Infectious Disease 3 Flashcards
what type of cellular response does influenza A illicit?
cytopathic/cytoproliferative
influenza A
RNA, segmented genome
H and N antigens- H allows fusion to host, N allows virus to uncoat
primary viral pneumonia- necrosis of ciliated epithelium, lymphocytes in the submucos
causes localized necrosis, inflammation in respiratory epithelium, and systemic symptoms
HOW IS VIRAL pneumonia differ on x ray compared to bacterial
appears diffusely opaque rather than concentrated in a lobe- inflammation is interstitial
what is the primary cell type in interstitial pneumonia
macrophages and lymphocytes
what happens to the lining of the alveoli in viral pneumonia
exudated material in the airspace condenses into hyaline membrane
are the avian influenza strains better or worse than human strains
worse
what type of cellular response does measles illicit?
cytopathic/cytoproliferative
why was influenza of 1918 so bad?
- caused extremely aggressive cytokine profile resulting in severe systemic symptoms
- aggressive replicator
measles pathology
one strain, systemic disease
multiplies in epithelial and mononuclear cells
viral growth controlled by T cells, infections controlled by B cells
suppression of cell-mediated immunity = increased disease
pneumonia- peribronchiolar and interstitial lymphocytoic and mononuclear infiltrate- causes multinuclear giant cells in lung
defining features of measles pneumonia
clusters of lymphocytes
multinuclear giant cells
what type of cellular response does CMV illicit?
cytopathic/cytoproliferative
CMV pathology
opportunistic DNA herpes virus
infection of epithelia/endothelial cells- relatviely minor inflammation
causes owl eye inclusion bodies
organs: lungs, liver, kidney, GI tract, CNS (retina)
how do you diagnose CMV?
must measure viral load via qPCR
two mechanisms for necrotizing inflammation
- pathogen comes and “eats” host cells
2. pathogen secretes toxins
what type of cellular response does amebic dysentery illicit?
necrotizing- eating
amebic dysentery
entamoeba histolytica- motile and invasive
single nucleus w/ lots of cytoplasm
invasive trophozoite kills PMNs and is resistant to complement
causes sterile abcess and flask-shaped ulcers in the colon
what type of cellular response does pseudomembranous colitis illicit?
toxic necrosis
pseudomembranous colitis pathology
caused by clostridium difficle- toxin producing
most common cause of hospital acquired diarrhea
gram pos, spore forming, anaerobic bacillus
colonizes bowel after use of antibiotics disturbs natural microbiome
produces toxins A and B
causes diarrhea and pseudomembrane (fibrin, inflammatory cells, dead cells) formation
pseudomembrane
fibrin, inflammatory cells, dead cells
what type of cellular response does cryptococcal meningitis illicit?
little inflammation
cryptococcal meningitis pathology
cryptococcus neoformans- encapsulated yeast
found in high nitrogen soils
common repiratory infection but can disseminate to meninges
virulence factor- polysaccharide capsule
no toxin, little inflammatory response
what are the differential outcomes of cryptococcal meningitis
normal- causes loose granuloma
immunosuppressed- chronic meningitis w/ insidious onset. can cause hydrocephalous
cryptococcal meningitis diagnosis
stain and india pink preparation
Ag detection of polysaccharide
culture yeast
what disease creates a stainable analogue of melanin
cryptococcal meningitis
