Sleeping Sickness
sickness /sick·ness/ (sik´nes) disease.
sleeping sickness.
sleeping sickness
Patient discussion about Sleep fever.
Definition
Sleeping sickness (also called trypanosomiasis) is an infection caused by Trypanosoma protozoa; it is passed to humans through the bite of the tsetse fly. If left untreated, the infection progresses to death within months or years.
Description
Protozoa are single-celled organisms considered to be the simplest life form in the animal kingdom. The protozoa responsible for sleeping sickness are a variety that bear numerous flagella (hair-like projections from the cell that help the cell to move). These protozoa exist only on the continent of Africa. The type of protozoa causing sleeping sickness in humans is referred to as the Trypanasoma brucei complex, which can be divided further into Rhodesian (Central and East African) and Gambian (Central and West African) subspecies.
The Rhodesian variety live within antelopes in savanna and woodland areas, and they cause no problems with the antelope's health. The protozoa are then acquired by tsetse flies when they bite and suck the blood of an infected antelope or cow.
Within the tsetse fly, the protozoa cycle through several different life forms; ultimately they migrate to the salivary glands of the tsetse fly. Once the protozoa are harbored in the salivary glands, they are ready to be deposited into the bloodstream of the fly's next source of a blood meal.
Humans most likely to become infected by Rhodesian trypanosomes are people such as game wardens and visitors to game parks in East Africa, who may be bitten by a tsetse fly that has fed on game (antelope) carrying the protozoa. The Rhodesian variety of sleeping sickness causes a much more severe illness, with even greater likelihood of eventual death than the Gambian form.
The Gambian variety of Trypanosoma thrives in tropical rain forests throughout Central and West Africa; it does not infect game or cattle, and is primarily a threat to people dwelling in such areas, rarely infecting visitors.
Causes and symptoms
The first sign of infection with the trypanosome may be a sore appearing at the site of the tsetse fly bite about two to tree days after having been bitten. Redness, pain, and swelling occur, but are often ignored by the patient.
Stage i illness
Two to three weeks later, Stage I disease develops as a result of the protozoa being carried through the blood and lymph circulation of the host. This systemic (meaning that symptoms affect the whole body) phase of the illness is characterized by a fever that rises quite high, then falls to normal, then respikes (rises rapidly). A rash with intense itching may be present, and headache and mental confusion may occur. The Gambian form, in particular, includes extreme swelling of lymph tissue, with enlargement of both the spleen and liver, and greatly swollen lymph nodes. "Winterbottom's sign" is classic of Gambian sleeping sickness, and consists of a visibly swollen area of lymph nodes located behind the ear and just above the base of the neck. During this stage, the heart may be affected by a severe inflammatory reaction, particularly when the infection is caused by the Rhodesian variety of trypanosomiasis.
Many of the symptoms of sleeping sickness are actually the result of attempts by the patient's immune system to get rid of the invading organism. The heightened activity of the cells of the immune system result in damage to the patient's own organs, anemia, and leaky blood vessels. These leaks in the blood vessels end up helping to further spread the protozoa throughout the afflicted person's body.
One reason for the intense reaction of the immune system to the presence of the trypanosomes is also the reason why the trypanosomes survive so well despite the efforts of the immune system to eradicate them. The protozoa causing sleeping sickness are able to rapidly change specific markers (unique proteins) on their outer coats. These kinds of markers usually serve to stimulate the host's immune system to produce immune cells that will specifically target the marker, allowing quick destruction of those cells bearing the markers. Trypanosomes, however, are able to express new markers at such a high rate of change that the host's immune system is constantly trying to catch up.
Stage ii illness
Stage II sleeping sickness involves the nervous system. Gambian sleeping sickness, in particular, has a clearly delineated phase in which the predominant symptoms involve the brain. The patient's speech becomes slurred, mental processes slow, and the patient sits and stares for long periods of time, or sleeps. Other symptoms resemble Parkinson's disease, including imbalance when walking, slow and shuffling gait, trembling of the limbs, involuntary movements, muscle tightness, and increasing mental confusion. Untreated, these symptoms eventually lead to coma and then to death.
Diagnosis
Diagnosis of sleeping sickness can be made by microscopic examination of fluid from the original sore at the site of the tsetse fly bite. Trypanosomes will be present in the fluid for a short period of time following the bite. If the sore has already resolved, fluid can be obtained from swollen lymph nodes for examination. Other methods of trypanosome diagnosis involve culturing blood, lymph node fluid, bone marrow, or spinal fluid. These cultures are then injected into rats, which develop blood-borne protozoa infection that can be detected in blood smears within one to two weeks. However, this last method is effective only for the Rhodesian variety of sleeping sickness.
Treatment
Without treatment, sleeping sickness will lead to death. Unfortunately, however, those medications effective against the Trypanosoma brucei complex protozoa all have significant potential side effects for the patient. Suramin, eflornithine, pentamidine, and several drugs that contain arsenic (a chemical which in higher doses is highly poisonous to humans), are all effective anti-trypanosomal agents. Each of these drugs, however, requires careful monitoring to ensure that the drugs themselves do not cause serious complications such as fatal hypersensitivity (allergic) reaction, kidney or liver damage, or inflammation of the brain.
Prevention
Prevention of sleeping sickness requires avoiding contact with the tsetse fly. Insect repellents and clothing that covers the limbs to the wrists and ankles are advisable. Public health measures have included drug treatment of humans who are infected with one of the Trypanosoma brucei complex. There are currently no immunizations available to prevent the acquisition of sleeping sickness.
Resources
Organizations
Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.
sickness /sick·ness/ (sik´nes) disease.
African sleeping sickness African trypanosomiasis.
air sickness airsickness.
altitude sickness a condition due to difficulty adjusting to lowered oxygen pressure at high altitudes; it may take the form of mountain sickness, high-altitude pulmonary edema, or cerebral edema.
car sickness carsickness.
decompression sickness divers' paralysis; joint pain, respiratory problems, skin lesions, and neurologic signs, due to rapid reduction of air pressure in a person's environment.
green tobacco sickness transient, recurring nicotine poisoning in tobacco harvesters.
high-altitude sickness altitude s.
milk sickness an acute, often fatal disease in humans after they ingest milk, milk products, or flesh of cattle or sheep who have eaten certain toxic plants; human disease is marked by weakness, anorexia, vomiting, and sometimes muscular tremors.
morning sickness nausea of early pregnancy.
motion sickness nausea and malaise due to unaccustomed motion, such as in travel by airplane, automobile, ship, or train.
mountain sickness a type of high altitude sickness with oliguria, dyspnea, blood pressure and pulse rate changes, and neurological disorders.
radiation sickness a condition resulting from exposure to a whole-body dose of over 1 gray of ionizing radiation and characterized by the symptoms of the acute radiation syndrome.
sea sickness seasickness.
serum sickness a hypersensitivity reaction after administration of foreign serum or serum proteins, marked by urticaria, arthralgia, edema, and lymphadenopathy.
sleeping sickness increasing lethargy and drowsiness due to a disease process such as African trypanosomiasis or types of encephalomyelitis.
sleep·ing sickness (sl  p ng)n. |
sleeping sickness.
sleeping sickness
any disease characterized by drowsiness or somnolence. See also pregnancy toxemia (1) of ewes, equine viral encephalomyelitis, cryptobiacyprini, trypanosomiasis.
sleeping sickness
1 African trypanosomiasis, see there 2 Narcolepsy, see there
Patient discussion about Sleep fever.
Q. Need Help.I could not enjoy the blessings of nature. I have sleep problem which affects me to a great extent. Hi friends, I need your help. I could not enjoy the blessings of nature. I have sleep problem which affects me to a great extent. Is there any remedy that I can try other than sleeping pills?
A. Many things can interfere with sleep ranging from anxiety to an unusual work schedule. But people who have difficulty in sleeping often discover that their daily routine holds the key to night-time woes.
? Cut down on caffeine.
? Stop smoking or chewing tobacco.
? Use alcohol cautiously
? Avoid a sedentary life
? Improve your sleep surroundings.
? Keep a regular schedule
? Keep a sleep diary
? Use strategic naps
If you try all the above suggestions and still have sleep problem, talk to your health-care provider.
Read more or ask a question about Sleep fever? Cut down on caffeine.
? Stop smoking or chewing tobacco.
? Use alcohol cautiously
? Avoid a sedentary life
? Improve your sleep surroundings.
? Keep a regular schedule
? Keep a sleep diary
? Use strategic naps
If you try all the above suggestions and still have sleep problem, talk to your health-care provider.
How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content.
| ?Page tools | ||
|---|---|---|
|