking is that once the parasite has been eliminated from the system it is gone unless you get bitten again.

ANSWER

There are several different types of malaria that infect humans, and two of these species (Plasmodium ovale and Plasmodium vivax) can recur from year to year after a single infection.

The way it happens is that these types of malaria are able to form dormant life stages which hide in the liver. Most malaria medication only targets the blood stage form of malaria, and so these liver stages escape being killed by the medication, and can survive for long periods of time without the patient knowing about them. Then, at some point later (no one knows exactly what triggers the relapse—there is evidence that infection with other forms of malaria can instigate relapse, or being bitten by mosquitoes, or even just the climate), the liver stages activate again and re-enter the blood stream, which causes a renewal of symptoms.

It is possible to prevent these relapses—there is one type of medication, called primaquine, which is able to kill the dormant liver stages and thus completely clear the patient of malaria. However, it is important to talk to your doctor before taking primaquine, as it is not suitable for some people (especially those with G6DP deficiency).

Apart from these two types of malaria, the other three forms that infect people (P. falciparum, P. malariae and P. knowlesi) cannot reoccur in the same way as described above – if you have been infected with one of these, and then been successfully treated, you cannot get the disease again unless you are bitten by another infected mosquito.

Treatment of Chronic Vivax Malaria

QUESTION

What is the treatment of chronic Vivax malaria?

ANSWER

Blood stage infection with Plasmodium vivax can usually be treated successfully with chloroquine, though resistance is spreading in some areas (notably the Pacific Islands, Papua New Guinea, parts of south-east Asia and especially Indonesia, and Peru). P. vivax is also sensitive to artemisinin-based combination therapies (ACTs) and as no resistance to artemisinin has been reported, these are widely recommended (though combinations which include sulfadoxine-pyrimethamine should be avoided as many strains of P. vivax appear to be resistant to pyrimethamine).

Liver stage (i.e. relapsing) P. vivax can only be treated with one drug: primaquine. Instances of liver stage treatment failure are relatively commonplace, and may be strain or dosage dependent. Primaquine is not recommended for people with G6DP deficiency, so potential patients, and particularly those from locations or ethnic groups known to have high levels of G6DP deficiency, should be tested prior to treatment.