* Five countries have totally blocked Brazil beef imports
* Saudi Arabia among top 10 Brazil beef importers
* Russia, Hong Kong and Egypt still importing
SAO PAULO, Dec 18 (Reuters) - Top global beef exporter Brazil has yet to contain the spread of international fears over mad cow disease that have now spilled into a large importer of Brazilian beef: Saudi Arabia.
Saudi Arabia and South Korea on Tuesday suspended imports of Brazilian beef, joining Japan, China and South Africa, small importers that stopped all shipments from Brazil last week after confirmation of a 2010 case of atypical mad cow disease in Parana state.
Egypt implemented a partial ban on beef from Parana on Monday, when Russian officials said that if the country were to apply restrictions they would apply only to beef coming from that state. The cow that died there two years ago never developed full-blown bovine spongiform encephalopathy (BSE), known as mad cow disease.
Brazil's agriculture ministry confirmed the new bans despite government efforts to calm market concerns that could hurt the country's $167.5 billion beef industry.
President Dilma Rousseff discussed beef trade with her counterparts in Moscow on a diplomatic visit to Russia, Brazil's largest beef importer, soon after her government made public on Dec. 7 the 2-year-old case of atypical BSE.
The visit is largely seen by analysts as responsible for Moscow's decision to impose no new immediate restrictions on Brazilian beef imports.
Brazil has also dispatched technical emissaries to Japan and other Asian countries to provide clarifying details on the cow that died in the state of Parana in 2010.
The president of national cattle industry association Uniec, Francisco Victer, credited the government for trying to clear the air and said that, if it were not for Brazil's well-developed national animal health system, the case might have remained undiscovered and never turned into global news.
"We are going through a period of clarification. It's natural for countries that are not immediately convinced," he added. "We're here, we're certain of what's going on, but the world is not here."
The 13-year-old animal had tested positive for the causal agent for BSE, a protein called a prion, which can arise spontaneously in elderly cattle. In such cases it is referred to as atypical BSE.
A similar case of atypical BSE occurred in the United States in April. Like the Brazilian cow, that animal never entered the food chain. The event had no major effect on U.S. beef exports.
Between January and October, Saudi Arabia imported 31,300 tonnes of beef, according to the agriculture ministry, putting it among the top 10 largest importers from Brazil, the world's largest beef exporter.
South Korea imported just 15 tonnes in that period.
Top buyers Russia, Hong Kong and Egypt account for more than half of the 896,000 tonnes of beef that Brazil has exported this year through September.
Brazilian companies like JBS SA, the world's biggest meat producer, as well as rival Minerva SA and food processor Marfrig Alimentos SA, have played down the case's impact on their operations.
After Brazil confirmed the case of atypical BSE, the World Animal Health Organization issued a statement maintaining Brazil's status as a country with "insignificant risk" of mad cow disease.
"This (OIE) classification has been followed by important countries, blocks and consumers," Minerva said in a statement on Tuesday, adding that sales to Saudi Arabia accounted for approximately 2.5 percent of gross sales so far this year.
Some analysts said the bans could even be a way for importing nations to exert pressure on high beef prices at a time cattle for slaughter are scarce.
"I think it seems to be more commercially motivated. This is a mechanism for you to negotiate with your supplier much more than a health problem. If there were some risk OIE would have said so," said Nadia Alcantara, an analyst with São Paulo-based consultancy Informa Economics FNP.