Which assessment is a nonverbal sign of pain? (Select all that apply.)

Choice A reason: A susceptible host is not an infectious disease, but a factor that influences the transmission of an infectious disease. A susceptible host is a person who is vulnerable to infection due to factors such as age, health status, immunization, or genetic predisposition. A susceptible host may become infected by a communicable disease, but it is not the disease itself.

Choice B reason: A communicable disease is an infectious disease that can be transmitted directly from one person to another. A communicable disease is caused by a pathogen, such as a virus, bacterium, fungus, or parasite, that can spread through contact, droplet, airborne, vector, or vehicle transmission. Examples of communicable diseases are influenza, tuberculosis, measles, malaria, and HIV/AIDS.

Choice C reason: A portal of entry to a host is not an infectious disease, but a factor that influences the transmission of an infectious disease. A portal of entry to a host is a route through which a pathogen can enter the body of a susceptible host and cause infection. A portal of entry to a host may be a break in the skin, a mucous membrane, or a body opening, such as the mouth, nose, eyes, or genitals. A portal of entry to a host may facilitate the transmission of a communicable disease, but it is not the disease itself.

Choice D reason: A portal of exit from the reservoir is not an infectious disease, but a factor that influences the transmission of an infectious disease. A portal of exit from the reservoir is a route through which a pathogen can leave the body of an infected person or animal and reach another susceptible host. A portal of exit from the reservoir may be a body fluid, such as blood, saliva, urine, or feces, or a body part, such as the skin, hair, or nails. A portal of exit from the reservoir may enable the transmission of a communicable disease, but it is not the disease itself.

Choice A reason: This is an incorrect answer because a pathogenic infection is caused by a microorganism that can cause disease in a healthy host. Pathogens are usually able to overcome the host's immune defenses and cause symptoms and damage. Examples of pathogenic infections are strep throat, tuberculosis, and malaria.

Choice B reason: This is the correct answer because an opportunistic infection is caused by a microorganism that normally does not cause disease in a healthy host, but can take advantage of a weakened immune system and cause serious illness. Opportunistic infections are common and often lifethreatening complications of HIV infection, as the virus destroys the CD4 cells that help fight infections. Examples of opportunistic infections are pneumocystis pneumonia, candidiasis, and toxoplasmosis.

Choice C reason: This is an incorrect answer because a nosocomial infection is acquired in a health care setting, such as a hospital, clinic, or nursing home. Nosocomial infections are usually caused by microorganisms that are resistant to antibiotics and can spread easily among patients and staff. Examples of nosocomial infections are methicillinresistant Staphylococcus aureus (MRSA), Clostridioides difficile (C. diff), and urinary tract infections.

Choice D reason: This is an incorrect answer because a root cause infection is not a valid term in medical terminology. A root cause is the underlying factor or reason that leads to a problem or outcome. A root cause analysis is a process of identifying and addressing the root causes of a problem or event, such as an infection, to prevent recurrence and improve quality and safety.