Gastrointestinal Issues or Malaria?

Question: I have had health issues since I became ill in the South of Vietnam five years ago. My original symptoms were an extreme pain in my left flank under the ribs, numbness all over the left side of my body, extreme fever, confusion, brain fog and general gastrointestinal issues.

Given that I was in a rural area at the time I was unable to seek medical care until I’d recovered enough to travel to Ho Chi Minh city around around a week later. By the time I received treatment, I had come down with severe gastroenteritis and was diagnosed with a bacterial infection with concurrent rotavirus through a stool sample. I don’t remember bloods being taken. I was placed on ciprofloxacin but never fully recovered.

Since then, my condition has always been treated as a gastrointestinal issue even though I know that there were two separate infections with different and overlapping symptoms initially. I have since experienced three full relapses of the original infection wherein all symptoms have returned and caused me great stress with an accompanying temperature over 40°.

Over the years, I have been treated for parasites (Dientamoeba Fragilis 3 years ago and as recently as 2 weeks ago for a supposed Entamoeba Histolytica infection that I picked up in Cambodia).

I have tested negative for gastrointestinal parasites after treatment previously (and I am currently waiting on test results for the current infection after antibiotic treatment and returning to Australia).

Regardless of the potential current E. Histolytica infection, I’m concerned that I could have contacted Malaria years ago and that the diagnosis may have been missed due to concurrent gastrointestinal parasites/issues.

My general symptoms over the past five years when not relapsing have been left flank pain in the area of the spleen, occasional numbness in the left side of the body, and a feeling of fogginess. These symptoms are for the most part mild, but if I don’t take excellent care of myself they are seriously exacerbated.

My questions are as follows:

1) Do you think it’s possible considering my symptoms that I had a missed malaria diagnosis 5 years ago?

2) Does this sound like a P. Vivax infection specifically?

3) If relapsing/dormant malaria is suspected, what is the best way to have it diagnosed now?

And 4) Is there a particular doctor in Melbourne, Australia, you’d recommend for malaria/tropical diseases?

Answer: Thanks very much for the post, and for providing detailed information about your case history! In answer to your questions:

1. Yes, it’s definitely a possibility. Your symptoms are certainly consistent with malaria, but then one of the challenges with malaria diagnosis is that the symptoms are usually quite general and can be confused with many other conditions. The numbness is a strange one, as while muscle aches and pains are common with malaria, numbness is less frequently cited as a symptom; were you taking malaria prophylaxis while in Vietnam? Another challenge is that the side effects of anti-malaria prophylaxis can sometimes mirror the symptoms of malaria. Chloroquine in particular has been associated with numbness, though it would not be a recommended form of prophylaxis for Vietnam so I doubt you would have been taking it. With regards to your fever, have you noticed a periodicity in its intensity? A classic symptom of malaria is the cyclical fever, with periods of sweating followed by chills. For P. falciparum, this cycle repeats every 24 hours; for P. vivax and P. ovale every 48 hours, and every 72 hours for P. malariae.
2. Given your history of relapses, yes, P. vivax malaria would make sense. The other, less common, form of malaria that also causes relapses is called P. ovale – it’s very similar to P. vivax, and from a treatment/management perspective, no different.
3. There are two options for diagnosis. The first would be to ask your medical practitioner for a serological test to look for antibodies in your blood against malaria. These antibodies can last months or years, and therefore a positive test will confirm that you have at least been exposed to malaria at some point in the past. I believe some tests exist which can distinguish between antibodies to the different forms of malaria but I am not sure they are commercially available; you would have to ask your medical practitioner, or a specialist if you can identify one. However, one challenge with this approach is that it sounds like you travel quite a bit, and so may have been exposed to malaria at other points in your life (even if the exposure didn’t result in a full blown infection). As such, it would be impossible to say whether a positive test results means you definitely had malaria during that specific episode in Vietnam, or that it is necessarily causing your relapses (though a strongly positive antibody test would be suggestive of more recent immune response to malaria, and thus could reasonably be linked to the relapses). The other, more direct, diagnostic option unfortunately requires waiting for another relapse, and then taking a blood test. If you are experiencing symptoms, then a blood smear or rapid diagnostic test will be able to detect the presence of malaria parasites in your blood stream. A trained technician will be able to tell the species of malaria from the blood smear (and some rapid diagnostic tests can also do species-level ID).
4. I’m afraid I am not familiar with specific doctors in your area but I do know that the University of Melbourne has a very strong parasitology department, including a number of researchers who work on tropical diseases including malaria, so that might be a place to start!