CDC — African Trypanosomiasis — General Information — West African Trypanosomiasis FAQs

West African Trypanosomiasis FAQs

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What is West African trypanosomiasis?

There are two types of African trypanosomiasis (also called sleeping sickness); each named for the region of Africa in which it was found historically. Individuals can become infected with West African trypanosomiasis if they receive a bite from an infected tsetse fly, which is only found in Africa. West African trypanosomiasis, also called Gambian sleeping sickness, is caused by a parasite called Trypanosoma brucei gambiense carried by the tsetse fly. In recent years, 7,000-10,000 new cases of West African trypanosomiasis have been reported to the World Health Organization annually. However, many cases are not recognized or reported and the true number of annual cases is likely to be higher. Cases of West African trypanosomiasis imported into the United States are extremely rare.

How can I get West African trypanosomiasis?

A person gets West African trypanosomiasis through the bite of an infected tsetse fly. Occasionally a pregnant woman may pass the infection to her baby. In theory, the infection can be transmitted through a blood transfusion, but such cases rarely have been documented.

Is West African trypanosomiasis a serious illness?

Yes. West African trypanosomiasis is eventually fatal if it is not treated.

Where can I contract West African trypanosomiasis?

Tsetse flies are found only in Africa and they live in rural environments. West African trypanosomiasis can be contracted in parts of central Africa and in a few areas of West Africa. Most of the reported cases are found in central Africa (Democratic Republic of Congo, Angola, Sudan, Central African Republic, Republic of Congo, Chad, and northern Uganda).

What are the signs and symptoms of West African trypanosomiasis?

Occasionally, within 1 to 3 weeks, the infective bite develops into a red sore, also called a chancre. Several weeks to months later, other symptoms of sleeping sickness occur. These include fever, rash, swelling of the face and hands, headaches, fatigue, aching muscles and joints, itching skin, and swollen lymph nodes. Weight loss occurs as the illness progresses. Progressive confusion, personality changes, daytime sleepiness with nighttime sleep disturbances, and other neurologic problems occur after the infection has invaded the central nervous system. These symptoms become worse as the illness progresses. If left untreated, death will eventually occur after several years of infection.

How soon after infection will I have symptoms of West African trypanosomiasis?

Symptoms may be minimal or intermittent during the first months of infection. They are usually apparent within a few months to a year after getting an infected tsetse fly bite.

What should I do if I think I have African trypanosomiasis?

If you suspect that you may have West African trypanosomiasis, see your health care provider who will order several tests to look for the parasite. Common tests include examination of blood samples and a spinal tap. Your physician may also take a sample of fluid from swollen lymph nodes.

Is treatment available for West African trypanosomiasis?

Medication for the treatment of West African trypanosomiasis is available. Treatment of West African trypanosomiasis should begin as soon as possible and is based on the infected person’s laboratory results. Hospitalization for treatment is usually necessary. Periodic follow-up exams that include a spinal tap are required for 2 years.

Who is at risk for contracting West African trypanosomiasis?

The tsetse flies that transmit West African trypanosomiasis are found only in rural areas. Travelers to urban areas are not at risk. The flies bite during daylight hours. They inhabit forests and areas of thick vegetation along rivers and waterholes. Even in areas where the disease is present, most flies are not infected with this parasite, so the risk of infection increases with the number of times a person is bitten by the tsetse fly. Therefore, tourists are not at great risk for contracting West African trypanosomiasis unless they are traveling and spending long periods of time in rural areas of central Africa where the disease is present.

Can I take medication to prevent West African trypanosomiasis?

There is neither a vaccine nor recommended drug available to prevent West African trypanosomiasis.

How can I prevent African trypanosomiasis and other insect bites?

  1. 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.
  2. Wear neutral-colored clothing. The tsetse fly is attracted to bright colors and very dark colors.
  3. Inspect vehicles for tsetse flies before entering. The tsetse fly is attracted to moving vehicles.
  4. Avoid bushes. The tsetse fly is less active during the hottest period of the day. It rests in bushes but will bite if disturbed.
  5. Use insect repellant. Though insect repellants have not proven effective in preventing tsetse fly bites, they are effective in preventing other insects from biting and causing illness.

This information is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider.

10 Cockroach Hiding Spaces

Cockroaches have an almost Transformer-like capability to scuttle, fly, walk upside down and flatten their crunchy bodies before disappearing into sliver-thin crevices. And unless they’re hissing or have enough weight to make noise while they take a flagrant stroll across your paper or plastic goods, they are generally silent. Hard to kill? Yes, that too. All of these factors make them the most successful insect species in the United States, whether they belong to the half-inch or 2-inch (or longer) varieties.

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Armies of these brown and black, six-legged, winged, long-antennaed and hardened crawlers are known to roam in moist basements and crawl spaces and in multi-unit dwellings in cities, not to mention in a few states known for them, including Texas and Florida, but where else do cockroaches hide out in the hundreds and millions when we don’t see them?

One hint: If you see dead ones, no need to draw a little chalk line around their corpses; where you find them is a clue to their origin, route and destination. But if you see a live one that means there are likely whole cities of them hiding in your home.

Have the creepy-crawlies yet? Let’s find out where these bacteria-carrying bottom-draggers hide.

Causes — Malaria

Malaria is caused by the Plasmodium parasite. The parasite can be spread to humans through the bites of infected mosquitoes.

There are many different types of plasmodium parasite, but only 5 types cause malaria in humans.

  • Plasmodium falciparum – mainly found in Africa, it’s the most common type of malaria parasite and is responsible for most malaria deaths worldwide
  • Plasmodium vivax – mainly found in Asia and South America, this parasite causes milder symptoms than Plasmodium falciparum, but it can stay in the liver for up to 3 years, which can result in relapses
  • Plasmodium ovale – fairly uncommon and usually found in West Africa, it can remain in your liver for several years without producing symptoms
  • Plasmodium malariae – this is quite rare and usually only found in Africa
  • Plasmodium knowlesi – this is very rare and found in parts of southeast Asia

How malaria is spread

The plasmodium parasite is spread by female Anopheles mosquitoes, which are known as «night-biting» mosquitoes because they most commonly bite between dusk and dawn.

If a mosquito bites a person already infected with malaria, it can also become infected and spread the parasite on to other people. However, malaria can’t be spread directly from person to person.

Once you’re bitten, the parasite enters the bloodstream and travels to the liver. The infection develops in the liver before re-entering the bloodstream and invading the red blood cells.

The parasites grow and multiply in the red blood cells. At regular intervals, the infected blood cells burst, releasing more parasites into the blood. Infected blood cells usually burst every 48-72 hours. Each time they burst, you’ll have a bout of fever, chills and sweating.

Malaria can also be spread through blood transfusions and the sharing of needles, but this is very rare.

Page last reviewed: 22 August 2018
Next review due: 22 August 2021

Top 10 Peculiar Pets

Some might think this is the grossest pet ever, but many people consider this large, hissing insect their love bug. If you can get past the idea of keeping a cockroach on purpose, you might realize these hissers actually make really good pets. They don’t fly or bite, and the hissing sound they make is pretty cool, too.

Caring for This Pet

These roaches need small living spaces with places to hide from light, and sticks to climb. They are excellent climbers and have been known to climb right out of their enclosures. Experts recommend keeping the top couple inches of the enclosures coated with petroleum jelly to inhibit the roaches from escaping. These insects like fresh veggies with any type of dry pellet food that’s high in protein — even dog food will do the trick.

Is This Pet Right for You?

Some states might require you to get a permit before bringing these large cockroaches into your life, so check your city and state laws before bringing the bugs home. Because they don’t bite or sting, these cockroaches could make excellent first pets for children, especially those interested in bugs. Just remember, as with all of the pets on this countdown, owning these rather peculiar pets can present some challenges. Make sure you’re up for them before diving in.


If you’ve found a white or albino cockroach in your home, business or neighborhood, you might be a little excited or nervous about this seemingly rare observation. Relax. They actually aren’t rare at all. It’s true of most cockroach species that all roaches spend a few hours, several times during their lives, as white cockroaches. So if it’s that common, why don’t you see white roaches or albino roaches more often?

Is a white cockroach an albino cockroach?

First, it’s important to note that these are two different conditions. As common as white cockroaches are, there has never been a documented case of an albino cockroach, at least not one that fits the definition of albinism.

According to the National Organization for Albinism and Hypopigmentation, albinism is a genetic condition that affects an organism’s ability to produce a sufficient quantity of the pigment melanin, the material that gives color to the skin, hair and eyes. There are many levels of albinism and it doesn’t always result in noticeable non-pigmentation of the skin and hair, but almost always affects vision.

An accurate diagnosis is not reliably made by observing the color of the skin. Instead, it is most commonly diagnosed by a simple eye exam. But don’t open up a cockroach eye exam center just yet. Albinism is not a genetic condition that is known to affect roaches. In other words, when it comes to a white cockroach, albinism is not the cause.

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What causes white cockroaches?

The real cause of a cockroach’s white appearance is that when roaches molt, they don’t only shed their outer shell, they also lose most of the pigmentation in their bodies, which must then be replaced. This is a chemical reaction that occurs within the body, usually taking a few hours to fully restore pigmentation. The pigmentation not only colors their bodies, it may affect their circadian rhythms, or biological clocks, according to a study on the neural organization of the circadian system of the cockroach Leucophaea maderae.

Why do you rarely see a white cockroach?

Cockroaches are arthropods, and just like all arthropods, they don’t have a spine, making them invertebrates. In fact, cockroaches don’t have any other bones either. But in order for a cockroach’s muscles to properly operate their legs, wings and other moving parts, they have to be attached to something rigid. This is why insects have hard outer bodies.

This exterior skeleton, or exoskeleton, provides the structure their bodies need to operate properly. Because the exoskeleton is rigid and cannot change size once it is “set” on the insect, cockroaches must get larger and grow by a process called “molting.” Molting is when cockroaches periodically shed their exoskeleton, replacing it with a roomier model that allows them the internal space they need to continue growing.

Before they shed their old outer shell, or skin, they must form a new one, just inside the old one, to keep their body parts together and retain body moisture when they molt. This new skin, or exoskeleton, is soft and pliable at first and has no pigmentation, which is what gives the shell its color. When roaches are ready to molt, they split the old skin and crawl out of it. The new skin is ready to go, but it is still very soft. Because the pigmentation process has not yet been completed, the new skin is also white.

Roaches are highly vulnerable to drying out and to attack by predators just after molting, so roaches that have molted stay hidden, out of the light and moving air. The new shell is not rigid enough for the muscles to provide much movement at this point, making it hard to run and hide when predators are chasing them. These factors, combined with the possible disorder of their biological clocks, provides plenty of incentive for roaches to stay out of your sight while they’re white.

What happens to the white cockroach next?

The exoskeleton will start to harden and regain normal coloration over the next few minutes, and life will soon return to normal for the temporarily white cockroach. Some species of roaches may take several hours to fully transform. At this point, the cockroach, now sporting a new suit of armor, is ready to go find food, water and shelter. If this is their final molt, the cockroach has reached adulthood and a mate will soon be located.

Why would I see a white cockroach?

All roaches are white cockroaches for a short period of time, every time they molt. They stay in deep harborage areas for protection when they feel a molt coming on, so if a white cockroach is observed, something has disturbed the harborage area. Professional pest control technicians see white roaches quite often as they apply treatments deep within harborage areas. This disturbs them during the molting process, running them out of hiding places and ensuring that cockroach control will be successful.

Chronobiol Int. 2003 Jul; 20(4):577-91. Neural organization of the circadian system of the cockroach Leucophaea maderae. Homberg U1, Reischig T, Stengl M.

Understanding rabies

Thanks to widespread pet vaccinations, effective post-exposure treatment and the relative rarity of undetected bites by rabid animals, the number of human deaths from rabies in the United States caused has declined to an average of only one or two per year—far less than the number of human fatalities caused by lightning strikes. But this doesn’t mean you shouldn’t take precautions to protect yourself, your family and your pets. The best ways to guard against rabies:

  • Don’t approach or handle wild animals, especially sick wild animals.
  • Vaccinate your pets.
  • Get prompt post-exposure treatment when advised to do so by a doctor or health department.

What is rabies?

Rabies (Lyssavirus) is an infectious disease that affects the central nervous system in mammals. It’s transmitted through the saliva a few days before death when the animal «sheds» the virus. Rabies is not transmitted through the blood, urine or feces of an infected animal, nor is it spread airborne through the open environment. Because it affects the nervous system, most rabid animals behave abnormally.

Signs of rabies in animals

In the «furious» form, wild animals may appear to be agitated, bite or snap at imaginary and real objects and drool excessively. In the «dumb» form, wild animals may appear tame and seem to have no fear of humans.

There are other signs, such as the animal appearing drunk or excessively wobbly, circling, seeming partially paralyzed, acting disorientated or mutilating itself. However, most of these signs can also be indicative of other diseases like distemper or lead poisoning. There are few behavioral signs that are telltale of rabies alone.

If a typically nocturnal animal, such as a raccoon or skunk, is active during the day and exhibiting abnormal behavior, you should seek advice from your local animal control, animal organization, wildlife rehabilitator or state wildlife agency.

Key facts

  • Rabies travels from the brain to the salivary glands during the final stage of the disease—this is when an animal can spread the disease, most commonly through a bite.
  • Rabies can’t go through unbroken skin. People can get rabies only via a bite from a rabid animal or possibly through scratches, abrasions, open wounds or mucous membranes in contact with saliva or brain tissue from a rabid animal.
  • The rabies virus is short-lived when exposed to open air—it can only survive in saliva and dies when the animal’s saliva dries up.
  • If you handle a pet who has been in a fight with a potentially rabid animal, take precautions such as wearing gloves to keep any still-fresh saliva from getting into an open wound.
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Which species carry rabies?

Any warm-blooded mammal can carry or contract rabies, but the primary carriers in North America are raccoons, skunks, bats, foxes and coyotes. Thanks to an increase in pet vaccinations, wildlife now account for more than 90 percent of all reported rabies cases.

Rabies tends to be more common in different species in different places, but is certainly not limited to these trends:

  • Raccoons suffer the most from this disease in the eastern U.S.
  • Skunks are the dominant rabies victims in the north- and south-central states, although skunk rabies also occurs in the East.
  • Bats suffering from rabies are not limited to any particular area but scattered widely.
  • Foxes in western Alaska, parts of Arizona and Texas, and the eastern United States are victims more frequently than foxes in other areas.
  • Coyotes with rabies have been found in southern Texas in the past but rarely in recent years.
  • Rodents (squirrels, chipmunks, rats, mice, hamsters, gerbils and guinea pigs), rabbits and hares rarely get rabies and have not been known to cause rabies among humans in the United States. Squirrels may suffer from the fatal roundworm brain parasite, which causes signs that look exactly like rabies.
  • Opossums are amazingly resistant to rabies. Hissing, drooling and swaying are part of the opossum’s bluff routine. It is intended to scare away potential predators, yet it looks just like rabies and is the reason people can be convinced they’re seeing rabid opossums when they’re not.

Federal and state wildlife officials have been vaccinating wildlife in many regions over the past two decades. They distribute vaccine-laden baits that the target animals eat and thereby vaccinate themselves. Right now, oral rabies vaccination of wildlife focuses on halting the spread of specific types of rabies in targeted carrier species. It’s hoped that this tool can also shrink the disease’s range.

People and rabies

Given all the media attention that rabies receives, it may be somewhat surprising to learn that very few people die from rabies nationwide each year. There are fewer than three fatalities each year nationwide, on average.

People who contracted rabies in the United States were mostly infected by a bat. Most didn’t even know they were bitten. Some may have been sleeping when bitten. Others handled a bat bare-handed without realizing they’d been potentially exposed to rabies. But don’t panic over every bat sighting. Less than one-half of one percent of all bats in North America carries rabies.

Although raccoons suffer from rabies more than any other mammal in the United States (about 35 percent of all animal rabies cases), only one human death from the raccoon strain of rabies has been recorded in the United States.


Despite the long odds of contracting rabies, the remote possibility of infection exists and should not be taken lightly:

  • Don’t approach or handle wild animals.
  • Vaccinate your pets—both cats and dogs—and any free-roaming cats under your care.
  • If you see a wild animal who may be sick, contact your local animal control, veterinarian or wildlife rehabilitator for help. Don’t handle sick wildlife!
  • If anyone is bitten by any wild animal, get medical advice from a doctor or health department immediately.
  • If your pet is bitten by any wild animal, get medical advice from your veterinarian immediately.
  • Scrub any bite wound immediately and aggressively with soap and water, use antiseptic soap such as betadine or Nolvasan®, if available. Flush the wound thoroughly with water.
  • If anyone is bitten by a potentially rabid animal, scrub and flush the wound, then go to your doctor or an emergency room.
  • If possible, the animal should be captured and tested for rabies. Unless you can do it without risking further bites, leave this task to animal control professionals.
  • If you find a bat in a room where someone was sleeping or where children might have had contact with them, the National Centers for Disease Control and Prevention (CDC) recommends that you assume the bat has bitten the sleeper or children and take the step for a known bite. CDC suspects that adults may overlook and children may underreport the bites of tiny bat teeth.
  • Timely treatment after a bite or other exposure is 100 percent effective. The very few people who die from rabies are those who don’t get timely treatment.

World Rabies Day

Since its launch in 2007, World Rabies Day has helped educate over 200 million people and vaccinated millions of dogs through events in 150 countries. Globally, World Rabies Day is important because most deaths from rabies occur in countries with inadequate public health resources and limited access to preventive treatment. Since 1982, the World Health Organization has recommended vaccination—rather than removal—of free-roaming dogs to control rabies.

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