Authorities in Yanggu county, Shandong province, have shut down a cattle farm in the county's Qiji town after discovering cases of anthrax. All livestock on the farm has been slaughtered and put through safe disposal procedures, said the county's disease control and prevention center on Friday.

The farm's vicinity has been disinfected, and no additional positive livestock cases were found. Contaminated animal products didn't enter the market, the center said in a statement.

Local authorities have conducted sampling and symptom monitoring on workers who had been in contact with the infected livestock. By 10 am Friday, five farmworkers who had direct exposure to the sick animals were diagnosed with cutaneous anthrax, it added.

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The workers' symptoms were mild, and they have been isolated for treatment. All other close contacts are under strict health surveillance, with no new infections reported to date, said the center.

Cattle and sheep contract anthrax by ingesting the bacterium Bacillus anthracis in the soil while grazing, leading to transmission among animals and sporadically to humans under specific conditions, according to a report from China National Radio on Friday.

Although human-to-human transmission of anthrax is rare, it poses hazards. Chinese regulations mandate the isolation and treatment of individuals diagnosed with anthrax.

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The main source of anthrax transmission is diseased animals. If livestock such as cattle or sheep show signs of illness or sudden death, it is imperative to avoid contact and promptly notify local veterinary authorities for appropriate intervention, it added.