Ch 8: Infectious Disease Flashcards
what are the 7 classes of infectious agents
viruses
bacterial
prions
fungi
parasites
helminths
ectoparasites
what is virulence
harmfulness of an agent
what three factors affect virulence (harmfulness)
ability to adhere to host cells
ability to invade cells and tissues
ability to deliver toxins
what is an opportunistic infection
microbial disease occurring in an immunosuppressed individual
what is a nonsocomial infection
hospital acquired microbial disease
what is bacteremia
bacteria in the blood
what is septicemia
bloodstream invasion and spreading of pathogens - blood infection
what is a gram stain
stain that differentiates between gram positive and gram negative bacteria
gram negative stain red
gram positive stain blue
ex. modified brown and brenn stain
what type of stain is the modified brown and brenn stain
gram stain
what is a acid-fast (AFB) stain
tests for mycobacteria spp and nocardia spp
ex. ziehl-neelsen stain
(stains very blue)
what type of stain is the Ziehl-neelsen stain
acid-fast bacillus stain
what is the silver stain
tests for fungi
ex. Grocott-gomoris methenamine silver stain (GMS)
(stains teal)
what type of stain is Grocott-gomoris methenamine silver stain (GMS)
silver stain
what is periodic acid-schiff (PAS) stain
tests for fungi and amebae
also tests for glycogen in tissues
tissue adjacent to fungi can be better visualized
(fungi nuclei stain blue and cytoplasm stain pink)
which type of antibody in the Peyer’s patches of the GI tract prevents microbes from entering
IgA
what is micturition
peeing
women are ___ times more likely to get a UTI
10 times
which vaginal bacteria help protect women from microbes
lactobacilli
what is vertical transmission
pathogen spreads from mother to baby
placental-fetal
during birth
through breastmilk
what are two ways microbes can spread throughout the body
peripheral nerves - bring microbes to CNS
bloodstream
what is the most common/efficient way for microbes to travel through the body
bloodstream
what are the three routes of person-to-person transmission of microbes
respiratory (coughing)
fecal-oral
sexual
what is a way that pathogens bypass respiratory defense mechanisms
ciliary paralysis by toxins
what are the 5 major histologic patterns of tissue reactions in infections
suppurative (purulent) inflammation
mononuclear and granulomatous inflammation
cytopathic-cytoproliferative reaction
tissue necrosis
chronic inflammation and scarring
what is suppurative (purulent) inflammation
pyogenic bacteria enter body, leading to increased vascular permeability
neutrophils go to site and attack bacteria
dying/dead neutrophils leads to liquefactive necrosis and pus
what is pyogenic
puss-forming
what is mononuclear and granulomatous inflammation
specific mononuclear cells
aggregates or accumulated macrophages become giant cells
what type of mononuclear cells are seen in syphilis
plasma cells
what type of mononuclear cells are seen in HBV infections
lymphocytes
what type of mononuclear cells are seen in mycobacterium avium/AIDS
macrophages
what is a cytopathic-cytoproliferative reaction
caused by viruses
causes little inflammation, necrosis, or cell proliferation
viral aggregates and inclusion bodies
polykaryon (multinuclear cell) aggregates
what is a CMV inclusion body
hepatocyte with a large intranuclear inclusion body, surrounded by a clear halo; cytoplasm may also contain dark inclusions
appears as an owl eye
only seen in cytomegalovirus
what is tissue necrosis
toxins secretes by organisms can lead to gangrenous necrosis
ulcers and abscesses from parasites can lead to liquefactive necrosis
what is chronic inflammation and scarring
things like hepatitis B leads to dense fibrosis of liver
macro nodular cirrhosis
what is Masson’s Trichrome
three color staining procedure to test for macronodular cirrhosis that has fibrotic bands, loss of architecture, and nodule formation (all characteristics of chronic inflammation)
what are the three different states of viral infections
acute, latent, or transforming
what is influenza
acute/transient virus
presents with: hyperemia, mucosal hemorrhages, and edema of larynx, trachea, and main bronchi
in lung causes: diffuse congestion, pleural hemorrhages, and hemorrhagic consolidation
what are some microscopic presentations of influenza
edema of alveolar air spaces, hyaline membranes, lymphocytes
the flu of 1918 caused how many dead wordwide
50 million
what is measles
acute/transient viral infection
virus of paramyxoviridae family that is transmitted through respiratory secretions where it eventually spreads to lymphatic tissues
affects multiple organs
koplik spots are pathognomonic for which viral infection
measles
what is mumps
acute/transient viral infection
virus of the paramyxoviridae family
affects salivary glands usually bilaterally
inhaled through the respiratory system where it eventually spreads to the lymphatic system
mumps orchitis, seen in 20-30% post pubescent males, it a condition seen in which viral infection
mumps
what is SARS-COV-2 (COVID-19)
acute/transient virus transmitted through respiratory droplets
affects mainly the lungs but sometimes the heart (eosinophilic myocarditis)
what type of virus is the herpes virus (acute, latent, or transient)
latent virus
what is latent
persistence of viral genomes in cells that do not produce infectious virus
what are the three types of herpes virus
herpes simplex 1+2, cytomegalovirus, and varicella zoster virus
what is herpes simplex virus (HSV)
latent virus that replicates in the skin and mucous membranes (mouth and genitals)
travels to neuronal cell bodies where they establish latent infection
which virus is the major infectious cause of corneal blindness in the US
HSV-1
what is cytomegalovirus (CMV)
latent virus that can produce a variety of disease manifestations
different routes of transmission
causes immunosupression of: lungs and GI tracts
has owl eye inclusion bodies
what are the 5 routes of transmission of cytomegalovirus
transplacental
neonatal
saliva
genital
iatrogenic
what are the effects of neonatal transmission of cytomegalovirus
effects on hearing and intelligence
what is varicella-zoster virus (VZV)
chickenpox and possibly shingles down the road
most frequent in dermatomes innervated by the trigeminal ganglia
what are characteristics of chickenpox lesions
intraepithelial vesicles with intranuclear inclusions in epithelial cells at the base of the vesicles
what is the epistein-barr virus (EBV)
transforming viral infection
virus causes infectious mononucleosis
what is infectious mononucleosis
benign lymphoproliferative disorder
infects B-cells causing a latent infection
presents with: fever, sore throat, splenomegaly, etc.
can cause lymphomas and nasopharyngeal carcinomas
“kissing disease”
what is staphylococcal aureus
bacteria that causes skin lesions (boils and carbuncles), abscesses, toxic shock syndrome, sepsis, etc
what is methicillin-resistant S aureus (MRSA)
antibiotic resistant strain of staphylococcal aureus
what is a furuncle
boil
focal pus inflammation of skin and subcutaneous tissue
seen in staphylococcal aureus infections
what is hidradentitis
chronic pus inflammation of apocrine glands, usually in the armpit
seen in staphylococcal aureus infections
what is a carbuncle
cluster of furuncles
deeper pus infection that spreads beneath the deep subcutaneous fascia and then erupts in multiple adjacent skin sinuses
seen in staphylococcal aureus infections
what is pseudomonas aeruginosa
aerobic gram negative bacillus
can be deadly in people with cystic fibrosis, severe burns, or neutropenia
usually acquired in a hospital
causes corneal keratitis in lens wearers, endocarditis in drug abusers, swimmers ear in healthy individuals, and otitis in people with diabetes
what is mycobacterium tuberculosis
bacteria that causes chronic pulmonary and systemic disease
can be active or latent
which bacteria has the most deaths worldwide
TB
what is a Ghon complex
combination of parenchymal lung lesion and nodal involvement seen in TB cases
what is miliary tuberculosis
bacteria move through systemic arterial system
often seen as gray-white tubercles in liver and spleen
what is mycobacterium avium complex
bacteria that are through to be inhaled or ingested
can cause disease in immunocompromised patients
lots of acid-fast bacilli in macrophages
confirmed by AFB stain