Which type of agent includes bacteria and viruses?

The correct answer is infectious agents because this category specifically encompasses organisms that can cause disease, such as bacteria and viruses. Infectious agents are living microorganisms that invade the body, multiply, and can lead to illness. Examples include pathogens like Streptococcus (a type of bacteria) and influenza virus. Understanding this classification is crucial in community health and population-focused nursing practice since it helps identify sources of infection and guides prevention and intervention strategies.

Chemical agents involve substances that can cause harm or disease through chemical interactions, while physical agents refer to environmental factors like radiation or temperature extremes that can cause injury but do not include living organisms. Environmental agents include broader factors in the surroundings that can influence health, but again, this does not specifically denote bacteria and viruses. Therefore, recognizing infectious agents as the category that includes both bacteria and viruses is vital for understanding the foundations of infectious disease control and prevention in community health.