Ch. 13 Pt 1
What are viruses?
acellular, obligate intracellular parasites
What are viroids
naked RNA molecules - lack a capsid; infect plants
Define eitology
Cause of disease
What is a reservoir of infection?
Source of microbes
Which of the RNA viruses can serve directly as mRNA?
+ RNA virus
What are prions and what do they lack?
Prions are proteins that infect animals; they lack nucleic acid
Explain the difference between signs and symptoms and give an example for both.
Symptoms are subjective: headache, dry throat
Signs are objective: fever, rash, swelling
What are the 3 type of transmission of disease?
Contact, vector, and vehicle
What is viral taxonomy and how is it classified?
A viral species is a group of viruses sharing the same genetic information and host range; classified based on genome type and presence or lack of an envelope
Where does viral assembly occur in DNA and RNA viruses?
dna viral assemblies in the nucleus while rna is outside the nucleus
What is herd immunity? What is it caused by?
Immune individuals act as barriers to the spread of infection. Caused by the use of vaccinations
What is the difference between morbidity and mortality? Which one should ALWAYS be higher?
Morbidity: incidence of disease
Mortality: deaths from disease
Morbidity should ALWAYS be higher
What are the different bacteriophage life cycles and explain them
lytic cycle: phage quickly replicates killing host cell
lysogenic cycle: does not necessarily kill the host immediately, can we reactivate to become Lytic based on environmental cues, integrates into cell chromosome as prophage
Persistent vs latent viruses
latent viral infections is a virus that infects host cell, but does not cause disease and can remain endurance state for long periods
persistent viral infection occurs gradually over a long period of time
Viruses are continuously released
What is the infection classification called if I had an infection on the tip of my finger and it spread to the rest of my hand?
Focal infection
What are EID's? What are the criteria to identify EID's?
EID's are emerging infectious diseases.
Criteria:
- distinctive disease symptoms
-improved diagnostic techniques allow ID of pathogen
-local disease becomes widespread
-rare disease becomes common
-mild disease becomes more severe
Explain the process of the viral life cycle
host recognition and attachment, genome entry, synthesis, and virion assembly, exit and transmission
Explain the animal virus life cycle
attachment, entry, uncoating
Explain all the phases of the development of disease and which phase would an opportunistic pathogen be able to enter the body
1. Incubation
2. Prodromal
3. Period of illness
4. Period of decline
5. Period of convalescence
What are HAI’s? What are different interactions that can cause transmission? What are the levels of precautions?
Healthcare Associated Infections