Experts talk about the brucellosis incident in Lanzhou Institute of Veterinary Medicine： the scale is rare, or it is due to irregular laboratory operation.
Recently, the recessive infection of brucellosis (hereinafter referred to as brucellosis) in Lanzhou Veterinary Research Institute of China Academy of Agricultural Sciences has attracted attention.
According to CCTV news reports, as of 12: 00 on December 7th, 317 teachers and students of Lanzhou Veterinary Research Institute had been tested for Brucella, of which 96 were serologically positive and had no obvious symptoms, and were diagnosed as recessive infection. Fortunately, the probability of brucellosis transmission from person to person is extremely low, and there are no previous cases.
On December 9th, many doctors who have long been concerned about epidemiology accepted an interview with The Paper, saying that brucellosis patients/infected people are usually people who have been engaged in the work related to slaughtering or raising cattle and sheep for a long time, but researchers are rare, and collective infection incidents of this scale are even more rare in China. They concluded that the incident was related to the irregular operation of the laboratory.
How did so many people get infected with brucellosis in a short time?
The Paper previously reported that some students claimed that their classmates had been infected with brucellosis because of their experiments with diseased mice, and suspected that aerosol infected by germs had formed in the air.
In this regard, Li Qiong, vice president of the Fourth Hospital of Chaoyang City, Liaoning Province, said that pathogenic bacteria pollute the air, form aerosols in the air, and are inhaled and infected through the respiratory tract. This is indeed one of the three main ways of brucellosis transmission, and the aerosols are invisible and intangible. Even professionals can’t tell whether the air contains pathogen aerosols. The other two modes of transmission are: direct contact through skin and mucosa, such as direct contact with sick animals by shearing and milking workers in livestock farms and slaughterhouses, which leads to infection; And eating food contaminated by pathogenic bacteria leads to digestive tract infection.
Li Qiong said that some researchers were infected in clinical experiments, but it was the first time that nearly 100 people were found to be positive for brucellosis antibody in a short time.
Cai Yudong, a retired chief physician in beijing ditan hospital, has been engaged in the research of infectious diseases for 40 years. In her experience, the most common people infected with brucellosis are engaged in the work related to breeding and slaughter. Because of the long contact with animals and many links, it is difficult to prevent the source of infection. He speculated that the collective infection of teachers and students in the laboratory must have violated the operating norms.
Cai Yudong said that the operation specifications involved include: whether the laboratory hardware facilities are available (for example, tests involving Brucella diseases should be carried out under P3 safety protection standards), whether the human operation is standardized, and whether there is sudden accidental infection (for example, the container containing Brucella is broken to form aerosol inhalation infection).
Wu Hao, a professor at the Infection Center of Beijing You ‘an Hospital affiliated to Capital Medical University, also speculated that there may be loopholes in laboratory protection: "(Brucellosis infection) does not mean that adults can be infected by traveling to the countryside or eating mutton and beef, and this probability is very low. If you follow the rules, these teachers and students should not be infected. "
As for two serological tests, RBPT (Tiger Red Slide Agglutination Test) and SAT (Tube Agglutination Test), which some students told The Paper, were positive, Wu Hao thought that brucellosis infection could be judged by these two tests, but because some patients will also show positive results after self-healing, it should be only a preliminary screening at present. As for whether the human body has recovered or is still infected, doctors need to make further judgments based on clinical manifestations.
Cai Yudong also said that if the above two tests are positive at the same time, "it can basically be judged as brucellosis infection".
According to public information, brucellosis is a zoonotic infectious disease caused by Brucella, and it is a Class B infectious disease stipulated in the Law of People’s Republic of China (PRC) on the Prevention and Control of Infectious Diseases. The acute cases showed fever, hyperhidrosis, muscle and joint pain, fatigue and lymphadenopathy of liver and spleen. In the chronic stage, most cases show joint damage, joint stiffness, long-term fever, etc., and they can’t engage in manual labor. The masses call it the disease of paralysis and laziness. Brucellosis can also harm male testis, female ovary and other reproductive systems.
After the incident of brucellosis recessive infection, Lanzhou Veterinary Research Institute has successively inspected the teachers and students in the institute, and invited a team of experts to give lectures on knowledge in the school. Other institutes affiliated to China Academy of Agricultural Sciences have also successively organized physical examinations for students.
On December 7th, all graduate students of Lanzhou Veterinary Research Institute said that some students from Harbin Veterinary Research Institute had come to Lanzhou Veterinary Research Institute for internship this summer, and they were also found to be positive for brucellosis antibody recently after returning to Harbin. On December 9th, Heilongjiang Provincial Health and Health Commission confirmed to The Paper that imported cases of brucellosis were also found in Harbin. The staff of the Center for Disease Control of Harbin Health and Health Commission said that the Harbin Institute of Veterinary Medicine had found a hidden infection of brucellosis.