Microbiological hazard classification

1. Microbial hazards are generally divided into the following four levels of biohazard level 1: Microorganisms that are of low hazard to individuals and groups and are known not to cause disease to healthy adults and animals.
Biological hazard level 2: Moderately harmful to individuals, low to groups, mainly spread through skin, mucous membranes, and digestive tract. It is pathogenic to humans and animals, but it has effective prevention and treatment measures for animal pathogenic microorganisms that will not cause serious harm to laboratory personnel, animals and the environment.
Biological hazard level 3: High degree of harm to individuals and high degree of harm to groups. Animal pathogenic microorganisms that can be transmitted through aerosols and cause serious or fatal diseases, serious economic losses, or foreign animal pathogenic microorganisms. It has effective prevention and treatment measures for human-induced diseases.
Biohazard level 4: Animal-causing microorganisms that have a high degree of harm to individuals and groups, usually cause serious epidemics, and have no effective prevention and treatment measures. It is a highly contagious and lethal animal pathogenic microorganism transmitted by aerosol; or an unknown dangerous animal pathogenic microorganism.
2 When determining the hazard level of microorganisms according to the pathogenic characteristics of the target microorganism itself, the following factors must be considered ● the pathogenicity and virulence of the microorganism ● the scope of the host ● the morbidity and mortality of the disease ● the vector of the disease ● The amount and concentration of pathogens in the environment ● Possibility of the spread of the waste ● The survival time of the pathogen in the natural environment ● The local epidemic characteristics of the pathogen ● Possibility of cross-contamination ● The degree of obtaining effective vaccines, preventive and therapeutic drugs
3 In addition to considering the inherent pathogenic hazards of specific microorganisms, the hazard assessment should also include ● the possibility of generating aerosol ● operation methods (in vitro, in vivo or challenge)
● Recombinant microorganisms should also be evaluated for their genetic characteristics (virulence genes and toxin genes), host adaptability changes, gene integration, proliferative capacity, and ability to revert to wild type.