<unk>  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, however, 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 lympadenopathy developing only rarely. Trypanosomal chancre Systemic disease is sometimes presaged by a trypanosomal chancre developing at the site of the infectious fly bite within 2 days of infection. The chancre is most commonly observed in T. b. rhodesiense infection, and only rarely in T. b. gambiense (however, in T. b. gambiense infection, chancres are more common in persons from non-endemic areas). Hemolymphatic phase Incubation period is 1–3 weeks for T. b. rhodesiense, and longer (but less precisely characterised) in T. b. gambiense infection. The first/initial stage, known as the hemolymphatic phase, is characterized by non-specific, generalised symptoms like: fever (intermittent), headaches (severe), joint pains, itching, weakness, malaise, fatigue, weight loss, lymphadenopathy, and hepatosplenomegaly. Diagnosis may be delayed due to the vagueness of initial symptoms. The disease may also be mistaken for malaria (which may in fact occur as a co-infection). Intermittent fever Fever is intermittent, with attacks lasting from a day to a week, separated by intervals of a few days to a month or longer. Episodes of fever become less frequent over the course of the disease. Lymphadenopathy Invasion of the circulatory and lymphatic systems by the parasite is associated with severe swelling of lymph nodes, often to tremendous sizes. Posterior cervical lymph nodes are most commonly affected, however, axillary, inguinal, and epitrochlear lymph node involvement may also occur. Winterbottom's sign, the tell-tale swollen lymph nodes along the back of the neck, may appear. Winterbottom's sign is common in T. b. gambiense infection. Other features Those affected may additionally present with: skin rash, haemolytic anaemia, hepatomegaly and abnormal liver function, splenomegaly, endocrine disturbance, cardiac involvement (e.g. pericarditis, and congestive heart failure), and ophthalmic involvement. File:PMC5373517 pntd.0005324.g001.Chancre of human<unk>  File:AcuteSleepingSickness.Typical fine-spotted pink rash of acute<unk>  on the skin of the abdomen (”trypanid rash”) File:SSHemorragicRash.Numerous spots of bleeding into the skin of the leg in a person infected with T. b. rhodesiense Neurological phase The second phase of the disease, the neurological phase (also called the meningoencephalic stage), begins when the parasite invades the central nervous system by passing through the blood–brain barrier. Progression to the neurological phase occurs after an estimated 21–60 days in case of T. b. rhodesiense infection, and 300–500 days in case of T. b. gambiense infection. In actuality, the two phases overlap and are difficult to distinguish based on clinical features alone; determining the actual stage of the disease is achieved by examining the cerebrospinal fluid for the presence of the parasite. Sleep disorders Sleep-wake disturbances are a leading feature of neurological stage and gave the disease its common name<unk>  sleeping sickness. Infected individuals experience a disorganized and fragmented sleep-wake cycle. Those affected experience sleep inversion resulting in daytime sleep and somnolence, and nighttime periods of wakefulness and insomnia. Additionally, those affected also experience episodes of sudden sleepiness. Neurological/neurocognitive symptoms Neurological symptoms include: tremor, general muscle weakness, hemiparesis, paralysis of a limb, abnormal muscle tone, gait disturbance, ataxia, speech disturbances, paraesthesia, hyperaesthesia, anaesthesia, visual disturbance, abnormal reflexes, seizures, and coma. Parkinson-like movements might arise due to non-specific movement disorders and speech disorders. Psychiatric/behavioural symptoms Individuals may exhibit psychiatric symptoms which may sometimes dominate the clinical diagnosis and may include aggressiveness, apathy, irritability, psychotic reactions and hallucinations, anxiety, emotional lability, confusion, mania, attention deficit, and delirium. Advanced/late disease and outcomes Without treatment, the disease is invariably fatal, with progressive mental deterioration leading to coma, systemic organ failure, and death. An untreated infection with T. b. rhodesiense will cause death within months whereas an untreated infection with T. b. gambiense will cause death after several years. Damage caused in the neurological phase is irreversible.
African trypanosomiasis
Leishmaniasis
Trypanosomiasis
Psittacosis
Visceral leishmaniasis
Human trypanosomiasis
Babesiosis
Mansonelliasis