What is the basis of classifying organisms into four risk groups?
Organisms are classified into four risk groups on the basis of risk factors involved as per WHO guidelines. The classification depends on the pathogenicity of the microorganism, its mode of transmission, and the availability of effective treatment and preventive measures.
The groups are defined by the level of individual risk and community risk. Risk Group 1 has no or low individual and community risk, whereas Risk Group 2 has moderate individual risk and low community risk. Risk Group 3 is characterized by high individual risk and low community risk, while Risk Group 4 presents high individual as well as high community risk.
Explanation
The answer is derived from Box 6 and the subsequent descriptions of Risk Groups 3 and 4 in the provided context. The text explicitly states that classification is 'on the basis of risk factors involved as per WHO guidelines'. It further details that these factors constitute the degree of 'individual risk' and 'community risk' associated with the pathogen.