Strep Throat
(ADENOVIRAL) Signs & Symptoms
Fever, sore throat, severe cough, swollen lymph nodes on neck, pus on tonsils/throat, sometimes conjunctivits, less frequently pneumonia
(ADENOVIRAL) Causative Agent
naked dsDNA adenovirus. more than 45 types
(STREP) Epidemiology
-Direct contact and droplet infection -Ingestion of contaminated food
(RHINO) Epidemiology
-Inhalation of droplets -Mucus to nose -ID50 = 1 -RNA allows antigenic drift -No protective antibody responses to original virus
(ADENOVIRAL) Treatment/prevention
"Treatment = more BS. Prevention = handwashing. avoid people with symptoms. No vaccine"
(STREP) Signs and symptoms
-Red sore throat with pus and hemorrhages -Enlargement and tenderness of lymph nodes in neck -Abscess formation with tonsils -Glomerulonephritis -Rheumatic fever
(RHINO) Pathogenesis
-Virus attaches to respiratory epithelium -Infect, spread to adjacent cells -Cilliary action ceases, cells slough -Increased mucous secretion -Inflammatory reaction -IFN stops infection -Humoral/cell immunity
(STREP) Virulence factors
1) M proteins degrades C3b, bacteria cannot be opsonized (Fig.16.9) a. Inhibits C3b functioning to be an opsonin b. 2) Hyaluronic acid capsule (similar to human hyaluronic acid) a. Human tissue kinda shit, masks its presence. Inhibits activation of classical pathway of complement 3) Protein G inhibits antibody functions by binding Fc region of antibodies (Fig. 16.10) a. Inhibits activation of complement because area activating complement is bound by receptor b. Cannot attract PNMs because antibody is bound to wrong area 4) C5a peptidase (Fig.16.9) a. Keeps pnms from coming to kill i. No way to pull in
(DIPTHERIA) Virulence
A-B toxin B binds to membrane receptor on cell, toxin enters via endocytosis A subunit separates, enters cytoplasm, inactivates 80S ribosome proteins, stopping protein synthesis
(STREP) SEQUELA
Acute Rheumatic Fever - leading cause of heart disease in young in third world countries, but not US. a. Signs and Symptoms: fever, joint pain, rash, uncontrollable body movement, carditis b. Recurrent infections produce cross-reactive antibodies (due to molecular mimicry). These are created to different strains of M proteins. These antibodies bind to mitral valve proteins. Production of disease producing antibody response appears to be dependent on MHC identity/M protein. c. Antibodies binding to tissues (Type II hypersensitivity response/ADCC/NK cells, complement activation)" _________________________________ "Acute Glomerulonephritis due to small immune complexes developing to strep antigens after clearing infection. a. Signs and Symptoms: fever, fluid retention, high blood pressure, blood and protein in urine. b. Strep antigens/antibody complexes form. (Type III hypersensitivity response-small antigen antibody complexes)" " Scarlet fever -strains of GAS producing SPE: streptococcal pyrogenic exotoxin erythrogenic toxin (superantigen -Fig. 16.12) a. Signs and symptoms: causes "cytokine storm": b. high fever, sandpaper rash, strawberry tongue.
(DIPTHERIA) Pathogenesis
Bacteria colonize URT, no bacteremia; lysogenicly infected species secrete highly virulent A-B diptheria exotoxin ---> toxemia; toxin interferes with protein synthesis, affects cells with toxin receptors - heart, kidney, nerve.
(DIPTHERIA) Epidemiology
Inhalation of infectious droplets; direct contact with patient or carrier; indirect contact with contaminated articles
(ADENOVIRAL) Epidemiology
Inhalation of respiratory droplets, possible spread through gastrointestinal tract. Human reservoir, but can remain in environment for a long time.
(DIPTHERIA) Causative agent
Lysogenic infected Corynebacterium diptheriae, gram positive rod, secrete exotoxin AB
(RHINO) Causative Agent
Naked ssRNA rhinovirus, 100 types (50%), other viruses
(RHINO) Signs & Symptoms
Scratchy throat, nasal discharge, malaise, headache, cough. NO FEVER
(STREP) Incubation
Short
(DIPTHERIA) Signs/Symptoms
Sore throat, fever, fatigue, malaise; pseudomembrane forms on tonsils and throat or in nose; paralysis, heart/kidney failure
(STREP) Causative agent
Strep Pyogenes; group A Beta hemolytic streptococci
(RHINO) Prevention/Treatment
Treatment: doesn't work, possibly prolongs symptoms Prevention: Handwashing
(DIPTHERIA) Treatment/Prevention
Treatment=antitoxin; antibiotics to prevent transmission of bacteria Prevention = toxoid vaccine DTAP Booster every 10 years Toxin produces antibodies that prevent toxin from binding to target tissues
(ADENOVIRAL) Pathogenesis
Virus multpilies in host cells; cell destruction, inflammation. can delay apoptosis, block IF alpha/beta production, MHC antigen presentation