Published Date: 2011-03-13 23:50:00
Subject: PRO/AH> Theileria, bovine - Australia (02): (NS)
Archive Number: 20110313.0805
THEILERIA, BOVINE - AUSTRALIA (02): (NEW SOUTH WALES)
A ProMED-mail post
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International Society for Infectious Diseases
Date: 12 Mar 2011
From: Tristan Burgess [edited]
I do not have specific information on this outbreak, but I can give
background on the status of theileria in Australia for interested
This article appears largely to be reporting the occurrence of a tick
incursion into New South Wales (NSW), though the property near Casino
is perhaps more interesting, as it seems to represent another case of
atypical benign theileriosis.
"Cattle tick" generally refers to _Boophilus microplus_, a common
vector for tick fever (including both babesiosis and anaplasmosis) in
northern Australia, but is uncommon, and the subject of eradication
plans in northern NSW.
I am not aware of reports that indicate _B. microplus_ is considered
a vector for theileria in Australia. In Australia, theileriosis is
transmitted by ticks of the genus _Haemaphysalis_ but, despite some
research, the exact vector assemblage is unclear. Some work has shown
Australian _H. longicornis_ (known in Australia as the "scrub tick")
isolates to be poor vectors, though some overseas strains appear to be
competent. The endemic species _H. bancrofti_ (Wallaby tick) and _H.
humerosa_ (bandicoot tick) are excellent vectors.
The term benign theileriosis is normally used to refer to _Theileria
buffeli_ (the only species of theileria believed to occur in
Australia) to distinguish it from the exotic species. _T. buffeli_ is
widespread in cattle in northern Australia (Steward, et al. 1992) and
was long characterised as largely benign with only occasional cases of
In 2008 in increased number of outbreaks of theileriosis were seen in
NSW, outside the area where it is common, though its presence had
previously been recorded in NSW. 8 such cases were reported in the
Australian Veterinary Journal (Izzo, et al. 2010).
Clinical signs (per NSW department of primary industries lab) were
typically of haemolytic anaemia and included lethargy, loss of
appetite, exercise intolerance, tachycardia, tachypnoea, pale and
jaundiced mucous membranes, transient pyrexia, abortions and, in dairy
cows, reduced milk production. Izzo et al (2010) noted that
periparturient disorders (such as metritis, left-displaced abomasum)
were common in clinically ill animals. Infected animals were also
commonly reported to have recently been moved to a coastal area from
So in the absence of specific information on this event, the likely
interpretation of this is that 2 events are contained in this news
report; the 1st being an incursion of cattle tick, likely _B.
microplus_, into NSW on the first farm, probably from neighbouring
Queensland. The other item appears to be that a 2nd nearby property
has been cleared for suspected tick fever, but a diagnosis of clinical
theileriosis has been made, which is interesting in its own right.
Stewart, et al. Australian Veterinary Journal 1992; 69(3).
Izzo, et al. Australian Veterinary Journal 2010; 88(1-2).
Tristan Burgess BVSc
Massey University NZ, 2009
[We appreciate Tristan sharing this information and enlightening us
about the ticks and diseases in NSW. â Mod.TG]