Introduction to Infection Flashcards
(53 cards)
Infection
Colonization of a host by a microbial species
-Can be localized or systematic (whole body)
Cause of infection
Common:
-Virus
-Bacteria
Rare:
-Fungal
-Protozoa
-Helminths
-Prions
Virus
-Only DNA or RNA, surrounded by a protein shell
-Viruses have to have host to divide and multiply
Ex. COVID, Chickenpox, Influenza
Bacteria
-Much larger than a virus, single-celled organisms
-Can reproduce inside or outside of cells
-Adapt & suppress human body defenses
Ex. Strep, TB, UTI
Fungal
-Spore forming organism
Ex. Yeast infection
Protozoa
Typically live in water/environment
Ex. malaria
Helminths
Parasitic worms
Ex. Roundworm, hookworm
Prions
Proteinaceocus infectious particles, only composed on protein
-Rarest
-Misfolded proteins (small) that attach to other proteins
Ex. Madcow disease (aka creutzfield-jacob disease)
Microorganisms must have a _____
Resorvoir
Resorvoir
Habitat where organism usually lives and grows
-Can be human, animals, insects, environments
Direct mode of transmission
-Direct contact w/ contamination
-Kissing
-Sex
-Soil or vegetation
-Droplet: sneezing or coughing
Indirect mode of transmission
-Airborne or droplet (nuclei stay in air)
Ex. Measles, TB
Vehicle
Indirect transfer of infectious material through water, food, blood
Ex. Hep A (food)
Vector
Something else carries disease like ticks, mosquitoes, fleas
Ex. Malaria, Rocky mnt spotted fever, Lyme disease
How do organisms get into the body? Portal of entry?
-Oropharynx
-Nasopharynx
-Genitourinary tract: STDS, Catheter
-Translocation
-Blood
-Maternal-Fetal transmission
-Wounds
-Cuts
-Skin integrity issues
What is the bodies biggest barrier to organisms getting into the body?
The Skin
Translocation
-Movement of bacteria across the intestinal lining
-Occurs frequently in the perotineal cavity
-Bloodstream
Ex. Infection in blood & blood takes nutrients to bone can get bone infection
Blood Portal of entry
-Blood transfusion contamination
-Needle sticks
Maternal-Fetal transmission
-Cross the placental barrier and directly to fetus
-Can occur during childbirth
Ex. Zika, listera
What are the stages of infection?
- Incubation period
- Prodromal stage
- Acute stage
- Convalescent stage
- Resolution phase
Incubation
Time when microorganisms gets into body to when symptoms 1st appear. Typically no symptoms it is just growing and multiplying
Prodromal stage
Onset of nonspecific symptoms like not feeling goof or extra tired
Acute stage
Specific S/S, full blown can’t get out of bed
Convalescent stage
Coming out of acute stage, symptoms starting to get better, illness disappearing