Term
What do bordetella, haemophilis, Legionella have in common |
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Definition
- aerobic gram negative rods
- resp. disease with wide range of clinical manifestations
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Term
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Definition
- nonmotile
- aerobic gram negative rod/coccobacilli
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Term
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Definition
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Term
cause of resp./genital tract disease |
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Definition
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Term
cause of Legionnairs disease |
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Definition
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Term
epidemiology of Bordetella pertussis |
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Definition
- exclussive human pathogen
- spread by aerosolized dropletes (cough)
- 20-30% of adults with prolonged cough may have pertusus
- wannin post vaccine immunity, so adults/adolescents are at risk for disease
- 90% of cases found in developing world
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Term
DPT vaccine effect on epidemiology of Bordetella pertussis |
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Definition
- vaccine has changed epidemiology
- prevaccine
- seen in age 1-5 (women surviving infection pass on to kids)
- post
- moms dont give passive immunity
- immunity wanes after 12 yrs
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Term
pathogenesis of Bordetalla pertussis |
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Definition
- exposure thorugh inhalation of aerosolized bacteria (infected human reservoir)
- attach to ciliated epithelial cells of bronchial tree
- bacteral prolif.
- VFs produce
- localized tissue damage
- systemic toxicity
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Term
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Definition
- filamentaous Hb- block neutrophil phagocytosis, help bind to resp. ciliia
- pertussis toxin (can be local and systemic)
- pili and peractitin- attachment of bacteria to epithelium
MAINLY BINDING/ATTACHMENT |
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Term
stages of clinical manifestation of pertussis |
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Definition
- stage one: incubation period (7-21 days); asymptomatic
- bacteria attach, prolif on ciliated epithelium
- stage 2: catarrhal stage (1-2 wks); most contagious
- symptoms- rhinitis, malaise, low grade fever, sjneezing, anorexia, increase WBC
- peak bacteria prod., disease not recognized
- stage 3: paroxysmal stage (2-4 wks)- 40 to 50 paroxysms/day
- symptoms- repetitive cough with whooping (expir. cough with inspir. gasp), vomit, exhaustion
- extrude ciliated epithel. cells impair mucus clearance, lead to mucus plug airway
- stage 4- convulescent stage (improved paroxysmal cough)
- development of secondary sysmptoms including pneumonia (main cause of mortality), seizures, enxephalopathy
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Term
complications of pertussis |
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Definition
- rare encephalopathy and seizures
- paroxysomal cough can increase intrathoracic and intraabdominal pressure cause:
- subconj. hemorrhage
- truncal hemorrhage
- epistaxis
- pneumothorax
- rectal prolapse
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Term
Paraxysomal cough can lead to what |
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Definition
frenal ulcer (traumatic ulcer because of tongue protrudin against sharp teeth during coughing) |
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Term
Radiograph of pneumonia due to pertusus? cause of pneumonia |
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Definition
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Xray- collapse of lung resulting from mucus plugging of smaller bronchi and bronchioles
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cause- aspiration durin cough, impaired sec.
MAIN CAUSE OF MORTALITY |
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Term
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Definition
- difficult
- organisms decrease as symptoms increase
- clinical clue- cough 2 wks
- culture Bordet Gengou media (up to 2-7 days)
- direct flurescent Ab (DFA)
- serology- rise between acute and convalescent sera
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Term
Tx, prevention of pertussis |
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Definition
- supportive therapy (ex: if pneumonia, antibiotics with oxygen therapy)
- current vaccine
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Term
Haemophilius influenzae growth requirements |
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Definition
- aerobic growth requires two supplements X factor (hemin) and V factor (NAD)
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Term
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Definition
- made against type B capusule producin strains (this strain assoc. with most invasive infections)
- have six Ag distinct capsular types (A to F)
- strains without capsule called nontypeable
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Term
Appearance of H influenzae on gram stain |
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Definition
small, pleomorphic, pale staining gram negative bacilli |
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Term
epidemiology of H influenzae |
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Definition
- humans only natural host
- transmission via contact w/secretions or airborne droplets
- since advent of widespread vaccinations, H influenzea infections most likely to occur:
- nonencapsulated forms, (A-C, F)
- type B infection if nonimmune children or elderly with waning immunity
- risk factors
- HIV/AIDS
- sickle cell disease
- splenoectomy
- chronic lung disease
- smoking
- malignancy
- pregnancy
- alcoholism
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Term
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Definition
- capsule- inhibit opsonization, intracell. killing
- LPS
- initiate invasive disease
- endotoxin like activity, tissue damage
- facilitate survival on mucosal surface (nasopharynx)
- outer membrane proteins (OMP)
- contribute to Fe scavengin and bindin required for organism survival
- fimbriae
- on bacterial surface
- enhance adherance
- present in typeable and nontypable
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Term
pathogen. of H influenzae |
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Definition
- humoral immunity
- protective Ab;'s opsonize bacteria
- increase reisk if functional asplenia or splenomegally
- complement (susceptible if def. in C2, C3)
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Term
clincial syndromes of H influenzae |
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Definition
- meningitis
- epiglotis
- otitis media, sinusitis (URT)
- pneumonia (LRT
- arthritis
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Term
mejningitis of H influenza |
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Definition
- occurs after bacteremic spread of organism from nasopharynx
- assoc. with trauma, neurourgery, CSF leak or paranasal sinusitis
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Term
epiglotitis with H influenza |
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Definition
- a life threatening emergency with cellulitis and swelling of supraglottic tissues
- presentation
- pharyngitis, fever
- drooling, difficulty swallowing and breathin
- may progress rapidly to complete airway obstructiona d death
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Term
diagnosis of H influenze epiglottitis |
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Definition
- lateral neck radiograph will show thumbprint sign
- cherry red epiglottis
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Term
Who is at risk of otitis/sinusitis and pneumonia from H influenzae |
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Definition
- most common cause of ottits media in young children
- occur in immunocompromised, chronic lung disease
- exacerbation of bronchitis
- pneumonia- lobar consolidation, effusions/empyema
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Term
arthritis from H influenzae |
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Definition
- bacteremic spread to single large joins
- usually on immmunocomp. or with previously damaged joints
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Term
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Definition
- blood cultures for meningitis, epiglottitits, cellulitis, arthritis, pneumonia
- supplement media (X and V factor, chocolate agara)
- Ag detection ELISA (urine, CSF)
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Term
treatment of H influenzae |
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Definition
- serious infections always should be given IV with epiglottitis and meningtis
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Term
prevention of H influenzae |
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Definition
- Hib vaccine substantially decreases incidence (98% effective)
- chemoprophylaxis with Rifampin
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Term
H ducreyi (chancroid cause) (clinical manifestations) (description of appearance) |
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Definition
- STD
- cause of genital ulcers in Asia and Africa, and major contributer to transmission of HIV
- tender papule with erythematous base onthe geintal and perianal area
- lesion ulcerates and is painful with suppurative inguinal lymphadenopathy
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Term
Legionella pneumophilia (morphology, what they cause) |
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Definition
- slender, plemorphic, obligately aerobic gram negative bacilli
- seasonal
- 90% of cases of disase caused by this bacteria (serogroup 1 most common)
- use charcoal yeast enriched media
- nutritionally fastidious
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Term
epidemiology of L. pneumophila |
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Definition
- fresh water (lakes, streams)
- most epidemic in summer, fall
- humans are accidental hosts
- optimal for symbiotic microorganisms
- environmental spread through water distrubution
- showers
- humidifiers
- resp. therapy equipment
- evaporative cooling towers of AC symptoms
- microaspiration during and after ingestion of contaminated water/ice
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Term
pathogenesis of Legionella pneumophila |
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Definition
- pulm. alveolar macrophages engulf bacteria
- no intracellular killing
- oxidative and nonoxidative intracellular killing mech. are inh.
- blunted or absent resp. burts with release of microbial oxygen derivatives
- no acidification of phagosome by lysosome to expose bacteria to toxic lysosomal contents
- multiplies within specialized endosome and produce cytotoxins
- macrophage killed and new bacter released and infect other macrophages
Host defense via NK and cytotoxic T cells lyse infected macrophages to end cycle while humoral immunity increases uptake of bacterial into neutrophils where it cannot replicate |
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Term
clinical manifestion of L pneumonphila |
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Definition
- Pontiac fever
- Legionellosis
- febrile systemic illness with pneumonia (another "atypical" pneumonia)
- pulm. infiltrates- rapid progress of alveolar infiltrates of multilobar consolidation
- resp. deterioration, multisystem failure and DIC
- mortality 15-20%
- pathology
- intense inflam. changes present in alveoli, alveolar ducts, bronchioles, alveolar septa
- complications- pleuritis, pleural empyema, pericarditis, cavitary lung disease/abscesses
- extrapulm. legionellosis
- occurs in immunocompromised
- occurs by bacteremic spread
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Term
diagnosis of L pneumophilia |
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Definition
- high clinical suspicion required
- culture in enriched media- buffer charcoal yeast extract agar
- urine Ag- enzyme immunoassay detects serogroup 1 Ag
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Term
treatment of L pneumophila |
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Definition
- Ab's must have high intracellular concentrations to be effective
- NEED HIGH CLINICAL SUSPICION
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Term
prevention and surveilance of L pneumophila |
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Definition
- routine envir. culturing of hospital envir. sources only on discovery of cases
- routine envir. culturing of hospitals performing organ and bone marrow transplants
- not contagious- isolation precautions not required
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