Breaking the cycle of disease transmission by targeting the parasite vector, the tsetse fly, provides an important means of disease control. The trypanosome parasite is famous for its ability to avoid elimination in the mammalian host through its capacity to change its surface proteins and so stay ahead of recognition by host antibodies. This allows the parasite to be sustained long-term in chronic infections and so increases the likelihood of the parasite being picked up by tsetse flies during their blood meal, ensuring continuation of the life cycle.
The parasite uses an elegant approach to ensure the continuation of its life cycle. Although the parasite proliferates rapidly in the blood and tissues of its mammal host, the parasite controls its own population growth to prevent overwhelming the host too quickly. These forms are also adapted for survival when taken up by a tsetse fly in their blood meal.
By generating these stumpy forms, the parasite both prolongs host survival and prepares for vector transmission — each increasing the chance of successful disease spread. Similar behaviours are shown by many bacterial communities and these are often regulated by the release of small signalling molecules. Trypanosomes were thought to use a similar approach and biochemical assays had shown that the parasites generated a signal that was small less than about Dal and stable in culture.
The expectation was that this was a metabolite released and sensed by the parasites and used to assess their population density. Recent work by Rojas and colleagues has shed new light on how quorum sensing operates. This surface TbGPR89 protein can drive the parasites to arrest their growth and develop into stumpy forms when over-expressed in the parasite, suggesting it may be linked to stumpy generation.
Supporting this, the effect was not seen on parasites that had been selected to be unable to show quorum sensing through laboratory passage, or through the silencing of a gene previously shown to be needed for the sensing mechanism. Section Navigation. Facebook Twitter LinkedIn Syndicate. African Trypanosomiasis FAQs. Minus Related Pages. What is African trypanosomiasis?
How is African trypanosomiasis spread? Is African trypanosomiasis a serious illness? East and West African trypanosomiasis are eventually fatal if not treated. Where can you become infected with African trypanosomiasis? What are the signs and symptoms of African trypanosomiasis?
How soon after infection will I have symptoms of African trypanosomiasis? What should I do if I think I may have African trypanosomiasis? What is the treatment for African trypanosomiasis? Once infected, am I immune to African trypanosomiasis?
Even if you had the disease once, you can become re-infected. Who is at risk for contracting African trypanosomiasis?
Can I take a medication to prevent African trypanosomiasis? There is neither a vaccine nor recommended drug available to prevent African trypanosomiasis. How can I prevent African trypanosomiasis and prevent other insect bites? Wear protective clothing, including long-sleeved shirts and pants. The tsetse fly can bite through thin fabrics, so clothing should be made of medium-weight material.
Wear neutral-colored clothing. The tsetse fly is attracted to bright colors and very dark colors. Inspect vehicles for tsetse flies before entering.
The flies are attracted to moving vehicles. Open survey. In: Facts Targeting Disease. What is trypanosomiasis? Trypanosomiasis refers to a group of diseases caused by Trypanosoma parasites. There are two types of trypanosomiasis that affect humans, they are divided according to their geographical location: African trypanosomiasis, or sleeping sickness, is caused by Trypanosoma brucei parasites in sub-Saharan Africa and is transmitted by the tsetse fly Glossina.
Trypanosomiasis can also affect animals. Nagana disease is a form of trypanosomiasis that affects vertebrate animals such as cattle. It is caused by several kinds of Trypanosoma including Trypanosoma brucei and Trypanosoma vivax.
Animals, such as wild game and domestic animals, can also act as a reservoir host for the human trypanosome parasites. While wild animals are mostly tolerant to the disease, for domestic animals, the infection can be severe and sometimes fatal. Scanning electron micrograph SEM of a Trypanosoma brucei parasite.
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