Trypanosomiasis Discovery: An Argument for Basic Research

One of the differences among the current four candidates for POTUS is the recognition, by only one of them, of the great importance of basic research. By that, I mean, give the scientists funding to pursue the questions that interest them. A sort of free market of ideas driven not by profits of the Bayers, Koch Borthers, and Cargils of the world, but rather, by how cool stuff is and how much untethered knowledge is advanced each time something else cool happens.

Tsetse fly

Trypanosomiasis is a terrible disease. I know only one person who had it, he was treated, survived, but his brain did get fried, at least for a while, and since that was a key asset for him, that was very sad. I did work extensively in a region that had been made into the world's largest contiguous parkland, spanning three countries, because much of it had been depopulated due to a major epidemic of trypanosomiasis. And, the insect carrier of the disease, the tsetse fly, was there in abundance.

For those who have not met a tsetse fly, think of it as a tropical version of the Horse Fly, that large black thing that looks like a house fly on steroids with the bite that hurts like hell. They are very distant relatives, but have a similar love of human flesh and similar approaches to getting it.

The disease affects both humans and cattle, and has a very high mortality rate, so cattle keeping people such as the BaHama and others who lived in that area were very seriously affected.

Trypanosomiasis is caused by a protozoan, Trypanosoma, which has phylogenetically obscure associations and is probably polyphyletic. There is almost no recent research on the evolution of this protozoan, that I know of, yet it is probably very interesting, being found in both the old and new world, and probably having differentiated a very long time ago. Given the very interesting ways that protozoans reproduce, this would likely be a massively difficult project, above the PhD level. But if you are interested in making a contribution ...

You know of trypanosomiasis as "sleeping sickness." Africanists, trapped between the silliness of the common name and the tongue twistiness of the scientific name call it "tryps." You don't want tryps.

Anyway, here's the thing. Despite major efforts, the disease was never eradicated. It would be totally gone in a region, impossible to find blood samples with the parasite in the sample, and then suddenly re-emerge. Nobody knew where it was hiding.

It turns out that where it was hiding, just discovered, is in retrospect totally obvious, and the kind of thing that, in my view, would have either been thought up or observed by accident, as happened here, had there been more basic research on all the different elements of this sad story of disease and death.

Annette MacLeod of the University of Glasgow was working on related matters, when (to oversimplify and shorten the story a bit) she discovered that the tryps parasite can hide in the skin, staying out of the blood supply and thus off the blood test radar. This may say something of our heavy reliance on blood tests as a sort of Ultimate Truth when it comes to infectious disease. Anyway, the tryps protozoan can remain in the skin, where, possibly, it gets picked up by a biting tsetse, and the, if all goes well for the protozoan, gets spread into the bloodstream of a downstream victim, and the whole things starts over again.

The story is written up here in Science.

Will other researches, working on other diseases, even those thought to be entirely blood borne, have a look in alternative tissues from now on? They should. Adding a sort of "look both ways" rule to the study of disease may not be a bad idea. Don't assume the typically focal tissue is the only place a microbe of some sort carries out its activities. Check around. Look in the closet. Behind the door. Under the bed. You never know what will be lurking.

This seems to be unpublished research, but The research is here, and you can check out MacLeod's publications to get a bead on this, and perhaps keep an eye out for the work in print.