Chapter 14 Flashcards
Q: Compare normal vs. transient microbes.
A:
Normal microbiota permanently colonize the host and protect the host, and do not cause disease under normal conditions;
Transient microbiota are temporary, possibly for days, weeks or months.
Q: How can infectious diseases be classified by spread?
A:
Communicable Disease: A disease that is spread from one host to another.
Contagious Disease: Diseases that are easily and rapidly spread from one host to another.
Non-communicable: A disease that is not spread from one host to another(A result from opportunistic microbes, or when introduced into the body from a wound)
Q: What is incidence vs. prevalence?
A:
Incidence: Number of people who develop a disease during a particular time period
Prevalence: Number of people who develop a disease at a specified time, regardless of when it first appeared
*takes in account both old and new cases
Q: Define sporadic, endemic, epidemic, and pandemic.
A:
Sporadic: Rare; Disease that occurs occasionally in s population(Typhoid fever)
Endemic: Constant presence; Disease constantly present in a population(Common cold)
Epidemic: Increase in cases; Disease acquired by many hosts in a given area in a short time(Mumps)
Pandemic: Global outbreak; Worldwide epidemic- more than one continent at the same time(H1N1, Covid-19)
Q: What is herd immunity?
A:
Protection of a population by immunity in a high percentage of individuals, hindering spread.
This can be achieved through vaccination, this protects those who are vulnerable(ie; the elderly)
There is a threshold of a population needed to be vaccinated in order to prevent the spread of a disease. The threshold of people that need to be vaccinated depends on the infectious disease.
Q: Classify disease severity/duration: acute, chronic, subacute, latent.
A:
Acute: Short-term; Symptoms develop rapidly but the disease lasts only a short period(Influenza)
Chronic: Long-lasting; Symptoms develop slowly(Mono or Hep B)
Subacute: Intermediate; Intermediate between acute and chronic(Subacute sclerosing panencephalitis)
Latent: Dormant periods; Causative agent is inactive for a time but then activates and produces symptoms(Chicken Pox)
Q: Define types of infection involvement: local, systemic, focal, sepsis, etc.
A:
Local: Confined; Pathogens are limited to a small area of the body(boils; abscesses)
Systemic: Spreads; An infection throughout the body- through blood or lymph(Measles)
Focal: Begins local, spreads; Local infection that spreads to other, confined parts of the body(ie; when an infection in your gums spreads to your heart)
Sepsis: Infection-related inflammation; Toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection
Septicemia: Also known as blood poisoning; growth of bacteria in the blood.
Bacteremia: Bacteria in the blood
Toxemia: Toxins in the blood
Viremia: Viruses in the blood.
Q: What are primary, secondary, and subclinical infections?
A:
Primary: Initial infection; Acute infections that cause initial illness(AIDS)
Secondary: Following initial; Opportunistic infection after a primary(predisposing) infection(AIDS patients developing pneumocystis carinii pneumonia(PCP))
Subclinical: No symptoms; No noticeable signs or symptoms(inapparent infection)
Q: What are the 5 stages of disease?
A:
Incubation: Interval between initial infection and first signs and symptoms. Some diseases and first signs and symptoms. Some diseases can be transmitted at this time(depends on # of and specific microorganisms involved and host resistance)
Prodromal: Short period after incubation; early, mild symptoms
Period of illness: Disease if most severe; exhibits overt signs and symptoms of disease
Decline: Signs and Symptoms subside
Convalescence: Body returns to its prediseased state
Q: What are the three contact transmission methods?
A:
Direct Contact: Requires close association between infected and susceptible host; Modes of transmission: Touching, Kissing, and Sex; Sicknesses: Common Cold or Flu, Staph infections, STD’s
Indirect Contact: Agent of disease is spread by fomites(non-living objects); Mode of transmission: Tissues, Needles, Cups, Money, Bedding; Sicknesses: AIDS, Hepatitis B
Droplet Transmission: Transmission via Airborne droplets(traveling less than 1 meter from host); Modes of Transmission: Coughing, laughing, talking; Sicknesses: Influenza, Pneumonia, Pertussis
Q: Name three vehicle transmission avenues.
A: Waterborne, foodborne, airborne.
Q: Name two vector transmission types.
A:
Mechanical: Arthropod carries pathogen on feet(typhoid fever, bacillary dysentery)
Biological: Pathogen reproduces in vector; transmitted via bites or feces(malaria, trypanosomiasis)
Q: What are three factors in Healthcare Associated Infections/Nosocomial Infections?
A:
1.Microorganisms in hospitals
2. Compromised hosts: An individual whose resistance to infection is impaired by disease, therapy, surgical wounds or burns.
3. Chain of transmission.
Affects 1 in 25 hospital patients
Q: What is case reporting?
A: Case Reporting: A procedure that requires health care workers to report specified diseases to local, state and national health officials.
- provides early warning for possible outbreaks
- provides epidemiologists with an approximation of the incidence and prevalence of diseases and monitor emerging infectious diseases
- can help in identifying a causative agent and reservoir
