Trypanosoma equiperdum ("Dourine")
X0018 - Ultrasensitive qualitative detection of
the etiologic agent of Dourine or "Covering Sickness," by real time polymerase chain reaction
is a protozoan that causes Dourine, or Covering Sickness, in
horses and other equines such as donkeys and mules. Horses are
most susceptible, donkeys much less so. Unlike other species of
Trypanosome, this parasite can be sexually transmitted, and does
not require a vector. However, spread of the disease has been
documented as far north as Canada and Russia, and as far south
as Chile and South Africa. The disease has been eradicated from
many parts of the world, mainly by repeated clinical testing and
slaughter of positive animals.
symptoms can result from infection with this protozoan.
Classically, there are three stages. During the first stage, the
genitalia become swollen and in mares there is a discharge from
the vagina. Often a
patchy loss of pigment in the mucosa of the vulva or penis is
observed. Slight fever and a loss of appetite may be noticeable.
After four weeks or so, the second stage begins, with round
urticarial areas on the neck, the chest, the flanks and the
rump. The appearance of these plaques has been described as “a
coin inserted under the skin”. They are visible for a few days
before disappearing, but may come back. In the third stage, a
paralysis sets in, involving various muscles, and spreading to
the hind legs, causing loss of coordination. Complete paralysis
of all four legs may finally occur.
these classical symptoms may not occur with the infection. Many
infected animals, especially in long-standing endemic regions,
develop symptoms that are rather mild without any apparent
stages. There also appear to be differences in virulence between
strains. Even in cases terminating fatally, the disease may last
for a year or even two years.
dourine can be difficult. Classical symptoms, if present, can be
of great help in an area where the disease is known to occur.
Trypanosomes are not normally found in the circulating blood,
but may be detectable in fresh preparations or stained smears of
discharge from the vagina or tissue fluid taken from the swollen
genitalia or the urticarial plaques. Traditionally, the
complement fixation test has been used to identify carriers.
Although the complement fixation test is still mandatory in some
countries, modern, more sensitive tests are now preferable, eg
IFA or ELISA. Nevertheless, none of these serological methods
can differentiate between T. equiperdum and other
trypanosomes, such as T. evansi and T. brucei.
Molecular detection of T. equiperdum by PCR is not only
rapid and highly sensitive, but is also able to differentiate it
from other Trypanosomes (Zablotskij et al., 2003).
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
diagnosis of T.
Help ensure that animal herds and populations are free of
Early prevention of spread of this parasite among a herd
Minimize personnel exposure to this parasite
Safety monitoring of biological products and vaccines
that derive from equines
Zablotskij, V.T., Georgiu, C., de Waal, T., Clausen, P.H.,
Claes, F. and Touratier, L. (2003) The current challenges of
dourine: difficulties in differentiating Trypanosoma
equiperdum within the subgenus Trypanozoon. Rev.
Specimen requirement: 0.2 ml urine, or urogenital or vaginal swab.
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
real time PCR