Infectious Disease pt. 2 Flashcards
Bacteria Pathogens
(7)
• Transient bacterial infections
• Localized infections
• Systemic infections
• Extracellular pathogens
• Intracellular pathogens
• Toxins
• Grow on media
Tuberculosis
(4)
• Mycobacterium tuberculosis
• Pulmonary infection most common
• Intracellular pathogen
• Granulomatous disease
Tuberculosis
• — of world population infected
One-third
Tuberculosis
Leading infectious cause of death after —
AIDS
Tuberculosis
• Disadvantaged populations
(3)
– Homeless
– Malnourished
– Overcrowded
• Active tuberculosis cases increasing
(2)
– HIV infection
– Immigration
Infection -
growth of the organism in a
patient
Active disease -
destructive,
symptomatic disease
Transmission of Tuberculosis
(3)
• Droplet nuclei (1 - 5 microns)
• Stay airborne for long periods of time
• Reach the pulmonary alveol
Primary Pulmonary Tuberculosis
(6)
• Previously unexposed (unsensitized) person
• Gohn complex (parenchymal lung lesion and hilar nodal lesion)
• Cell-mediated immunity controls infection
• Fibrosis and calcification
• Viable organisms dormant in lesions (latent disease)
• May reactivate if immune defenses lowered
Secondary Pulmonary Tuberculosis
(2)
• Reactivation of dormant primary lesions in a
previously sensitized host
• Cavitation leads to erosion into airway and
production of contaminated sputum
Tuberculosis
Diagnosis
(3)
• Chest radiograph
• Sputum culture
• Molecular biologic tools
Tuberculosis
Treatment
• Multi-drug regimens
(6)
– Isoniazid
– Rifampin
– Ethambutol
– Streptomycin
– Pyrazinimide
– Rifabutin
Symptoms of Active
Tuberculosis
(5)
• Chronic cough
• Hemoptysis
• Weight loss
• Night sweats
• Fever
Mantoux Tuberculin Skin Test:
PPD Test
(4)
• Type IV delayed hypersensitivity reaction to
protein from M. tuberculosis
• Intracutaneous tuberculin injection
• T-cells sensitized by prior infection recruited
to area
• Produces an area of induration
Positive Tuberculin Skin Test:
(3)
• Individual has been infected
• Cell-mediated hypersensitivity exists
• Does not indicate active disease
Bacillus Calmette-Guerin (BCG)
Vaccination
(4)
• Live, attenuated strain of Mycobacterium bovis
• Causes positive PPD reaction
• Effectiveness uncertain
• Not used in United States
Scrofula
(4)
• Tuberculous lymphadenitis of neck
• Mycobacterium bovis infection from infected milk
• Pasteurization of milk
• Tuberculosis control for cattle
SYPHILLIS
(4)
• Treponema pallidum
• Sexually-transmitted systemic disease
• Sequential clinical stages
• Years of latency
2 FORMS OF SYPHILLIS
• Acquired syphilis -
sexual transmission
• Congenital syphilis - in
utero transmission
Clinical Stages of Untreated Acquired
Syphilis
(3)
• Primary - 1 week to 3 months
• Secondary - 1 to 12 months
• Tertiary (Late) - 1 to 30 years
Lesions of Secondary Syphilis
(3)
• Skin rash
• Mucous patch
• Condyloma lata
Tertiary Syphilis
(5)
• Most destructive stage
• Gumma
• Syphilitic glossitis
• Nervous system –neurosyphilis
– Tabes dorsalis
• Cardiovascular system
– Aneurysm of ascending aorta
Stage: Primary
Lesion:
Infectious:
Chancre
yes
Stage: Secondary
Lesion:
Infectious:
Mucous Patch
yes
Stage: Tertiary
Lesion:
Infectious:
Gumma
no
Lesion of Congenital Syphilis
(5)
• Snuffles
• Saddle nose
• Rhagades
• Hutchinson’s incisors
• Mulberry molars
Congenital Syphilis - Depressed Nasal
Bridge “—”
Saddle Nose
Dental Stigmata of Congenital Syphilis
(2)
• Hutchinson’s
incisors
• Mulberry molars
Hutchinson’s Triad of
Congenital Syphilis
- Blind - intersitital keratitis
- Deaf
- Dental anomalies
Laboratory Tests for Syphilis
• Culture –
• Microscopy –
cannot culture
dark field or fluorescence microscopy
Serologic tests for Syphilis:
• Non -Treponemal Tests - reagin - antibody to cardiolipin
(2)
– VDRL –Venereal Disease Research Laboratory
– RPR –Rapid Plasma Reagin
Serologic tests for Syphilis:
• Treponemal Tests –specific for T. pallidum
(2)
– FTA-ABS –Fluorescent Treponemal Antigen Absorption
– MHA-TP –Microhemagglutinin –Treponema pallidum
Diseases Caused by Fungi
• Superficial
- skin, hair, nails
– Dermatophytes
Diseases Caused by Fungi
• Subcutaneous
- dermis and subcutaneous tissue
– Sporotricosis
Diseases Caused by Fungi
• Systemic
- deep infections of internal organs
– Histoplasmosis
Diseases Caused by Fungi
• Opportunistic
–immunocompromised host
– Candidiasis
Histoplasmosis
• Endemic to
• Transmission by
• — infection usual
• —like syndrome
Mississippi River Valley
inhalation of spores
– Bird droppings, dust particles
Sub-clinical
Flu
Mississippi Valley Fever
Histoplasmosis
Histoplasmosis - Deep Fungal Infection of
the Lungs
(5)
• Inhalation of spores
• Phagocytosis
• Specific immunity
• Killing of organism
• Dystrophic calcification
Histoplasma Capsulatum
(2)
• Dimorphic fungus - yeast at body temperature, mold in nature
• 80% - 90% population infected
Most common systemic fungal infection in USA
Histoplasma Capsulatum
Disseminated Histoplasmosis
(4)
• Elderly,
debilitated,
immunosupressed
, AIDS
• Spreads to extra-
pulmonary sites
• Adrenal lesions -
Addison’sdisease
• Oral lesions
Coccidioidomycosis (3)
• Deep fungal infection of the lungs
• 40% develop respiratory symptoms
• Disseminated disease may occur
Sarcoidosis
(4)
• Multi-system granulomatousdisorder
• Unknown cause
• Young adults
• African-Americans - 10:1
Sarcoidosis
• Common findings
(2)
– Hilar lymphadenopathy
– Skin and eye lesions
Hilar Lymphadenopathy in Sarcoidosis
Non-caseating granulomas
Sarcoidosis is a Diagnosis of Exclusion
(5)
• Clinical
• Radiographic
• Laboratory –elevated Angiotensin Converting Enzyme (sACE), serum Calcium
• Biopsy
– Bronchoscopic biopsy
– Salivary gland biopsy
• Histopathologic –non-caseating granulomas
– Special stains negative
– Cultures negative
Sarcoidosis –Non-Caseating Granulomas
(2)
Asteroid Bodies
Schaumann Bodies
Oral Lesions of Sarcoidosis
(2)
• Uncommon
• A non-specific
submucosal
papule affecting
any site
Salivary Gland Involvement in Sarcoidosis
(3)
• Parotid enlargement
• Xerostomia
• Facial nerve weakness
Treatment of Sarcoidosis
• Mild disease –
• Severe disease –
observation, no treatment, may resolve spontaneously
systemic corticosteroids
Clinical Forms of Oral Candidiasis
(5)
• Pseudomembraneous (Thrush)
• Erythematous (Atrophic)
• Hyperplastic
• Angular Cheilitis (Perleche)
• Central Papillary Atrophy
