Unit 2 Infection Control

• Infectious organisms • Reservoir of Infection • Portal of exit • Susceptible host • Portal of entry • Transmission of disease

pathogens or pathogenic organisms

• Place where pathogens can thrive in sufficient numbers to pose a threat • Must have: ➢Moisture ➢Nutrients ➢Suitable temperature • May be human or nonhuman (e.g., food, water, animals)

Any route through which blood, body fluids, excretions, or secretions leave the body • Examples: ➢GI tract ➢Open wound ➢Respiratory tract

• Patients are often hosts because of a reduced immune system. • Nosocomial infection, also called HAI ➢hospital-acquired infection ➢health care-associated infection • Healthcare workers are also at risk. ➢Exposure to blood and other bodily fluids

hospital-acquired infection

• The route by which microorganisms gain access into the susceptible host • Examples: ➢Respiratory tract ➢Urinary tract ➢GI tract ➢Open wound or break in skin ➢Mucous membranes of the eyes, nose, or mouth ➢Bloodstream

Most direct way to break the cycle of infection is to prevent transmission of the infectious organism from the reservoir to the susceptible host

➢Direct contact ➢Fomites ➢Vectors ➢Vehicles ➢Airborne ➢Droplet contamination

• Infected person must touch susceptible host. • Requires the pathogens to be placed in direct contact with susceptible tissue • Examples: ➢Syphilis ➢HIV infections ➢Staph infections

• An object that has been in contact with pathogenic organisms • Examples: ➢Contaminated gloves ➢X-ray table ➢Positioning sponges

• An arthropod in whose body an infectious organism develops or multiplies before becoming infective to a new host. • Transmission occurs when an infected insect bites host. • Examples: ➢Mosquitos—malaria ➢Ticks—Lyme disease

• Any medium that transports microorganisms • Examples: ➢Contaminated food, water, drugs, or blood

Occurs when an infectious individual coughs, sneezes, speaks, or sings in the vicinity of a susceptible host • Involves contact of the mucous membranes of the eyes, nose, or mouth of a host with large droplets (greater than 5 µm) that contain microorganisms - Travel 3ft at most

3 feet or less

➢Influenza ➢Meningitis ➢Diphtheria ➢Pertussis ➢Streptococcal pneumonia

Occurs from dust that contains spores or by means of droplet nuclei ➢Droplet nuclei are particles of evaporated droplets containing microorganisms and measuring 5 microns (micrometers, µm, 0.001 mm) or smaller. ➢Can remain suspended in the air for long periods

➢TB ➢Varicella viruses like chickenpox (also transmitted via direct contact)

Provided by mechanical barriers of intact skin and mucous membranes -Skin -Mucous membranes -Body’s chemicals -Inflammatory response -Interferons

Occurs when an individual develops antibodies to a particular organism as a result of either infection or immunization -History with the disease -Vaccines -Build antibodies

Occurs following an injection of preformed antibodies to a particular infection • Patients given antibodies and they “go to work” to prevent the disease • Weaken over time • Newborns have passive immunity from mom’s circulatory system and may continue with breastfeeding • Short term because individual’s own body is not producing the antibodies

➢New diseases appearing in the population ➢Existing diseases that are rapidly increasing in incidence or geographic range ➢Resurgent or recurrent old diseases caused by an old or mutated pathogen

➢CDC: recommendations, recommends hospitals or healthcare settings in ways to prevent spread of infection ➢WHO: studies, collects, and complies infection data all around the world

➢Increased human exposure to vectors in nature ➢Population growth and migration to crowded cities ➢Rapid international travel and transportation of goods ➢Contact with new strains of dangerous pathogens ➢Pathogen mutation caused by overuse of antimicrobial agents ➢Breakdown in public health measures ➢Climate change ➢Bioterrorism