Author, Donkey, Bureaucrats, Administrators
53,803
edits
Changes
Jump to navigation
Jump to search
no edit summary
==Introduction==
==Introduction==
The '''piroplasms''' are a group of blood-borne protozoa which are transmitted by [[Suborder: Metastigmata, ticks|ticks]]. The species of most veterinary importance are ''Babesia'', ''Cytauxzoon'' and ''Theileria''.
The '''piroplasms''' are a group of blood-borne protozoa which are transmitted by [[Ticks|ticks]]. The species of most veterinary importance are ''Babesia'', ''Cytauxzoon'' and ''Theileria''.
Piroplasms are apicomplexan protozoa which inhabit [[Erythrocytes - WikiBlood|erythrocytes]], and sometimes other cells of vertebrates, but do not form pigment from haemoglobin. All piroplasms are small and round or pear-shaped (erythrocyte forms) and are parasitic to fish, amphibians, birds and mammals.
Piroplasms are apicomplexan protozoa which inhabit [[Erythrocytes - WikiBlood|erythrocytes]], and sometimes other cells of vertebrates, but do not form pigment from haemoglobin. All piroplasms are small and round or pear-shaped (erythrocyte forms) and are parasitic to fish, amphibians, birds and mammals.
*Babesiosis has severe effects on cattle production in parts of the world
*Babesiosis has severe effects on cattle production in parts of the world
**Prevents European breeds from being successful in tropical regions where [[Suborder: Metastigmata, ticks|ticks]] are endemic.
**Prevents European breeds from being successful in tropical regions where [[Ticks|ticks]] are endemic.
**Occurs sporadically in the UK and Ireland causing losses of around £8 million per year
**Occurs sporadically in the UK and Ireland causing losses of around £8 million per year
'''Life Cycle'''
'''Life Cycle'''
*Both [[Suborder: Metastigmata, ticks#Disease Transmission|trans-stadial]] and [[Suborder: Metastigmata, ticks#Disease Transmission|trans-ovarian]] transmission occurs
*Both [[Ticks#Disease Transmission|trans-stadial]] and [[Ticks#Disease Transmission|trans-ovarian]] transmission occurs
*Each female [[Suborder: Metastigmata, ticks|tick]] produces 3000 eggs
*Each female [[Ticks|tick]] produces 3000 eggs
*The [[Suborder: Metastigmata, ticks|tick]] is the definitive host
*The [[Ticks|tick]] is the definitive host
*''Babesia'' multiplies in the red blood cells by '''budding'''
*''Babesia'' multiplies in the red blood cells by '''budding'''
'''Epidemiology'''
'''Epidemiology'''
*Determined by:
*Determined by:
**Number of infected [[Suborder: Metastigmata, ticks|ticks]] seeking a blood meal ('''tick pressure''')
**Number of infected [[Ticks|ticks]] seeking a blood meal ('''tick pressure''')
**Calves under 9 months are refractory to disease
**Calves under 9 months are refractory to disease
***Can develop immunity if exposed without showing clinical signs
***Can develop immunity if exposed without showing clinical signs
*Predisposing factors:
*Predisposing factors:
**Susceptible animals introduced into an infected area
**Susceptible animals introduced into an infected area
**Infected [[Suborder: Metastigmata, ticks|ticks]] introduced into a clean area
**Infected [[Ticks|ticks]] introduced into a clean area
**Infected cattle introduced into an area with clean [[Suborder: Metastigmata, ticks|ticks]]
**Infected cattle introduced into an area with clean [[Ticks|ticks]]
**Temporary reduction in the [[Suborder: Metastigmata, ticks|tick]] population decreasing the transmission rate (causing enzootic instability)
**Temporary reduction in the [[Ticks|tick]] population decreasing the transmission rate (causing enzootic instability)
**Infected are transported or stressed in other ways, e.g. parturition
**Infected are transported or stressed in other ways, e.g. parturition
**Sporadic disease
**Sporadic disease
**Enzootic instability
**Enzootic instability
**Occurs mostly during the spring and autumn during periods of greatest [[Suborder: Metastigmata, ticks|tick]] activity
**Occurs mostly during the spring and autumn during periods of greatest [[Ticks|tick]] activity
**Occurs mostly in stressed cattle under 2 years old on rough grazing
**Occurs mostly in stressed cattle under 2 years old on rough grazing
**''B. divergens'' the most common species
**''B. divergens'' the most common species
**[[Suborder: Metastigmata, ticks#Ixodes spp.|''Ixodes ricinus'']] is the vector
**[[Hard Ticks - UK#Ixodes spp.|''Ixodes ricinus'']] is the vector
**[[Suborder: Metastigmata, ticks#Disease Transmission|Trans-ovarial]] transmission to the next generation occurs
**[[Ticks#Disease Transmission|Trans-ovarial]] transmission to the next generation occurs
**''B. major'' occurs in South East England but is not pathogenic
**''B. major'' occurs in South East England but is not pathogenic
***Vector is [[Suborder: Metastigmata, ticks#Important Hard Ticks|''Haemaphysalis'']]
***Vector is [[Hard Ticks - UK#Important Hard Ticks|''Haemaphysalis'']]
*Overseas
*Overseas
**''B. bovis'' causes considerable losses in cattle in many tropical and sub-tropical areas
**''B. bovis'' causes considerable losses in cattle in many tropical and sub-tropical areas
***In Australia an attenuated vaccine is used
***In Australia an attenuated vaccine is used
***Vector is [[Suborder: Metastigmata, ticks#Important Hard Ticks|''Boophilus'']]
***Vector is [[Hard Ticks - Overseas|''Boophilus'']]
**''B. bigemina'' causes problems in Africa and South America
**''B. bigemina'' causes problems in Africa and South America
***Vector is [[Suborder: Metastigmata, ticks#Important Hard Ticks|''Boophilus'']]
***Vector is [[Hard Ticks - Overseas|''Boophilus'']]
*Dogs
*Dogs
**Large species comprises 3 subspecies
**Large species comprises 3 subspecies
***''B. canis canis'' is the most important
***''B. canis canis'' is the most important
****[[Suborder: Metastigmata, ticks#Important Hard Ticks|''Dermacentor'']] vector
****[[Hard Ticks - Overseas|''Dermacentor'']] vector
****Largely confined to southern Europe but is spreading
****Largely confined to southern Europe but is spreading
***''B. canis'' uses [[Suborder: Metastigmata, ticks#Important Hard Ticks|''Rhipicephalus'']] as a vector and is spreading northwards through Europe
***''B. canis'' uses [[Hard Ticks - Overseas|''Rhipicephalus'']] as a vector and is spreading northwards through Europe
***''B. gibsoni'' is now established in the USA and South-East Asia
***''B. gibsoni'' is now established in the USA and South-East Asia
**British dogs have no immunity as no species are endemic to the UK so are highly susceptible if taken abroad
**British dogs have no immunity as no species are endemic to the UK so are highly susceptible if taken abroad
**Prevention of [[Suborder: Metastigmata, ticks|tick]] bites by use of an 'Amitraz' collar is currently the best method of protection
**Prevention of [[Ticks|tick]] bites by use of an 'Amitraz' collar is currently the best method of protection
*Horses
*Horses
*Low rate of transmission
*Low rate of transmission
*Few infected [[Suborder: Metastigmata, ticks|ticks]]
*Few infected [[Ticks|ticks]]
*Infrequent exposure
*Infrequent exposure
'''Pathogenicity'''
'''Pathogenicity'''
*[[Suborder: Metastigmata, ticks|Ticks]] are implicated as the natural vector for ''Cytauxzoon''
*[[Ticks|Ticks]] are implicated as the natural vector for ''Cytauxzoon''
**Most cases of infection have been associated with the presence of these parasites on the hosts
**Most cases of infection have been associated with the presence of these parasites on the hosts
**Experimentally, ''Dermacentor variabilis'' can transmit the organism from bobcats to domestic cats. In a white tiger that developed a natural, fatal infection in Florida, two female Lone Star ticks (''Amblyomma americanum'') were present on the inguinal skin.
**Experimentally, ''Dermacentor variabilis'' can transmit the organism from bobcats to domestic cats. In a white tiger that developed a natural, fatal infection in Florida, two female Lone Star ticks (''Amblyomma americanum'') were present on the inguinal skin.
***Severe, proliferative lymphatic disease of cattle
***Severe, proliferative lymphatic disease of cattle
***Central and Eastern Africa
***Central and Eastern Africa
***Transmitted by [[Suborder: Metastigmata, ticks#Ticks of Veterinary Importance|''Rhipicephalus appendiculatus'']]
***Transmitted by [[Hard Ticks - Overseas|''Rhipicephalus appendiculatus'']]
***[[Suborder: Metastigmata, ticks#Disease Transmission|Trans-stadial]] transmission
***[[Ticks#Disease Transmission|Trans-stadial]] transmission
*Other ''Theileria'' species cause production losses in cattle and sheep in the Middle East, Mediterranean and in Northern Africa
*Other ''Theileria'' species cause production losses in cattle and sheep in the Middle East, Mediterranean and in Northern Africa
**Pyrexia
**Pyrexia
**Enlarged local [[Lymph Nodes - Anatomy & Physiology|lymph node]]
**Enlarged local [[Lymph Nodes - Anatomy & Physiology|lymph node]]
***Usually parotid [[Lymph Nodes - Anatomy & Physiology|lymph node]] as [[Suborder: Metastigmata, ticks#Ticks of Veterinary Importance|''Rhipicephalus appendiculatus'']] feeds in the ear
***Usually parotid [[Lymph Nodes - Anatomy & Physiology|lymph node]] as [[Hard Ticks - Overseas|''Rhipicephalus appendiculatus'']] feeds in the ear
**Loss of condition
**Loss of condition
'''Control'''
'''Control'''
*Integrated control of both the [[Suborder: Metastigmata, ticks|tick vector]] and disease
*Integrated control of both the [[Suborder: Metastigmata, ticks|tick vector]] and disease
**[[Vaccines - WikiBlood|Vaccination]] and [[ectoparasiticides]]
**[[Vaccines - WikiBlood|Vaccination]] and [[Ectoparasiticides]]
*Current [[Vaccines - WikiBlood|vaccination]] is live unattentuated
*Current [[Vaccines - WikiBlood|vaccination]] is live unattentuated