Infection
Occurs when pathogens enter and multiply in body tissues
Infectious disease
Caused by microorganisms or their products
Normal flora
Resident, indigenous, normal microflora
Endogenous infectious agents
Arise from microbes that are the patient's own normal flora
The human body typically begins to be colonized by its normal flora...
During, and immediately after birth
Resident flora are found...
On/in the skin, mouth, nasal passages, and large intestine
Resident flora of the skin
Staphlococcus, Corynebacterium, Micrococcus, Mycobacterium
Resident flora of intestines
Bacteroides
Resident flora of mouth, large intestine, and from puberty to menopause, the vagina
Lactobacillus
Most common resident flora of mouth surfaces
Streptococcus
Resident flora that produces beneficial body products, including vitamin K and several other vitamins
Large intestine
Virulence factors
Capsules, exoenzymes, endotoxin, exotoxin
STORCH
Represents most common infections of the fetus and neonate
Examples of exoenzymes
Microbial hyaluronidase, coagulase, and streptokinase
Exotoxins
Are proteins
Enterotoxins
Are virulence factors, toxins that target the intestines, proteins, exotoxins
Fimbraie
Adherence to substrate
Capsules
Antiphagocytic factor
Leukocidins
Damage WBCs
Hemolysins
Damage RBCs
Period of invasion
Specific signs and symptoms are seen and the pathogen is at peak activity
The time from when pathogen first enters the body and begins to multiply, until symptoms first appear
Incubation period
Prodromal Stage
Initial, brief period of early, general symptoms such as fatigue and muscle aches
Mixed infection
Several agents established at infection site
Acute infection
Rapid onset of severe, short-lived symptoms
Local infection
Pathogen remains at or near entry site
Toxemia
Pathogen's toxins carried by the blood to target tissues
Symptom
The subjective evidence of disease sensed by the patient
Sign
The objective, measurable evidence of disease evaluated by an observer
Inflammation
Local edema, swollen lymph nodes, fever, soreness, and abscesses
Immunology
The study of frequency and distribution of a disease in a defined population