Page 213 - The Veterinary Laboratory and Field Manual 3rd Edition

182 Susan C. Cork and Mani Lejeune

disorders. Prevention is based on vector control the ‘one Health’ approach
and avoiding insect bites.
In Africa, human trypanosomiasis takes In rural areas, throughout the world, there are
two forms depending on the parasite involved. often concurrent human and animal health
Trypanosoma brucei gambiense (T.b.g.) is found in issues to deal with. This provides an ideal oppor-
west and central Africa and currently accounts tunity for medical and veterinary teams to work
for over 95% of reported cases of sleeping sick- together with other experts to provide techni-
ness. In this chronic infection a person can be cal support for district and regional human and
infected for months or even years without major animal health extension services. The latter are
signs or symptoms of the disease. When symp- responsible for delivering health advice to the
toms emerge, the patient is often already in an local community and may often be required to
advanced disease stage where the central nervous visit villages where human and animal disease
system is affected. Trypanosoma brucei rhodesiense outbreaks are occurring concurrently. In the case
(T.b.r.) is found in eastern and southern Africa. of vector borne zoonotic diseases there may be
According to the WHO, this form now repre- a link between human and animal disease out-
sents less than 5% of reported cases and causes breaks but even though this is often not the case
an acute infection. First signs and symptoms are there can be significant benefit to taking a col-
observed a few months or weeks after infection. laborative approach to ensure that good hygiene
The disease develops rapidly and invades the cen- and sanitation practices are implemented and
tral nervous system. The parasite is transmitted that potential disease vectors are effectively con-
by tsetse flies (Glossina sp.) which are found in trolled. Where possible, the focus should be on
sub-Saharan Africa although only certain species disease prevention with the promotion of good
transmit the disease. Rural populations living in animal husbandry practices and support pro-
regions where transmission occurs and which vided for community education on topics such
depend on livestock agriculture or hunting are as food and water safety and how to prevent dis-
the most exposed to the tsetse fly and therefore ease transmission between humans and between
to the disease although not all areas where tse- humans, animals and the wider environment.
tse flies occur have cases of sleeping sickness. The latter is often best achieved by engag-
The disease develops in areas ranging from a ing a local leader who is well placed to involve
single village to an entire region. There are vari- schools and community groups in educational
ous treatment options available depending on activities.
the stage of the disease. Prevention is based Zoonotic diseases endanger people’s live-
on vector control and avoiding insect bites. lihoods by affecting their livestock as well as
Chagas disease and African sleeping sickness directly compromising their own health and
are both diseases in which the parasitic agent survival. A list of common zoonotic diseases is
causing the disease also occurs in animal spe- provided in the Appendix 1. The effective con-
cies. Although the transmission from animals to trol of any zoonotic disease, including vector
humans is not direct, the arthropod vectors that borne parasitic diseases such as sleeping sick-
transmit these diseases are not host specific so ness, enteric protozoal infection and helminth
interspecies transfer of the parasites is possible. parasites such as Taenia saginata and T. solium,
For this reason, in areas where trypanasomes has the potential to alleviate illness and poverty,
and their vectors are endemic, vector control particularly in marginalized rural and peri-
and monitoring of animal health is important urban communities living in close contact with
for maintaining community health. animals.

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