2. Context
• Name of the parasite
• Name of the disease
• Characteristics of the disease
• Geographical distribution
• Habitat in the human
• Morphology
• Life cycle
• Pathogenic effects, symptoms, complications
• Diagnosis
• Prevention
3. Name of the disease
African trypanosomiasis, also called sleeping sickness, is a disease
caused by a parasite. People can get this parasite when an infected
Tsetse fly bites them.
4. Characteristics of the disease
• Progressive confusion, personality changes, and other neurologic problems
occur after infection has invaded the central nervous system. If left
untreated, infection becomes worse and death will occur within months.
5. Geographical distribution
Both forms of sleeping sickness are transmitted by the bite of the
tsetse fly (Glossina species). Tsetse flies inhabit rural areas, living in
the woodlands and thickets that dot the East African savannah. In
central and West Africa, they live in the forests and vegetation along
streams.
6. Habitat in the human
Disease pathology often correlates with sites of
accumulation of the infectious agent within its host,
including the brain, which is associated with
characteristic neuropsychiatric symptoms and sleep
disorder. Weight loss is another typical clinical
feature of sleeping sickness pathology
7. Morphology
Tsetse have large heads, distinctly separated eyes, and unusual
antennae. The thorax is quite large, while the abdomen is wider,
rather than elongated, and shorter than the wings. Tsetse have a
distinct proboscis, a long and thin structure attached to the bottom
of the head, pointing forward.
10. Diagnosis
Examination of a sample of blood or fluid from a lymph nodeSpinal tap
and analysis of cerebrospinal fluidDoctors diagnose African sleeping
sickness by examining a sample of blood or fluid from a lymph node and
identifying the protozoa in it. Sometimes doctors check for the protozoa by
examining a sample of bone marrow or fluid from the sore.
Doctors do a spinal tap (lumbar puncture) using a needle inserted along the
person's lower spine to obtain a sample of cerebrospinal fluid (the fluid
that surrounds the brain and spinal cord) to determine whether the
infection involves the cerebrospinal fluid and brain. Doctors check the
fluid sample for the protozoa and for other signs of the infection. Such
signs include increases in the fluid's pressure and in the number of white
blood cells in the fluid.
11. Prevention
There is no vaccine or drug for prophylaxis against African trypanosomiasis.
Preventive measures are aimed at minimizing contact with tsetse flies. Local
residents in endemic countries are usually aware of the areas that are heavily
infested and may be able to provide advice about places to avoid. Other
helpful measures include:
Wear long-sleeved shirts and pants of medium-weight material in neutral
colors that blend with the background environment. Tsetse flies are attracted
to bright or dark colors, and they can bite through lightweight clothing.Inspect
vehicles before entering. The flies are attracted to the motion and dust from
moving vehicles.Avoid bushes. The tsetse fly is less active during the hottest
part of the day but will bite if disturbed.Use insect repellent. Permethrin-
impregnated clothing and insect repellent have not been proved to be
particularly effective against tsetse flies, but they will prevent other insect bites
that can cause illness.
