An indurated, painful chancre at the site of inoculation may be the first symptom of WAT, but dermatological findings are not described in all cases [1]. Swelling of the tissue surrounding the insect bite may be attributed to the local replication of parasites and an early immune response. After a prolonged incubation period of weeks to months, patients start suffering from intermittent fever and chills. Febrile episodes typically last for a few days and occur at intervals of several weeks. At the same time, patients may develop lymphadenopathy. Posterior cervical lymphadenopathy is most commonly observed and referred to as Winterbottom's sign, a sign of West and East African trypanosomiasis [2].

General weakness and lethargy are other hallmarks of WAT and increase during the course of the disease, hence the name sleeping sickness. The fatigue of WAT patients is at least partially induced by anemia, and severely anemic patients tend to appear pale. Additionally, they may experience headaches, myalgia, and arthralgia. An evanescent, papuloerythematous rash and pruritus are also common [1].

As the disease progresses, patients enter the so-called meningo-encephalitic stage, and cognitive decline becomes apparent. Mental deficits may be associated with physical decay, but neurological symptoms typically dominate the clinical picture. Family members frequently describe personality changes. WAT patients suffer from confusion and memory impairment, sleepiness during daytime, and insomnia at night. Motor deficits may be present and may manifest in abnormal movements, gait disturbance, tremor, or incontinence, among others [2].

Magnetic resonance imaging of the brain may reveal diffuse hyperintensity of the white matter [2].

• Splenomegaly

  Posterior cervical lymphadenopathy (Winterbottom's sign) and splenomegaly are not infrequent. Gradually over a period of months, neurological symptoms begin to manifest. 80% become somnolent. [ncbi.nlm.nih.gov]

  Splenomegaly and lymphadenopathy may be seen in early disease, although this and other early manifestations are nonspecific. The marked somnolence and eventual altered mental status that is the hallmark of sleeping sickness can be seen. [infectiousdiseaseadvisor.com]

  […] in endemic areas may therefore show evidence of lymphadenopathy (especially in the posterior cervical region in the case of T. b. gambiense disease which is known as Winterbottom's sign), haemolytic anemia, hepatomegaly and abnormal liver function, splenomegaly [frontiersin.org]

  Splenomegaly is another nonspecific sign and is more commonly found than hepatomegaly (14). This highly variable clinical picture grossly corresponds to the first, or hemolymphatic, stage of the disease. [cmr.asm.org]

• Generalized Lymphadenopathy

  Symptoms include characteristic skin lesions, intermittent fever, headache, rigors, transient edema, generalized lymphadenopathy, and often fatal meningoencephalitis. [merckmanuals.com]

• Fever

  Intermittent fever. Myalgia. Headache. Pruritus, urticaria and facial oedema which sometimes occur. [patient.info]

  MELLÉKLETBEN TALÁLHATÓ LISTÁHOZ en concerning animal health control measures relating to African swine fever in certain Member States and repealing Implementing Decision 2014/178/EU hu Azt hiszed, én élvezem, hogy az egész napomat egy tizenkilenc éves [hu.glosbe.com]

  Symptoms Fever is the first symptom of infection with either type of African trypanosomiasis. [tripprep.com]

  Mosquito-borne illnesses like dengue fever or malaria are also significant public health concerns for those living in regions where African trypanosomiasis can spread. [verywellhealth.com]

  Patients with either subtype of the disease initially present with a painful nodule or chancre at the site of the bite, followed by a hemolymphatic phase with fever and lymphadenopathy (stage I). [amboss.com]

• Weight Loss

  The illness progresses after a few weeks to weight loss, as well as personality changes, slurred speech, seizures, difficulty balancing and walking resulting from central nervous system failure. [iamat.org]

  The patients suffer from increasing states of confusion, reduced coordination and sleeping disorders, seizures, apathy and weight loss. There can be extrapyramidal disorders or a clinical picture similar to that of Parkinson’s disease. [flexikon.doccheck.com]

  Anorexia, wasting and weight loss. Irritability, tremors, and increased muscle tone are usual signs; sometimes ataxia or hemiparesis occurs, but rarely meningism. [patient.info]

  loss, arthralgia Painless lymph node enlargement Erythematous, annular (targetoid), or maculopapular rash that may or may not be pruritic Symptoms of anemia Stage II (neurologic phase) Headache Behavioral changes: confusion, apathy, psychosis Daytime [amboss.com]

  Symptoms of Trypanosoma brucei gambiense infection are often non-specific, such as: fever headache and muscle aches itchiness swelling of the face swollen lymph nodes weight loss Neurological symptoms, like sleep disturbances, poor coordination, and changes [canada.ca]

• Fatigue

  General weakness and fatigue increasingly affect the patient's quality of life, which is why WAT is also referred to as Gambian sleeping sickness. [symptoma.com]

  Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness. Some people develop a skin rash. [cdc.gov]

  Weight loss and general fatigue are also common symptoms associated with infection by this subspecies. [microbewiki.kenyon.edu]

• Malaise

  Symptoms tend to be nonspecific, including: General malaise. Intermittent fever. Myalgia. Headache. Pruritus, urticaria and facial oedema which sometimes occur. [patient.info]

  Trypanosomal chancre (local primary lesion) A red, painful, indurated, nodular swelling; 2–5 cm in size that develops at the bite site within 2 weeks of the bite Resolves spontaneously within 1–2 weeks Intermittent fever: caused by antigenic variation, malaise [amboss.com]

  This is called the haemolymphatic phase and may be associated with bouts of general malaise, fever, headaches, joint pain, itchiness, swelling of the hands, face, and feet, enlarged lymph nodes, and anaemia. [dermnetnz.org]

  After a prolonged incubation period, patients develop intermittent fevers lasting for a few days and spaced by weeks, accompanied by headache, myalgia, malaise and weight loss. [ncbi.nlm.nih.gov]

  In T. b. gambiense, early symptoms may develop gradually with intermittent fever, headaches, malaise, weight loss, and rash. Occasionally symptoms will present years after exposure. [infectiousdiseaseadvisor.com]

• High Fever

  Travellers who have been bitten by a tsetse fly and develop high fever should seek early medical attention. With appropriate medication, the infection is usually curable. [travelhealth.gov.hk]

  Symptoms of Trypanosoma brucei rhodesiense infection: Symptoms usually appear from three days to a few weeks after the bite from an infected tsetse fly and may include: painful chancre (small ulcer) at the site of the infected tsetse fly bite high fever [canada.ca]

  T.b. rhodesiense is more virulent and causes a much more aggressive febrile disease with the incubation period, non-specific symptoms (high fever, myalgia, rigors, sweating) and neurological involvement progressing over a matter of weeks. [antimicrobe.org]

• Loss of Appetite

  Early findings include insomnia, loss of appetite, behavioural changes, mood disorders, apathy, and headaches. A variety of muscle disorders may follow, including tremors and disturbances of speech, gait, and reflexes. [dermnetnz.org]

• Hepatosplenomegaly

  HAT comprises an initial hemo-lymphatic stage characterized by fever, weakness, musculoskeletal pain, anemia, and lymphadenopathy, along with dermatologic, cardiac and endocrine complications or hepatosplenomegaly, followed by a meningo-encephalitic stage [orpha.net]

  Signs include intermittent fever, joint pain, lymphadenopathy (firm, mobile, painless lymph nodes, mainly cervical), hepatosplenomegaly and skin signs (facial oedema, pruritus). – The second stage (meningoencephalitic stage) corresponds to the invasion [medicalguidelines.msf.org]

  Intermittent fever, headache, pruritus and other dermatologic problems, lymphadenopathies, weakness, asthenia, anemia, cardiac disorders, endocrine disturbances, musculoskeletal pains, and hepatosplenomegaly are the main signs and symptoms of the first [dovepress.com]

• Arthralgia

  […] lesion) A red, painful, indurated, nodular swelling; 2–5 cm in size that develops at the bite site within 2 weeks of the bite Resolves spontaneously within 1–2 weeks Intermittent fever: caused by antigenic variation, malaise, headache, weight loss, arthralgia [amboss.com]

  Additionally, they may experience headaches, myalgia, and arthralgia. An evanescent, papuloerythematous rash and pruritus are also common. [symptoma.com]

  Fatigue, arthralgia and headache, and often a fleeting truncal rash are observed with parasitemia. Patients are relatively asymptomatic between febrile periods. Myocarditis is common, and jaundice may occur from either hemolysis or hepatic damage. [antiinfectivemeds.com]

  Its adverse effects include vomiting, seizures, bone marrow toxicity, arthralgias, and rash. However, it is better tolerated than melarsoprol. Nifurtimox can be used in combination with other drugs in relapsed trypanosomiasis. [infectiousdiseaseadvisor.com]

  Thus, such features as lassitude, intermittent fever, arthralgia, and headache may initially predominate raising the possibility of malaria which may of course co-exist in patients with HAT (1). [frontiersin.org]

• Myalgia

  Additionally, they may experience headaches, myalgia, and arthralgia. An evanescent, papuloerythematous rash and pruritus are also common. [symptoma.com]

  Myalgia. Headache. Pruritus, urticaria and facial oedema which sometimes occur. [patient.info]

  After a prolonged incubation period, patients develop intermittent fevers lasting for a few days and spaced by weeks, accompanied by headache, myalgia, malaise and weight loss. [ncbi.nlm.nih.gov]

  T.b. rhodesiense is more virulent and causes a much more aggressive febrile disease with the incubation period, non-specific symptoms (high fever, myalgia, rigors, sweating) and neurological involvement progressing over a matter of weeks. [antimicrobe.org]

• Chancre

  The disease is diagnosed if the trypomastigote is found in chancre fluid, lymph node aspirates, or blood smears. [amboss.com]

  Trypanosoma brucei gambiense symptoms usually appear weeks or months after exposure to the protozoa although a chancre at the site of the bite develops 1 to 2 weeks after infection. [iamat.org]

  Chancres are reported in about one-third of infections and generally appear on the exposed surface of the skin where the flies have bitten. A chancre lasts ~ 3 weeks. Initially chancres are warm and tender but then scar or infrequently ulcerate. [antiinfectivemeds.com]

  The skin signs of trypanosomiasis include chancre, trypanids, itching and petechiae. A trypanosomal chancre may appear around 48 hours after the tsetse bite. This is an itchy, painful, inflammatory reaction at the site of the bite. [dermnetnz.org]

  A chancre appears at the bite site. Early symptoms include intermittent fever, swelling in the lymph nodes, and an itchy rash. [tripprep.com]

• Skin Rash

  Some people develop a skin rash. 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. [cdc.gov]

  Signs and symptoms are initially nonspecific like fever, skin rash, edema and lymph node enlargement. The infection can progress to inflammation of the brain and meninges. [travelhealth.gov.hk]

  Some people develop a skin rash. Progressive confusion, personality changes, slurred speech, seizures, and difficulty in walking and talking occur when infection has invaded the central nervous system. [webmd.com]

• Pruritus

  Signs include intermittent fever, joint pain, lymphadenopathy (firm, mobile, painless lymph nodes, mainly cervical), hepatosplenomegaly and skin signs (facial oedema, pruritus). – The second stage (meningoencephalitic stage) corresponds to the invasion [medicalguidelines.msf.org]

  An evanescent, papuloerythematous rash and pruritus are also common. As the disease progresses, patients enter the so-called meningo-encephalitic stage, and cognitive decline becomes apparent. [symptoma.com]

  Pruritus, urticaria and facial oedema which sometimes occur. [patient.info]

  It is potentially effective, but it has been associated with side effects including nausea, vomiting, photophobia, hyperesthesias, peripheral neuropathy, nephrotoxicity, urticaria, and pruritus. [merckmanuals.com]

  Side effects include nausea, vomiting, pruritus (itching), uricaria (hives), hypesthesia (decreased sensitivity), photophobia (increased sensitivity to light), and peripheral neuropathy. [web.stanford.edu]

• Eruptions

  The tsetse fly bite erupts into a red sore and within a few weeks the person can experience fever, swollen lymph glands, aching muscles and joints, headaches and irritability. [who.int]

  "[34] In 1901, a devastating epidemic erupted in Uganda, killing more than 250,000 people,[35] including about two-thirds of the population in the affected lakeshore areas. [en.wikipedia.org]

• Headache

  The second phase of the illness usually becomes evident 1 to 2 years after infection and is characterized by fever, headache, muscle and joint pain, itchy skin, weakness, weight loss, insomnia, confusion, personality changes, slurred speech, seizures, [iamat.org]

  weight loss, arthralgia Painless lymph node enlargement Erythematous, annular (targetoid), or maculopapular rash that may or may not be pruritic Symptoms of anemia Stage II (neurologic phase) Headache Behavioral changes: confusion, apathy, psychosis [amboss.com]

  During this stage, patients experience headaches, joint pain, and fever. If untreated, the parasite next enters the central nervous system (CNS). [news-medical.net]

  Trypanosoma brucei rhodesiense infection: Symptoms usually appear from three days to a few weeks after the bite from an infected tsetse fly and may include: painful chancre (small ulcer) at the site of the infected tsetse fly bite high fever severe headache [canada.ca]

  In the first stage, infected persons typically experience fever, headache, muscle and joint pain, and inflammation of the lymph nodes. [britannica.com]

• Seizure

  The illness progresses after a few weeks to weight loss, as well as personality changes, slurred speech, seizures, difficulty balancing and walking resulting from central nervous system failure. [iamat.org]

  Behavioural changes such as mania or psychosis with speech disorders and seizures. Seizures occur in children but rarely in adults. Stupor and coma (hence the name sleeping sickness). [patient.info]

  In advanced stages, the disease attacks the central nervous system and people present with changes in personality, alteration of the biological clock (the circadian rhythm), confusion, slurred speech, seizures and difficulty in walking and talking. [who.int]

  100 mg/kg every 6 hours for 14 days – In the event of a relapse after NECT or eflornithine: melarsoprol slow IV Children and adults: 2.2 mg/kg once daily for 10 days Melarsoprol is highly toxic: reactive encephalopathy (coma, or recurrent or prolonged seizures [medicalguidelines.msf.org]

  The patients suffer from increasing states of confusion, reduced coordination and sleeping disorders, seizures, apathy and weight loss. There can be extrapyramidal disorders or a clinical picture similar to that of Parkinson’s disease. [flexikon.doccheck.com]

• Somnolence

  Abstract West-African trypanosomiasis caused by Trypanosoma brucei gambiense is a rare imported infection presenting with somnolence, lymphadenopathy and wide-ranging neurological symptoms. [ncbi.nlm.nih.gov]

  […] loss, arthralgia Painless lymph node enlargement Erythematous, annular (targetoid), or maculopapular rash that may or may not be pruritic Symptoms of anemia Stage II (neurologic phase) Headache Behavioral changes: confusion, apathy, psychosis Daytime somnolence [amboss.com]

  The marked somnolence and eventual altered mental status that is the hallmark of sleeping sickness can be seen. Cachexia can develop in T. b. gambiense infection since worsening is gradual and patients become too somnolent to eat. [infectiousdiseaseadvisor.com]

• Insomnia

  The second phase of the illness usually becomes evident 1 to 2 years after infection and is characterized by fever, headache, muscle and joint pain, itchy skin, weakness, weight loss, insomnia, confusion, personality changes, slurred speech, seizures, [iamat.org]

  General symptoms include: Mood changes, anxiety Fever, sweating Headache Weakness Insomnia at night Sleepiness during the day (may be uncontrollable) Swollen lymph nodes all over the body Swollen, red, painful nodule at site of the fly bite Diagnosis [medlineplus.gov]

  Erythematous, annular (targetoid), or maculopapular rash that may or may not be pruritic Symptoms of anemia Stage II (neurologic phase) Headache Behavioral changes: confusion, apathy, psychosis Daytime somnolence, which may be associated with night-time insomnia [amboss.com]

  Early findings include insomnia, loss of appetite, behavioural changes, mood disorders, apathy, and headaches. A variety of muscle disorders may follow, including tremors and disturbances of speech, gait, and reflexes. [dermnetnz.org]

  Neurologic: disturbed sleep patterns (diurnal somnolence, nocturnal insomnia), mental status changes, cerebellar signs. Laboratory: Blood smear with Giemsa stain shows hemoflagellates. [antiinfectivemeds.com]

• Personality Change

  The illness progresses after a few weeks to weight loss, as well as personality changes, slurred speech, seizures, difficulty balancing and walking resulting from central nervous system failure. [iamat.org]

  Family members frequently describe personality changes. WAT patients suffer from confusion and memory impairment, sleepiness during daytime, and insomnia at night. [symptoma.com]

  Without diagnosis and treatment in the first phase, the disease progresses to the second stage where mental deterioration (i.e. personality changes, daytime sleepiness, progressive confusion), partial paralysis, balance problems, and eventually death [infontd.org]

  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. [cdc.gov]

  Progressive confusion, personality changes, slurred speech, seizures, and difficulty in walking and talking occur when infection has invaded the central nervous system. [webmd.com]

In endemic areas, clinical findings warrant a tentative diagnosis of WAT. Outside Central and West Africa, though, it's the patient's history of travel that causes their physicians to consider tropical infectious diseases as differential diagnoses. In the absence of anamnestic data indicating a recent stay in rural areas of Africa, WAT is highly unlikely.

Upon clinical suspicion, blood samples should be analyzed. Standard laboratory analyses may reveal anemia, thrombocytopenia, raised erythrocyte sedimentation rate, increased levels of C-reactive protein, hyperglobulinemia, and hypoalbuminemia [2]. Even though these findings suggest an infectious disease, they are non-specific. It's the microscopic examination of peripheral blood smears that allows for the visualization of trypanosomes. The aspiration of swollen lymph nodes should be considered if parasites cannot be detected in peripheral blood, because lymphatic fluid generally contains large quantities of trypanosomes.

Serological studies constitute a sensitive alternative to the direct proof of pathogens, and they allow for a distinction between West and East African trypanosomiasis. Furthermore, parasitemia diminishes during the chronic phase of the disease, but antibodies remain detectable. Wherever available, the presence of antibodies may be proven by immunofluorescent antibody test or enzyme-linked immunosorbent assay. In endemic areas, the rapid card agglutination test is preferred over other techniques. For samples to be analyzed with the rapid card agglutination test, they need to be cooled, and tests are run on an electrical device. In high-risk areas, cooling facilities and electricity may not be available, so more easily applicable rapid diagnostic tests are currently developed. They would allow for reliable diagnoses, even if technicians received little training [3]. Molecular biological studies may also be carried out to identify the etiological agent [4].

In case of positive results, samples of cerebrospinal fluid should be obtained to assess for progression to the meningo-encephalitic stage and involvement of the central nervous system. White blood cell counts exceeding 5/µl are generally interpreted as a sign of advanced-stage WAT [1] [5].

• Decreased Platelet Count

  platelet count (<50 x 109/L) Infections Skin infection at puncture site Vertebral deformities (scoliosis or kyphosis), in hands of an inexperienced physician.[11][12] Adverse effects[edit] Headache[edit] Post spinal headache with nausea is the most common [en.wikipedia.org]

• Hyperglobulinemia

  Standard laboratory analyses may reveal anemia, thrombocytopenia, raised erythrocyte sedimentation rate, increased levels of C-reactive protein, hyperglobulinemia, and hypoalbuminemia. [symptoma.com]

WAT is a curable disease. Pentamidine, suramin, or diminazene may be administered to those who are diagnosed during the early, haemolymphatic stage of WAT. Since they these drugs are unable to cross the blood-brain-barrier, they are ineffective in the meningo-encephalitic stage of WAT [1] [6] [7]. Here, difluoromethylornithine, a selective and irreversible inhibitor of ornithine decarboxylase better known as eflornithine, is indicated. It is administered four times a day at a dose of 100 mg/kg. Cure is achieved in 95% of all cases where the patient is treated with eflornithine for two weeks. Alternatively, eflornithine may be combined with nifurtimox and administered for seven days. This regimen is associated with less toxicity [2]. In general, eflornithine is better tolerated than melarsoprol, an effective, yet more toxic drug able to cure advanced-stage WAT [6].

If WAT treatment is initiated in a timely manner, long-term sequelae due to central nervous system involvement may be avoided. If therapy is delayed until the meningo-encephalitic stage, complete recovery cannot be guaranteed, even though alertness, cognition, memory, and motor skills are likely to improve under therapy [2]. If left untreated, WAT runs a fatal course. Years may pass until the disease progresses to coma and death, which usually follows aspiration pneumonia.

T. brucei gambiense are extracellular parasites. In mammalian hosts, they replicate by longitudinal division. The ingestion of the mammal's blood by arthropod vectors, namely by tsetse flies belonging to the species of Glossina palpalis and, in a minor scale, Glossina fuscipes and Glossina tachinoides, allows for trypanosomes to pass to their intermediate hosts. They eventually reach the midgut and salivary glands, where they continue to replicate. In the insect, they go through distinct phases of development until reaching the stage of metacyclic trypomastigotes. The latter are infective and may be transferred to a new mammalian host, usually a human being, when the fly takes another blood meal.

In men, trypanosomes initially replicate at the site of the insect bite. Within about a week, the parasites start to disseminate in the individual's body fluids. They can now be detected microscopically in blood samples. Large quantities of T. brucei gambiense can also be found in lymph nodes, which is why patients develop lymphadenopathy. Besides blood and lymph, the parasites may eventually reach the cerebrospinal fluid.

Beyond the direct transmission by infected flies, T. brucei gambiense may be transmitted vertically from a pregnant mother to her child [8] [9]. WAT could probably be transmitted through the transfusion of donated blood, but such cases are very rare.

WAT accounts for the majority of cases of African trypanosomiasis, with about 97% of cases being caused by T. brucei gambiense [9]. Over the past decade, the disease' incidence has been decreasing, with <4,000 cases being reported in recent years. Most likely, though, WAT is underdiagnosed. The majority of cases occurs in the very poor regions of the Democratic Republic of Congo and the Central African Republic, where large parts of the population have limited access to medical care.

Because the etiological agent exhibits marked vector specificity and relies on determined Glossina spp. for transmission, the distribution range of WAT and T. brucei gambiense largely corresponds to that of the flies. To date, WAT is endemic in 24 countries of sub-Saharan Africa, and about 70 million people are considered at risk of infection with T. brucei gambiense [10]. Occasionally, WAT cases are imported to countries outside the endemic area [1] [2]. Most infections occur during the dry season, when larger populations of tsetse flies and humans gather around a limited number of water sources.

The progression of hemolymphatic WAT to meningo-encephalitic WAT marks a turning point in the course of the disease. For trypanosomes to reach the cerebrospinal fluid, they have to cross the blood-brain barrier, but the mechanism underlying trypanosome invasion of the brain remain incompletely understood. The most widely accepted hypothesis to this end is that blood-brain barrier impairment is mediated by the immune system before the parasites can reach the central nervous system [11] [12].

The World Health Organization aims at eliminating WTA as a public health problem by 2020, and distinct strategies have been followed to achieve this goal [13]. Vector control, case detection, and treatment are the pillars of disease prevention. An even more ambitious objective has been set for 2030: The transmission of the disease shall be terminated by this time [10] [13].

With regard to individual prophylaxis, travelers can only be recommended to avoid staying in rural areas of Central and West Africa. Those who are unable to do so should take measures to reduce their exposure to tsetse flies. They may wear long-sleeved, light-colored clothes and use insect repellant [6]. Medical prevention of WAT is not available.

African trypanosomiasis is considered a neglected tropical disease. There are two types of African trypanosomiasis, namely the West and East African variants. The former is caused by T. brucei gambiense, the latter by T. brucei rhodesiense. Both Trypanosoma species are highly vector-specific, so cases of West and East African trypanosomiasis have only been reported where the respective tsetse flies are endemic. These flies live in forests, wooded areas, and bushes, and those that are able to transmit WAT are distributed throughout sub-Saharan Africa. T. brucei gambiense has occasionally been isolated from pigs, sheep, cattle, and antelopes, but human beings are considered the main reservoir of the parasite, whose life cycle involves mammals and hematophagous Glossina spp [7]. The absence of greater reservoirs in wild animals allows focussing WAT prevention on the control of tsetse fly populations, the screening of populations at increased risk of infection, and treatment of infected people. By 2030, the World Health Organization hopes to have stopped disease transmission globally [10] [13]. Interestingly, WAT had almost been eradicated in the 1960s, but a collapse of surveillance and control activities in most endemic countries, often exacerbated by civil conflicts, led to its reemergence [7].

West African trypanosomiasis (WAT) is an infectious disease. It is caused by Trypanosoma brucei gambiense, a parasite transmitted by tsetse flies in Central and West Africa. The flies are mainly distributed in rural areas, so the risk of infection is low for casual travelers who don't leave the urban regions.

If a person is bitten by an infected fly, the affected site may turn into a red sore. Additional symptoms may not develop until months or even years later, when affected individuals suffer from intermittent fever and swollen cervical lymph nodes. General weakness and fatigue increasingly affect the patient's quality of life, which is why WAT is also referred to as Gambian sleeping sickness. During these early stages of WAT, trypanosomes distribute via blood and lymphatic vessels, but eventually, the central nervous system becomes involved. Then, patients may experience cognitive decline, confusion, memory impairment, motor deficits, and personality changes, among others. If left untreated, WAT leads to coma and death.

Fortunately, though, the disease is relatively easily diagnosed and treated with a high-cure rate. Trypanosomes and antibodies against these parasites can be detected in blood, lymph, and possibly cerebrospinal fluid. Even though the diagnosis of WAT may be confirmed after the identification of Trypanosoma brucei gambiense in peripheral blood, cerebrospinal fluid has to be examined to assess for central nervous system involvement. Depending on the stage of WAT, patients may be administered distinct drugs. Alertness, cognition, memory, and motor skills are very likely to improve under therapy, and the majority of patients recovers completely. In severe cases, neurological deficits may partially persist.

Prevention is the best cure. Those who travel to the Democratic Republic of Congo, the Central African Republic, or other sub-Saharan countries where tsetse flies are endemic, should avoid staying in rural areas. Measures should be taken to reduce the exposure to flies, e.g., by wearing long-sleeved, light-colored clothes and using insect repellant.

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