without treatment, why does african sleeping sickness invariably lead to death

by Prof. Newell Will Published 3 years ago Updated 2 years ago

Without treatment, why does African sleeping sickness invariably lead to death? The disease changes with every generation, so once the immune system figured out how to fight one generation a new one appears. The immune system can never keep up, so the disease can never be cured. Massive infection eventually leads to host organ failure and death.

Without treatment, why does African sleeping sickness invariably lead to death? The trypanosomes that cause this disease are capable of expressing a glycoprotein coat with a different molecular structure with each generation.

Full Answer

Why does African sleeping sickness invariably lead to death?

Without treatment, African sleeping sickness leads invariably to death because of damage it does to the nervous system. During epidemic periods, mortality from the disease can be high.

How does killing Anopheles mosquitoes affect the Plasmodium protists?

How does killing Anopheles mosquitoes affect the Plasmodium protest? If the mosquito population were decreased, then fewer Plasmodium would be able to develop and be transmitted to humans, thereby reducing the incidence of human infections with this parasite.

Which of these groups consist of parasitic flagellated cells such as Trypanosoma the organism that causes sleeping sickness?

Which of these groups consist of parasitic flagellated cells, such as Trypanosoma, the organism that causes sleeping sickness? Parasitic flagellated cells, such as Trypanosoma, are classified as kinetoplastids.

Which parasitic protist evades the host immune system by altering its surface proteins with each generation?

Trypanosomes

Trypanosomes. T. brucei, the parasite that is responsible for African sleeping sickness, confounds the human immune system by changing its thick layer of surface glycoproteins with each infectious cycle ([Figure 5]).

What is the ecological importance of Kingdom Protista?

Protists are essential sources of food and provide nutrition for many other organisms. In some cases, as with zooplankton, protists are consumed directly. Alternatively, photosynthetic protists serve as producers of nutrition for other organisms.

Why are protists important ecologically?

Protists function at several levels of the ecological food web: as primary producers, as direct food sources, and as decomposers. In addition, many protists are parasites of plants and animals that can cause deadly human diseases or destroy valuable crops.

What does African sleeping sickness do?

Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness. Some people develop a skin rash. Progressive confusion, personality changes, and other neurologic problems occur after infection has invaded the central nervous system.

Who is at risk for African sleeping sickness?

Who is at risk for African sleeping sickness? The only people at risk for African sleeping sickness are those who travel to Africa. That's where the tsetse fly is found. The parasites that cause the disease are passed on only by the tsetse fly.

What causes African sleeping disease?

Parasites - African Trypanosomiasis (also known as Sleeping Sickness) African Trypanosomiasis, also known as “sleeping sickness”, is caused by microscopic parasites of the species Trypanosoma brucei. It is transmitted by the tsetse fly (Glossina species), which is found only in sub-Saharan Africa.

How does the immune system respond to protists?

Protozoa activate quite distinct specific immune responses, which are different from the responses to fungi, bacteria and viruses. Protozoa may be phagocytozed by macrophages, but many are resistant to phagocytic killing and may even replicate within macrophages.

Do protists cause disease?

Most protist diseases in humans are caused by protozoa. Protozoa make humans sick when they become human parasites. Trypanosoma protozoa cause Chagas disease and sleeping sickness. Giardia protozoa cause giardiasis, and Plasmodium protozoa cause malaria.Mar 5, 2021

What is it called when protists extend part of their bodies to move by scooting or oozing?

Pseudopodia - This is when the protist extends part of its cell body to scoot or ooze along.

How does Trypanosoma brucei affect the immune system?

Trypanosoma brucei, the parasite that is responsible for African sleeping sickness, confounds the human immune system by changing its thick layer of surface glycoproteins with each infectious cycle ( [link] ). The glycoproteins are identified by the immune system as foreign antigens, and a specific antibody defense is mounted against the parasite. However, T. brucei has thousands of possible antigens, and with each subsequent generation, the protist switches to a glycoprotein coating with a different molecular structure. In this way, T. brucei is capable of replicating continuously without the immune system ever succeeding in clearing the parasite. Without treatment, T. brucei attacks red blood cells, causing the patient to lapse into a coma and eventually die. During epidemic periods, mortality from the disease can be high. Greater surveillance and control measures lead to a reduction in reported cases; some of the lowest numbers reported in 50 years (fewer than 10,000 cases in all of sub-Saharan Africa) have happened since 2009.

Why do trypanosomes cause organ failure?

The trypanosomes that cause this disease are capable of expressing a glycoprotein coat with a different molecular structure with each generation. Because the immune system must respond to specific antigens to raise a meaningful defense, the changing nature of trypanosome antigens prevents the immune system from ever clearing this infection . Massive trypanosome infection eventually leads to host organ failure and death.

What is a pathogen?

A pathogen is anything that causes disease. Parasites live in or on an organism and harm the organism. A significant number of protists are pathogenic parasites that must infect other organisms to survive and propagate. Protist parasites include the causative agents of malaria, African sleeping sickness, and waterborne gastroenteritis in humans. Other protist pathogens prey on plants, effecting massive destruction of food crops.

What causes black slime on potatoes?

Phytophthora infestans is an oomycete responsible for potato late blight, which causes potato stalks and stems to decay into black slime ( [link] ). Widespread potato blight caused by P. infestans precipitated the well-known Irish potato famine in the nineteenth century that claimed the lives of approximately 1 million people and led to the emigration of at least 1 million more from Ireland. Late blight continues to plague potato crops in certain parts of the United States and Russia, wiping out as much as 70 percent of crops when no pesticides are applied.

What is the cause of Chagas disease?

In Latin America, another species, T. cruzi, is responsible for Chagas disease. T. cruzi infections are mainly caused by a blood-sucking bug. The parasite inhabits heart and digestive system tissues in the chronic phase of infection, leading to malnutrition and heart failure due to abnormal heart rhythms. An estimated 10 million people are infected with Chagas disease, and it caused 10,000 deaths in 2008.

What is the cause of malaria in red blood cells?

Red blood cells are shown to be infected with P. falciparum, the causative agent of malaria. In this light microscopic image taken using a 100× oil immersion lens, the ring-shaped P. falciparum stains purple. (credit: modification of work by Michael Zahniser; scale-bar data from Matt Russell)

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