African Sleeping Sickness

Trypanosoma

Genus of parasite that causes african sleeping sickness

Flagella

Used to move

Kinetoplast

Single, large body, within the cell that contains mitochondria.

Glycocalyx

surface coat which is visible using an electron microscope

heteroxenous

more than one host

hemoflagellates

flaggallate that moves in the blood.

Location

They are widely distributed in Africa between the latitudes 15°N and 25°S, an area commonly known as the fly belt.

T.b. Brucei

Infect antelopes, cattle, pigs, but does not go to humans.

Polymorphic

Ranges in shape and size

What is a vector?

Tsetse Fly

Parisitemia

Parasites in the blood

Antigenic Variation

changes in surface antigens that occur in a microbial population

Life Cycle of Tsetse Fly

When the parasite is sucked up by the fly, the parasite takes up residence in the posterior end of the midgut where it multiplies for about ten days. The individuals produced move to the foregut, which takes 12-20 days to arrive here. They then migrate to the esophagus, then the pharynx, the hypopharynx, and eventually enter the salivary gland. In the salivary gland they transform from trypomastigote form to the epimastigote form and attach to host cells. At this point, they transform into a metacyclic trypomastigote form, which are the infective form of vertebrates. The Tsetse fly then bites the vertebrate and can inject several thousand parasites in one bite. The whole process takes 15-35 days.

Where do typanosomes live

trypanosomes live in the blood, lymph nodes, spleen and cerebrospinal fluid.

Tb. Brucei Symptoms

Only in animals

What is the prognosis for Tb. Rhodescience?

Death in a few weeks or few months

What is a common symptom of Tb. Rhodescience?

Small sore at the site of infection

What is the Winterbottom sign associated with Tb. Rhodescience?

Swollen lymph nodes at the bottom of the neck

Scientific Name for Tsetse Fly

Glossina

What disease is caused by Tb. gambiense?

Chronic sleeping sickness

How does Tb. gambiense affect the body?

It invades the CNS

What are some symptoms of Tb. gambiense infection?

Increased apathy, mental dullness, poor coordination, tremors in hands, tongue, and trunk

What is the outcome of untreated Tb. gambiense infection?

Slow death

How is Tryposomiasis Diagnosed?

seeing the parasite in a sample of blood, bone marrow or cerebrospinal fluid

How is it treated?

treated with arsenical drugs. These drugs are toxic and have severe side effects and can also cause death in about 10% of the cases.

How to control the population?

control the population is to cut/trim bushes because this is where adults rest. Another way to control the population is to eliminate wild game reservoirs, graze cattle at night. Kill them as they try to bite, use insecticides.