RESPIRATORY INFECTIONS Flashcards
- acute rhinitis or coryza. occurrence increases during rainy season. Close personal contact is common. Sneezing, nose blowing, contamination of external surfaces w/ nasal secretions.
Common cold
- main cause of common cold. Affect nose & conjunctiva, killed by gastric acid when swallowed.
Rhinovirus
- 2nd most common cause of common cold.. SARS(severe acute respiratory syndrome) implicated in 2002.
Corona viruses
- tonsillitis, tonsillopharyngitis, nasopharyngitis
Pharyngitis
- illness of childhood, in cold weather months. Common cause adenovirus . Fever occurs. self limiting 4-10 d.
Nasopharyngitis
non enveloped DNA viruses, causes variety of URT & LRT disease. ( pharyngitis, common cold.
Adenoviruses
(laryngitis, laryngotracheitis, laryngotracheobronchitis) characterized by inspiratory stridor, cough hoarseness,
sealbark results to obstruction in larynx. Occur w/n 1st 3 yrs of life. Can be caused by RSV (resp syncitial virus) MOT: resp
droplets
Croup
-occurs in assoc w/ strep pharyngitis, caused by strep pyogenes strains that produced erythrogenic toxin.
Pinkish red rash on skin. strawberry appearance of tongue. As disease progresses, skin peels off →sunburned. Tx: Pen G
Scarlet fever
- allergies, w/ large tonsils or adenoids, dental & ear infection. Pathogen: H. influenza, Strep. Pneumonia
Sinusitis
-inflammation of auditory canal. Pseudomonas, Staph, aureus common cause. Prevention: minimize swimming
Otitis externa
- inflammation of middle ear. Cough & coryza prior to infection. S. pneumonia, H.influenzae, RSV, adeno, rhinovirus
Most common s/s : Otalgia-ear pain, otorrhea(ear discharge), tinnitus (ringing in ears).
Otitis media
- mainly upper resp tract. Caused by influenza virus.MOT: resp droplets Has 3 immnulologic types
Influenza A
Influenza B
Influenza C
Influenza
responsible for cases of epidemics & pandemics. Also the cause of influenza in birds (avian flu)
Influenza A –
- mainly epidemics 2 types of antigenic change in Influenza A and B.
Influenza B
- minor shift, due to accumulation of point mutations in gene results to amino acid changes
Antigenic drift
- major change, involve rearrangement of gene segments, results in dev of new strains.
–Responsible for pandemics, occurs only in influenza A
Antigenic shift
- antigenically stable, causes mild illness. No antigenic changes
Influenza C
- Etiologic agent: Corynebacterium diphtheria Gm (+)non spore forming rods, club-shaped arranged in V or L
shaped formations, giving rise to Chinese character appearance. Produce toxin.
Dipththeria
- an inflammatory condition involving bronchi. Recurrent bacterial infection often precipitate by viral infections
Chronic Bronchitis
- severe inflammatory condition involving bronchioles. Most commonly caused by RSV.(Respiratory Syncitial Virus).
Bronchiolitis
(whooping cough):
Etiologic agent: Bordatella pertussisGm (-) rod. Pathogenic for humans.
MOT: Airborne
droplets. Highly contagious. occurs in infants & young children. 3 stages: Catarrhal, Paroxysmal, convalescent
3 STAGES:
- Catarrhal- most contagious stage. Manifests mild URTI no specific s/s
- Paroxysmal- series of 5-20 forceful,hacking cough, w/ copious sputum ends in inspiratory breath whoop).
During paroxysms, tongue protrudes, eye bulges, neck vein engorge.
- Convalescent
Pertussis
- Typical Pneumonia, Atypical Pneumonia, Lobar Pneumonia- involve entire lobes Interstitial Pneumoniato interstitial spaces. Bronchopneumonia- involved bronchus and alveoli
- . inflammation of interstitial spaces. Common caused by RSV, Parainfluenza virus,
influenza
PNEUMONIA
- aka woolsorter’s disease, inhalation of spores to lungs. S/s resembles influenza progresses to pleural
effusion, septic shock, death. DOC: Ciprofloxacin. Doxycycline- alternative drug
Pulmonary anthrax
- Etiologic agent: mycobacterium tuberculosis-acid fast, obligately aerobic bacillus. Cell wall has mycolic acid.
MOT: person to person- resp aerosol- generated by coughing of infected individuals. Kissing, ingestion of
unpasteurized cows milk, (gi tuberculosis by M. bovis), fomites (utensils, glass wares)
Tuberculosis
- Hemophillus “blood loving”
- Found in mucous mem of URT in man H. influenza Type B most Virulent Strain
- Infection in children 6mos to 6 yrs Enters through RT Humans only reservoir
- Sinusitis Otitis media Epiglotittis Meningitis Bronchitis Pneumonia
- DOC: Cephalosporins Ampicillin Prevention: Hib vaccine
Haemophilus influenzae
- Gm (+) lancet Shaped diplococci
- Aka pneumo Coccus Capsule-main virulence
- Normal habitat Of URT 5-40% MOT- droplet Secretions Most common Cause of CAP
- Rusty sputum Dx: Gm Stain Quellung reaction (capsular swelling) Optochin sensitivity
- DOC: Pen G
Streptococcus pneumoniae
- Smallest free Living organis
- Can self replicate in laboratory media ABSENCE OF CELL wall Resistant to Penicillin
- Atypical Pneumonia “walking Pneumonia” Dx: Serologic testing
- DOC: Macrolides (Azithromycin) Tetracycline Doxycycline
Mycoplasma pneumoniae
- Opportunistic Pathogen Nosocomial Infection Common in alcoholics
- Found in large intestine soil, water Has Very Large Capsule- anti Phagocytic
-Lobar pneumonia w/ thick bloody sputum (currant jelly) sputum - Infections in Elderly, diabetics Alcoholics Necrosis & Abscess
Klebsiella pneumoniae
- Gm (+) rod w/ Gm (-) type of Cell wall
- Major virulence is LPS – lipopoly saccharide
- Assoc w/ air Conditioners & Water cooling towers
- Pontiac fever – Mild flu lke form Does not result in pneumonia
- Legionnaire’s Dse- high fever Mental confusion Non bloody diarrhea
- DOC: Azithromycin
Legionella Pneumophilia
- Gm (+) cocci
- Most common cause of nosocomial pneumonia In many hosp
- Can occur in post Operative Patients following Viral RTI
- Leads to Empyema (Lung abscess)
- DOC: Nafcillin
Staphylococcus aureus
- Gm (-) bacilli
- Major cause of nosocomial pneumonia
- From Contaminated respirators
- Results in Necrotizing pneumonia
Pseudomonaaeruginosa
