chapter 3

• Infection is a condition that results when a microorganism (microbe for short) is able to invade the body, multiply, and cause injury or disease.
• Most microbes are nonpathogenic, meaning that they do not cause disease under normal conditions.
• Microbes that are pathogenic (causing or productive of disease) are called pathogens.
• Infections caused by pathogens can be local (restricted to a small area of the body)
• Infections caused by pathogens can be systemic, in which case the entire body is affected.
• Some pathogenic microbes cause infections that are communicable (able to spread from person to person)
• The National Institute for Occupational Safety and Health (NIOSH), which is part of the CDC, is responsible for conducting research and making recommendations for the prevention of work-related illness and injury.
• the Healthcare Infection Control Practices Advisory Committee

  (HICPAC), which provides the CDC with advice and guidance regarding the practice of infection control and prevention in healthcare settings
• Antibiotic-resistant infection - the ability of microbes to develop resistance to specific antibiotics, and a growing problem that is of great concern to public health.
• The source of an infectious agent is called a reservoir. It is a place where the microbe can survive, grow, or multiply. include humans, animals, food, water, soil, and contaminated articles and equipment.
• Infectious Agent - bacteria, fungus, protozoon, rickettsia, virus
• Susceptible Host - elderly, newborn, acute/chronically ill, immune suppressed, unvaccinated
• Entry Pathway - body orifices, mucous membranes, broken skin
• Exit Pathway - blood, exudates, excretions, secretions
• Means of Transmission - airborne, contact, droplet, vector, vehicle
• Reservoir -animal, human, equipment, food, soil, water
• An individual or animal infected with a pathogenic microbe is called a reservoir host.
• Human reservoir hosts can be patients, personnel, or visitors and include those with an active disease, those incubating a disease, and chronic carriers of a disease.
• the viability or ability of the microbe to survive on the object
• the virulence or degree to which the microbe is capable of causing disease, and the amount of time that has passed since the item was contaminated.
• An exit pathway is a way an infectious agent is able to leave a reservoir host.
• The means of transmission is the method an infectious agent uses to travel from a reservoir to a susceptible individual.
• Airborne transmission involves dispersal of infectious agents that can remain infective for long periods of time in particles,.The particles, generated by sneezing, coughing, talking, and activities that produce aerosols,
• any patient with an airborne infection requires an airborne infection isolation room (AIIR) that has special air handling and ventilation.
• Anyone who enters an AIIR should wear a NIOSH certified N95 (N category, 95% efficiency) or higher-level respirator
• Contact transmission is the most common means of transmitting infection.
• Direct contact transmission is the physical transfer of an infectious agent to a susceptible host through close or intimate contact such as touching or kissing.
• Indirect contact transmission can occur when a susceptible host touches contaminated objects. The transfer of infectious agents from contaminated hands to a susceptible host
• Droplet transmission is the transfer of an infectious agent to the mucous membranes of the mouth, nose, or conjunctiva of the eyes of a susceptible individual via infectious droplets
• Vector transmission is the transfer of an infectious agent carried by an insect, arthropod, or animal.
• Vehicle transmission is the transmission of an infectious agent through contaminated food, water, or drugs.
• The entry pathway is the way an infectious agent is able to enter a susceptible host. Entry pathways include body orifices (openings); mucous membranes of the eyes, nose, or mouth; and breaks in the skin.
• susceptible host is someone with a decreased ability to resist infection. Factors that affect susceptibility include age, health, and immune status.
• A healthy person who has received a vaccination against an infection with a particular virus or recovered from one has developed antibodies against that virus and is considered to be immune, or unlikely to develop the disease.
• A microorganism that primarily infects individuals with weakened immune systems is called an opportunist.
• Breaking the chain of infection involves stopping infections at the source, preventing contact with substances from exit pathways, eliminating means of transmission, blocking exposure to entry pathways, and reducing or eliminating the susceptibility of potential hosts.
• infection control program responsible for protecting patients, employees, visitors, and anyone doing business within healthcare institutions from infection. implements procedures aimed at breaking the chain of infection, monitors and collects data on all infections occurring within the institution, and institutes special precautions in the event of outbreaks of specific infections.
• employee screening and immunization programs - Screening for infectious diseases typically takes place prior to or upon employment and on a regular basis throughout employment.
• evaluation and treatment - includes Occupational Safety and Health Administration (OSHA)-mandated confidential medical evaluation, treatment, counseling, and follow-up as a result of exposure to blood-borne pathogens.
• surveilllance - This involves closely watching patients and employees at risk of acquiring infections as well as collecting, evaluating, and distributing data on infections contracted by patients and employees.