PPRESENTATION ON WILDLIFE
DISEASES-- TRYPANOSOMIASIS
GROUP NO. 6
INTRODUCTION.
Trypanosomiasis
o Is a disease caused by protozoa parasites known as
Trypanosomes of species Trypanosoma brucei and
Trypanosoma vivax that are primarily transmitted by tsetse
flies Glossina spp, and can infect a wide range of wild
mammal species but these are mostly trypanotolerant and also
affect almost all domestic mammals and human.
o There two subspecies of the parasite that are responsible for
initiating the disease in human, Trypanosoma brucei
gambiense causing a disease in west and central Afrca,
Trypanosoma brucei rhodesiense causing a disease in east and
southern Africa.
o The third subspecies Trypanosoma brucei brucei is responsible
for affecting animals and not humans.
CONT……………..
 The
other species Trypanosoma vivax is a parasite in
the genus Trypanosoma. Cause the disease Nagana,
also known as animal trypanosomiasis, affecting cattle
and wildlife mammals. It mainly occur in west Africa,
although it has spread to South America.
GEOGRAPHICAL DISTRIBUTION
o
Trypanosomes can be found wherever the tsetse fly vector
exists. Tsetse flies are endemic in Africa between latitude
15° N and 29° S, from the southern edge of the Sahara
desert to Zimbabwe, Angola and Mozambique.
Geographical distribution
CAUSATIVE AGENT AND MODE
OFTRANSMISSION
Causative agent
o Trypanosomes, protozoan parasites of the genus Trypanosoma
that live in the blood, lymph and various tissues of vertebrate
hosts. The most important species for this disease are
Trypanosoma vivax and Trypanosoma brucei.
Mode of transmision
o Trypanosomes must first develop within tsetse fly vectors for
one to a few weeks. They are then transmitted through tsetse
fly saliva - when flies feed on an animal they inject saliva
before sucking blood. Tsetse flies will remain infected for life.
Trypanosomes can also be mechanically transmitted by biting
flies when these flies transfer blood from one animal to
another.
Mode of transmission cont…..
SYMPTOMS
o
o
o
o
Changes of behavior,
confusion,
sensory disturbances and poor coordination,
Disturbance of the sleep cycle.
CLINICAL SIGNS
o
The primary clinical signs are an irregular fever, signs of
anemia, lymphadenopathy and weight loss. Animals lose
condition and become progressively skinny. Milk yield
may be decreased in dairy animals, , diarrhea, keratitis,
lacrimation and appetite loss.
DIAGNOSIS
o
o
The disease should be confirmed by health professionals identifying
pathogenictry panosomes in blood or lymph node smears.
Anticoagulated fresh blood, dried thin and/or thick blood smears,
and smears of needle lymph node biopsies can be submitted from
live animals. Trypanosomes are most likely to be found in the blood
by direct examination during the early stages of infection. They are
less likely to be detected in chronically ill animals, and are almost
never seen in healthy carriers. Xenodiagnoses (looking for the
parasite in a previously uninfected vector which is exposed to the
host, rather than the host itself) is also a useful technique when
attempting to isolate from wildlife.
Samples should only be sent under secure conditions and to
authorized laboratories to prevent the spread of the disease.
Although the trypanosomes that cause African animal
trypanosomiasis are not known to be zoonotic, precautions are
recommended.
AFFECTED WILDLIFE SPECIES
o
Wild animals known to be infected but which are
trypanotolerant include greater kudu, warthog, bushbuck,
bush pig, African buffalo, African elephant, Black
rhinoceros, lion and leopard.
o
Several species of wild animal appear not to be
trypanotolerant, e.g. the southern white rhinoceros can die
from infection.
THREATS TO WILDLIFE
o
It pose a substantial threat to the conservation of global
biodiversity.
o
Wild animals rarely show clinical signs of trypanosomiasis
but wildlife hosts are a reservoir of trypanosomes. Some
species such as southern white rhinoceros, which prefers
open grassland, can suffer mortality from the disease.
DISEASE MANAGEMENT IN THE
WILD
o
In endemic areas of Africa, African animal trypanosomiasis
can be controlled by reducing or eliminating tsetse fly
populations with traps, insecticides and clearing of bush, and
by treating infected animals with antiparasitic drugs.(e.g.
diminazene aceturate and quinapyramine methylsulfate).
Control of tsetse fly in the wild
CONCLUSION
 It
seems that this disease is very dangerous to animals
and human being especially for those who are working in
Protected areas or leave in rural areas. It needs more
research for effective treatment in order to reduce the
number of death.
 Trypanosomiasis must be reported to state or federal
authorities immediately upon diagnosis or suspicion of
the disease.