Intro to Infection (Exam 1) Flashcards
What is an infection?
-Colonization of a host by a MICROBIAL species
-Localized or Systemic
What causes an infection?
Common: Virus (Only DNA or RNA surrounded by a protein cell.) (Most have a host cell) Bacteria (much larger than a virus and are single celled with one strand of DNA)
Rare: Fungal-Spore forming organisms. Protozoa-Typically live in water environment. Helminths- parasitic worms. Prions- Proteinaceocus infections particles. Misfolded proteins that attach and cause terrible disease.
Modes of Transmission
Microorganism must have a RESORVOIR. Can live in water animals humans
Two main types of transmission. Direct and Indirect
Direct transmission
Spread through direct contact of organism. Sneezing, coughing, sex, kissing.
Indirect transmission
Vehicle or Vector Born
Vehicle: Food, Water, Blood. HEP A through contaminated food.
Vector: Something carries disease. Ticks and etc.
How do organisms get into the body. Portal of entry
-Oropharynx and Nasopharynx (Airway, lungs, stomach, and GI tract)
-Genitoruinary Tract (Urninary tract. STD. Catheters
Biggest Barrier to prevent portal of entry
Our skin. Tight Cell Junctions
Translocation. Portal of Entry
-Movement of bacteria across the intestinal lining
-Occurs frequently in the PEROTINEAL cavity
-Bloodstream
Blood. Portal of Entry
-Blood transfusion contamination
-Needle sticks
Maternal-Fetal Transmission. Portal of Entry
-Cross the placental barrier and directly to fetus
-Can occur during childbirth
Largest Portal of Entry
The skin. So it is the biggest barrier and biggest risk
Stages of Infection
Incubation Stage
Prodromal Stage
Acute Stage
Convalescence Stage
Resolution Stage
Incubation Period of infection
The time from when the microorganism gets into the body to when symptoms first appear.
Microorganism is in body growing and spreading with no symptoms
Prodromal Stage of infection
-Onset of non-specific symptoms. Not feeling good a little extra tired. Small fever. No real full out symptoms
Acute stage of Infection
Full blown symptoms. Can not get out of bed.