DOI: 10.1515/ap-2016-0043
© W. Stefański Institute of Parasitology, PAS
Acta Parasitologica, 2016, 61(2), 329–336; ISSN 1230-2821
Vertical transmission of Trypanosoma evansi
in dromedary camels and studies on fetal pathology,
diagnosis and treatment
Shirish D. Narnaware*, Samar K. Ghorui, Sanjay Kumar and Nitin V. Patil
ICAR National Research Centre on Camel, Post Box 07, Jorbeer, Bikaner, Rajasthan 334001, India
Abstract
In the present study, a total of 14 (73.68%) cases of abortions and two (100%) cases of still births were detected positive for
Trypanosoma evansi infection by wet and dry blood smear examination and fetal tissue PCR in camels of an organized farm.
The abortions in infected dams were recorded from 8 to 11.5 month of gestation, however majority occurred during 9
th
to 10
th
month. The important laboratorial findings in infected dams were anemia, hypoglycemia, hyperproteinemia and leukocytosis.
At necropsy the T. evansi infected aborted and still born fetuses showed subcutaneous edema, presence of moderate amount of
dark red hemolysed blood in thoracic and abdominal cavity, bronchopneumonia, hepatic necrosis and acute congestion in
all vital organs. Microscopically, there was severe congestion, thickening of bronchial and alveolar wall and mononuclear
infiltration in the fetal lung, necrotic and degenerative changes in the liver, nephritis along with severe congestion and tubular
necrosis in the kidneys and necrotic and degenerative changes and congestion of capillaries in the brain. The T. evansi DNA
was detected by PCR from blood, lung, spleen, liver, kidney and brain of all the infected aborted and still born fetuses. The
results of the study indicated that T. evansi can cross placental barrier and cause pathological events in the fetus resulting into
abortion or still birth in pregnant camels.
Keywords
Abortion, camel, pathology, transplacental transmission, Trypanosoma evansi
Introduction
Camel trypanosomosis or surra is an important arthropod
borne disease caused by Trypanosoma evansi, and is the
most important single cause of morbidity and mortality in
camels in India and worldwide (Singh et al. 2004; Enwezor
and Sackey 2005; Desquesnes et al. 2013). Trypanosomosis
in camels may occur in both acute and chronic forms, but
generally, the chronic form is more common (Gutierrez et al.
2005). The disease in camels causes considerable economic
losses due to progressive anemia, parasitaemia, fever,
marked depression, dullness, loss of condition, icterus, sub-
cutaneous edema, neurological abnormalities, abortion in
pregnant animals and often rapid death (Elhaig et al. 2013).
Mechanical transmission by biting flies (Tabanus spp. and
Stomoxys spp.) is the most important mode of transmission
of T. evansi in camels as well as in other livestock
(Desquesnes et al. 2013). The disease can be managed or re-
duced but difficult to be eradicated due to mechanical trans-
mission by vector insects. Since limited drugs are available
for treatment of camel trypanosomosis, there is an emerging
problem of drug unresponsiveness (Enwezor and Sackey
2005). The anti-trypanocidal drugs are more effective when
the parasite is in the blood, but when it is in the peripheral
tissue or extravascular spaces, the efficacy of drug decreases
(Desquesnes et al. 2013).
Regarding the reproduction, abortions, premature births
and an inability to feed the young have been described in
camels, which greatly reduce reproductive potential in af-
fected herds (Yagil 1982; Gutierrez et al. 2005). Despite the
evidence of the negative effect of trypanosomosis on the re-
production of camels, the mechanism responsible for the re-
productive disturbs is not fully understood and detailed
clinico-pathological studies are also lacking (Gutierrez et al.
2005). In the present study, the pathological and diagnostic
studies were conducted in pregnant camels and their fetuses
during an outbreak of abortions and still births associated with
natural infection of T. evansi.
*Corresponding author: sdnarnaware@nrccamel.res.in
Unauthenticated
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