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FMD Control Strategy in Botswana
Wheel Bath
Carrier State
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Quarantine is the enforced separation of actually or potentially infected
animals from other susceptible stock. Quarantine is an essential element
of an FMD control policy in situations where animal movement is permitted
under controlled conditions. The minimum useful duration of quarantine
is one maximum incubation period. In practice, the period usually applied
for FMD is 21 or 28 days.
Animals quarantined before entry into FMD-free countries are usually blood sampled before entry
into quarantine and then subsequently on two separate occasions whilst they are in quarantine to ensure
freedom from antibody to FMD. In some circumstances, samples of oesophagopharyngeal fluid are collected
using a probang cup to check for the carrier state before entry is permitted.
In countries operating an intensive vaccination campaign as part of an FMD control programme,
animals in quarantine are usually vaccinated with a vaccine of known potency to ensure adequate immunity
before entry is permitted.
Quarantine is applied
To animals prior to import to an FMD-free country
To animals prior to entry onto farms of high disease security
To animals migrating through regions attempting to control FMD
Within farms in endemic areas to separate infected from susceptible stock
There is a perception that, as FMD is extremely contagious,
little can be done to prevent spread of an epidemic on a farm once the
virus has gained entry, even in situations where routine vaccination is
carried out. Experience has shown that this is not the case and that any
measures that can be taken to reduce the infection pressure on a farm
will reduce the number of animals which become clinically affected and
the severity of the disease in those that are.
In tropical and sub-tropical regions with extensive husbandry systems,
epidemics of FMD often spread more slowly than in temperate climates with
intensive husbandry systems. In these situations the physical separation
of infected from susceptible stock can severely limit the spread of an
outbreak. Affected animals must be housed at the perimeter of the holding
in a building physically separated from the rest of the animal houses.
Basic zoosanitary controls such as the use of disinfectant foot baths
and care of sick and healthy animals by different people can reduce spread
of the disease.
In zero-grazed intensive units in Saudi Arabia, where frequent prophylactic
vaccination is carried out, if animals are suspected of showing clinical
signs of FMD they are immediately segregated into isolation units. This
policy has been found to reduce significantly the subsequent extent of
any outbreak.
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