The key difference between Trypanosoma gambiense and Trypanosoma rhodesiense is that Trypanosoma gambiense is a subspecies belonging to Trypanosoma brucei species complex and accounts for 97% of reported cases of sleeping sickness, while Trypanosoma rhodesiense is a subspecies belonging to Trypanosoma brucei species complex and accounts for 3% of reported cases of sleeping sickness.
Human African trypanosomiasis, also called sleeping sickness, is a vector-borne parasitic disease. The protozoan parasites causing this disease belong to the genus Trypanosoma and the species complex Trypanosoma brucei. These parasites are transmitted to humans through tsetse fly bites. Moreover, sleeping sickness can be caused by two subspecies or forms of this complex. They are T. gambiense and T. rhodesiense. T. gambiense accounts for more reported cases, while T. rhodesiense accounts for fewer reported cases.
CONTENTS
1. Overview and Key Difference
2. What is Trypanosoma Gambiense
3. What is Trypanosoma Rhodesiense
4. Similarities – Trypanosoma Gambiense and Trypanosoma Rhodesiense
5. Trypanosoma Gambiense vs Trypanosoma Rhodesiense in Tabular Form
6. Summary – Trypanosoma Gambiense vs Trypanosoma Rhodesiense
What is Trypanosoma Gambiense?
Trypanosoma gambiense is subspecies that belongs to Trypanosoma brucei species complex. It accounts for 97% of reported cases of sleeping sickness. This species is normally described as Trypanosoma brucei gambiense. T. gambiense is usually found in 24 countries in west and central Africa. This form currently causes chronic infections of sleeping sickness. A person can be infected with this subspecies for months or even years without major signs or symptoms of African trypanosomiasis. When more evident signs and symptoms occur, the patient is already in an advanced stage of sleeping sickness, where the central nervous system is almost damaged.
Figure 01: Trypanosoma gambiense
Humans are thought to be the primary reservoir for this form of T. brucei. In 1973, David Hurst Molyneux identified this subspecies from wildlife and domestic animals for the first time. It was reported that in 2002, in addition to humans, this subspecies could also infect animals such as cattle. Furthermore, this subspecies is roughly 100% fatal. Moreover, the gene known as TgsGP provides the T. brucei gambiense resistance against human serum that contains anti-parasitic serum protein apolipoprotein-L1 (APOL1).
What is Trypanosoma Rhodesiense?
Trypanosoma rhodesiense is a subspecies that belongs to T. brucei species complex. It accounts for 3% of reported cases of sleeping sickness. This subspecies is generally described as Trypanosoma brucei rhodesiense. It causes fast onset or acute infection of African trypanosomiasis. This species is a highly zoonotic parasite. It is highly prevalent in southern and eastern Africa. Game animals and livestock are the primary reservoirs for this form. Moreover, T. brucei rhodesiense is found in 13 countries in eastern and southern Africa.
Figure 02: Trypanosoma Rhodesiense
The first signs and symptoms are observed a few months or weeks after T. rhodesiense infection. This parasitic infection develops rapidly. It also invades and damages the central nervous system. Both forms of T. brucei species complex (T. gambiense and T. rhodesiense) have only been found in Uganda. However, these forms are found in two separate zones in Uganda. Furthermore, the gene known as serum resistance-associated (SRA) provides T. brucei rhodesiense resistance against human serum that contains anti-parasitic serum protein apolipoprotein-L1 (APOL1).
What are the Similarities Between Trypanosoma Gambiense and Trypanosoma Rhodesiense?
- gambiense and T. rhodesiense are two subspecies of T. brucei species complex.
- Both subspecies belong to the genus Trypanosoma.
- They cause African human trypanosomiasis.
- They are found predominantly in Africa, especially in Uganda.
- Both subspecies can infect other animals as well.
- They invade and damage the central nervous system.
- Both contain specific genes that give them resistance against human serum.
- The infections caused by them can be diagnosed through serological testing.
- The infections caused by them can be treated through anti-parasitic drugs such as fexinidazole.
What is the Difference Between Trypanosoma Gambiense and Trypanosoma Rhodesiense?
Trypanosoma gambiense accounts for 97% of reported cases of sleeping sickness, while Trypanosoma rhodesiense accounts for 3% of reported cases of sleeping sickness. Thus, this is the key difference between Trypanosoma gambiense and Trypanosoma rhodesiense. Furthermore, T. gambiense causes chronic infection of sleeping sickness, while T. rhodesiense causes acute infection of sleeping sickness.
The below infographic presents the differences between Trypanosoma gambiense and Trypanosoma rhodesiense in tabular form for side-by-side comparison.
Summary – Trypanosoma Gambiense vs Trypanosoma Rhodesiense
T. gambiense and T. rhodesiense are two subspecies of Trypanosoma and the species complex of T. brucei. Both subspecies cause human African trypanosomiasis or sleeping sickness. However, T. gambiense accounts for 97% of reported cases of sleeping sickness. T. rhodesiense accounts for 3% of reported cases of sleeping sickness. So, this is the key difference between Trypanosoma gambiense and Trypanosoma rhodesiense.
Reference:
1. “Trypanosoma Brucei Gambiense.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.
2. “Trypanosoma Brucei Rhodesiense.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “Trypanosoma brucei gambiense – epimastigote” By Stefan Walkowski – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Epidemiology of Human African Trypanosomiasis” By Prof Reto Brun PhD aJohannes Blum MDa Francois Chappuis MDbc Christian Burri PhDa – (CC BY-SA 4.0) via Commons Wikimedia