Infections of Respiratory System Flashcards
(26 cards)
Pharyngitis
Streptococcus pyogenes
- respiratory droplets
- diagnose using latex agglutination kit that detects Ag in throat swab
scarlet fever / scarlatina
Streptococcus pyogenes
- some strains produce an erythrogenic exotoxin (toxin kills cells & causes intense inflammation)
- symptoms: small red bumps on neck & groin & then spread to rest of body. Rash feels like sand paper
- may have hyper pigmented areas: PASTIA’S LINES and/or STRAWBERRY TONGUE (covered with white membrane that sloughs in a few days)
rheumatic fever
Streptococcus pyogenes
- autoimmune disorder
- occurs after the strep throat infection is over or if strep throat is left untreated
- causes inflammation of joints, skin, brain, heart valves (endocarditis)
- can be prevented if strep is treated w/in first 10 days.
Streptococcus pyogenes
Diseases caused by….
G(+) cocci / alpha hemolytic / bacitracin sens. impetigo conjunctivitis otitis media sinusitis cellulitis necrotizing fasciitis PANDAS
Streptococcus pneumoniae
G(+) diplococci or chains / alpha hemolytic / optician sensitive
- capsule is critical factor in virulence
- (#1) MOST COMMON CAUSE OF: otitis media, sinusitis
- ALSO CAUSES: meningitis, pneumococcal pneumonia
- treat w/penicillin, altho some strains resistant
- Vaccine: Pneumovax, Prevnar
Haemophilus influenzae
G(-) rod
- needs a growth factor present in red blood, hence Haemophilus = blood loving
- major cause of virulence is capsule production
- adults produce Ab, but young children are at risk
- Vaccine: HiB; routinely given to babies
- 2nd leading cause of OTITIS MEDIA & SINUSITIS in kids
Haemophilus influenzae Type B
- cause MENINGITIS, CELLULITIS, & CONJUNCTIVITIS
- before the HiB, this was leading cause of meningitis and mental retardation in children
Moraxella catarrhalis
G(-) diplococci, aerobic
- causes OTITIS MEDIA, SINUSITIS, BRONCHITIS, & PNEUMONIA (in children & adults with underlying lung disease)
- usually produce beta-lactamase, so are resistant to penicillin & cephalosporins
- 3rd most common cause of OTITIS MEDIA & SINUSITIS in kids
Klebsiella pneumoniae
Pneumonia G(-) rods, LF, IMViC --++ - typical pneumonia - sputum compared to "red currant jelly" - more common in smokers/alcoholics
Mycoplasma pneumoniae
Primary Atypical Pneumonia / “Walking Pneumonia”
- lack a cell wall
- adhere to epithelial cells; don’t invade deeper tissues
- respiratory droplets
- occurs mostly in school-age kids & teens; comes on slowly; atypical (patchy) pneumonia
- treat w/tetracycline, erythromycin for pregnant women & young kids
- not sensitive to penicillins & cephalosporins (lack cell wall)
Acinetobacter baumannii
Nosocomial pneumonia, UTI, Periotonitis G(-) coccobacillus - opportunistic (immunocompromised) - part of ESKAPE pathogens - "Iraquibacter" - can remain on artificial surfaces for extended period of time - resistant to many drugs - infections are uncommon, but usually involve organ systems with high fluid content
ESKAPE
a group of pathogens w/high rate of antibiotic resistance that are responsible for majority of nosocomial infections:
Enterococcus faecium
Staphylococcus aureus
Klebsiella pneumoniae
Acinetobacter baumannii
Pseudomonas aeruginosa
Enterobacter speciesChlamydia psittaci
Ornithosis = Psittacosis = Parrot Fever
psittaci = parrot
- transmitted thru inhalation of dust from feces and secretions of infected birds.
- occupational hazard for those working in poultry industry
- fever can progress to persistent high fever; mental confusion
- atypical pneumonia
- prevent thru antibiotic supplements in feet & treatment of imported bird; imported birds should be quarantined
Q Fever
Coxiella burnetiii
Rickettsia - obligate intracellular parasite
- “Q”/query - etiologic agent unknown for years
- reservoirs - mainly sheep, goats, & cattle
- transmitted thru tick vector or by inhaling the microbe from infected animal
- severe frontal headache; atypical pneumonia
- can’t be distinguished between mycoplasmal pneumonia or parrot fever
- rare; high risk for pregnant women
Legionnaires’ disease / Pontiac Fever / Legionellosis
Legionella pneumonphila
- transmission - water supplies - a/c, fountains, spa pools, misting in grocery store
- sudden onset, weakness, headache, typical pneumonia, bloody sputum
- treat w/antibiotics (erythromycin); resistant to penicillins & cephalosporins
PONTIAC FEVER - more prevalent, milder form of disease, shorter incubation period
- no antibiotic needed; self-limiting
Whooping Cough
Bordetella pertussis
G(-) coccobacillus; produces exotoxins
- respiratory droplets, highly contagious
- violent coughing; break blood vessels in eye, may vomit; very serious in infants (may affect brain)
- treat w/antibiotics
- vaccine: part of DTP or DTaP
Tuberculosis (white death)
Mycobacterium tuberculosis
G(+), rod shaped obligate; waxy capsule/acid fast
- respiratory droplets
- primary infection: microbes enter lungs; are phagocytized by macrophages, but not killed
- dead tissue looks dry & crumbly, like cheese = CASEATION NECROSIS = “cheese like death”
- secondary (reactivation) infection: hypersensitivity reaction can destroy lungs; patients have a chronic cough; w/o treatment, disease is fatal.
- BCG vaccine - not entirely reliable
- treat w/single drug for 1 yr. If active, muti-drug therapy for 2 years. Biggest problem is people not continuing w/drugs. - leads to resistance
Leading cause of death in AIDS patients
- Elephant to human transmission officially confirmed in 2009
Inhalation/Repiratory Anthrax
Bacillus anthracis
G(+) rod, forms endosperm, facultative anaerobe
- vaccine available, but requires many shots
- treated w/penicillin until resistance shown; now Cipro used in combo with pen.
- widened mediastinum is a classic hallmark sign of anthrax infection
Respiratory influenza / Flu
Influenza virus
orthmyxoviridae
- composed of 8 separate pieces of RNA
- animal reservoirs are critical; virus can “jump” species
- H1N1 strain:
- H3N2 strain (swine): variant of a strain that has been around since 1990
- H7N9 (avian): China; so far only transmitted bird to human. Boy found w/co-infection which could lead to mutations allowing it to be communicable between humans.
Croup
Parainfluenza virus paramyxoviridae - respiratory droplets - LARYNGOTRACHEOBRINCHITIS causes airway to narrow; common in toddlers; loud, barking cough. Symptoms worse at night;- - treat w/cold air; cool mist humidifier - no vaccination, treat symptoms
Bronchiolitis pneumonia
Respiratory syncytial virus (RSV)
paramyxoviridae
- most common cause of fatal lower respiratory infection in young kids/infants (especially preemies)
- respiratory droplets, hand to hand, nosocomial
- wheezing during expiration; rapid breathing
- no vaccine, but preemies given RESPIGAM or SYNAGIS
Hantavirus Pulmonary Syndrome (HPS)
Hantavirus
- appeared in 4 Corners area of SW US
- transmitted by long-tailed deer mouse - shed in urine, feces & saliva
- fever, muscle aches, respiratory distress; 70% of cases die in 5-6 days (catastrophic lung failure)
Severe Acute Respiratory Syndrome (SARS CoV))
Coronavirus
- originated in China
- respiratory droplets
- IP 2-7 days
Middle Eastern Respiratory Syndrome( MERS CoV)
Coronavirus
- first reported in Saudi Arabia 9/12
- IP 12 days
- bats & camel reservoirs; no evidence yet of communicable between humans
- acute respiratory illness; acute pneumonia & renal failure; often fatal
- more males than females get it because of their head/face coverings
