Chapter 14 Flashcards
A person or animal that harbors an infectious organism and transmits the organism to others, although having no symptoms of the disease.
Carrier
The presence and multiplication of infectious organisms without invading or causing damage to tissue.
Colonization
An outbreak characterized by exposure to a common, harmful substance.
Common source outbreak
Communicable by direct or indirect contact.
Contagious
The constant or usual prevalence of a specific disease or infectious agent within a population or geographic area.
Endemic
Significant increase in the number of new cases of a disease than past experience would have predicted for that place, time, or population; an increase in incidence beyond that which is expected.
Epidemic
Originating in a healthcare facility.
Healthcare-associated infection
Time period between initial contact with the infectious agent and the appearance of the first signs or symptoms of the disease.
Incubation period
Presence and replication of an infectious agent in the tissues of a host, with manifestation of signs and symptoms.
Infectious disease
Ability of the agent to produce an infectious disease in a susceptible host.
Pathogenicity
Outbreak resulting from direct or indirect transmission of an infectious agent from an infected person to a susceptible host; secondary infections can occur.
Propagated outbreak
Location where an infectious agent is normally found, where it lives and reproduces under normal circumstances.
Reservoir
Infections that occur within the accepted incubation period following exposure to a primary case.
Secondary infection
A continual dynamic method for gathering data about the health of the general public for the purpose of primary prevention of illness.
Surveillance
The transfer of an infectious agent from one person or place to another.
Transmission
Ability of the agent to invade the host and replicate.
Infectivity
Severity of the infectious disease that results from exposure to the agent.
Virulence
Ability of the agent to produce toxins.
Toxicity
Ability of the agent to produce specific immunity within the host.
Immunogenicity
Ability of the agent to destroy body cells.
Invasiveness
Microorganisms are carried in the air in small particles, called droplet nuclei, at distances that exceed a few feet.
Airborne transmission
Direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected/colonized person (or animal).
Direct contact
Contact of a susceptible host with a contaminated intermediate inanimate object, called a vehicle.
Indirect contact
Generated from the source person primarily during coughing, sneezing, and talking, and are propelled a short distance (< 3 ft) through the air and deposited on the conjunctivae, nasal mucosa, or mouth of another person.
Droplet transmission
Norovirus “stomach flu”
- Most common cause of acute infectious gastroenteritis in people of all ages
- Spread primarily from one infected person to another via the fecal-oral route through contaminated hands, food, or water, or by contact with contaminated objects
- Incubation period is 12-48 hrs, causes more vomiting than diarrhea; usually resolves within 48 hrs
- Elderly, children, and those w/severe underlying medical conditions at increased risks
- oral hydrating fluids should be given; in severe cases IV fluid and electrolyte replacement may be necessary
- At first signs, good hand washing, thorough and immediate disinfection w/appropriate solutions and isolation of sick ppl until 72 hrs after they are symptom free are critical
Campylobacter enteritis
- most common cause of bacterial food-borne illness
- important cause of diarrheal illness
- consumption of contaminated poultry is most common source
- has been linked to undercooked meats, ground beef, pork, cheese, eggs, shellfish, unpasteurized milk, and direct exposure to pets and farm animals
- incubation period ranges from 2-5 days; usually lasts no longer than a week
- S/S: N/V, abdominal pain, fever, H/A, and muscle pain
- Diagnosed by stool culture; treated w/antidiarrheal (Loperamide); in more severe cases, antibiotics are prescribed
- drink plenty of fluids and wash hands
Listeria Monocytogenes
- can cause listeriosis, uncommon, potentially fatal foodborne illness
- primarily affects older adults, pregnant women, newborns, adults w/weakened immune systems
- suspected in high-risk patients who become ill with diarrhea and flu-like symptoms and have a recent history of eating delicatessen food, soft cheeses, or smoked seafood
- risk may be reduced by recommendations for safe food preparation, consumption, and storage
Nontyphoid Salmonella
- bacterial disease transmitted by contaminated food and water, or contact w/infected animals/reptiles
- salmonella serotypes: Typhimurium and Enteriditis are most common in US
- characterized by diarrhea, fever, abdominal cramps 12-72 hrs following exposure, and lasts around 4-7 days; majority recover w/out treatment
- small number develop pain in their joints; called reactive arthritis, can last for months or years, can lead to chronic arthritis
- treatment of dehydration and electrolyte imbalance is essential
- antibiotics not necessary unless infection spreads from intestines
E. coli 0157:H7
- Shiga toxin-producing E. coli is a deadly form
- produces symptoms of severe abdominal cramps, bloody and non-bloody diarrhea, and vomiting
- generally resolves within 7-10 days
- in very young and elderly, infection can cause fatal hemolytic–uremic syndrome and renal failure
- includes temporary anemia, profuse bleeding, and kidney failure
- several outbreaks associated with commercially packaged foods and fresh produce
