Infectious Disease II Flashcards
what are bacteria pathogens
- transient bacterial infections
- localized infections
- systemic infections
- extracellular pathogens
- intracellular pathogens
- toxins
- grow on media
what is the causative agent for TB
mycobacterium tuberculosis
describe TB and the cells seen in the histology
- pulmonary infection is most common
- intracellular pathogen
- granulomatous disease
- epithelial histiocytes
- multinucleated giant cells
- lymphocytes
what is the prevalnce of TB
- 1/3 of the world population infected
- leading infectious cause of death after AIDS
what populations are susceptible to TB
- homeless
- malnourished
- overcrowded
why are active TB cases increasing
- HIV infection
-immigration
what is infection
growth of the organism in a patient
what is active disease
destructive, symptomatic disease
how is TB spread
-droplet nuclei of 1-5 microns
- stay airborne for long periods of time
- reach the pulmonary alveoli
what is primary pulmonary TB
- previously unexposed person
- cell mediated immunity controls infection
- fibrosis and calcification
- viable organisms dormant in lesions - latent disease
- may reactivate if immune defenses are lowered
what is seen in primary pulmonary TB
Gohn complex- parenchymal lung lesion and hilar nodal lesion
what type of mcirobe is TB
acid fast bacilli
how does mycobacterium TB intracellular pathogen cause virulence
TB cord factor- blocks fusion of phagosome with lysozome
what area in the oral cavity is susceptible to tuberculous ulcer
lateral border of the tongue
how is TB diagnosed
- chest radiograph
- sputum culture
- molecular biologic tools
what is the treatment for TB
multi drug regimen
- isoniazid
- rifampin
- ethambuton
- streptomycin
- pyrazinimide
- rifabutin
what are the symptoms of active TB
-chronic cough
- hemoptysis
- weight loss
- night sweats
- fever
describe the mantoux tuberculin skin test: PPD test
- type IV delayed hypersensitivity reaction to protein from M TB
- intracutaneous tuberculin injection
- T cells sensitized by prior infection recruited to area
- produces an area of induration
what does a positive tuberculin skin test indicate
- individual has been infected
-cell mediated hypersensitivity exists - does not indicate active disease
what is the bacillus calmette Guerin (BCG) vaccine
- live attenuated strain of Mycobacterium bovis
- caused positive PPD reaction
- effectiveness uncertain
- not used in US
what is scrofula
- tuberculous lymphadenitis of neck
- mycobacterium bovis infection from infected milk
- pasteurization of milk
- tuberculosis control for cattle
what is the causative agent of syphillis
- treponema pallidum
describe syphillis
- STD
- sequentail clinical stages
- years of latency
what are the 2 forms of syphillis
- acquired syphilis- STD
- congenital syphilis - in utero transmission