Sleeping Sickness
Disease Details
Family Health Simplified
- Description
- Sleeping sickness, or African trypanosomiasis, is a parasitic disease caused by Trypanosoma brucei and transmitted by the tsetse fly, leading to severe neurological symptoms and potentially fatal outcomes if untreated.
- Type
- Sleeping sickness, also known as African trypanosomiasis, is a parasitic disease transmitted by the bite of infected tsetse flies. It is not genetically transmitted. The disease is caused by protozoa of the species Trypanosoma brucei, with two subspecies responsible for the disease in humans: Trypanosoma brucei gambiense (chronic form) and Trypanosoma brucei rhodesiense (acute form).
- Signs And Symptoms
- African trypanosomiasis symptoms occur in two stages: the hemolymphatic stage and the neurological stage (the latter being characterised by parasitic invasion of the central nervous system). Neurological symptoms occur in addition to the initial features, and the two stages may be difficult to distinguish based on clinical features alone.The disease has been reported to present with atypical symptoms in infected individuals who originate from non-endemic areas (e.g. travelers). The reasons for this are unclear and may be genetic. The low number of such cases may also have skewed findings. In such persons, the infection is said to present mainly as fever with gastrointestinal symptoms (e.g. diarrhoea and jaundice) with lymphadenopathy developing only rarely.
- Prognosis
- If untreated, T. b. gambiense almost always results in death, with only a few individuals shown in a long-term 15 year follow-up to have survived after refusing treatment. T. b. rhodesiense, being a more acute and severe form of the disease, is consistently fatal if not treated.Disease progression greatly varies depending on disease form. For individuals which are infected by T. b. gambiense, which accounts for 92% of all of the reported cases, a person can be infected for months or even years without signs or symptoms until the advanced disease stage, where it is too late to be treated successfully. For individuals affected by T. b. rhodesiense, which accounts for 2% of all reported cases, symptoms appear within weeks or months of the infection. Disease progression is rapid and invades the central nervous system, causing death within a short amount of time.
- Onset
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Sleeping sickness, also known as African trypanosomiasis, generally has an onset that varies depending on the type. There are two forms:
1. East African trypanosomiasis (Trypanosoma brucei rhodesiense) - The onset is typically acute, with symptoms appearing a few weeks after the bite of an infected tsetse fly.
2. West African trypanosomiasis (Trypanosoma brucei gambiense) - The onset is usually more chronic, with symptoms developing months to years after the tsetse fly bite.
"nan" stands for "not a number," which is irrelevant in the context of disease onset. If you meant something else, please clarify. - Prevalence
- The prevalence of sleeping sickness, also known as Human African Trypanosomiasis (HAT), is declining due to intensified control efforts. As of recent data, fewer than 1,000 cases are reported annually. The disease is primarily found in sub-Saharan Africa, especially in rural areas where the tsetse fly, the vector for the Trypanosoma parasite, is prevalent.
- Epidemiology
- In 2010, it caused around 9,000 deaths, down from 34,000 in 1990. As of 2000, the disability-adjusted life-years (9 to 10 years) lost due to sleeping sickness are 2.0 million. From 2010 to 2014, there was an estimated 55 million people at risk for gambiense African Trypanosomiasis and over 6 million people at risk for rhodesiense African trypanosomiasis. In 2014, the World Health Organization reported 3,797 cases of Human African Trypanosomiasis when the predicted number of cases were to be 5,000. The number of total reported cases in 2014 is an 86% reduction to the total number of cases reported in 2000.The disease has been recorded as occurring in 37 countries, all in sub-Saharan Africa. It occurs regularly in southeast Uganda and western Kenya, and killed more than 48,000 Africans in 2008. The Democratic Republic of the Congo is the most affected country in the world, accounting for 75% of the Trypanosoma brucei gambiense cases. The population at risk being about 69 million with one third of this number being at a 'very high' to 'moderate' risk and the remaining two thirds at a 'low' to 'very low' risk. The number of people being affected by the disease has declined. At this rate, sleeping sickness elimination is a possibility. The World Health Organization plans to eradicate sleeping sickness by 2030.
- Intractability
- Sleeping sickness, also known as African trypanosomiasis, is not considered intractable. The disease can be effectively treated with antiparasitic medications, particularly if diagnosed early. However, if left untreated, it can progress to a severe and potentially fatal stage. Early detection and timely treatment are crucial for a favorable outcome.
- Disease Severity
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Sleeping sickness, also called African trypanosomiasis, is a potentially fatal disease caused by parasites of the genus Trypanosoma, which are transmitted by the tsetse fly. Disease severity can vary but generally progresses through two stages:
1. **Early Stage (Hemolymphatic Phase):** Symptoms may include fever, headaches, joint pains, and itching. If left untreated, the severity can escalate.
2. **Late Stage (Neurological Phase):** The parasite crosses the blood-brain barrier, leading to serious neurological symptoms such as confusion, sensory disturbances, poor coordination, and disruption of sleep patterns (hence the name "sleeping sickness"). Without treatment, this stage can be fatal.
The severity of the disease necessitates prompt diagnosis and treatment to prevent progression to the neurological phase. - Healthcare Professionals
- Disease Ontology ID - DOID:10112
- Pathophysiology
- Tryptophol is a chemical compound produced by the trypanosomal parasite in sleeping sickness which induces sleep in humans.
- Carrier Status
- Sleeping sickness, also known as African trypanosomiasis, is primarily transmitted by the tsetse fly. The fly serves as the carrier for the Trypanosoma parasites responsible for the disease. Humans and animals can become infected through the bite of an infected tsetse fly.
- Mechanism
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Sleeping sickness, also known as African trypanosomiasis, is caused by the parasite Trypanosoma brucei. There are two subspecies: Trypanosoma brucei gambiense, which causes a chronic form of the disease, and Trypanosoma brucei rhodesiense, which causes an acute form.
**Mechanism:**
1. **Transmission:** The disease is primarily transmitted through the bite of an infected tsetse fly (genus Glossina).
2. **Parasitic Life Cycle:**
- The tsetse fly injects metacyclic trypomastigotes into the human host.
- These parasites transform into bloodstream trypomastigotes, which multiply by binary fission.
- The trypomastigotes can then be taken up by another tsetse fly when it takes a blood meal.
3. **Invasion and Systemic Spread:**
- The parasites proliferate in the blood, lymph, and eventually the central nervous system (CNS), which leads to the neurological symptoms characteristic of the disease.
**Molecular Mechanisms:**
1. **Antigenic Variation:**
- One of the key survival strategies of T. brucei is its ability to undergo antigenic variation, which involves changing the variant surface glycoproteins (VSGs) on its surface.
- This mechanism allows the parasite to evade the host's immune system by continuously altering its antigenic profile.
2. **Immune Evasion:**
- Besides antigenic variation, T. brucei employs other mechanisms like modulation of host immune responses and destruction of host immune components.
3. **Trypanosomal Surface Coat:**
- The VSG coat is densely packed on the parasite surface, providing a physical barrier to immune effector molecules.
- The genes encoding VSGs are predominantly located in telomeric regions and their expression involves complex regulation including gene conversion and transcriptional switching.
4. **Neurological Invasion:**
- The mechanism by which the trypanosomes cross the blood-brain barrier is not fully understood, but it involves factors like metalloproteases and possibly manipulation of host cellular processes.
- Once in the CNS, the parasites induce inflammation and damage that lead to the characteristic sleep disturbances and other neurological symptoms.
Understanding these mechanisms is crucial for developing interventions and treatments to combat sleeping sickness. - Treatment
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Treatment for sleeping sickness (African trypanosomiasis) varies depending on the disease stage and the infecting parasite, either Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense. Early-stage treatment for T. b. gambiense includes Pentamidine, while T. b. rhodesiense is treated with Suramin.
For late-stage disease that affects the central nervous system, treatment options include:
- **T. b. gambiense:** Eflornithine, often combined with Nifurtimox
- **T. b. rhodesiense:** Melarsoprol
Early diagnosis and treatment are crucial to prevent severe progression and complications. - Compassionate Use Treatment
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Compassionate use treatment for sleeping sickness (Human African Trypanosomiasis) may involve the use of investigational drugs that are not yet approved or available through normal regulatory channels. Eflornithine, historically used in combination with nifurtimox, has been provided under compassionate use.
Off-label or experimental treatments could include new investigational drugs being tested in clinical trials. For instance, fexinidazole has transitioned from experimental to primary treatment for both stages of the disease. Other potential treatments under study might involve novel drug combinations or new molecular entities targeting the Trypanosoma parasite. Specific details would depend on ongoing research and clinical trial outcomes. - Lifestyle Recommendations
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Sleeping sickness, also known as African trypanosomiasis, is a parasitic disease caused by the Trypanosoma brucei parasite and transmitted by the tsetse fly. For lifestyle recommendations to manage and prevent sleeping sickness, consider the following:
1. **Avoid Tsetse Fly Habitats**: Limit travel to or within areas where tsetse flies are common, such as rural regions of sub-Saharan Africa. Stay away from dense vegetation during the peak activity of the flies.
2. **Protective Clothing**: Wear clothing that covers as much skin as possible. Long sleeves, long pants, and sturdy shoes can minimize skin exposure to tsetse fly bites.
3. **Use Insect Repellents**: Apply insect repellents containing DEET or Picaridin on exposed skin and clothing to deter tsetse flies.
4. **Stay in Fly-Proof Accommodation**: When traveling in endemic areas, choose accommodations with effective fly-proofing measures like screened windows, insecticide-treated nets, and air conditioning.
5. **Avoid Bright Colors**: Tsetse flies are attracted to bright and dark colors. Wear neutral-colored clothing to reduce the risk of bites.
6. **Regular Monitoring and Medical Check-ups**: If residing in or traveling frequently to endemic areas, regular health check-ups can help in early detection and treatment.
7. **Community Awareness and Vector Control**: Support and participate in local vector control programs, such as fly trapping and insecticide spraying, to reduce tsetse fly populations.
By taking these preventive measures, individuals can lower their risk of contracting sleeping sickness while traveling or living in endemic regions. - Medication
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Sleeping sickness, also known as African trypanosomiasis, can be treated with different medications depending on the stage of the disease:
1. **First Stage** (hemolymphatic stage):
- **Pentamidine**: Used for Trypanosoma brucei gambiense infection.
- **Suramin**: Used for Trypanosoma brucei rhodesiense infection.
2. **Second Stage** (neurological stage):
- **Eflornithine**: Effective for Trypanosoma brucei gambiense.
- **Melarsoprol**: Used for both Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense.
- **Nifurtimox**: Often used in combination with eflornithine for better effectiveness.
Treatment should be promptly administered, and patients need to be monitored closely due to the potential side effects of these medications. - Repurposable Drugs
- Currently, there are no widely accepted repurposable drugs specifically for sleeping sickness, which is also known as African trypanosomiasis. Treatment typically involves drugs specifically targeted at the Trypanosoma parasites, such as pentamidine, suramin, melarsoprol, eflornithine, and nifurtimox. Research is ongoing to find new treatments or repurpose existing drugs, but as of now, no alternative medications are recommended for this disease.
- Metabolites
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Metabolites related to sleeping sickness, or Human African Trypanosomiasis, include:
1. **Trypanothione:** A unique thiol metabolite in trypanosomes, essential for their redox balance and survival.
2. **Polyamines:** Involved in the synthesis of trypanothione, important for cell growth and differentiation of the parasite.
3. **Glycolytic intermediates:** The parasite relies heavily on glycolysis for energy production, resulting in high levels of glycolytic metabolites.
Understanding these metabolites is crucial for the development of targeted treatments against Trypanosoma brucei, the causative agent of sleeping sickness. - Nutraceuticals
- There is no substantial evidence supporting the use of nutraceuticals (food-derived products) in the treatment or prevention of sleeping sickness, also known as African trypanosomiasis. Research has primarily focused on pharmaceutical treatments for this parasitic disease, which is caused by Trypanosoma brucei and transmitted by the tsetse fly. Early-stage treatment often involves drugs like pentamidine or suramin, while later-stage treatment may require nifurtimox-eflornithine combination therapy (NECT) or melarsoprol. Consult a healthcare professional for appropriate diagnosis and treatment options.
- Peptides
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Sleeping sickness, also known as human African trypanosomiasis, is caused by protozoan parasites belonging to the genus *Trypanosoma*. Currently, there is limited direct involvement or use of peptides in the diagnosis or treatment of sleeping sickness. However, research is ongoing to explore novel therapeutic approaches, including the potential use of peptides in drug development to target the disease more effectively.
Nanotechnology, on the other hand, has shown promise in advancing the treatment and diagnosis of sleeping sickness. Nanoparticles can be engineered to deliver drugs more efficiently to the affected tissues, reduce toxicity, and improve drug solubility and stability. Researchers are investigating these nano-based delivery systems to enhance the effectiveness of existing medications or develop new treatment options.
In summary, while peptides have not yet played a major role in managing sleeping sickness, nanotechnology is being explored as a potential tool to improve both therapeutic outcomes and diagnostic methods.