aistand south~ern afrkca - (PDF, 101 mb) - USAID

ditions occur mostly in calves and vary from zero
to 50% (Staak, 1981; Moll et al, 1984; Berkvens
et al, 1989). Where endemic instability exists,
mortality may be as high as 80 to 100%
(Cunningham, 1977; Hooke, 1981; Julia, 1985;
Lawrence, 1992). However, these figures often
are derived from localised studies and may not
reflect the actual rates in larger populations.
Although mortality in indigenous cattle in
endemic areas can be low, calf growth is often
severely affected (Moll et al, 1985). However,
controlled studies of the effects of these mild
infections in cattle have not been carried out.
Animals which recover from ECF as a
complication may suffer from weight loss,
produce low milk yields, provide less draft power
and could possibly suffer from reduced fertility
and delays in reaching maturity. However,
extensive studies on these types of prodniction
losses caused by the disease have not yet been
undertaken. What should be kept in mind is that
these animals also remain carriers and can
spread infection (Lawrence and McCosker, 1981;
Brown, 1985).
Indirect production losses. Indirect production
losses occur when the disease acts as a constraint
on the use of improved cattle. In the affected
areas, farmers face a substantial risk if they try
to keep Taurine or crossbred cattle due to their
high susceptibility to the disease. Many farmers
are therefore constrained or piohibited from
utilising improved genotypes and improving
livestock productivity and efficiency (Callow,
1983).
Control costs
Tick control
East Coast fever is conventionally checked by the
control ofthe vector ticks through the application
of acaricides to the surface of an animal by
dipping, spraying or hand-washing to kill the
tick. In areas of heavy tick infestation, cattle are
treated with acaricides as often as twice a week.
In many smallholder areas, the dipping
service is provided by the government through
public dip tanks, either free of charge or at a
highly subaidised cost. Dipping is usually
compulsory at stated intervals to achieve more
effective and widespread control. Even though
the majority of farmers have access to this
assistance, there is a significant private sector of
commercial farmers, both small-and large-scale,
who bear the full cost of the fight to prevent the
disease.
Depending on the frequency of applications,
annual costs of acaricide to farmers who are
financially responsible for the purchase of these
drugs ranges from US$ 2 to US$ 20 per animal
(Lawrence and McCosker, 1981; de Leeuw and
Pasha, 1988; Young et al, 1988; Young et a], 1990;
Perry et al, 1990). lb the farmers who use public
dip tanks, the real cost of tick control includes
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loss of animal traction time and human labour
for the period spent in trekking animals to and
from the dip tanks, often several kilometres
away from the farm.
Losses are also incurred whilst driving
animals through dip tanks from stress-induced
abortions, drowning and physical injury.
In addition, the constant trekking of animals
to dip tanks often creates gullies and the
frequent concentration of animals around the
tanks leads to overgrazing, both of which cause
erosion and environmental degradation.
There are further indirect economic losses
which can be attributed to tick control. The
application of acaricides on vector ticks through
dipping, spraying or hand-washing animals
contributes to the pollution of the environment
and may endanger human health. This arises
from direct contact, spilled or misused acari cides
and also from consumption of products derived
from animais treated with acaricides (Keating,
1987; Young et al, 1988). In addition, the
occurreace of ticks and their control cause worry
and anxiety to the farmers who have to deal with
the problem on a daily basis.
Treatment
Effective treatment of ECF requires identification
ofthe disease through surveillance and
diagnosis followed by treatment of infected
animals with drugs.
In much of the affected region this service is
provided by governments, often free or at
subsidised charges, through veterinary
investigation laboratories and the veterinary
extension service. Farmers who pay for the
service can spend as much as US$ 10 to 20 per
animal per treatment (Mutugi et al, 1988; Young
et al, 1988). The relatively high cost of treatment
coupled with the poor veterinary services
available especially to smallholdee farmers
imply that only a small proportion of infected
animals have access to treatment.
Government expenditures on ECF
control
By providing curative and tick control services to
farmers free or at highly subsidised charges,
governments spend substantial sums of money
annually, especially in foreign exchange, for
the importation of drugs and acaricides. For
instance, Kenya spent about US$ 10 million in
1987 (Young et al, 1988) and Zimbabwe spent an
estimated US$ 9 million during the 1988/89
financial year (Perry et al, 1990). Even though
these cost estimates include costs of tick control
against all tick-borne diseases, ECF is the major
disease prompting the use of acaricidal applicatons
in much of the region (Cunningham,
1977).
Governments also spend considerable funds
on research, training and extension services