BEIJING: More than 6,000 people in Lanzhou, the capital of Gansu province in northwest China, have tested positive for a bacterial disease called brucellosis, the local government was cited as saying, in an outbreak caused by a leak at a vaccine plant over a year ago.
The government has tested 55,725 people in the city, of which 6,620 are positive for brucellosis as of now, the Lanzhou government said at a press conference, according to a report on Thursday by the state-owned Global Times.
That represents a big jump from 3,245 positive cases for brucellosis as of Sep 14.
READ: Thousands in China test positive for bacterial disease after leak from biopharmaceutical plant last year
Humans get brucellosis with flu-like symptoms through direct contact with infected animals, by eating or drinking contaminated animal products, or by inhaling airborne agents, according to the World Health Organization. Some symptoms can become chronic and never go away.
According to a statement from Lanzhou's health commission dated September, the outbreak originated at a biopharmaceutical factory owned by China Animal Husbandry Industry.
The factory used expired disinfectants during July to August 2019 to manufacture brucellosis vaccines, leaving the bacteria in its polluted waste gas, it said, citing the results from an official investigation.
The contaminated waste gas later formed aerosols, which were carried by wind down to the Lanzhou Veterinary Research Institute, where the outbreak was first recorded in November last year, the health commission said.
The brucellosis vaccine production workshop was shut down in December last year and was dismantled in October, according to Global Times.