URTI Flashcards
examples of upper resp tract infection (URTI)? (4)
- influenza
- common cold
- pharnygitis
- rhinosinusitis
- otitis media
examples of lower resp tract infection? (2)
- pneumonia
- bronchitis
- tracheitis
clinical presentations of pharyngitis?
- acute onset of sore throat
- pain with swallowing
- fever
- erythema and inflammation of pharynx
- tender and swollen lymph nodes
microbio of pharyngitis
virus (80%)> bac
- virus: rhinovirus, coronavirus, influenza
- bac: group A hemolytic streptococcus eg. S pyrogenes
pathogenensis of pharyngitis
- direct contact with droplets of infected saliva
- short incubation of 24-48h
complications of pharyngitis
- Viral: self limiting
- S. pyrogenes: self lim or complicatiosn pos (occurs 1-3 weeks later)- acute rheumatic fever, acute glomerulonephritis
how to prevent complications of pharyngitis (eg. acute rheumatic fever)?
early initiation of effective ab
diagnosis of pharyngitis
testing for s. pyrogenes
- throat culture (24-48h)- high sensitivity 90-95%
rapid antigen detectiontest (minutes)- sen 70-90
pharyngitis treatment
both viral and bac: supportive care
- analgesic/ antipyretic: paracetamol, NSAIDs
- topical analgesic lozenges/ sprays (eg. benzydamine)
- saltwater gargle
- adequate fluid and rest
ONLY BAC’- PO ab (10 days)
what PO ab are used to treat pharyngitis?
1st line: penicillin VK alt - amoxicillin - cephalexin - clindamycin - clarithromycin
monitoring of pharyngitis
clinical response expected within 24-48 h
counsel on completing ab course
use of corticosteroids controversial (adverse SE)
what is rhinosinusitis/ sinusitis?
acute (within 4 weeks) inflam and infectionof paranasal and nasal mucosa
what are the major sx of rhinosinusitis
- purulent anterior nasal discharge
- purulent or discoloured posterior nasal discharge
- nasal congestion/ obstruction
- facial congstion
- facial pain/pressure
- fever
minor sx of sinusitis?
- headache
- ear pain, pressure
- halitosis
- dental pain
- cough
- fatigue
hwo to confirm presence of sinusitis?
> = 2 major sx OR
1 major + >= 2 minor sx
sinusitis microbio
virus (90) >> bac virus - rhonivirus, adenovirus, influenza bac - strep pneuno, H flu
sinusitis pathogenesis
- direct contact with droplets of infected saliva or nasalsecretions
- bacterial cases usually preceded by viral URTI (eg. pharyngitis, common cold)
- inflam results in sinus obstruction (nasal mucosal secretions trapped, medium of bacterial trapping and multiplication)
sinusitis diagnostic challenges
- bac and viral have similar sx
- limited use of diagnostic tests (imaging studies: non specific, non discrimatory_, sinus aspirate: invasive, time consuming , painful)
hwo to diagnose presence of BAC sinusitis?
sx thing +
presence of any ONE criterion
- persistent of sx. >10 days (viral self limiting, resolves in 7-10 days)
- severe sx at onset eg. purulent discharge for 3-4 days or high fever >39
- double sickening (worsening sx after 5-6 days after initial improvement)
why give PO ab tx for bacterial sinusitis
start empiric ab
- shorten duration of sx
- earlier sx releif
- restore quality of life
- prevent complications
sinusitis tx
supportive care
- analgesic/ antipyretic: paracetamol, NSAID
- nasal steroid spray
- saline irrigation
- expectorant: guaifenesin
- nasal/systemic decongestant/ antihis
sinusitis first line ab
amoxicillin or amox/clav (augmentin)
sinusitis alt ab
- resp FQ: LEVOfloxacin or MOXIfloxacin
- *CIPROfloxacin is NOT a resp FQ–> poor activity against Strep pneumo (more common bac that causes sinusitis)
- trimethoprim/ sulfamethoxazole
- oral 2nd cephalosporin: cefuroxime
sinusitis tx considerations ( resistance)
- strep pnuemo
- multistep penicillin binding proteins mutation
- increase penicillin MIC with each mutation– therefore gets more resistant
- penicillin resistant isolates uncommon locally
thus, prefer high dose amox for effective tx - h flu
- beta lactamase production
- inhibited by beta lactamase inhibitor
what is the preferred dose for amox to treat sinusitis?
standard: 45mg/kg/day (ped), 250-500mg (Adults) high dose (preferred): 80-90mg/kg/day, 1g (adult)
when to use amox/clav for sinusitis?
use for beta lactamase positive H flu, and has any criteria
- recent course of ab
- recent hospitalisation (30 days)
- failure to improve after 72h of amox
how long is the tx duration for sinusitis
adult: 5-10 days
- improves compliance
- reduce ab related ADR
- simialr clinical cure
ped: 10-14 days
what is acute otitis media (AOM)
infection of middle ear space resulting in inflammation and fluid accum
AOM clinical presentation
- ear pain
- ear discharge (otorrhea)
- ear popping
- ear fullness
- hearing impariment
- dizziness
- fever
- non specific in young infants: ear rubbing, excessive crying, change in sleep or behavioural pattern
AOM prevention
- avoid exposure to tobacco smoke
- exclusive breastfeeding for 1st 6 months (passive immunity of ab)
- minimize pacifier use
- vaccinations (influenza, pneumococcal, H flue type B vaccine)
AOM microb
- bac (55%), viral (40-45) virus - resp synctial virus, rhinovirus, adenovirus bac - strep pneumo, H. influenzae (similar to sinusitis)
AOM diagnosis
pneumatic otoscope as standard tool
AOM diagnostic criteria in children
- acute onset (<48h)
- otalgia (holding , tugging, rubbing in non verbal), erthyema of tympanic membrane
- bulging of tympanic membrane
AOM challenges in management
- unable to distinguish bac vs viral
- bac AOM : prompt ab initiation decreaes duratino of sx by 1 day, 80% of cases reoslve without ab
- overprescribing ab–> resistance
AOM tx- supportive care
- analgesic. antipyretic: paracetamol, NSAID
- decongestant and antihistamine NOT shown to be benficial
AOM tx : Ab
- ear drops not rec, use PO ab
1. immediate initiation - start ab at the initial doctors visit where AOM is diagnosed
2. observation period - no ab given at the initial doctors visit supportive care x 48-72h
- improves–> no ab
- worsens or fails to improve –> ab
- req reliable follow up
- may req 2nd trip to doctor
3. watch and wait - prescription given at initial doctors visit
- fill in 48 hours only if worsens or fial to improve
- 2/3 prescriptio not filled
- increased convenience and parent satisfaction
- more used in western/ bigger country coz inconvenient to travel to hospital
when is observation period considered? what are the criterias?
- > 6months
- non severe illness, absence of all severe (severe: otalgia, otalgia>48h, >39C in last 48h)
- no otorrhea
- pssible for close follow up
- shared decision making with parent.caregiver (parent to monitor child)
AOM first line tx ab
amoxicillin
- pt needs to fulfill ALL 3 criteria
a. no amox in the last 30 days (more likely to hv resistant if took)
b. no concurrent purulent conjunctivitis
c. not allergic to penicillin`
AOM alt first line ab tx
amox/clavu give if any 1 is applicable - amox in last 30 days - concurrent purulent conjuctivitis - hx of AOM non responsive to amox
AOM alternative ab
- cefuroxime, ceftriaxine (IM)
- clindamycin (severe pen allergy)
AOM monitoring
- may worsen in first 24h
- improvement expected in 48-72h
re-evaluate if worsensof fail - amox–> change to amox/clavu (wider spec)
- augmentin–> cefuroxime, ceftriaxone
AOM tx duration
<2yo: 10 days
severe sx: 10days
2-5yo AND non severe sx: 7 days
>6yo AND non severe: 5-7 days
what type of distribution does influenza have in SG?
bimodal- 2 peaks
who is the host of influenza A?
humans, swine, avian…
host of influenza B>
humans only
host of influenza C?
humans, swine
clinical presentation of influenza A?
- most severe
- causes epidemics and pandemics
clinical presentation of influenza B?
severe illness in older adult or high risk pt
influenza complications (5)
- viral penumovia
- post influenza bacterial pneumonia (esp those caused by s aureus)
- resp failure
- exacerbate underlying pulmn or caridac comorb
- ferbile seizure
- myocarditis
what population is at high risk for influenza related complciations?
- children >5yo
- elderly >65
- women pregnant or within2 weeks post partum
- residents of nursing homes of long term care facil
- obese
- chronic medical conditions eg. asthma, COPD (cardio-pulmn conditions)
influenza prevention
- good personal hygiene
- wash hands
- minimise touching of eyes, nose, mouth
- cover nose and motuh when coughing, sneezing - healthy lifestyle
- balanced diet
- exercise regularly
- adequate sleep
- do not smoke - vaccination (most effective)
- inactivated trivalent or quad vaccine
- indicated for ALL indv >6months - chemoprophylaxis (use drugs to prevent)
a. pre-exposure (prevent before being exposed)
- institutional outbreak or high risk insv >3 months yo who cannot receive vaccination
- HOW: initiate as soon as outbreak or influenza activity is identified
b. post exposure
- all high risk indv >3months yo OR unvaccinated indv who are household contacts of high risk indv
- HOW: initiate asap (within 48h) of exposure
influenza diagnosis
- viral culture not rec (long time to get results)
- molecular testing avail (but limited use in outpatient–> mostly treated empirically. used inpt)
influenza tx
initiate asap within 48h of sx onset for isv who fulfill any ONE of the following
- hospitalised
- high risk for complications
- severe, complicated or progressive illness
influenza antiviral tx
- oseltamivir PO is first line for tx and chemoprophylaxis- active against influenza A and B
MOA: neuraminidase inhibitor - interferes with protein cleavage
- inhibit release of new virus/ replication
well tolerated (se eg. headache, mild GI)
dose for oseltamivir to treat chemoprophylaxis ininfluenza
75mg PO daily
duration 7 days
dose for oseltamivir for tx of influenza
75mg PO BD 5 days
prolong if pt is critically ill
