Invasion of body tissues by pathogens is called?

• A. Infection
• B. Infectious Disease
• C. Cross-Contamination
• D. Disinfection

Answer: (A)

When pathogens invade and multiply in body tissues, that is called infection. It describes the process of organisms entering tissues and starting to grow, which can trigger the body’s immune response and sometimes lead to illness. This is different from infectious disease, which is the condition or illness that can result from an infection. Cross-contamination refers to the transfer of microorganisms between surfaces or people, not the invasion of tissues. Disinfection is the cleaning process aimed at reducing or eliminating pathogens on surfaces, not what happens inside tissues. So, the invasion of body tissues by pathogens is infection.