Variant surface glycoprotein

Well, yes, trypanosomes are absolute masters of immune evasion.

The entire parasite surface is covered by a dense glycoprotein coat composed of what we call variant surface glycoproteins, abbreviated as VSG.

The trypanosome genome contains nearly 2,000 different VSG genes.

Through a process called antigenic variation, the parasite periodically switches its VSG coat expression.

Just as the host immune system generates neutralizing antibodies against one VSG variant, a subpopulation switches to a new coat, triggering successive waves of parasitemia and recurring fever spikes.

Well, that explains the cyclic intermittent fever pattern for sure.

But humans also possess an innate serum lytic factor called apolipoprotein L1 or APOL1, which is part of the trypanosome lytic factor.