Malaria Test – Can Malaria Return?

by

QUESTION

I am working in Tanzania. I felt sick about 10 days ago and I went for a test for malaria and the test was positive. The doctor gave me some pills and said I must come back in one week for a test again. I went back and it was negative but now I don’t feel too good. Is it possible for the malaria to come back after 10 days?

ANSWER

It is unlikely that the malaria has come back, and if your malaria test is negative, then you probably don’t have malaria any more, and you can be confident the treatment worked. It sometimes takes a few days or even a couple of weeks to fully recover from the infection, since it takes quite a toll on the body’s immune system. Also, the medication you take to treat malaria can also have side effects, such as nausea and headaches, which actually seem similar to the symptoms of malaria itself.

Diagnostic Blood Test: Malaria in Nepal and India

by

QUESTION

My daughter has returned from a 6 week trip to Nepal and then India. About 20 minutes into the flight home she developed pains and aches in her hips and legs, fever, generally feeling dreadful but no nausea or diarrhea. When she arrived after the 10 hour flight her temperature was 100.5. We were concerned about malaria, but when she saw her primary care doctor the next morning she felt much better and her temperature was normal.

Blood taken at that visit showed no sign of malaria, but the doctor said that she could develop a recurrence in 3-4 weeks time when blood test should be repeated to confirm malaria if present.

I don’t doubt her doctor, but do these symptoms suggest malaria? How common is it for an initial episode of malaria to show up as negative on blood tests? She started taking tablets 3 days before entering a high risk area and took them for 3 weeks, but stopped during a brief diarrheal illness and did not restarted her anti malaria tablets.

ANSWER 1 – From Malaria.com Editor:

I think your GP might be mistaken about this – the only way to diagnose malaria is through a blood test which is positive for the disease! I have never heard of any cases where the initial blood test is negative, followed by a positive recurrence several weeks later. There are cases were the initial level of infection is quite low, in which case sometimes the parasites can be missed when looking at the blood film; however, when symptoms are present, this is rare. Moreover, there is no biological reason for a recurrence in several weeks; usually, reoccurrence occurs when treatment is given and for whatever reason is unsuccessful, allowing the malaria parasites to come back (and this assumes they are positively observed in the first place!).

Another diagnostic option, if you want to double check, is to see if you can find a rapid diagnostic test for malaria, which uses a drop of the patient’s blood to look for proteins produced by the malaria parasite. Similarly, there are tests which look for antibodies against malaria; this kind of test, known as serology, is not good for diagnosing active infections since antibodies can persist after the infection has been cleared, but may give you an indication of whether your daughter was exposed to malaria at all during her time in Nepal. Both of these are even more sensitive than blood smears, and although not as common as blood smears, are available in many places, particularly through hospitals which have tropical medicine departments or experts. All in all, if your GP is insisting on a second malaria test in a few weeks, by all means there is no harm in doing that, but in the meantime I would seek a second opinion since I think it is more likely your daughter has another infection (possibly a gastrointestinal bug, or a viral infection) which may risk going undiagnosed if your GP fixates on malaria as the answer.

Regarding the symptoms, unfortunately the symptoms of malaria are very general and it is almost impossible to accurately diagnose the disease on the basis of symptoms alone, hence why a blood test is so important. The blood test, with positive observation of the malaria parasites, is also crucial to determine which species of malaria the patient has, which may have implications for the appropriate treatment.

Answer 2: From Malaria.com Medical Advisor (MD)

The diagnosis of malaria should always be considered for patients with a fever who have traveled to malaria endemic areas. Your concerns that this may be malaria are well founded. Malaria symptoms in the first few days of infection are similar to the early stages of many other febrile illnesses, including viral and bacterial infections. In malaria, the fever also typically waxes and wanes in the manner you described. Confirming the diagnosis requires detecting parasites or their products in a blood sample. The most common test involves inspecting blood under a microscope for the presence of malaria parasites. Sometimes early in the disease there aren’t enough parasites for detection by this method. For this reason, several blood smears taken at 12-24 hour intervals are sometimes required to rule out a diagnosis of malaria in a symptomatic patient.

Additionally, your daughter was vulnerable to infection because she stopped taking antimalaria medicines while traveling in a region of malaria risk. To offer protection, these medicines must be taken for the duration of the stay, and depending on the medicine, up to 4 weeks after the last possible malaria exposure.

Unfortunately most medical doctors in regions where malaria is very rare, like the the United States and Europe, have little experience diagnosing and managing malaria. I would advise you to seek attention at a travel clinic or infectious disease specialist without delay, where it is likely further blood tests will be undertaken immediately to establish laboratory confirmation, and the prompt initiation of treatment for malaria if present.

Relapsing Malaria

by

QUESTION

I’m constantly on malaria drugs, fall ill every 2 weeks and always diagnosed with malaria.I’m getting really fed up and need a permanent solution to all of this. I want to live a healthy life and I’m tired of being on malaria drugs. How do I overcome malaria permanently?

ANSWER

It is very unusual to be reinfected so constantly with malaria. First of all, how are you getting diagnosed? You should be getting a blood test, and not relying on symptoms only; the symptoms of malaria are very general and it could be that you are suffering from something else entirely.

The two main methods for accurate diagnosis are blood smear and rapid diagnostic test. The blood smear is used throughout the world, but can sometimes miss light infections (though if you feel sick, your infection is likely heavy enough to be detected by this method). The problem is that it requires a trained technician to take the sample, prepare it properly, and read it thoroughly and accurately. In my experience, many clinics, especially if they are rushed and busy, will not take the time to read a blood slide properly, and will just diagnose malaria without looking. This is really bad!

It is very important to be properly diagnosed, so you can get the correct treatment, and if you don’t have malaria, you can be diagnosed for something else. The second kind of diagnostic is a rapid diagnostic test, or RDT. This looks for antibodies to malaria in your blood, and is very sensitive and quick. In an ideal world, you should try to have both done, to cross-check the results.

The next thing is to check whether you are receiving the correct treatment for the type of malaria that you have (if you are positively diagnosed with malaria). In many parts of the world, malaria has become resistant to some of the main medications used against it. Notably, this is the case in many places with Plasmodium falciparum, the most dangerous kind of malaria, which has become resistant to chloroquine in many parts of the world, to sulfadoxine-pyrimethamine (sold as Fansidar in many places) and also to mefloquine (sold as Lariam) in some places. As such, the World Health Organisation NEVER recommends these treatments be given as first line drugs against P. falciparum malaria—instead, they recommend artemisinin-combination therapies (ACTs), such as Alu, Coartem or Duo-Cotecxin. If you have been diagnosed with P. falciparum, you must try to take these kinds of drugs first. No resistance to ACTs has been reported, so if you take the full dose correctly, as prescribed by your doctor (and check to make sure the drugs are not expired), then you should be cured of malaria.

However, treatment does not stop you from getting infected again, and this is where prevention comes it. Preventing malaria is a cornerstone of control efforts. Since malaria is transmitted by a mosquito, preventing mosquitoes from entering the house, and particularly stopping them from biting you at night, is crucial. Screening all doors and windows can help stop mosquitoes from getting in, and in high transmission areas, many people will also spray inside their houses every once in a while with insecticides to kill any lingering insects.

In addition, sleeping under a long-lasting insecticide treated bednet can drastically reduce the number of mosquitoes that are able to bite you at night. If you already have a net, it may be worth re-dipping it in insecticide (usually permethrin) to make sure it is still working effectively. The mosquitoes that transmit malaria feed at night, so if you are walking around outside in the evenings or at night, it is important to try to wear long-sleeved clothing, to prevent them from accessing your skin.

All of these efforts will help prevent you from getting malaria again in the future.

High Count of Malarial Antibodies

by

QUESTION

In 2007 we travelled to Kenya and Zanzibar. We took the normal anti-malarial tablets and were unaware of having been bitten. My older son has recently had a full medical and one of the blood tests which he had to repeat came back with a high count for malaria antibodies for Plasmodium falciparum. The doctor told him that he had had malaria at some time. We are puzzled as he has never been ill since returning. Can this happen? On the other hand my younger son has not been fully fit since returning from the trip, flu like symptoms, lack of energy etc. He has had several blood tests including one for glandular fever but nothing has shown up. Should he be tested for malarial antibodies? Could this be the reason he has had recurrent bouts of illness.

ANSWER

It is certainly possible to be exposed to malaria, but for your body to successfully fight the infection before it can reproduce and establish, thus the person will never experience the full illness. This is likely what happened with your elder son. As for your younger one, malaria tends to be an acute illness rather than a long-lasting chronic one, particularly the types of malaria that are found in East Africa.

Since your elder son was exposed and seems to have antibodies to malaria, I don’t think an antibody test will be particularly illuminating with regards to diagnosing your younger son. It would be better to have the doctors test him for malaria using the traditional thick and thin blood smears, which are then looked at under the microscope. This test will better inform the doctors whether your son has an active malaria infection, and will also be able to determine the species of malaria he has (if positive), and thus what treatment would be most effective for him. Again, though you should do this test to rule out malaria for sure, I think it is unlikely that your son has been experiencing symptoms caused by malaria for this length of time.

Severe Head Pain with Malaria

by

QUESTION

Can severe head pain be a symptom of mistreated malaria? My son just returned from an 8 month trip to Ghana. He had malaria 3 times and typhoid 1 time. He is now dealing with a severe head pain in his frontal lobe.

He took doxycycline every day and when he got really sick, he took Coartem. He was finally sent home because they couldn’t figure out why he has such severe head pains. Where do we go from here? He has an MRI scheduled and an appointment with an Infectious Disease Doctor. I am afraid they will not know what to do to help him. I am seeking more advice. Hopeful…CT

ANSWER

Severe head pain is not associated with mistreated malaria, nor indeed is considered a possible lasting effect of malaria infection. You are doing the right thing by going to see a doctor, including one who is an infectious disease specialist—I hope they also have experience with tropical medicine, since in the US and Europe, many very well-trained doctors are still not very familiar with the types of infections which are more commonly observed in the tropics.

Your son was right to take Coartem when he had malaria, but do you know whether he went to a clinic for diagnosis first? The symptoms of malaria are very general, such as fever, chills, nausea and aches, and many people in malarial areas (particularly visitors) often assume they have malaria when in fact their symptoms could be caused by a number of other things.

Secondly, doxycycline is considered a very effective preventive medication against malaria, but only if taken properly. Since doxycycline can cause mild stomach upset, many people take it with milk, which can lessen these symptoms; however, the calcium in the milk can bind to the drug, preventing successful absorption and reducing its efficacy as a malaria preventive.

If your son had a diet high in diary products or took antacids while in Ghana, this could explain why he suffered several malarial episodes. Alternatively, if he took the drug regularly and correctly, and particularly if he did not seek diagnosis via blood test from a clinic, that may be an indication that he wasn’t suffering from malaria at all, and other causes should be explored.

Finally, one of the very well-described side effects of doxycycline is its tendency to cause people to become very sun sensitive. While this usually manifests itself in skin sensitivity, it could also be that your son has become more visually sensitive to light, which in itself could lead to severe headaches. I hope he feels better soon!

Number of Species of Malaria

by

QUESTION

I recently read an ISOS world malaria day poster saying 5 species of plasmodium cause malaria. I think that is confusing as we always talked about 4, ovale, vivax, falciparum and malaria….are they referring to the way we now split ovale into 2 sub species? or is this a typo on their part?

ANSWER

That is a really interesting question, and a good observation on your part! I imagine the fifth species they are referring to is Plasmodium knowlesi, which is found in parts of south-east Asia, with the majority of cases being reported from Borneo. Originally known only from macaque monkeys, it appears to be occurring more frequently in humans. However, it is not known whether this is a new host switch, or whether it is simply a matter of better detection methods—the morphology of P. knowlesi closely resembles that of P. falciparum in its early trophozoite stages, and P. malariae in later trophozoite and other life stage forms. Moreover, some molecular-based tests for P. knowlesi cross-react with other forms of malaria, such as P. vivax, leading to greater diagnostic confusion.

There is also a hypothesis that changes in land use in tropical forests may be resulting in greater human exposure to the vectors which carry P. knowlesi, which accounts for its increased recent prevalence in humans. P. knowlesi is the only known malaria in humans (and indeed, in all primates) with a 24-hour reproductive cycle, which means that without treatment, high levels of parasitaemia can accumulate rapidly in the blood, and lead to severe clinical symptoms. This makes its apparent emergence of great public health concern in south-east Asia. Luckily, at this point, P. knowlesi is completely susceptible to chloroquine treatment and other medications, and so is easily controlled once diagnosed.

One of our contributors, Christina Faust, wrote a blog post last year on P. knowlesi entitled Of Macaques and Men. More information on recent research about P. knowlesi can be found in the article, Monkeys Provide Malaria Reservoir for Human Disease in South-East Asia.

Repeated Malaria Cases, New Guinea

by

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.

Comparison of Molecular Tests for the Diagnosis of Malaria in Honduras

by

Honduras is a tropical country with more than 70% of its population living at risk of being infected with either Plasmodium vivax or Plasmodium falciparum. Laboratory diagnosis is a very important factor for adequate treatment and management of malaria. In Honduras, malaria is diagnosed by both, microscopy and rapid diagnostic tests and to date, no molecular methods have been implemented for routine diagnosis. However, since mixed infections, and asymptomatic and low-parasitaemic cases are difficult to detect by light microscopy alone, identifying appropriate molecular tools for diagnostic applications in Honduras deserves further study. The present study investigated the utility of different molecular tests for the diagnosis of malaria in Honduras. [Read more…]

Malaria in the United States, Years Later

by

QUESTION

For years, I have questioned what sickness I got years ago after a series of bug bites in a bayou in New Orleans. I’ve just read the symptoms described here and they fit everything I was suffering with. I even had problems with my liver, but I was never tested for Malaria because I had immediately left New Orleans for Italy. I never thought of mentioning it. This mysterious illness cropped up in different forms over the years and really I was never the same after it. It has been almost 12 years, and I still suffer from recurring illness which antibiotics help for a while, but it always comes back. Could it be that I have had Malaria in my system all this time?

ANSWER

While malaria was officially eradicated from the US in the 1950s, certainly the swamps and bayous of Louisiana and the rest of the Gulf were a key habitat and a major source of transmission prior to eradication. I just found a news report in the New York Times from October 1883 which reported 16 deaths due to “malarial fever” in the previous week alone!

While these days, virtually all of the 1,500 or so cases of malaria observed in the US every year are attributed to overseas travel, in 2002 a handful of cases of malaria in northern Virginia were believed to be due to local transmission. Prompt treatment, personal protective measures (such as screening houses) and vector control quickly quelled that mini-outbreak.

Given this history along with your symptoms, and particularly your recurrent episodes of fever, I would not rule out malaria, obtained in Louisiana, as a possibility! You should talk to your doctor about the possibility of a serological test for the antibodies against malaria—if positive, you should try to have a blood test done next time you have the recurrence of symptoms. If malaria is confirmed, you should report your case to the Centers for Disease Control (CDC) Domestic Malaria Unit, which monitors all malaria cases in the US.

Malaria while in Addis Ababa, Ethiopia?

by

QUESTION

My husband and I recently adopted our second child from Ethiopia about 3 months ago. We did NOT take Malaria medication because we only stayed in Addis Ababa and did not travel outside the city—or very far from out hotel for that matter. I’ve recently started very odd symptoms—aches, chills but no fever, general feeling of malaise, runs, dry cough, hot flashes followed by sweats, and fatigue so severe I sometimes don’t have the energy to talk. The weird part is that the symptoms come and go. I feel fine for a few days, and then boom! Down for the count again, then fine the next day. I’m going to see my Dr. tomorrow, but could I have Malaria???

ANSWER

While the cyclical symptoms, occurring every few days, are similar to the cycles experienced by malaria sufferers, the lack of a fever is a good indication that you don’t have malaria. Moreover, as you clearly researched before your trip, Addis Ababa is not a transmission zone for malaria, so it is unlikely that you would have been infected during your trip. By now you will have probably seen your doctor, and I suspect s/he will have ruled out malaria. If you really want peace of mind, you can also ask for a blood test, just to check. I hope your condition is diagnosed and treated soon, and you recover quickly!