MICRO

upper respiratory tract- streptococcly pharyngitis, Gram positive cocci with large capsule found in 40% of cases of the "sore throat" in kids and 15% in adults, peak incidence in 5-15 years, very COMMON in 600 million cases, humans are the only known reservoir , Transmitted by droplet transmission- from a host with a current and active disease or from a host who has recovered without treatment (asymptomatic for 2-3 weeks)

1. strep enters upper resp tract (thraot) and attatched to epithelail cells 2. strep miltiplies in throat and evades hot defenses and secretes hemolysin and extentoxins 3. symptoms appear- inflamamtion, sorness in throat, exudate, swollen lymph nodes,

-diease is sefl-limiting (resovery without treatment) - no immunity to re-infection, unless you encounter the same strain -treat with antibiotics is nessecary to orevent the patient from becomming asymatic carreirs and prevent more serious complications from arising

1. scarlet fever 2. glomerulonephritis 3. rhumatic fever

Strep throat symptoms and skin rash, caused by certain strains of strep which produce "erythrogenic exotoxin" which is carried via blood in body and damages the small blood vessels causing pink bony rash and strawberry tongue and inflamamtion rare (1000cases/year)

Immune complexes occur in the glomular of blood vesssels and kdneys causing fever, blood in urine (hemetruria), and increased bp occurs during the recovery stage of untreated strep throat is only caused by some strains

autoimmune disease- the antibodies formed against strep proteins cross-react with antigens found in heart and joint tissues

Caused by strains with greater virulences than pharyngitis strains

Strains produce enzymes which degrade connective tissues, tissues seperates and allows strep to invade into depper tissues causing a high fever, tissues damage and necrosis, rapidly spreading inflammation, not respiratory spread, occurs after entry of STREP into skin via cuts, 100-200 cases/year, 30% fatility

Very common, relativelty mild and easily treated, serious complications arise if not treated , it requires a prompt accurate diagnosis, sore throat may be caused by a virus sp avoid unnessecary antibioltic use but must be treated if present preform a throat swab in blood agar media and look for hemolytic colonies

In the LOWER respiratory tracts

Affects an entire lobe of the lung

Bronchial penumonia

S-strepnococcus pneumoniaM-mycoplasma plunmonia H-heamonphilius influnza

1. infection d/t pre-disposing risk factors2. bacterial capsules are important virulence factors 3. bacteria trigger an immune reactions