African trypanosomiasis

A tiny bug can make people sick.

It lives in a tsetse fly. The fly bites a person or an animal. This can spread the sickness.

At first, a person might feel hot. They may have a bad headache. It might feel itchy or sore. This happens soon after the bite.

Later, the sickness changes. It can make a person feel very confused. They might have trouble moving well. It can also change how they sleep.

People might sleep during the day. They might stay awake at night. This is why it is called sleeping sickness.

Doctors can use tests to find the bug. It is best to get help early. This helps the medicine work well.

Some people call it sleeping sickness. It is caused by tiny bugs called parasites.

These parasites live inside tsetse flies. The flies bite people and animals in rural parts of Africa.

The sickness happens in two main stages. The first stage is the hemolymphatic stage. This means the parasites are in the blood and the lymph system. This part can cause fevers, headaches, and itchy skin. It can also make lymph nodes swell up.

The second stage is the neurological stage. This happens when the parasites cross into the brain. This stage changes how the body works. It can cause confusion or trouble moving. It also changes the circadian rhythm. This is the body's internal clock.

Because the clock is broken, people sleep during the day. They stay awake at night.

Doctors use blood tests to find the parasite. They may also check fluid from the spine. It is very important to find the sickness early. Medicine works best before the brain is affected. Without help, the sickness can be fatal.

African trypanosomiasis is a serious illness caused by tiny living things called parasites.

Many people call it sleeping sickness because of how it changes sleep. This disease affects humans and animals in rural parts of sub-Saharan Africa.

The parasites are passed to people by the bite of an infected tsetse fly. There are two main types of these parasites. One type is called Trypanosoma brucei gambiense. This type causes over 92% of all reported cases. The other type is Trypanosoma brucei rhodesiense, which can also infect animals like cattle.

The sickness happens in two distinct steps. First, the parasites enter the hemolymphatic stage. During this stage, the parasites live in the blood and the lymph system. People might feel fever, headaches, or itchy skin. They may also see their lymph nodes swell up.

Later, the disease moves into the neurological stage. This happens when the parasites cross a barrier to enter the central nervous system. This part of the sickness affects the brain and spinal cord. It can cause confusion, trouble moving, or even seizures. This second stage is much harder to treat.

Doctors have many ways to find the parasite in a person. They can look for it in a blood smear or in fluid from a lymph node. To see if the sickness has reached the brain, they might perform a lumbar puncture. This test checks the fluid around the spine. Finding the disease early is very important for health. Medicines like pentamidine or suramin work well for the first stage. For the later stage, doctors use different drugs like eflornithine. A newer medicine called fexinidazole can even be taken by mouth.

History shows us how much this disease has changed over time. There were three major outbreaks in recent years. One happened from 1896 to 1906 in Uganda and the Congo Basin. Two other outbreaks occurred in 1920 and 1970. In 1990, there were about 34,000 deaths from this sickness. By 2015, that number dropped to around 3,500 deaths. Most cases, more than 80%, happen in the Democratic Republic of the Congo. Today, about 70 million people in 36 countries are at risk of infection.

One of the most interesting parts of this sickness is how it breaks the body's internal clock. This clock is called the circadian rhythm. It tells our bodies when to be awake and when to sleep. The parasites attack the genes that run this clock.

This causes people to sleep during the day and stay awake at night. This is why the disease is often called sleeping sickness. Without medicine, the sickness is always fatal. However, the sleep patterns can return to normal after a person is treated.

African trypanosomiasis is a serious parasitic infection that affects humans and animals.

It is commonly known as sleeping sickness due to the way it disrupts sleep patterns. The disease is caused by microscopic organisms called Trypanosoma brucei. This infection is classified as a neglected tropical disease. It primarily occurs in rural areas of sub-Saharan Africa. People living or traveling in these regions face the highest risks. Occupations like farming, fishing, and hunting increase the chance of exposure.

The infection is spread through the bite of an infected tsetse fly. There are two specific species of the parasite that cause human disease. Trypanosoma brucei gambiense is responsible for over 92% of reported cases. This type is primarily transmitted between humans. The second type is Trypanosoma brucei rhodesiense. This version is zoonotic, meaning it lives in animals like cattle and wildlife.

When animals like cows are infected, the disease is called nagana. The transmission process depends on the presence of these flies in the environment.

Doctors divide the disease into two distinct clinical stages. The first is the hemolymphatic stage. During this phase, the parasites live in the blood and the lymphatic system. Patients may experience intermittent fevers, severe headaches, and joint pains. It can also cause lymphadenopathy, which is the swelling of lymph nodes. A specific sign called Winterbottom's sign involves swollen nodes at the base of the skull.

The second is the neurological stage, also called the meningoencephalitic phase. This begins when the parasites cross the blood-brain barrier. Once they invade the central nervous system, they affect the brain and spinal cord.

The transition between these stages varies by parasite type. For T. b. rhodesiense, the neurological stage may begin in 21 to 60 days. For T. b. gambiense, it can take 300 to 500 days. Because the stages often overlap, symptoms can be hard to distinguish. Doctors use a lumbar puncture to check cerebrospinal fluid for parasites. This test confirms if the central nervous system is involved. This distinction is vital because the treatment methods change significantly between stages.

Treatment success depends heavily on early detection. For the hemolymphatic stage, drugs like pentamidine or suramin are used. A newer option, fexinidazole, can be taken by mouth for either stage of gambiense infection. If the disease reaches the neurological stage, more intensive drugs are required. These include eflornithine or a combination of nifurtimox and eflornithine. Melarsoprol is used for rhodesiense, but it has serious side effects. Without medical intervention, the disease is invariably fatal. Untreated rhodesiense kills within months, while gambiense can take years.

One of the most fascinating aspects is how the parasite affects the circadian rhythm. This is the body's internal biological clock. The parasite alters the expression of clock genes in brain regions like the suprachiasmatic nucleus (SCN). It also triggers inflammation by increasing TNF-α levels. This disruption causes sleep inversion, where patients sleep during the day and stay awake at night. They may also experience sudden episodes of sleepiness. Interestingly, sleep patterns can return to normal after successful treatment.

History shows both the impact and the progress in fighting this disease. Major outbreaks occurred between 1896 and 1906 in Uganda and the Congo Basin. Other significant outbreaks happened in 1920 and 1970. In 1990, there were approximately 34,000 deaths. By 2015, annual deaths had dropped to about 3,500. Currently, about 70 million people in 36 countries are at risk. More than 80% of all cases occur in the Democratic Republic of the Congo.