A worker spreads salt on meat which will be dried and then packed at a plant of JBS S.A, the world's largest beef producer.

SAO PAULO, March 2 (Reuters) - A confirmed case of mad cow disease in Brazil discovered last month is "atypical," the agriculture ministry said on Thursday, adding it will work to lift beef export suspensions swiftly enacted by several countries in Asia.

The suspension on exports represents a major risk for Brazil's key livestock sector, one of the world's largest.

In a statement, the agriculture ministry pointed to an analysis conducted by the World Organization for Animal Health (WOAH) that confirmed the unusual case of mad cow disease.

The ministry added that it will schedule a virtual meeting with Chinese officials to discuss a resumption of beef exports.

The case of mad cow disease, known scientifically as bovine spongiform encephalopathy (BSE), was found in a nine-year old bull from northern Para state.

The discovery was made public on Feb. 20 and triggered an automatic ban on Brazilian beef sales to China.

Earlier on Thursday, three additional Asian markets - Thailand, Iran and Jordan - slapped temporarily bans on beef imported from anywhere in Brazil.

Russian authorities also halted Brazilian beef imports, but only from Para state, according to an earlier statement from the ministry.

There is only one meatpacking plant in Para authorized to sell beef to Russia.

Brazil's ministry of agriculture and livestock emphasized that it aims to re-establish beef exports "as soon as possible."

The infected animal has already been destroyed. Officials explained that atypical cases of mad cow disease can occur spontaneously in cattle populations and such infections do not depend on ingestion of feed contaminated by abnormal pathogens known as prions.

But BSE is considered more serious because it involves contamination by so-called prion proteins, and could trigger potentially ruinous trade bans.