FACTBOX-Foot and mouth disease

(Reuters) - Following are facts about foot and mouth disease after a second outbreak was reported in southern Britain.

CHARACTERISTICS

Foot and mouth is a highly infectious disease affecting mostly sheep, pigs and cattle in which fever is followed by the development of blisters, chiefly in the mouth or on the feet.

The disease is rarely fatal, except in very young animals, but does cause lameness and reduced milk yields.

The interval between exposure to infection and the appearance of symptoms usually varies between 24 hours and 10 days, but can be longer. The average is three to six days.

It is very rare in humans and even then is mild, short-lived illness requiring no medical treatment.

Animals generally pick up the virus either by direct contact with an infected animal or by contact with feed that has been infected by such an animal. The virus can also spread on the wind, on boots and clothing or on trucks used for animal transport. It can even be picked up and carried on the wheels of passing vehicles. Dogs and cats, poultry, wild game and vermin can also transmit the infection.

TREATMENT

Culling remains the basic control policy used to stop the spread of the virus. Vaccination is possible, but it can also conceal the presence of the virus in an animal. For this reason, many countries ban the import of vaccinated livestock, making vaccination unpopular with many farmers.