On the Run

Life as a parasite is a constant race to evade host defences. For African trypanosomes (pictured) – responsible for diseases such as sleeping sickness – staying ahead means they have to keep moving. Each is a single cell with a long hair-like structure, or flagellum, anchored to the cell body and rotating to propel it through vertebrate bloodstreams, as shown here by 3D imaging. The host immune system detects threats using antibodies, molecules that recognise and bind to specific proteins on the surface of the parasite, marking it out for destruction. Rapid swimming generates a strong enough current to drag these antibodies to the base of the flagellum, where the cell can absorb them, thus allowing trypanosomes to go unnoticed. However, this swimming behaviour could ultimately be their downfall, as research into the mechanisms of trypanosome motion and its molecular underpinnings may reveal new targets for treatment.

Written by Emmanuelle Briolat

Trypanosomes: commonly known for being a blood borne parasite responsible for African sleeping sickness. 

But, I only found out when attending a seminar about cell wall structures, that trypanosomes only have a tiny pore located just before the flagellum (tail that helps them swim) that it takes ALL of it’s nutrients from. 

This must be incredibly limiting as most prokaryotes uptake across their whole cell surface. 

Its boggles the mind to think of the organsation of the proteins beneath this single pore if it is responsible for the only intake/outtake from the cell! 

It must also be very limiting to growth by size exclusion through the pore along with diffusion limiting protein movement. 

When discussing it one of the academics said that “It’s like wearing a suit of armor and only being able to see through a tiny slit in your visor”

This is true, but when your in the blood of a host, EVERYTHING is trying to detect and kill you, so being so heavily armored isn’t a bad thing!

Trypanosoma cruzi

T. cruzi causes Chagas disease in Central and South America and is considered a neglected tropical disease. T. cruzi is a flagellated protozoa which is a zoonoses found in forest animals. It is transmitted by the Reduvid bug when feces of the bug containing trypomastigotes of the parasite gets into bites. It can also be transmitted by blood transfusion or organ transplantation. 16-24 million are infected with 100 million at risk. The parasite itself has aerobic respiration with a mitochondria for all stages of life. It can be diagnosed by a blood smear or by a muscle tissue biopsy. Symptoms include asymmetrical swelling of eyes, fever, and enlarged spleen which lasts for 2-7 weeks and may lead to death. It may progress to the intermediate and then chronic phase in which can lead to nerve damage and cardiomyopathy. It can be treated with Nifurtmox as well as some antimalarials. Disease can be prevented by administering prophylaxis, regular screening, and insect prevention. 


Among the animal-like flagellates, many of which are parasitic, are the trypanosomes. They cause the dreaded disease known as “sleeping sickness,” so prevalent on the African continent. It is possible for these parasitic flagellates to live in insects and most vertebrates in Africa without causing a great disturbance to the host. However, when they are present in man or a domesticated animal, they usually produce fatal results.

The tsetse fly introduces the trypanosomes into the bloodstream. Once there, they reproduce rapidly among the blood corpuscles.

After a while they invade the fluid surrounding the brain and spine, causing a loss of consciousness and finally death. The elimination of the disease necessitates the destruction of the flies themselves.

shit I have written 725 words of a 1k word max essay and I haven’t even answered the first question damnit. this is called overcomplication and writing irrelevant information, kids; don’t do it!