Trypanosoma brucei - Revision history

Aidan: tidied the table and added Rx

2020-08-21T12:08:53Z

tidied the table and added Rx

← Older revision		Revision as of 12:08, 21 August 2020
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	\|-		\|-
	\|Vector		\|Vector
	\|~~Tsetse~~ fly, ''palpalis'' group ~~(forests and wooded areas)~~		\|tsetse fly, ''palpalis'' group
	\|~~Tsetse~~ fly, ''morsitans'' group ~~(savanna and woodlands)~~		\|tsetse fly, ''morsitans'' group
			\|-
			\|Habitat
			\|forests and wooded areas
			\|savanna and woodlands
	\|-		\|-
	\|Primary reservoir		\|Primary reservoir
			\|humans
	\|Humans
	\|~~Antelope~~ and cattle		\|antelope and cattle
	\|-		\|-
	\|Human illness		\|Human illness
	\|~~Chronic~~ (late CNS disease)		\|chronic (late CNS disease)
	\|~~Acute~~ (early CNS disease)		\|acute (early CNS disease)
	\|-		\|-
	\|Duration of illness		\|Duration of illness
	\|~~Months~~ to years		\|months to years
	\|< 9 months		\|< 9 months
	\|-		\|-
	\|Lymphadenopathy		\|Lymphadenopathy
			\|prominent
	\|Prominent
			\|minimal
	\|Minimal
	\|-		\|-
	\|Parasitemia		\|Parasitemia
	\|~~Low~~		\|low
			\|high
	\|High
	\|-		\|-
	\|Epidemiology		\|Epidemiology
			\|rural
	\|Rural
	\|~~Tourists~~ and workers in game parks/wild areas; rural		\|tourists and workers in game parks/wild areas; rural
			\|-
			\|Treatment
			\|[[pentamidine]] (non-CNS) or [[eflornithin]] (CNS)
			\|[[suramin]] (non-CNS) or [[melarsoprol]] (CNS)
	\|}		\|}

Aidan: /* Epidemiology */

2020-08-07T14:53:01Z

Epidemiology

← Older revision		Revision as of 14:53, 7 August 2020
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	*Present only in sub-Saharan Africa		*Present only in sub-Saharan Africa
	*Transmitted by the [[Vector::~~tsetse~~ ~~fly~~]] ~~species~~ (~~genus~~ ~~''Glossinai''~~) in their saliva during feeding		*Transmitted by flies in the genus [[Vector::Glossina species\|Glossina]] (tsetse flies) in their saliva during feeding
	**Tsetse ~~fly~~ exists only in Africa		**Tsetse flies exists only in Africa
	*Animal reservoirs include cattle and possibly wild ungulates (''T. b. rhodesiense''); non-human animals are less important for ''T. b. gambiense''		*Animal reservoirs include cattle and possibly wild ungulates (''T. b. rhodesiense''); non-human animals are less important for ''T. b. gambiense''

Aidan: /* Epidemiology */

2020-08-05T13:50:55Z

Epidemiology

← Older revision		Revision as of 13:50, 5 August 2020
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	== Background ==		==Background==

	*Causes '''African trypanosomiasis''', also known as '''African sleeping sickness'''		*Causes '''African trypanosomiasis''', also known as '''African sleeping sickness'''
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	*Present only in sub-Saharan Africa		*Present only in sub-Saharan Africa
	*Transmitted by the tsetse fly species (genus ''Glossinai'') in their saliva during feeding		*Transmitted by the [[Vector::tsetse fly]] species (genus ''Glossinai'') in their saliva during feeding
	**Tsetse fly exists only in Africa		**Tsetse fly exists only in Africa
	*Animal reservoirs include cattle and possibly wild ungulates (''T. b. rhodesiense''); non-human animals are less important for ''T. b. gambiense''		*Animal reservoirs include cattle and possibly wild ungulates (''T. b. rhodesiense''); non-human animals are less important for ''T. b. gambiense''
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	====Stage 1 disease (hemolymphatic)====		====Stage 1 disease (hemolymphatic)====

	*Incubation period weeks to months		*Incubation period [[Usual incubation period::weeks to months]]
	*Intermittent high fever lasting days, with intervening afebrile periods		*Intermittent high fever lasting days, with intervening afebrile periods
	*Lymphadenopathy develops		*Lymphadenopathy develops

Aidan at 17:28, 30 July 2020

2020-07-30T17:28:36Z

Show changes

Aidan at 12:53, 16 August 2019

2019-08-16T12:53:30Z

← Older revision		Revision as of 12:53, 16 August 2019
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	{{DISPLAYTITLE:''Trypanosoma brucei''}}		{{DISPLAYTITLE:''Trypanosoma brucei''}}
	[[Category:~~Parasites~~]]		[[Category:Protozoa]]

Aidan at 12:26, 16 August 2019

2019-08-16T12:26:12Z

← Older revision		Revision as of 12:26, 16 August 2019
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	* Causes '''African trypanosomiasis''', also known as '''African sleeping sickness'''		* Causes '''African trypanosomiasis''', also known as '''African sleeping sickness'''

	{\| ~~style~~="wikitable"		{\| class="wikitable"
	!		!
	! West African		! West African
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	* Vector avoidance with insect repellant, long-sleeve clothes, and avoiding known endemic areas		* Vector avoidance with insect repellant, long-sleeve clothes, and avoiding known endemic areas

			{{DISPLAYTITLE:''Trypanosoma brucei''}}
	[[Category:Parasites]]		[[Category:Parasites]]

Aidan: Aidan moved page Trypanosoma brucei (African trypanosomiasis) to Trypanosoma brucei without leaving a redirect

2019-08-16T12:25:50Z

Aidan moved page Trypanosoma brucei (African trypanosomiasis) to Trypanosoma brucei without leaving a redirect

← Older revision		Revision as of 12:25, 16 August 2019
(No difference)

Aidan at 12:25, 16 August 2019

2019-08-16T12:25:40Z

← Older revision		Revision as of 12:25, 16 August 2019
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		⚫	* Causes '''African trypanosomiasis''', also known as '''African sleeping sickness'''
	= ''Trypanosoma brucei'' (African trypanosomiasis) =

			{\| style="wikitable"
⚫	also known as African sleeping sickness

	{\|
	!		!
	! West African		! West African
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	=== CDC Guidelines ===		=== CDC Guidelines ===

			{\| class="wikitable"
	{\|
	! Species		! Species
	! Drug		! Drug
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	* Treatment of infected humans and animals		* Treatment of infected humans and animals
	* Vector avoidance with insect repellant, long-sleeve clothes, and avoiding known endemic areas		* Vector avoidance with insect repellant, long-sleeve clothes, and avoiding known endemic areas

			[[Category:Parasites]]

Maintenance script: Imported from text file

2019-08-11T18:06:00Z

Imported from text file

New page

= ''Trypanosoma brucei'' (African trypanosomiasis) =

also known as African sleeping sickness

{|
!
! West African
! East African
|-
| Organism
| ''T. b. gambiense''
| ''T. b. rhodesiense''
|-
| Vector
| Tsetse fly, ''palpalis'' group (forests and wooded areas)
| Tsetse fly, ''morsitans'' group (savanna and woodlands)
|-
| Primary reservoir
| Humans
| Antelope and cattle
|-
| Human illness
| Chronic (late CNS disease)
| Acute (early CNS disease)
|-
| Duration of illness
| Months to years
| < 9 months
|-
| Lymphadenopathy
| Prominent
| Minimal
|-
| Parasitemia
| Low
| High
|-
| Epidemiology
| Rural
| Tourists and workers in game parks/wild areas; rural
|}

== Microbiology ==

* Vector-borne flagellated protozoan parasite transmitted by the tsetse fly belonging to the genus ''Trypanosoma'', subgenus ''Trypanozoon''
* Two subspecies that are morphologically indistinguishable
** ''T. b. gambiense'', causing chronic African trypanosomiasis (“West African sleeping sickness”)
** ''T. b. rhodesiense'', causing acute African trypanosomiasis (“East African sleeping sickness”)
** Also, ''T. b. brucei'', which infects cattle and occasionally other animals
* No intracellular phase, in contrast to Chagas disease

== Life Cycle ==

[[File:SleepingSick_LifeCycle_19.jpg|T. brucei life cycle]]

== Epidemiology ==

* Present only in sub-Saharan Africa
* Transmitted by the tsetse fly species (genus ''Glossinai'') in their saliva during feeding
** Tsetse fly exists only in Africa
* Animal reservoirs include cattle and possibly wild ungulates (''T. b. rhodesiense''); non-human animals are less important for ''T. b. gambiense''

== Pathophysiology ==

* Procyclic trypomastigotes develop in the midgut then migrate to the salivary glands, where they develop into epimastigotes and then metacyclic trypomastigotes
* Metacyclic trypomastigotes are transmitted in the saliva during feeding
** Local replication in the trypanosomal chancre followed by lymphatic and hematogenous dissemination
* They multiply in the bloodstream and are thus exposed continuously to the immune system
** They undergo antigenic variation to periodically change their external glycoprotein structures (VATs)
** VAT: variant antigen type

== Clinical Presentation ==

* Almost all cases lead to death if not treated

=== West African trypanosomiasis ===

* Typically more chronic than East African trypanosomiasis

==== Trypanosomal chancre ====

* Incubation period of 1 to 2 weeks
* Painful, indurated trypanosomal chancre, which resolves after several weeks
** May ulcerate
** May have regional lymphadenopathy
** Often not present

==== Stage 1 disease (hemolymphatic) ====

* Incubation period weeks to months
* Intermittent high fever lasting days, with intervening afebrile periods
* Lymphadenopathy develops
** '''Winterbottom sign''': enlargement of posterior cervical lymphadenopathy
* Hepatosplenomegaly
* Transient edema in face, hands, feed, and periarticular areas
* Pruritis, often with an irregular erythematous circinate rash on trunk, shoulders, buttocks, and thighs (5-10 cm with central clearing)
* May also have malaise, headache, weakness, weight loss/cachexia, arthralgias, and tachycardia
* Anemia, thrombocytopenia
* Mott cells on tissue biopsy

==== Stage 2 disease (meningoencephalitic) ====

* Multiple neurological manifestations are possible, following months to years of infection
** Irritability, personality changes, and loss of concentration may be the earliest symptoms
** Progressive indifference with daytime somnolence and sometimes restlessness and insomnia at night
** Headache is common
** Extrapyramidal signs with choreiform movements, tremors, fasciculations
** Ataxia
** Parkinsonian features
** Coma and death over weeks to months
* CSF should be abnormal, with elevated protein and WBCs
* Extraneurological symptoms may include hypothyroidism and adrenal insufficiency (not necessarily confirmed on bloodwork)

=== East African trypanosomiasis ===

* Typically more acute than West African trypanosomiasis
* Incubation period of days to weeks
* In returned travelers, may present with fever, malaise, and headache
* Fever becomes intermittent and a rash develops
* Lymphadenopathy is less prominent
* Persistent tachycardia
* No clear distinction between hemolymphatic and meningoencephalitic stages
* Patients may die from arrhythmias or heart failure related to pancarditis
* Untreated, death within weeks to months

== Diagnosis ==

* Diagnosis requires parasite in tissue or fluid on microscopy, '''including CSF in all patients'''
** For chancre, express fluid and examine under light microscopy for motile trypanosomes
** Fix and stain with Giemsa
** Aspiration of lymph nodes with kneading (may need multiple aspirates)
** Thin and thick Giemsa stained blood films is most useful in hemolymphatic stage
* PCR and LAMP may be sensitive and specific but is not currently well-enough developed

== Management ==

* Treatment is more toxic in meningoencephalitic stage

== Side effects of treatment are many ==

=== CDC Guidelines ===

{|
! Species
! Drug
! Adult Dosage
! Pediatric Dosage
|-
| ''T. b. rhodesiense'', hemolymphatic stage
| Suramin
| 1 gm IV on days 1, 3, 7 ,14, and 21
| 20 mg/kg IV on days 1, 3, 7, 14, and 21
|-
| ''T. b. rhodesiense'', CNS involvement
| Melarsoprol
| 2-3.6 mg/kg/day IV x 3 days. After 7 days, 3.6 mg/kg/day x 3 days. Give a 3rd series of 3.6 mg/kg/d after 7 days.
| 2-3.6 mg/kg/day IV x 3 days. After 7 days, 3.6 mg/kg/day x 3 days. Give a 3rd series of 3.6 mg/kg/d after 7 days.
|-
| ''T. b. gambiense'', Hemolymphatic stage
| Pentamidine
| 4 mg/kg/day IM or IV x 7-10 days
| 4 mg/kg/day IM or IV x 7-10 days
|-
| ''T. b. gambiense'', CNS involvement
| Eflornithine
| 400 mg/kg/day in 4 doses x 14 days
| 400 mg/kg/day in 4 doses x 14 days
|}

* Patients should be followed with a lumbar puncture every 6 months (or sooner, if symptoms return) for 2 years after treatment to detect a relapse should it occur
* New treatment, '''fexinidazole''', may be a reasonable oral treatment

== Prevention ==

* Vector control programs
* Treatment of infected humans and animals
* Vector avoidance with insect repellant, long-sleeve clothes, and avoiding known endemic areas