The Chinese authorities had hitherto silenced this incident.
But more than a year after the leak of this bacterium from a biopharmaceutical plant producing animal vaccines, they have yet had to recognize the facts and especially the infection of more than 3,000 people.
A case that comes in the context of the coronavirus pandemic that began in Wuhan in China, where a laboratory is suspected, in particular by the United States of Donald Trump, of having let the virus escape into nature.
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3245, according to health authorities in Lanzhou, the capital of Gansu province, who therefore tested positive for brucellosis, a condition transmitted by livestock or animal products.
It is generally not contagious between humans.
But it can cause fevers, joint pain, and headaches.
Local health authorities said that no case of human-to-human transmission has been observed.
Blame it on an expired disinfectant
As for the progress of this leak, they explain that this public laboratory located in the city of Lanzhou used in July-August 2019 an expired disinfectant during the production of anti-brucellosis vaccines for animals.
Consequence: sterilization was incomplete and the bacteria were still present in the company's gas emissions.
This contaminated gas then spread through the air to the nearby Veterinary Research Institute, where it had infected nearly 200 people last December.
The Lanzhou Health Bureau said on Friday that the bacteria usually come from sheep, cattle or pigs.
The laboratory had apologized this year and had its authorization to produce vaccines against brucellosis withdrawn.
The patients will receive financial compensation from October, according to the authorities in Lanzhou.