African Trypanosomiasis, also known as “sleeping sickness”, is caused by microscopic parasites of the species Trypanosoma brucei. It is transmitted by the tsetse fly (Glossina species), which is found only in sub-Saharan Africa.
1. Shri Shivaji Education Society, Amravati's
Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly. Dist. Buldana
Topic: Trypanosomiasis
Class: B.Sc-I, Sem-I
Shantaram Bhoye
Assistant Professor, Department of Zoology
M.Sc., NET-JRF, SET, M.A.(Eng.)
2. Trypanosomiasis:
The disease caused by Trypanosoma is called trypanosomiasis.
Forde (1901), first observed this parasite in the blood of man.
Castellani reported this parasite in the cerebrospinal fluid of man.
Bruce discovered that the disease is transmitted by tsetse fly, Glossina palpalis.
Ford and Dutton (1902), were the first to report it was human parasite and the disease
‘Gambian fever’ was caused by it.
Trypanosoma:
Trypanosoma gamabiense causes African sleeping sickness in man.
It is found in the blood, lymph, spleen or cerebrospinal fluid of man and in the intestine of
blood sucking fly, Tse tse fly, Glossina palpalis, (the vector which transmits the parasite
from man to man).
Of all the species of Trypanosoma, only three species are pathogenic to man.
These are T. gambiense, T. rhodesiense and T. cruzi.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana
3. T. Gambiense has a slender elongated,
sickle shahped, flattened, microscopic
body, tapering at both the ends.
Body is covered with a thin, protective
pellicle.
A single flagellum present.
When flagellum beats the pellicle is
pulled out into an irregular membranous
fold, which is called undulating
membrane.
It contains a single nucleus, single long,
elongated mitochondrion, a Golgi body,
endoplasmic reticulum and ribosome.
The vector of this parasite is Tse tse fly,
Glossina palpalis.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana
Tse tse fly
Trypanosoma gamabiense
4. Species of Trypanosoma and their symptoms:
1) Trypanosoma gambience:
It causes disease called African sleeping sickness in man.
African sleeping sickness occurs in Western parts of Africa.
Vector of this organism is G. palpalix.
Symptoms:
The bite of infected Tse tse fly causes irritation and a dark button like lesion around the wound.
They attack the central nervous system and cerebrospinal fluid.
Irregular recurrent fever is the first symptom of this disease.
Other symptoms are weakness, loss of weight, anaemia, increase in pulse rate and severe
headache.
Progressive confusion, personality changes, and other neurologic problems occur after
infection has invaded the central nervous system.
The patient falls asleep, loses consciousness, first at regular intervals and then goes into coma
and ultimately death results.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana
5. 2) Trypanosoma cruzi:
It is causative agent of American trypanosomiasis or Chaga’s disease.
It is wide spread in south and Central America and is common in children. It is transmitted by
bug, Triatoma.
It is transmitted through the faecal matter of the bug.
Symptoms:
Swelling of body parts, severe headache and continuous fever are some symptoms of this
disease.
Anaemia and injuries to heart muscles lead of death.
3) Trypanosoma rhodesiense:
It is the causative agent of Rhodesian sleeping sickness.
Vector is Glossina morsitans.
It is found in the blood of man.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana
6. Treatment:
The Gambian or African trypanosomiasis can be treated in early stage.
But once the parasites have entered the cerebrospinal fluid it is very hard to control it.
A number of drugs have been used to control it.
Bayer 205, Atoxyl, Pentamidine, Lomidine have been effective in early stage.
When parasites enters CNS, arsenic compound Tryparasamide is commonly used in this
infection.
Now days Melarsoprol or Melarsen oxide are used, which are rapid in action and less
toxic.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana
7. Prevention:
African sleeping sickness can be prevented by eradication of the vector, i.e. Tse
tse fly. For this endemic areas should be kept clean. Regular spray of insecticides
like DDT over the busy area is effective in controlling these flies.
Human population from endemic areas may be isolated.
Contact of human population with tsetse fly should be avoided.
Preventive medicine should be taken.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana