Upper Respiratory Tract Infection

What are professional invaders

Pathogens that can infect healthy RT

Which pathogen adhere to normal mucosa

Respiratory virus, s pyogenes, s pneumoniae

Which pathogen interfere with cilia

Pertussis, mycoplasma pneumoniae, s pnuemoniae

Which pathogen have the ability resist destruction in macrophage

Legionella, TB

Which pathogen can damage local tissue

Corynebacterium diphtheriae, S pnuemoniae

What are some mechanisms professional invaders use

Adhere to normal mucosa, interfere with cilia, resist macrophage, damage local tissue

What are secondary invaders

Infect when host defense is impaired

What are some mechanisms used by secondary invaders

Initial infection by other virus, impaired local defense chronic issue, depressed immune response, depressed resistance

Which pathogen infect after other virus

S aureus, s pneumoniae

Which pathogen infect when local defense is impaired

S aureus, pseudomonas

Which pathogen infect with chronic bronchitis, local foreign or tumor

H influenzae, S pneumoniae

Which pathogen infect with depressed immune response

Pneumocystis jirovecii, CMV, MTB

Which pathogen invade with depressed resistance

S pneumoniae, S aureus, H influenzae

What are the causes of otitis and sinusitis

Viral: Mumps and RSV; Bacterial: S pneumoniae, H. influenzae, Moraxella catarrhalis

What is otitis externa

Swimmer’s ear; caused by pseudomonas aeruginosa and S aureus

What is acute otitis media

Fluid in ear = glue ear; found in 6-24 month olds

What are the causes of AOM

Bacteria: S pneumoniae, H influenzae, Moraxella catarrhalis; Viral: RSV, corona

Bulging ear drum; AOM

What is mastoiditis

Found in kids <2 y/o; AOM complication

What is mastoiditis caused by

S pneumoniae, GAS, S aureus

What is sinusitis

Erythematous swollen nasal mucosa and pus; nasal congestion/blockage/discharge

Sinusitis cause

50% from RSV; other 50% from H influenzae, S pneumoniae, Moraxella Catarrhalis

What is parotitis

Caused by mumps

What causes oral cavity infection

Decreased salivary flow increases bacteria in saliva

What is oral candidiasis

Prolonged administration of BSA allows candida to fluorish; vit C def and HIV more susceptible

What are caries

Microorgs that form film (dental plaque); streptococci and anaerobic filamentous bacteria surround teeth

What is periodontal disease

Infection of gums; caused by actinomyces etc

What is rhinitis/acute coryza

Most common URTI; fever, nasal edema and increase in mucous secretion

Pathogenesis of common cold infection

Infection → Viral absorption → Viral replication → Virus shedding → Overgrowth of bacteria

Common pathogens that cause common cold

Rhinovirus, coronavirus, HRSV (adult), Parainfluenza, Influenza A and B

How does rhinovirus and enterovirus cause common cold

Capsid protein bind to ICAM-1 on cell

What is the difference between cold and flu

Cold are milder; flu can lead to severe illness and death

Flu complications

Sinus and ear infection, pneumonia; organ failure, inflammation of major organs

What is pharyngitis

Appearance of erythema and swelling of tissue; 10% caused by GAS

Pharyngitis

What is EBV

Saliva transmission, causes mono; latent in B lymphocyte

EBV diag

IgM Ab to erythrocyte (cold agglutinin); VCA, atypical lymphocytes

Mono diag sign

Mono characteristic = palatal petechiae in mouth

Atypical lymphocytes

Oral petechiae

What cancers are associated with EBV

Burkitt lymphoma, nasopharyngeal carcinoma, B cell lymphoma

What is CMV

transmit by saliva and sex; cause mono; similar to EBV; cause intellectual disability

Owl’s eyes

Presence of owl’s eyes in BAL indicates what

CMV pneumonitis

What is bacterial pharyngitis

Caused by GAS, sometimes corynebacterium diphtheriae, N. gonorrhoeae if there was sexual activity

Bacterial pharyngitis

What is streptococcal pharyngitis

10% caused by GAS, transmit by saliva and direct skin contact

Streptococcal pharyngitis

What is diphtheria

Greyish/yellowish false membrane; highly infectious, NP diphtheria is most severe

Pharyngeal diphtheria

What are the complication of diphtheria

Can cause fatal heart failure and polyneuritis

What is whooping cough

Caused by bordetella pertussis; paroxysm of coughing (100 day cough)

What is acute epiglottitis

Caused by Hib; emergency that NEEDS intubation and treatment with antibiotics

Acute epiglottitis thumb sign

What is laryngitis and tracheitis

Parainfluenza, C diphtheriae; easily obstructed in children