Upper Respiratory Tract Infections Flashcards
What is a primary vs secondary infection?
Primary - infectious organism is a pathogen
Secondary - infectious organism is an opportunist who strikes following a primary infection (i.e. viral pneumonia destroys innate immune system)
What is chronic marginal gingivitis?
Infection caused by oral anaerobes between teeth and gums, leading to inflammatory infiltrate in connective tissue associated with teeth.
Associated with improper tooth care - within 2 weeks
What is the primary virulence factor of oral anaerobes?
Release of PMN contents and complement activation exacerbates tissue damage - few virulence factors on their own
What is peridontitis?
The result of progressive gingitivits, leads to resporption of bone around neck of tooth, and loss of periodontal ligament and the tooth.
Where do the oral anaerobes typically live and what do they form?
Typically live in dental plaque and are polymicrobial autoinfections, causing abscesses
What is trench mouth?
Acute necrotizing ulcerative gingivitis, invasion of oral epithelium leading to bone resorption and tooth loss (similar to periodontitis)
What is the morphology and metabolism of Actinomyces israelii?
Gram positive, filamentous rods resembling fungi. It is an obligate anaerobe of the normal flora
Think Israeli soldier with purple bandage and branching tree in the background
What allows Actinomyces to colonize and what is the progression of the infection?
Some trauma, often a dental operation, that penetrates the epithelial barrier. It is slowly progressing, leading to pus and bacteria which flow in sinus tracts which drain the pus directly onto the skin
In severe infection, aspiration may lead to thoracic actinomycosis
How is Actinomyces identified?
Often by staining of pus, with “sulfur granules” being seen in the pus, diagnostic for infection.
Also, abscesses are usually polymicrobial as well, with gram negative rods.
What is the primary virulence factor of Viridans Streptococci? What is associated with dental caries?
Glucans (dextrans in sketchy) which permit attachment to teeth, caries.
S. mutans is associated with dental caries
How can Viridans cause endocarditis?
Can colonize damaged heart valves when you have transient bacteremia from tooth extraction
Think of the Jester wearing the damaged valve mitre
How is Viridans strept identified in the lab?
No Lancefield grouping, gram positive cocci which are catalase negative, optochin resistant
What is stomatitis? What is a common causative pathogen?
Inflammation of the oral cavity
Commonly oral thrush, caused by Candida albicans, on the tongue or palate. Appears and white cheesy plaques loosely adhering to mucosal surface
What are factors predisposing to oral candidiasis?
- Antimicrobial therapy depressing competing flora
- Immuncompromised - leukopenia, AIDS, corticosteroids
- Disruption of mucosa by indwelling devices
- Diabetes -> increases glucose concentrations and surface receptors
In what way is Candida an AIDS-defining disease?
Esophageal candidiasis is very common in AIDS - loss of cell-mediated immunity (max 100 CD4 count / lbs in sketchy slide)
What are the predisposing factors to Streptococcal Acute Otitis Media?
- Viral infection
- Allergies
- Young age - eustachian tubes are shorter and more pliable than adults, so they drain worse
How does otitis media occur?
Bacteria enter middle ear from naopharynx, and S. pneumonia has a high nasopharynx carrier rate (10-30%), predisposing people to URIs
What is another non-serious infection caused by S. pneumoniae?
Sinusitis, acute and chronic common of all age groups
Following allergies, viral infection, of anatomical obstruction