September 15, the Health Commission of Lanzhou City made an online announcement on the Handling of the Brucella Antibody Positive Incident of Lanzhou Veterinary Research Institute.
According to the announcement, the incident first happened on November 28, 2019. Up to September 14, 2020, 21847 people have been tested for Brucella Antibody, 4646 have showed as positive on first tests and 3245 confirmed after second tests.
It says on December 26, 2019, a joint investigation team of national and provincial experts identified the cause of the incident as from July 24 to August 20, 2019, Zhongmu Lanzhou Biology Medicine Factory using expired disinfectant leading to incomplete sterilization of waste gas emissions from production fermentation tanks and forming aerosol transmission by wind affecting people at the Lanzhou Veterinary Research Institute. It was an “incident”, a “short exposure”.
Lanzhou City is the capital city of northwest China’s Gansu province.
Source of information: Health Commission of Lanzhou City online announcement