Question

Gambia fever or sleeping sickness is caused by
(a) Plasmodium
(b) Entamoeba
(c) Giardia
(d) Trypanosoma

Answer 1

This parasite belongs to the genus of kinetoplastids, a monophyletic group of unicellular parasitic flagellate protozoa. The name is derived from the Greek words and was given because of their corkscrew-like motion. The disease sleeping sickness is transmitted by the tsetse fly (Glossina genus) bites that have acquired their infection from human beings or animals harboring human pathogenic parasites.

Complete answer:
The human African trypanosomiasis which is also known as sleeping sickness is a vector-borne parasitic disease. A protozoan parasite belonging to the genus Trypanosoma causes this infection. The host flies which are called Tsetse flies are found just in sub-Saharan Africa though only certain species transmit the disease. In many regions where tsetse flies are found but not the sleeping sickness for some reasons that are so far unexplained.

In rural populations, most exposure to the tsetse fly, and the disease is due to living in such regions where transmission occurs and which depend on agriculture, fishing, animal husbandry, or hunting are. The disease is seen to be developed in areas ranging from a single village to an entire region. The intensity of the disease can vary from one village to the next within an infected area.
So, the correct answer is, ‘ Trypanosoma ’.

Additional information:

1. In Gambia in 1901, a trypanosome infection was found in man by Forde for the first time. He observed and found the parasites in the blood of a European person suffering from recurrent fevers. After him, Dutton identified those parasites a few months later as trypanosomes. In 1902, in his publication, Dutton proposed the species name Trypanosoma gambiense.
2. The people most exposed to the tsetse fly and the disease live in rural areas and depend on agriculture, fishing, animal husbandry, or hunting.
3. Depending on the parasite involved, human African trypanosomiasis takes 2 forms. But Trypanosoma brucei gambiense accounts for more than 98% of reported cases.
4. Sustained control efforts have reduced the number of new cases. In 2009 the number reported dropped below 10 000 for the first time in 50 years, and in 2018 there were 977 cases recorded.

Note: Jacobs (1883–1967) and the American immunologist Michael Heidelberger (1888–1991) discovered the organo-arsenical tryparsamide which is the first drug to treat late-stage sleeping sickness alone, or in combination with suramin, and was also used in the treatment of animal trypanosomiasis.