Malaria IgG Test

QUESTION
My uncle has been ill since returning from Belize, where he was bitten by multiple mosquitoes. He has every symptom of malaria, and did a malaria antibody IgG test, which came back high at 1.49 that was ordered by his primary care physician.

He has now been to a hematologist/oncologist and even an infections disease doctor who have both ignored the lab result. He has since done multiple biopsies and lab tests that reveal nothing. He continues to worsen, but they refuse to even consider malaria as an option of disease process. Please advise on steps that we can take to help get him well. We live in Oklahoma City, Oklahoma.

ANSWER
Transmission of malaria in Belize usually only occurs in mainland areas away from Belize City; as such, if your uncle was only there visiting the islands, for example, then while he may still have been bitten frequently by mosquitoes, it is unlikely he was infected with malaria.

Has your uncle ever traveled to other malarial areas of the world? I ask because one of the problems with the IgG test is that it looks for antibodies to malaria – as these can persist for a long time (weeks, months or even years) after the malaria infection has cleared, a positive IgG test just means that the patient was infected by malaria at some point, and doesn’t necessarily mean they have an active infection.

To check this, your uncle should ask his doctor (or better yet, an infectious disease or travel medicine specialist) to
check for an active malaria infection. This can be done two ways: either by looking at your uncle’s blood under a microscope (usually via thick and thin blood smears, the latter of which may be Giemsa stained) or by putting a drop of his blood into a malaria rapid diagnostic test (RDT). Both of these methods test for active infection, and depending on the type of RDT, both methods can also usually show which type of malaria has caused the infection. This is important in terms of ensuring the patient receives appropriate treatment.

I don’t know how you can convince your uncle’s medical team to give him a blood test, but that is the only definitive way to show he has malaria, if indeed that is what is causing his symptoms.