detection of Trichomonas/Tritrichomonas
by polymerase chain reaction
in the genus Trichomonas/Tritrichomonas
can infect man, but trichomoniasis is also a major problem in
poultry, birds and horses. All trichomonads have three to five
anterior flagella, an undulating membrane, and a recurrent
flagellum attached to the edge of the undulating membrane. There
is no cyst stage for this protozoan parasite.
are some Trichomonads posing major health threats to humans,
livestock, birds and other animals:
This parasite lives in the intestine of horses and can be a
potential cause of diarrhea in foals.
T. foetus and
T. suis are
almost identical in genomic composition, morphologic structures,
ultrastructure, distribution, host specificity, characteristics
of in vitro cultivation, immunology and biochemistry (Lun et
al., 2005). Thus, it has been proposed that
T. foetus and
T. suis are synonyms. While the parasite can be found in the
nasal passage, stomach, colon and large intestine of swine, it
does not appear to cause major health problems in them.
trichomonad, however, causes trichomoniasis in cattle, resulting
in significant economic loss. The parasite is sexually
transmitted and resides in the reproductive tract of cattle. In
females, the infection may result in low-grade inflammation,
sterility and poor conception rate. In males, symptoms vary from
no apparent signs to inflammation of the prepuce. Treatment is
difficult and usually not attempted. Slaughter or breeding rest
(females) are the usual methods employed in dealing with bovine
trichomonads, this organism multiplies by simple binary fission
and does not posses a cyst stage. This organism is called Tritrichomonas foetus because it has three long flagella at
diagnosis was mainly based on microscopic evaluation of the trophozoite stage. Mucus, exudates or saline washes from the
vagina and preputial cavity are the best samples for microscopic
examination. In cases of abortion, allantoic and amniotic fluids
as well as fetal tissues and membranes are examined. Serologic
detection by agglutination is also possible.
However, none of these testing methods are
very sensitive, resulting in
high false negative rates.
causes human trichomoniasis. This parasite also resides in the
human reproductive tract. This is one of the most common
sexually transmitted diseases of man and often occurs with other
more severe concurrent infections. Chronic reproductive and
urinary problems may result in females. The parasite is
transmitted sexually. Prevalence in human populations varies
between 10 and 25% among women. Only about 15% of infected
women show clinical signs; many infected women are asymptomatic
trichomonads known to infect humans include
from the tarter and gums of the mouth and
from the human colon.
The parasite causes avian trichomoniasis. When present, it is
usually found in the upper digestive tract of many species of
doves and gallinaceous birds. Some strains may also produce
liver and lung lesions. The parasite is transferred to young
from the mother during feeding. Transmission between birds may
also occur from contaminated feed and water. Infection by this
trichomonad can be fatal. The presence of this organism in doves
is a common source of infection of falcons and hawks feeding on
This parasite is mainly detected in cecum and liver of
gallinaceous birds but it can also be found in other visceral
organs of the infected animals.
affects many birds including poultry, and can cause morbidity
and mortality especially in young birds.
trichomoniasis may not be easy due to clinical symptoms which
may resemble those of poxvirus, candidiasis or vitamin A
can be misidentified in initial microscopic examination because
of its similarity to Giardia. The other difficulty in
identification of this parasite is that the trichomonad does not
survive long after the death of the host. Complementary testing
by PCR may be used to eliminate false negative microscopy
results. Molecular detection by PCR does not
require living parasites and provides a high degree of
sensitivity and specificity.
Help confirm the disease causing agent
Help ensure that herds are free of Trichomonas
Early prevention of spread of this parasite
Minimize human exposure to this parasite
Safety monitoring of biological products that derive
Lun, Z.R., Chen, X.G., Zhu, X.Q., Li, X.R. and Xie, M.Q. (2005)
Are Tritrichomonas foetus and Tritrichomonas suis synonyms?
Trends Parasitol. 21:122-125.
Preferred specimens -
Rectal, vaginal, oral or other mucous secretion swab, or 0.2 ml
- 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
tube, or 0.2 ml fresh, frozen or fixed tissue.
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