Disinfection of Foot and Mouth Disease Virus:
Resistance to physical and chemical action
(From the OIE: http://www.oie.int/eng/maladies/fiches/A_A010.HTM)
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Temperature:
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Preserved by refrigeration and freezing and progressively inactivated by
temperatures above 50 degrees C.
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pH:
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Inactivated by pH <6.0 or >9.0
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Disinfectants:
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Inactivated by sodium hydroxide (2%), sodium carbonate (4%), and citric
acid (0.2%). Resistant to iodophores, quaternary ammonium compounds, hypoclorite
and phenol, especially in the presence of organic matter.
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Survival:
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Survives in lymph nodes and bone marrow at neutral pH, but destroyed in
muscle when is pH <6.0 i.e. after rigor mortis. Can persist in contaminated
fodder and the environment for up to 1 month, depending on the temperature
and pH conditions.
Choice of Disinfectants
(From AVIS: http://aleffgroup.com/avisfmd/A010-fmd/mod4/4320-choice.html)
FMD virus is inactivated outside a narrow range of pH conditions (approximately
pH 7 to 8.5) at a rate dependent on pH, temperature and inactivant.
For disinfection of premises and equipment it is not generally necessary
to go to the expense of using proprietary disinfectants. The use of an
appropriate acid or alkali, together with a detergent to assist penetration
of organic matter, is usually sufficient. Many of the agents used are dangerous
and all appropriate safety measures should be taken, including the use
of masks, eye protection and protective clothing.
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Citric acid 0.2% solution
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Ten per cent stock solutions may be held in airtight sterile containers
for up to two weeks. Effectiveness improved by addition of small quantity
(no more than ml/litre) of detergent. Suitable for milking equipment and
bulk tanks. pH should be <4.
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Formalin 10.0% solution (containing no less than 34% formaldehyde).
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For use mix 1:9 with water. Suitable for spraying on hay, straw, bedding,
etc.
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Formaldehyde gas
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Produced by action of formalin on potassium permanganate
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Great care must be taken with the use of formaldehyde gas as it is extremely
noxious. This agent should only be used by experienced personnel with the
appropriate equipment.
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Ortho-phosphoric acid 0.3% solution
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Effectiveness improved by addition of small quantity (no more than 3 ml/litre)
of detergent. Suitable for milking equipment and bulk tanks. pH should
be <4.
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Sodium carbonate 4.0% solution
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Effectiveness improved by addition of small quantity (no more than 3 ml/litre)
of detergent. Suitable for animal pens and similar areas. pH should be
>10.
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Sulphamic acid 0.2% solution
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Stable in solution, and particularly suitable for metal, painted surfaces,
plastics and rubber. Effectiveness improved by addition of small quantity
(no more than 3 ml/litre) of detergent. Suitable for milking equipment
and bulk tanks. pH should be <6.
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Proprietary brands
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Labels will indicate their suitability for FMD and dilution rates.
Note that acid and alkali disinfectants, dependent for their activity on
pH, should not
be mixed.
List of MAFF Approved Disinfectants:
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