Upper Respiratory Tract Infections (URIs) Flashcards
What is the most common patient physician/emergency department infection?
upper respiratory tract infections (URIs)
- Pre-COVID: 25 million visits/year (US)
b/c obstruction of airways
Antibiotic resistance
bacteria that’s now resistant to the things you were treating them with
What are URIs a major driver of?
a major driver of bacterial ANTIBIOTIC RESISTANCE due to improper antibiotic prescriptions
b/c most start as viral, therefore a lot of antibiotics are being wrongly prescribed which drives antimicrobial resistance
What are the 4 most common URIs?
- Acute otitis media (ear infections)
- Acute rhinosinusitis (sinus infections)
- Acute pharyngitis (back of throat infections)
- Acute laryngitis (voice box infections)
What does the upper respiratory tract consist of?
nasal cavity, pharynx & larynx
‘oto’ =
ear
‘itis’ =
inflammation
‘media’ =
middle
Otitis media translates to…
middle ear infection
What are the 3 types of Otitis media conditions?
- Acute otitis media (AOM)
- Otitis media with effusion (OME) –> aka “glue ear”
- Chronic otitis media (COM)
AOM is normal after what?
a viral infection
What is OME (aka “glue ear”)?
hearing impairment (b/c effusion is blocking it), otorrhea but NO inflammation of tympanic membrane
COM is
long term middle ear inflammation causing damage often due to multidrug resistant infections (perhaps b/c if they had AOM before it they most likely have used some antibiotic therapy - therefore higher risk of resistance)
- typically comes if acute OM isn’t treated
Out of the >700 million cases of OM worldwide each year where do we see the most cases?
50% cases in children <5 yrs old –> results in a high risk of hearing loss (perhaps due to inability to communicate pain & higher risk of more severe infections)
How come we are recently seeing a downward trend in patient infections <2 yrs of age?
due to pneumococcal conjugate vaccine (PCV)-13 use
- costs healthcare system $7 billion in US (so less visits to hospital due to this helps tax payers pay less)
Where are we seeing inflammation in OM and where are we seeing fluid build-up?
inflammation in the eustachian tube (WBC response)
fluid build-up in the tympanic cavity (causing pressure)
What does an AOM look like?
inflamed bulging tympanic membrane (catch it here!)
- might see effusion
Severe AOM
perforated tympanic membrane (could req. surgical repair b/c can’t heal itself)
COM (chronic) vs. OME vs. Severe AOM
tissue damage (purple, dark brown & blue), & liquidity b/c bacteria is eating up tissues lining tympanic membrane
- lead to permanent or long-term
vs. with effusion
vs. severe AOM - perforated tympanic membrane
What are 70% of AOM cases/yr caused by?
by bacterial infections
Streptococcus pneumoniae
gram stain & proportion of AOM
positive
1/3
common cause of respiratory infection
non-typeable Haemophilus influenzae (NTHi)
gram stain & proportion of AOM
negative
1/3
(non-typeable - more difficult to type)
Moraxella catarrhalis
gram stain & proportion of AOM
negative
1/6 (less freq.)
What do most H. influenzae isolates & nearly all M. catarrhalis URI isolates produces…
B-lactamases (enzyme bact. can inherit & produce gives rise to microbial resis), more than half of all S. pneumoniae serotypes are resistant to penicillin
- chews up/degrades many penicillins - loses some effectiveness
AOM clinical presentation
- cases of AOM often follow viral URIs
- nonverbal children with ear pain might hold, rub, or tug their ear (fussing)
- infants might cry, be irritable, or have difficulty sleeping
AOM Signs & Symptoms
- bulging of the tympanic membrane
- otorrhea (ear discharge/drainage)
- otalgia (earache)
- fever
Otorrhea is determined by…
otoscopy
Otalgia is considered to be…
moderate or severe if pain lasts at least 48 hours
Fever is considered to be severe if temp is…
39 degrees C (102.2 degrees F) or higher
- much more sign. with BACTERIAL infections b/c with fever you can get systematic, therefore more difficult to treat by itself
- but can also be seen with viral infections
AOM Treatments (antibiotics)
Amoxicillin (go to for common infections), 1st-line (oral), if pen. allergy = no
Amoxicillin-clavulanate (used as double wammie/in combo), 1st-line (oral) - if had amox reg. in past 30 days, if pen. allergy = no
Ceftriaxone (1-3 days), 1st-line (IV), yes, if allergy is non-severe
Cefdinir, cefuroxime, cefpodoxime, 2nd-line , yes, if allergy is non-severe
Clindamycin, 2nd-line, yes
*many of the treatments are determined based on how many treatments are coming in & how effective they are (hospitals switch based on effectiveness)
S. pneumoniae, H. influenzae, & M. catarrhalis can all possess resistance determinants to…
B-lactam antibiotics due to the presence of a beta-lactamase (respons. for this - degrades PG) enzymes &/or PENICILLIN BINDING PROTEIN (PBP) (binds to PG’s formation)
(this is why we may have to move to other microbials that have more side effects & long term damage b/c these present will degrade PG)
Tympanocentesis
is considered after treatment failures or for persistent AOM (if seen patient multiple times, if severe/has gone to hospital)
- puncture of the tympanic membrane with a small gauge needle to aspirate fluids
- relieves pain & pressure –> (sunction fluid) can be used to collect fluid to identify the causative agent (used to examine cultures to identify & treat properly)
- with recurrent episodes, may offer tympanostomy tubes (T tubes) rather than prophylaxis (allows continued drainage to heal swelling by inserting tube in tympanic membrane - b/c body wants to heal so sometimes puncture won’t help so this can help by keeping it open more to prevent permanent hearing loss - given to children with chronic ear infections or multiple AOM infections)
What can be done to try prevent tympanocentesis for AOM from happening in the 1st place?
strong recommendation for children to receive pneumococcal conjugate vaccine-13 (PCV-13) & annual seasonal influenza vaccinations
Acute rhinosinusitis (AR)
is inflammation of the sinuses & nasal cavity mucosa (symptom of “the cold”)
What are the 2 types of Acute rhinosinusitis (AR)
- Acute VIRAL rhinosinusitis (AVR)
- Acute BACTERIAL rhinosinusitis (ABR)
Majority of acute rhinosinusitis (AR) infections are…
VIRAL –> “COMMON COLD” (rhinovirus)
Acute rhinosinusitis (AR)
Pre-COVID:
bacterial rhinosinusitis is freq. over-diagnosed & treated with antibiotics
- 30 million ABR cases/yr US
(many ppl thought they had a bacterial inf. when majority had a viral infection which normally doesn’t lead to severe bacterial inf. if healthy it’ll clear)
How many work days/yr does adult rhinosinusitis cases result in?
at least 1-2
What age groups are susceptible for AR?
AR is often seasonal
Risks increase in children, caregivers, & asthmatics
Why are viruses more susceptible to being seasonal than bacteria is?
many pathogenic bacteria want to be with ppl; therefore less likely to survive the delivery
- but some are spores that can travel with weather patterns but tend to be more localized, whereas viruses are much smaller so can divide easier
What are the 3 categories of symptoms of acute rhinosinusitis AR?
- Purulent (pus) nasal discharge
- Nasal obstruction/congestion
- Facial pain, pressure, headache, dental pain (b/c sinuses can drain & can feel it in jaw), fever, ear pain, halitosis (bad breath)
What are the 3 clinical presentations of acute rhinosinusitis (AR)?
- PERSISTENT symptoms for more than 10 days
- SEVERE/worsening symptoms (fever) over 10 days
- “DOUBLE SICKENING” initially improves after 10 days, then worsens
*don’t treat with antimicrobial within the 10 day window (i.e. don’t want to make antimicrobial resis. worse)
If signs & symptoms of AR is persistent, severe/worsening, “double sickening” over 10 days worsens/gets better than…
if YES it’ll be ABR (bacterial)
if NO it’ll be AVR (viral)
Acute bacterial rhinosinusitis (ABR) is caused by the same bacteria implicated in…
AOM
- S. pneumoniae & H.influenzae (50-70% of adult & child cases)
- M. catarrhalis (8-16% of adults & child cases)
- Less freq. detected: gram-negative bacilli, anaerobes, Streptococcus pyrogenes (strept throat), Staphylococcus aureus (many are fecal-oral - opportunist infections)
(military bunkers, daycare, dorms, cruise ships –> b/c outbreak related)
What is Acute bacterial rhinosinusitis (ABR) are often preceded by?
a VIRAL RESPIRATORY TRACT INFECTION that causes mucosal inflammation (ABR is a severe form b/c harder to treat b/c many are becoming more resis)
- leads to obstruction of the SINUS OSTIA which drain sinuses
- maxillary & ethmoid (LOWER) sinuses are most freq. inflammed in ABR
- swabs are not taken as they are freq. inconclusive (due to other bact. & flora there)
Why would swabs be inconclusive for ABR?
many not be able to find due to other bacteria & flora - difficult to find causitative agent
Viral infections infect ____ sinuses; bacterial infections infect _____ sinuses typically
ALL (b/c systemic; go everywhere)
LOWER (b/c of gravity & where they are located they stay - follow drainage)
How do viral & bacterial infections tend to differ in where they infect?
viral infection infect ALL sinuses, bact. infect LOWER sinuses (b/c of gravity - where they are located they stay)
Acute bacterial rhinosinusitis (ABR) treatments:
Symptomatic control + ANTIBIOTIC TREATMENTS (limit when possible)
- involves the same antibiotic treatment as AOM (b/c same pathogens)
Acute viral rhinosinusitis (AVR) treatments:
Symptomatic control + PAIN management (b/c viral infections will self-resolve with good immune system)
- decongestant usage: oral or nasal spray
(could treat with antiviral but not common b/c resistance to antivirals is growing)
When should you referral to specialist for acute bacterial rhinosinusitis (ABR)?
- mental/visual status changes
- immunosuppressive illness (ex: cancer)
- anatomical obstructing defects (more susceptible if scar tissue)
- recent surgery (in sinus cavities & URT regions)
- unusually severe symptoms
- recurrent ABR (sinuses always having problems)
Why is ABR treatment hindered?
due to the lack of a simple & accurate diagnostic test (not financially feasible)
- the gold standard for ABR diagnosis is SINUS PUNCTURE with recovery of bacteria in high density = 10^4 colony-forming units/ml [10^7 cfu/L] or greater (looking for highest density of bact.)
- SINUS PUNCTURE is invasive, costly, & painful, & not routinely done (reserved for ER/severe cases or in other countries)
Acute pharyngitis (AP)
pharyngitis is an acute infection of the OROpharynx or NASOpharynx
(back of throat)
Acute pharyngitis (AP) accounts for…
15 million healthcare visits/yr,
- cost of $539 million/year in pediatric visits
What are VIRAL infections the most common cause of?
Acute pharyngitis (AP)
- but if it becomes bacterial than GABHS is concerning
Group A B-hemolytic Streptococcus (GABHS; aka S. pyogenes) is the…
primary BACTERIAL cause = “STEP THROAT”
(RBC rupturing - has toxins lysing RBCs & infecting you)
What age groups are susceptible for Acute pharyngitis (AP)?
all age groups are susceptible, BUT INCREASED RISK for:
- CHILDREN 5 to 15 ys old
- Parents of school-age children
- Those who work with children
(bacteria changes throughout our lifetime; start of life is not same as end of life)
What causes the majority of Acute pharyngitis (AP) cases?
VIRUSES
Rhinovirus
20% of Acute pharyngitis (AP) cases (HIGHEST) - b/c so many variants, therefore v. difficult to make a vaccine
High cause of AVR
High cause of AOM
Why would we see differences in terms of what viruses are more predominant?
b/c of where they’re infecting 1st (diff. receptors) (i.e. where it’s travelling, which receptors it’ll attack)
Bacterial causes of Acute pharyngitis (AP) are…
less likely (BUT MORE severe (i.e. more inflammation & tissue damage (severe systemic infection) & for strept throat it can cause swelling that can close off pharynx)–> GABHS is the most common cause
Bacterial causes of Acute pharyngitis (AP) are less likely. Which is the most common cause?
GABHS is the most common cause
- 10%-30% of persons of all ages with pharyngitis in their life
- *GABHS is the only commonly occurring form of AP for which antibiotic therapy is indicated
_____ is the only commonly occurring form of AP for which antibiotic therapy is indicated
GABHS
Acute pharyngitis (AP) signs & symptoms
- a sore throat of sudden onset that is mostly self-limited
- fever & constitutional symptoms resolving in about 3-5 days (viral)
- clinical signs & symptoms are similar for GABHS, viral causes, & non-streptococcal bacterial causes (diff. to determine strept/non-strept for ex)
Bacterial Acute pharyngitis (AP) signs & symptoms
- SWOLLEN UVULA
- WHITE SPOTS
- red swollen tonsils
- throat redness
- GREY FURRY TONGUE
(lots of inflammation, stay/target 1 area b/c has good source of food there)
Viral Acute pharyngitis (AP) signs & symptoms
- red swollen tonsils
- throat redness
*redness all over b/c viruses like to be all over
Signs & symptoms of VIRAL Acute pharyngitis (AP)
• Conjunctivitis = Pink or red color in the white of the eye
• Coryza = acute inflammation of the mucous membrane of the nasal cavities
• Cough (*in GABHS often cough is absent)
(check other places b/c viruses like to be all over)
Why is the cough often absent in GABHS?
b/c throat is swelling & hard to swallow
How are viruses/bacteria usually spread?
Viruses/ bacteria are usually spread by people coughing or sneezing. It can also be spread when a person touches a contaminated object and then touches their mouth or nose.
GABHS Acute Pharyngitis (AP) Laboratory Tests
Throat swab is taken and used for:
• Rapid antigen-detection test (RADT) → Point of care test that detects GABHS antigens (cannot detect viral AP) *ONLY BACTERIA
• Microbiological culture (gold standard of bacterial or viral AP)
- don’t do unless seeing outbreak to determine causative agent
Viral Acute Pharyngitis (AP) treatments
prevent transmission to close contacts, and prevent acute rheumatic fever and suppurative complications
• Anti-pyretic (fever) medications
• analgesics, non-prescription lozenges and sprays containing menthol (calming/numbing feeling)
• topical anesthetics for temporary relief of pain (avoid lots for children, typically used for adults)
GABHS Acute Pharyngitis (AP) treatments
• GABHS has increasing resistance to penicillin treatments (not using penicillin’s b/c of B-lactamase transfer & PBP –> becoming v. drug resis.)
• 10-day oral treatment with First-line antibiotics: (heavy duty penicillins)
• Penicillin V, Penicillin G benzathine* (1 dose only, intramuscular (IM) - injectables, or Amoxicillin (don’t work as much anymore - children exposed to many microbials will probs be less responsive to those antimicrobials esp. depending on source of where infection was from)
• For penicillin allergies: (some extended spectrum B-lactamases b/c diff. allergy levels)
• cephalexin, cefadroxil, clindamycin, azithromycin** (5 day only treatment), clarithromycin (protein inhibiting antimicrobials - higher freq. of resis.)
- drug antimicrobial cocktails are popular now
Acute Infectious laryngitis (AL)
is caused by inflammation of the (vocal folds & cords of) larynx (hard to talk; raspy during sickness b/c of this)
How long does Acute Infectious laryngitis (AL) last & when does it become chronic?
- mild and self-limiting condition that typically lasts for 3 to 7 days
- If this condition lasts for over 3 weeks, then it is termed as CHRONIC LARYNGITIS
How is Acute Infectious laryngitis (AL) most commonly caused by?
viral organisms listed for other URIs (AVB, AVP)
- in pediatric (children are at higher risk) AL also includes “CROUP” (laryngotracheobronchitis) caused by PARAINFLUENZA VIRUS
Which infection doesn’t have viral cause & is mostly due to bacterial infection?
ottis media (ear infection)
AOM (ear infection) is commonly caused by…
bacterial (refer to earlier)
Signs & symptoms of Acute Infectious laryngitis (AL)
voice changes (hoarseness or a “raspy” voice), aphonia, or a dry cough, pain swallowing, dryness of throat, malaise, and fever
Acute Infectious laryngitis (AL) risk factors:
similar to AR/AP but also gastroesophageal reflux disease (GERD) is often a common co-morbidity (a lifestyle change) (& singers/radio hosts)
- esophagus is in close proximity to larynx; acid can spill into trachea (acid reflux can damage larynx too)
Acute Infectious laryngitis (AL) etiology
- Most commonly caused by viruses; the same viruses as AVR
- Bacterial causes are less common; same as ABR
Why are bacterial causes less common; but same as ABR? (i.e. why sinuses opposed to pharynx)
b/c of where sinuses are draining
- tend to drain further back of pharynx (greater chance of sinus infection getting to larynx than others)
Acute Infectious laryngitis (AL) diagnosis & treatment
Examination using LARYNGOSCOPE (fiberoptic or mirror scope)
• VOICE REST + similar supportive care (help fever etc.) as AVR unless bacterial etiology is suspected → then similar to AOM
• Treatment of uncontrolled GERD symptoms if present
• For CROUP add corticosteroid treatment (b/c should reduce swelling quickly due to their narrow airways)
Which common URI viruses are HIGH causes of AP cases?
RHINOVIRUS (20% - HIGH)
Which common URI viruses are HIGH causes of AVR cases?
- Rhinovirus
- Adenovirus
- Influenza virus
- Parainfluenza virus
Which common URI viruses are HIGH causes of AOM cases?
- Rhinovirus
- Respiratory syncytial virus (RSV)
