Sleeping sickness by RaghuvanshiS.K..pptx

Trypanosoma gambience is described.

1. Sleeping sickness Anukrity M.Sc. Previous (Zoology) Bareilly College , Bareilly

2. Introduction It is also known as Human African Trypanosomiasis, caused by Trypanosoma gambiense which is a parasite in humans . These animals are referred to as Vector, Tsetse fly is found only in the Sub Saharan Areas. It is reported from Central and West Africa, Nigeria , Congo and Central America.

3. Historical background Valentine was the first to report Trypanosoma in the blood of a Trout. Gruby established the genus and Lewis reported it from the blood of rat. Forde (1901) first observed this parasite in the blood of man. It was again confirmed by Dutton (1902). Castellani reported this parasite in the cerebrospinal fluid of man. Then, Bruce and Nabarro established the relationship of the disease sleeping sickness with this parasite. Bruce also discovered that the disease is transmitted by tsetse fly. David Bruce Gabriel Valentine

4. Life cycle and disease The life cycle is digenetic, a primary vertebrate and secondary invertebrate host. The vertebrate host is man and the invertebrate host is blood sucking fly, Glossina palpalis (Tsetse fly). Part of Life Cycle in Man: The parasites first live in the blood of the infected man, but later find their way into the cerebrospinal fluid. The parasites multiply by longitudinal binary fission in the blood and produce three forms of individuals, Long and thin form’s with a free flagellum, Short and stumpy forms with a reduced flagellum and Intermediate forms. It has been observed that the parasites number periodically fluctuate in the blood of man. During the period of decrease, the short and stumpy forms survive the period of depression and the rest die. These short and stumpy forms are capable of development in the intermediate host, Glossina palpalis (Testse fly).

5. Trypanosoma gambiense lives as a parasite in the blood, lymph, lymph node, spleen and cerebrospinal fluid of man and in the intestine of blood sucking fly Glossina palpalis (Tsetse fly).

6. Part of Life Cycle in Tsetse Fly: When a tsetse fly sucks the blood of an infected man, parasites enter into the midgut of the fly. These parasites remain there for a few days and start multiplying by longitudinal binary fission. After several more days, parasite ways to fly’s salivary gland. In the salivary glands they develops into crithidial forms. The crithidial forms are characterized by a shorter flagellum and undulating membrane. After the development for 2-5 days, the crithidial forms proceeds into metacyclic forms (infective). These metacyclic forms pass down through the ducts and hypopharynx. When the fly bites a man, the metacyclic forms enter the blood of man along with the saliva of the fly. The whole cycle in the fly usually takes 2-30 days.

7. As the parasite crosses blood-brain barrier, the sleep/wake cycle become reversed hence the common name is “African Sleeping sickness” with day time somnolence, nocturnal insomnia & sudden urge to sleep. Pathogenicity

8. Sign and Symptoms Stage 1 : itching , irritation near the wound, dark red lesion, fever, headache, joint pain , weakness, loss of weight and anemia . Stage 2 : Trouble sleeping , confusion , poor coordination ,swelling of lymph node ,

9. Diagnosis Screening: Serological test are used Microscopic : Lymph & Blood- Stage 1 Infection CSF-Stage 2 infection and for staging Parasites are not easily visible in T.gambiense infections and so concentration techniques may be used . Clinical Examination : For Posterior cervical 1ymphadenopathy Not a Preferred method for diagnosis

10. Arsenic and antimony compounds were until recently the drugs for treatment of Sleeping sickness, but now they are rarely used except for late stages when the parasites have invaded the central nervous system. Two drugs, Bayer 205 (also called Antrypol, Germanin or Suramin), and Lomidine are now widely used for treatment human infections. These drugs are low in toxicity, effective in treatment and prevent reinfection for several months. TREATMENT

11. Prevention Wear protective clothing Use bed net while sleeping Eradication vector( Tse Tse fly) Stay away from bushes Complete health check up at regular time Use insect repellant such as spray

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