What are the diseases caused by Trypanosoma?
Trypanosoma. Trypanosomes infect a variety of hosts and cause various diseases, including the fatal human diseases sleeping sickness, caused by Trypanosoma brucei, and Chagas disease, caused by Trypanosoma cruzi . The mitochondrial genome of the Trypanosoma, as well as of other kinetoplastids, known as the kinetoplast,...
Where does trypanosomiasis come from?
Human African trypanosomiasis takes 2 forms, depending on the parasite involved: Trypanosoma brucei gambiense is found in 24 countries in west and central Africa. This form currently accounts for 98% of reported cases of sleeping sickness and causes a chronic infection.
What is the monophyly of Trypanosoma?
The monophyly of the genus Trypanosoma is not supported by a number of different methods. Rather, the American and African trypanosomes constitute distinct clades, implying that the major human disease agents T. cruzi (cause of Chagas’ disease) and T. brucei (cause of African sleeping sickness) are not closely related to each other. [8]
What research is being done to treat trypanosomiasis?
Trypanosomiasis vaccines are undergoing research. Additionally, the Drugs for Neglected Disease Initiative has contributed to the African sleeping sickness research by developing a compound called fexinidazole. This project was originally started in April 2007 and enrolled 749 people in the DRC and Central African Republic.
What is the genus of Trypanosoma?
For the humans-specifics pathogens, see Trypanosoma brucei and Trypanosoma cruzi. Trypanosoma sp. among red blood cells. Trypanosoma is a genus of kinetoplastids (class Trypanosomatidae ), a monophyletic group of unicellular parasitic flagellate protozoa.
Where do trypanosomes develop?
Salivarian trypanosomes develop in the anterior gut of insects, most importantly the Tsetse fly, and infective organisms are inoculated into the host by the insect bite before it feeds. As trypanosomes progress through their life cycle they undergo a series of morphological changes as is typical of trypanosomatids.
How do stercorarian trypanosomes infect insects?
The organism then penetrates and can disseminate throughout the body. Insects become infected when taking a blood meal.
What are the trypanosomes of the Duttonella subgenera?
The latter branch splits into a clade containing bird, reptilian and Stercorarian trypanosomes infecting mammals and a clade with a branch of fish trypanosomes and a branch of reptilian or amphibian lineages. Salivarians are trypanosomes of the subgenera of Duttonella, Trypanozoon, Pycnomonas and Nannomonas.
Why is the trypanosome called the Borer?
The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous (requiring more than one obligatory host to complete life cycle) and most are transmitted via a vector.
What is the name of the disease that infects birds and biting midges?
T. boissoni, in elasmobranch. T. brucei, which causes sleeping sickness in humans and nagana in cattle. T. cruzi, which causes Chagas disease in humans. Trypanosoma culicavium, which infects birds and mosquitoes.
What is Trypanosoma kinetoplastidae?
Trypanozoon Lühe 1906. Trypanosoma is a genus of kinetoplastids (class Trypanosomatidae ), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion.
When was Chagas disease discovered?
Chagas disease is named after Carlos Ribeiro Justiniano Chagas, a Brazilian physician and researcher who discovered the disease in 1909 . In May 2019, following up on decision of the 72 World Health Assembly, the World Chagas Disease Day was established to be celebrated on 14 April (the date of the year 1909 when Carlos Chagas diagnosed the first human case of the disease, a two-year-old girl called Berenice).
Where did Chagas disease originate?
Chagas disease was once entirely confined to rural areas of the Region of the Americas – principally Latin America – but in the last decades, due to population movements, most infected people live in urban settings (urbanization) and the disease has spread to other continents (where T. cruzi is transmitted through non-vectorial routes).
What is the cause of T cruzi?
consumption of food or beverages contaminated with T. cruzi through, for example, contact with faeces or urine of infected triatomine bugs or marsupials (this kind of transmission typically causes outbreaks with more severe morbidity and higher mortality - infecting groups of people simultaneously with more frequent cases of severe disease and higher number of deaths);
What is Chagas disease?
Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite Trypanosoma cruz i. About 6 million to 7 million people worldwide are estimated to be infected with T. cruzi, the parasite that causes Chagas disease. The disease is found mainly in endemic areas ...
How many people in Latin America have Chagas disease?
About 6 million to 7 million people worldwide, mostly in Latin America, are estimated to be infected with Trypanosoma cruzi, the parasite that causes Chagas disease. The main route of transmission to humans has occurred in Latin America through the insect called triatomine bug (vector-borne), which can carry the Trypanosoma cruzi.
How long does Chagas disease last?
Chagas disease presents itself in two phases. The initial acute phase lasts for about two months after infection. During the acute phase, a high number of parasites circulate in the blood but in most cases, symptoms are absent or mild and unspecific.
What are the most effective methods to prevent Chagas disease in Latin America?
Vector control and other strategies aiming at reducing vector-borne transmission are the most useful methods to prevent Chagas disease in Latin America.
How long are trypanosomes?
Trypanosomes measure from 12 to 30 µm in length. Trypomastigotes may be seen in cerebrospinal fluid (CSF) in central nervous system infections; also the amastigote stage parasite may be seen in histopathology specimens from affected organs.
How is Trypanosoma cruzi transmitted?
Trypanosoma cruzi is transmitted by kissing bugs (Hemiptera: Reduviidae). The most common genera responsible for transmission of the disease are Triatoma, Rhodnius, and Panstrongylus. Infection usually occurs after bugs defecate on the bite site and are rubbed into the wound by the host scratching.
What is the life cycle of a triatomine bug?
Life Cycle. An infected triatomine insect vector (or “kissing” bug) takes a blood meal and releases trypomastigotes in its feces near the site of the bite wound. Trypomastigotes enter the host through the bite wound or intact mucosal membranes, such as the conjunctiva . Inside the host, the trypomastigotes invade cells near the site of inoculation, ...
What is the causative agent of Chagas disease?
Causal Agent. Trypanosoma cruzi, is a parasitic protozoan that is the causative agent of Chagas disease (American trypanosomiasis). Currently, six distinct lineages of T. cruzi are classified into discrete typing units (TcI-VI), which vary in their geographic occurrence, host specificity, and pathogenicity.
What is the diagnosis of Chagas disease?
Molecular diagnosis of Chagas disease is performed for cases of suspected acute infection (including transfusion or transplant transmission), congenital Chagas disease, and for monitoring of suspected laboratory exposures. For chronic Chagas disease, serology is generally most appropriate, although molecular detection may be performed for re-activated cases associated with immunosuppression.
What is T cruzi stained with?
T. cruzi in thin blood smears stained with Giemsa.
Where is T. cruzi found?
Geographic Distribution. T. cruzi is endemic in vectors and wildlife reservoirs throughout the Americas from the southern half of the United States down to Argentina. Chagas disease cases have been reported from South and Central American countries, particularly in rural, impoverished areas.
What is trypanosoma genus?
Overview. Trypanosoma is a genus consisting of hemoflagellate protozoa that exist as obligatory parasites of plants, mammals and other animals (fish, birds, reptiles etc). Members of this genus, known as trypanosomes, are unicellular organisms whose life cycle is dependent on both vertebrate and invertebrate hosts.
Which domain is Trypanosoma?
· Domain: Eukaryota - As members of the domain Eukaryota, Trypanosoma species have membrane-bound organelles. As such, they have more complex structures compared to members of the domain prokaryota .
How does the life cycle of a parasite start?
The life cycle of this parasite can be said to start when the metacyclic trypomastigotes stage of the parasite is deposited on the skin of the host (mammal e.g. man). Rather than transmitting the parasite through a bite during feeding (as is the case with Salivaria species) the insect vector (reduviid bug in this case) excretes the parasite form along with its excreta onto the skin surface of the host.
What organelle is a trypanosome cell?
For instance, like normal eukaryotic cells, a trypanosome cell has a membrane-bound nucleus, Golgi apparatus, E.R, as well as a plasma membrane among other important organelles. On the other hand, as members of order Kinetoplastida, Trypanosoma have a number of unique features including a kinetoplast, glycosomes, as well as acidocalcisomes (site of mineral storage).
What is the life cycle of Trypanosoma?
The life cycle of various Trypanosoma species involves the transmission of the parasite from one host to another. According to studies, there are three main modes of transmission, these include: · Cyclical transmission - In the cyclical mode of transmission, the parasite is transmitted by infected tsetse flies.
Which species of trypanosoma is transmitted by African tsetse flies?
Whereas Salivaria consists of trypanosomes that are transmitted by African tsetse flies, Stercoraria includes genera that complete their development in the posterior station.
Why do trypanosomes need to be stained?
Staining allows for better visualization of trypanosome cells that will appear as bluish/purple slender organisms with thin flagellum on one end.
What is the disease called that is transmitted by a triatomine bug?
Chagas disease ( T. cruzi infection) is also referred to as American trypanosomiasis. Images: Left and Right: Various species of triatomine bugs, which if infected can transmit T. cruzi. Center: T. cruzi trypomastigote in a thin blood smear stained with Giemsa. (Credit: DPDx)
What is the name of the parasite that causes Chagas disease?
Chagas disease is named after the Brazilian physician Carlos Chagas, who discovered the disease in 1909. It is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors and is found only in ...
Where is trypanosomiasis transmitted?
b. gambiense causes a slowly progressing African trypanosomiasis in western and central Africa and T. b.
What is the parasite that causes sleep sickness?
Parasites - African Trypanosomiasis (also known as Sleeping Sickness) minus. Related Pages. 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.
When did trypanosomiasis appear?
Based on genetic studies, it is believed that the causative agents of African trypanosomiasis emerged sometime around 300 million years ago . Around this time, these protozoa either parasitized or simply lived in (without harming or benefiting) early insects. It wasn't until 35 million years ago, however, that tsetse flies appeared.
What is the history of African trypanosomiasis?
History of African Trypanosomiasis ( African Sleeping Sickness) Artem has a doctor of veterinary medicine degree. This lesson goes over the fascinating and very long history of African trypanosomiasis, commonly known as the sleeping sickness. You'll learn how long it's been around and its earliest recorded occurrences.
How is Trypanosoma brucei transmitted?
This parasite is transmitted to people via the bite of a tsetse fly. Among other signs and symptoms, this parasite can lead to extreme lethargy and daytime sleepiness, hence its name. Trypanosoma brucei. This lesson doesn't focus on the medical or pathophysiological aspects of this disease, however.
Why are tsetse flies so common in ancient Egypt?
This is because the climate of the area was greener and a good habitat for the tsetse fly. The ancient Egyptians at that time raised domesticated animals but had difficulties, most likely due to widespread trypanosomiasis. Thus, game animals were also raised for food, likely because they were resistant to trypanosome parasites. There is also an ancient Egyptian veterinary papyrus from the 2nd millennium BCE that mentions that domesticated cattle were infected with something that sounds quite a bit like trypanosomiasis.
How long has the Tsetse fly been around?
The parasites that cause this disease have likely been around for hundreds of millions of years and its vector, or transmitter, the tsetse fly, has been around for around 35 million years. There is evidence that this disease was documented and potentially widespread in ancient Egypt.
What did Belgian scientists and physicians contribute to understanding?
The early 1900s saw numerous other Belgian, German, and British scientists and physicians contribute to understanding African trypanosomiasis, the pathogenic species, and the lifecycle of the parasites in both animals and humans. These discoveries occurred during the first severe African trypanosomiasis epidemic of the 20th century.
When did the first drug be developed?
This led scientists from the colonial empires ruling Africa to develop the first effective treatment for the drug in 1916 .
What are the three diseases that are associated with trypanosomiasis?
Kinetoplastids refer to a group of flagellate protozoa. Kinetoplastid infections include African sleeping sickness, Chagas' disease, and Leishmaniasis. All together, these three diseases accounted for 4.4 million disability adjusted life years (DALYs) and an additional 70,075 recorded deaths yearly. For kinetoplastid infections, the total global research and development funding was approximately $136.3 million in 2012. Each of the three diseases, African sleeping sickness, Chagas' disease, and Leishmaniasis each received approximately a third of the funding, which was about $36.8 million US dollars, $38.7 million US dollars, and $31.7 million US dollars, respectively.
What is the best test for trypanosomiasis?
Three serological tests are also available for detection of the parasite: the micro-CATT (card agglutination test for trypanosomiasis), wb-CATT, and wb-LATEX. The first uses dried blood, while the other two use whole blood samples. A 2002 study found the wb-CATT to be the most efficient for diagnosis, while the wb-LATEX is a better exam for situations where greater sensitivity is required.
What is the cause of African sleep sickness?
It is caused by the species Trypanosoma brucei. Humans are infected by two types, Trypanosoma brucei gambiense (TbG) and Trypanosoma brucei rhodesiense (TbR). TbG causes over 98% of reported cases. Both are usually transmitted by the bite of an infected tsetse fly and are most common in rural areas.
How many people died from sleeping sickness in 2000?
As of 2000, the disability-adjusted life-years (9 to 10 years) lost due to sleeping sickness are 2.0 million. From 2010–2014, there was an estimated 55 million people at risk for gambiense African Trypanosomiasis and over 6 million people at risk for rhodesiense African Trypanosomiasis.
How to treat TBG?
Treatment of the first stage has been with the medications pentamidine or suramin. Treatment of the second stage has involved eflornithine or a combination of nifurtimox and eflornithine for TbG. Fexinidazole is a more recent treatment that can be taken by mouth, for either stages of TbG. While melarsoprol works for both types, it is typically only used for TbR, due to serious side effects. Without treatment, sleeping sickness typically results in death.
How to prevent trypanosomiasis?
Although the risk of infection from a tsetse fly bite is minor (estimated at less than 0.1%), the use of insect repellants, wearing long-sleeved clothing, avoiding tsetse-dense areas, implementing bush clearance methods and wild game culling are the best options to avoid infection available for local residents of affected areas.
Which parasite causes the disease of the rhodesiense?
There are two subspecies of the parasite that are responsible for starting the disease in humans. Trypanosoma brucei gambiense causes the diseases in west and central Africa, whereas Trypanosoma brucei rhodesiense has a limited geographical range and is responsible for causing the disease in east and southern Africa. In addition, a third subspecies of the parasite known as Trypanosoma brucei brucei is responsible for affecting animals but not humans.
Overview
Trypanosoma is a genus of kinetoplastids (class Trypanosomatidae ), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous (requiring more than one obligatory host to complete life cycle) and most are transmitted via a vector. The majority of species are transmitt…
History
In 1841, Gabriel Valentin found flagellates that today are included in Trypanoplasma in the blood of trout.
The genus (T. sanguinis) was named by Gruby in 1843, after parasites in the blood of frogs.
In 1903, David Bruce identified the protozoan parasite and the tsetse fly vector of African trypanosomiasis.
Taxonomy
The monophyly of the genus Trypanosoma is not supported by a number of different methods. Rather, the American and African trypanosomes constitute distinct clades, implying that the major human disease agents T. cruzi (cause of Chagas’ disease) and T. brucei (cause of African sleeping sickness) are not closely related to each other.
Phylogenetic analyses suggest an ancient split into a branch containing all Salivarian trypanoso…
Selected species
Species of Trypanosoma include the following:
• T. ambystomae. in amphibians
• T. antiquus, extinct (Fossil in Miocene amber)
• T. avium, which infects birds and blackflies
Hosts, life cycle and morphologies
Two different types of trypanosomes exist, and their life cycles are different, the salivarian species and the stercorarian species.
Stercorarian trypanosomes infect insects, most often the triatomid kissing bug, by developing in the posterior gut followed by release into the feces and subsequent depositing on the skin of the host. The organism then penetrates and can disseminate throughout the body. Insects become i…
Meiosis
Evidence has been obtained for meiosis in T. cruzi, and for genetic exchange. T. brucei is able to undergo meiosis within the salivary glands of its tsetse fly host, and meiosis is considered to be an intrinsic part of the T. brucei developmental cycle. An adaptive benefit of meiosis for T. crucei and T. brucei may be the recombinational repair of DNA damages that are acquired in the hostile environment of their respective hosts.
External links
• Trypanosoma reviewed and published by Wikivet, accessed 08/10/2011.
• Trykipedia, Trypanosomatid specific ontologies
• Tree of Life: Trypanosoma
Overview
Distribution
- Chagas disease was once entirely confined to continental rural areas of the Region of the Americas (excluding the Caribbean islands). Due to increased population mobility over previous decades, most infected people now live in urban settings and the infection has been increasingly detected in the United States of America, Canada, and many European and some African, Easter…
Transmission
- In Latin America, T. cruziparasites are mainly transmitted by contact with faeces/urine of infected blood-sucking triatomine bugs. These bugs typically live in the wall or roof cracks of homes and peridomiciliary structures, such as chicken coops, pens and warehouses, in rural or suburban areas. Normally they hide during the day and become active at night when they feed on animal b…
Signs and Symptoms
- Chagas disease presents in two phases. The initial acute phase lasts for about two months after infection. During the acute phase, a high number of parasites circulate in the blood, but in most cases symptoms are absent or mild and unspecific. In less than 50% of people bitten by a triatomine bug, characteristic first visible signs can be a skin lesion or a purplish swelling of the l…
Treatment
- To kill the parasite, Chagas disease can be treated with benznidazole or nifurtimox. Both medicines are nearly 100% effective in curing the disease if given soon after infection at the onset of the acute phase, including the cases of congenital transmission. The efficacy of both diminishes, however, the longer a person has been infected and the adverse reactions are more …
Control and Prevention
- The large reservoir of T. cruziparasites in wild animals of the Americas means that the infection cannot be eradicated. Instead, the control targets are elimination of the transmission to humans and early health-care access of the infected people. There is no vaccine to prevent Chagas disease. T. cruzican infect many species of triatomine bugs, the majority of which are found in t…
Who Response
- Since the 1990s there have been important successes in parasite and vector control in the Americas, leading to a substantial reduction in transmission and increased access to diagnosis and antiparasitic treatment. The risk of transmission by blood transfusion decreased sharply through the universal screening in all blood banks of the continental Latin American countries, a…