(Clarifies Brazil world's largest beef exporter, not producer)
* South Africa follows Japan in restricting Brazil beef
* South Africa's Brazil beef purchases usually tiny
* Brazil striving to clear name over spontaneous BSE case
BRASILIA, Dec 13 (Reuters) - South Africa informed Brazil on Thursday that it is restricting imports of beef from the world's biggest exporter following a case of atypical BSE confirmed last week, a Brazilian agriculture ministry official said.
The statement from South Africa gave no details about exactly what restrictions the country planned to impose, a ministry press officer told Reuters. The announcement comes three days after Japan announced a suspension on Brazilian beef purchases while it investigates the case.
South Africa's imports of Brazilian beef are miniscule, having totaled just 647 equivalent tons from January to September this year, according to Brazil's Beef Exporters' Association ABIEC. The country ranks 70th among foreign buyers of Brazilian beef.
Brazil has launched a diplomatic offensive to clarify the details of the case of suspected atypical BSE, which it has been at pains to differentiate from regular BSE, known as mad cow disease.
BSE, which is usually caused by contaminated animal feed, reached epidemic proportions in Great Britain from the late 1980s. Outbreaks of mad cow disease in Europe, North America and Japan over the past decade often prompted beef importers to embargo shipments and caused temporary chaos in the industry.
Atypical BSE can arise in elderly cattle due to a spontaneous genetic mutation that causes it to begin producing the proteins known as prions. The proteins can trigger BSE, which eventually destroys the animal's nervous system.
In April, the United States reported a case of atypical BSE in an animal which never entered the food chain, but the country escaped a backlash from importers.
The 13-year-old cow in southern Brazil that tested positive for the prions, a result confirmed by the World Organization for Animal Health (OIE) last week, died of other causes in 2010 and never actually developed the neurodegenerative disease.
The Brazilian agriculture ministry's secretary for animal and plant health, Enio Pereira, told Reuters this week that much of the two-year delay between the cow's death and confirmation of prions in its tissue was caused by a logistical anomaly at the laboratory. (Reporting by Peter Murphy; Editing by Phil Berlowitz)