Which of the following host susceptibility factors is directly related to the characteristics of the pathogen?

• A. Virulence of the pathogen
• B. Host age
• C. Genetic predisposition of the host
• D. Nutritional status of the host

Answer: (A)

Verified step by step guidance

1. Understand the difference between host susceptibility factors and pathogen characteristics. Host susceptibility factors are traits or conditions of the host that influence their vulnerability to infection, while pathogen characteristics are properties of the microorganism itself.
2. Identify the options given: 'Host age', 'Genetic predisposition of the host', 'Nutritional status of the host', and 'Virulence of the pathogen'. Notice that three options describe host factors, and one describes a pathogen factor.
3. Recall the definition of 'virulence': it refers to the degree of pathogenicity or the ability of a pathogen to cause disease, which is an intrinsic property of the microorganism, not the host.
4. Analyze each option to determine if it relates to the host or the pathogen. 'Host age', 'Genetic predisposition', and 'Nutritional status' are all host-related factors affecting susceptibility, whereas 'Virulence of the pathogen' is a characteristic of the pathogen itself.
5. Conclude that the factor directly related to the characteristics of the pathogen is 'Virulence of the pathogen', as it describes how aggressive or harmful the pathogen is, influencing the outcome of infection.