Arthropod Borne Protozoa Flashcards
Haemoprotozoa
All arthropod borne protozoa have forms that dev in vert host in blood at some time so ref to as…
In most cases impact of abpro is on blood syst of vert host
Asex repro in both hists
Sex repro only in arthropod host
In most cases protozoa has to undergo a form of dev in arthropod host before being passed to another host ref to as cyclical or bio transmission
Arthro-parasite relationships are spec
So restrict distrib of protozoa to that of arthro host
So control proto by control arthro
Abproto transmission
Some directly between hists mech trans
Some bio trans
Mist can also be transmitted iatrogenically
Babesia
Intraerythrocytic Ixodes ticks Hugh vert and arthro spec Uk mainly in cattle sometimes sheep goat and deer without clin dis evidence Cattle form can infect imm suppr humans
Babesia divergens
Most widespread Main clin babesiosis cause Paired widely divergent intraerythrocytic organisms Ixodes ricinus Usually found near edge of RBC
Babesia major
Larger Uncommon Less pathogeniv than divergens Acutely paired organisms inside red cells Transmit by haemaphysalis punctata Mostly restrict to s england
Babesia divergens life cycle
Tick infected with babesia as adult female babesia repl in ovaries and infect eggs
Infected larve hatch
Moult and babesia multiply in salivary glands by binary fission
Injected into host when tick feeds
Multiply asex in host RBC
Released into circ after haemolysis
New RBC invaded
Vert can be infected for life new reservoir host
All stages of tick can transmit babesia but only adult f acquire it
Babesia adaptations for transmission
Synch repro to tick feeding behaviour
Able to be transmitted by all tick stages
Able to be vert passed between ticks
Host babesia relationship
Calves 3-9 mnth rarely show clin signs
If first infect at this age acquire imm carried to adulthood
If challenged in 2nd yr then less res and become clin affected
In endemic areas most are infect early
Give rise to endemic stabilitywith high infection rate but little dis seen
Outbreak of clin seen during endemic stability breakdown eg via naive animal intro
Clin babesiosis
Redwater
Anaemia
Seen when endemic stability is disrupted newly intro infected ticks newly intro naive animal
Intro animals from uninfect area to infect area
Babesiosi control
Rarely necessary in UK
At risk animals introduced carefully monitored and treated with drugs if needed
In some sub tropical control with vacc and tick reduction
Boophilis microplus transmit
Patjogenic babesia bigemima and bovis and anaplasma
Transovarian and transtadial transmission
Reservoir hosts
Babesia canis due to ripicephalus sanguineus risk
Cause pyrexia aevere inflam and anaemia
Divide to form pair and qudruplet and so on
RBC bursts releasing more infective piroplasms
Trypanosoma
EC
Haemoflagellates occur in range of vertebrates
Major problem in tropics in UK considered non patjogenic
Tryp theileri transmitted by biting flies like tabanids (cattle) and tryp melophagium by keds (sheep)
Tryp brucei evansi
Biting flies Mech transmission All dom animals affected but only fatal in horses Aneamia throygh extravasculat haemolysis Revurrent fever oedema anaemia
