infection 4

Viruses: Fact card

non living

protein/lipid coated

mutation is frequent (resistance is common)

contains replication material only

enters healthy human cells to survive

replicate using host cell infrastructure

tx must reach virus prior to entering host cell

disable viral release

Influenza: about

contagious

• 20% of pop. gets infected annually

• mortality risk increases in immunocompromised

virus family

• Orthomyxoviridae

• type A and B = 8 RNA segments

• type C = 7 RNA segments

• 2 subtypes: NA, HA

• can sometimes spread from animals to humans (bird flu)

upper airway - destroys mucosal + epithelial cells

lower airway - destroys cells like alveolar

• risk of complex pneumonia

allows for opportunistic infections

• bacterial or fungal

Influenza: s&s

profound malaise, common cold symptoms, fever

severe: diaphoresis, myalgia, tachycardia, hypoxia

complications → sinusitis, otitis media, pneumonia, bronchitis

Influenza: TX

supportive

• antipyretics, analgesics, decongestants, antitussives

antivirals

• oseltamivir (Tamiflu)

• zanamivir (Ralenza)

• neurominidase inhibitors - decrease viral release

• as prophylaxis - decrease duration only

hydrate

o2 if impaired gas exchange

influenza vaccine - annual per subtype

Pneumonia: etiology, about

either nosocomial or community acquired

either bacterial or viral

bacterial

• typical pneumonia

• alveoli fill w/ exudate

• more common and serious than viral

• immunizations target many bacterial strains

• pathogens

  • s. pneumoniae

  • haemophilus influenza

  • s. aureus

viral

• atypical pneumonia

• sometimes atypical can mean atypical bacteria (mycoplasms)

• affects lower resp. - alveoli, bronchioles

Pneumonia: DX and TX

DX:

assess for proper oxygenation

fever, malaise, wet cough = exudate s&s

and xray!! (white = exudate)

• bacterial pneumonia

  • localized

  • denser white areas

• viral pneumonia

  • spread out

  • hazy, cloudy

• covid-19 pneumonia

  • bilateral, peripheral

  • worse in lower lungs

  • hazy

TX:

according to pathogen

vaccines

• pneumoccal conjugate

• Hib

• Influenza

empiric tx

• macrolides (inhibiting protein synthesis)

Cyanosis: Peripheral, Central, Causes

Peripheral

• low o2 (<92%)

• upper/lower extremities

  • fingers, toes, lips

  • NOT mucosa

• can be normal

Central

• low o2 (<85%)

• oral mucosa

  • NEVER normal

• other body parts

Causes

• low perfusion

  • vasoconstriction

  • low CO

• low O2 due to pathology

  • pneumonia

  • asthma

• CAUTION

  • oxygenation failure → hypoxemia → organ ischemia

Protein Synthesis Inhibitors: Macrolides

‘-mycin’ suffix

tx efficacy

• community acquired adult pneumonia

• other infections - gonorrhea

meds

• erythromycin

• azithromycin (Zithromax)

• clarithromycin (Biaxin)

Aspiration Pneumonia: etiology and risks

lung infection by inhaling foreign particles into airways

= inflammation + bacterial infection

innate reflexes protect against aspiration

increase risk

• immunocomprised

• taking antitussives (suppress cough reflex)

• position (lying when eating)

• eating disorders

• CNS impairment of protective reflexes

  • drug-induced sedation/anesthesia

  • stroke/CVA

  • head injury

Aspiration Pneumonia: TX

bugsanddrugs

metronidazole/Flagyl (nucleic acid replication/transription inhibitor)

TB: about

Affects lungs, but any other organ can be infected

Pathogen

• bacteria

  • Mycobacterium tubercolosis

• diff to penetrate outer shell

• aerobic + airborne

Contagious

• LOTS of cases and annual deaths

• very resistant

TB: infection process

inhaled, deposits into alveoli = Active TB

• phagocytosis via macrophages

• immune response forms localized granuloma lesions (ghon foci)

  • ultimate necrosis of lung tissue (see on xray)

Latent TB

• not infectious to others

• necrosed tissue harbors the pathogen

Secondary TB

• latent becomes active again

TB: s&s, TX, DX

1st s&s

• malaise, cough, anorexia

Dx

• x-ray

• culture: sputum, bloof

• Tuberculin skin test

  • shows existence of immune response

  • not marker for active infection

    • once exposed, often + foreva

TX

• 6-12 months

  • Isoniazid (INH)

    • Cell wall inhibitor

  • Rifampin

    • DNA synthesis inhibitor

  • anti-TB meds

• but there are more resistant strains