URTI, CNS Flashcards
1
Q
Upper RTI Transmission
A
§ Droplets of aerosols containing virus are expelled when people with URTI cough/ sneeze/ talk
§ Spread indirectly when person touch surface with virus on it –> touch nose/ mouth
§ Shares food with others during mealtime w/o serving spoon
§ Inhaled into resp tract
- Invade upper airway mucosa (infection)
2
Q
Innate immunity against URTI
A
§ Nostril hair lining traps organisms
§ Mucus traps organisms
§ Angle b. pharynx and nose, prevents particles falling into airways
§ Mucocilliary system in lower airways that transport pathogens back to pharynx
§ Adenoids and tonsils contain immunological cells that attack pathogens
3
Q
Risk factors for URTI
Decr innate immunity
Incr bacterial load
A
§ Close contact with children (school, daycare)
§ Lack of personal/ HH
§ Medical disorder
□ Chronic resp disease – asthma, AR
§ Smoking
§ Immunocompromised indiv
□ Cystic fibrosis, HIV, corticosteroids, transplant, post-splenectomy
§ Anatomical anomalies
□ Facial dysmorphic changes
□ Nasal polyposis
4
Q
Prevention of URTI
A
Hand/ personal hygiene, wear mask, stay away from sick contact/ crowds
Vaccination
□ Influenza
□ Pneumococcal
□ Haemophilus influenzae
Manage risk factors: smoking cessation, control asthma, AR
5
Q
Management URTI
A
-Symptoms management
□ pharm, non-pharm self-care modalities
□ AB use
- Not indicated for COMMON COLD, INFLUENZA
- Sometimes for PHARYNGITIS, RHINOSINUSITIS, OTITIS MEDIA
- Prevent future recurrence (reduce risk factors)
6
Q
sx relief of URTI by
A
paracetamol
NSAID
nasal decongestant
antihistamine
nasal irrigation (saline)
lozenges
mucolytics
cough supp
expectorant
warm water// honey
7
Q
Common cold clinical presentation
Presence of infection
A
- Risk factors (URTI)
- Clinical presentation:
○ Low grade temp <38*C
○ Rhinorrhea
○ Nasal blockage
○ Sneeze
○ Sore throat
○ Productive cough
○ Headache
○ Body ache
- NO high fever, normal HR, lungs clear to auscultation support diagnosis of common cold
8
Q
2) Identify pathogen of common cold
A
- No microbial diagnostics required
○ Unless rule out influenza/ covid19 - Pathogen – rhinovirus, coronavirus
9
Q
common cold 3)Abx? 4) monitor
A
3) DO NOT USE ANTIBIOTICS
4) Monitor:
* Self-limit, recover in 7-10 days
* Normal for nasal discharge to change colour
○ Yellow, green due to infection viral/ bact
* Cough last 2-3 wks
○ Post nasal drip
* Feel better in 3-4 wks
○ Symptoms linger for few wks
○ May risk 2nd infection
See dr if symptoms does not improve after 10 days/ symptoms WORSEN
10
Q
Influenza (flu) 1) presence of infection
A
- Clinical presentation
○ Classic influenza sx
§ Fever (>38)
§ Chills
§ Headache
§ Malaise
§ Myalgia
§ Anorexia
○ Resp sx
§ Sore throat
§ Dry cough
§ Nasal discharge
○Elder pt (confusion)
11
Q
Complications of influenza
A
○ Primary viral pneumonia
○ 2nd bacterial pneumonia
§ Staphylococcus aureus
§ Streptococcus pneumoniae
§ Haemophiles influenzae
○ Exacerbation of chronic resp disease
myocarditis
12
Q
pt at high risk of influ complications
A
- Child <5// elderly >65
- Preg/ 2wks post-partum
- Nursing homes/ LT care
- Obese BMI > 40kg/m2
- Chronic medical conditions
Asthma, COPD, HF, DM, CKD, immunocompromised
13
Q
Confirm presence of influenza infection
A
- Diagnostics on nasopharyngeal swab/ aspirate
○ Rapid detection kits
○ POCT (immunofluorescence IF, enzyme immunoassay (EIA), immunochromatographic - Reverse-transcriptase, PCR
**hosp/ LT care
Not for outpatient setting
14
Q
influenza types
A
Human influenza A,B,C,D
A: seasonal epidemic
§ Cause pandemic
§ Subtypes based on 2 surface proteins
□ Hemagglutinin (H)
□ Neuraminidase (N)
□ Usual: H1NI, H3N2
B: seasonal epidemic
§ Classified into 2 lineage
B/Yamagata
B/ Victoria
C: mild, non epidemic
§ Febrile, mild URI
D: cattle
15
Q
influenza season
A
Seasonal (beginning, end, middle) due to North, Southern hemisphere winter mnths + travel
north (NOV – FEB)
south (MAY – JULY)
16
Q
Select antimicrobial tx for influenza
A
- Antiviral for documented or suspected influenza
○ Initiate ASAP best within 48HRS, up to 5 days
○ Of sx onset for indiv who fulfil:
§ Hosp, high risk of complications
§ Severe, complicated, progressive illness
○ Considered for outpt/ others if present within 48hrs of sx onset
17
Q
1) oseltamivir
A
a. First line
b. Active against influenza A, B
MOA: neuraminidase inhibitors
i) Inhibit release of new virus
ii) Interfere with protein cleavage
c. Dose: i) PO 75 mg BD for 5 days ii) Dose adj if CrCL <60ml/min d. ADR: Well tolerated, mild GIT (NV)
18
Q
influ vaccination
A
- Trivalent/ quadrivalent vaccine
- Prepared from prevailing strain of influenza A, B
- Vaccine updated every year (predicted predominant strain of season – guess work)
○ North: Nov, Feb
§ Vacc by oct
§ Release in apr/ may
○ South: May, Jul - IM once per yr
- For person > 6mnths old
○ Esp if high risk of complications - Takes 2 weeks for immunity
- Vaccine efficacy 75%
19
Q
monitor for influenza
A
- With flu, do not need medical or antiviral
- Sx may last up to 1 wk
- See dr if:
○ Sx not improve after 10 days
○ Sz improved –> developed (DOUBLE SICKENING)
§ New fevers, worsen dyspnea, cough
§*2nd bact infection
20
Q
pharyngitis presence of ifnection
A
- Clinical presentation
○ Sore throat
○ Fever
○ Erythema, inflammation of pharynx, tonsils
§ With or without patchy exudate (pus/ patch)
○ Tender, swollen lymph nodes
21
Q
VIRAL PHARNGITIS
A
Erythematous tonsils w/o hypertrophy, exudates
○Low grade fever < 38
○ Malaise
○ Fatigue
○ Rhinorrhea
○ Cough
○ Hoarseness
○ Oropharyngeal lesions
§ Ulcer, vesicles
○ Conjunctivitis
22
Q
BACT PHARYNGITIS
A
- Sore throat w/ tonsillar exudate
- Enlarged tonsils (hypertrophy)
- Fever
- Cervical lymphadenopathy
○ Enlarged lymph nodes
w/o typical viral symptoms
23
Q
Identify pathogen for pharyngitis
A
i. Virus (80%)
a. Rhinovirus, coronavirus, influenza, parainfluenza, Epstein-Barr
ii. Bact (<20%)
a. Grp A (b-hemolytic) streptococcus
b. Streptococcus pyogenes
- SSTI (non purulent)
24
Q
what tests to culture for pharyngitis
A
Strep. pyogenes:
○ Throat culture (24-48hr)**
○ Rapid antigen detection test (RADT) – in mins
25
viral vs bact pharyngitis
1. Viral: self-limit
2. Bact: S.pyogenes
a. Self-limit/ complications possible
b. Complication: 1-5/ 2-3 wks ltr
i. Acute rheumatic fever
- Prevented with early initiation of effective AB
ii. Acute glomerulonephritis
- Not prevented by AB
26
Centor criteria
○ Fever >38 (1)
○ Swollen, tender anterior cervical lymph nodes (1)
○ Tonsillar exudate (1)
○ Absence of cough (1)
○ Age
3-14 (1)
15-44 (0)
>45 (-1)
27
pts for centor criteria
0-1 (low risk s.pyogenes, viral)
2,3 (test for s.pyogenes, treat Abx if +ve)
4,5 (high risk s.pyogenes, empiric)
28
chocie of Abx for pharyngitis
○ PO penicillin VK 250mg q6h
- T > MIC, duration!
○ Amoxicillin 500mg q12h
No need broad spectrum, narrow (no need -ve, anaerobe cover) <-- amox-clavu
* duration: 10days
29
Abx for pharyngitis if pen allergy
○ Non severe: PO cephalexin 500mg q12h
- Unless amoxicillin allergy, same R1)
○ PO azithromycin 500mg OD
○ Clarithromycin 250mg q12h
○ Clindamycin 300mg q8h
- Growing resistance to macrolide (ACE)
(5 days if azithromycin -- accumulate well in tonsils)
30
monitor for pharyngitis
* Clinical response
○ If not given AB
§ Typical course of sore throat is <1wk, self limit
§ AB not for viral pharyngitis
○ Given AB
§ Fever, symptoms resolve 1-2 days
* NO NEED Microbiological test of cure
AB ADR
31
rhinosinusitis presence of infection
* Acute:
○ Within 4wks
○ Inflammation, infection of paranasal and nasal mucosa
32
rhinosinusitis pathogenesis
○ Direct contact with droplets of infected saliva/ nasal secretions
○ Bact:
§ Preceded by viral URTI
§ (common cold, pharyngitis)
○ Inflamm
§ Sinus obstruction as nasal mucosal secretions trapped
§ Medium of bact multiplication
33
Common sx for rhinosinusitis
○ Purulent nasal discharge
○ Facial pain, pressure
○ Fever
○ Nasal congestion, obstruction
○ Reduced sense of taste (hyposmia), smell (anosmia)
○ Headache
○ Cough
○ Ear fullness, pressure
○ Bad breath
○Dental pain
34
Confirm presence of infection for rhinosinusitis by culture/ imaging?
* NO NEED Culture swabs of nasal discharge
* NO imaging indicated
* Emergency Department for further eval IMAGING!:
○ Spread infection to orbitis
○ CNS
§ Limited ocular movements
§ Acute vision change
§ Confusion
§ Unilateral weakness
35
identify pathogen for rhinosinusitis
* Virus > 90%
* Bacterial <2%
○ 2nd infection from obstruction of sinus (from viral URTI)
* Most common:
* Streptococcus pneumoniae
* Haemophilus influenzae
* Some:
* Streptococcus pyogenes
* Moraxella catarrhalis
Anaerobic bact
36
culture for rhinosinusitis?
* Limited use of culture diagnostic to confirm if viral or bact sinusitis
Decision to treat bacterial sinusitis based on clinical presentation
37
Abx for rhinosinusitis (bact) only if
if any 1 of these following (3):
a. Symptoms persists > 10 days
i. w/o clinical improvement
b. Symptoms severe
i. Fever > 38*C
ii. Purulent nasal discharge
iii. Facial pain > 3 days consecutive
c. Symptoms worsen after initial improvement
*double sickness! (more than 3 days or (5-6 days)
i. New-onset fever
ii. Headache
iii. Incr nasal discharge
38
1st line Abx for rhinosinusitis
5-7 days for adults
1. PO amoxicillin 500mg q8h
2. PO amoxicillin/ clavulanate 625 mg q8h
.Penicillin allergy
1. Non severe: PO cefuroxime (2/3rd gen) 5oomg q12h
2. PO levofloxacin 500mg
3. PO moxifloxacin 400mg
39
incr resistance by strep pneumo against which Abx
No tetra/ TMP-SFX/ macrolides
40
strep pneumo vs H.influ
strep pneumo
- need High dose Amox to overcome penicillin resistant strep pneu
(change in PBP)
H.influ
- amox-clav used to overcome b-lactamase producing H.Influ
41
Monitor response for rhinosinusitis
* Clinical response
○ If not given AB
§ Typical course of 7-10d
§ AB not needed if viral/ non severe bact sinusitis
○ Given AB for 5-7d
§ Sx improve 7-10 days
* See dr if return develop persistent, severe, worsening sx
*AB ADR
42
flu vs covid
○ Clinical presentation similar
○ Wide spectrum of disease (many strains)
§ From self-limiting --> severe illness
§ Complications= hosp, death
○ Treatment, vaccination available
BUT COVID:
- more contagious (transmit before sx appear)
- more severe illness in vulnerable pop
43
CA bacterial meningitis causes
Meningitis is inflammation of (lepto) meninges
* Between the 2 layer = Arachnoid, pia mater
Cause:
* Infection
○ Bacteria (septic meningitis)
○ Virus (enterovirus, herpes)
○ Other micro-org
§ Fungal (cryptococci)
§ Parasitic (malaria)
§ Mycobacterium (TB)
§ Syphilis
* drugs
* autoimmune disease
**aseptic meningitis (if not bact cause)
44
2 drugs that may cause meningitis
TMP/ SMX
Ibuprofen
45
pathogenesis for meningitis
1) Immune deficiency/ corticosteroids
a. Prolonged close contact with ifnected
b. Endemic areas
2) Predispose infection and colonisation of bact
3) Bacteria enter body via various mechanism
4) Susceptible host. Bact enter CNS and colonise meninges (esp arachnoid)
46
how bact enter meninges
a. Invasion of mucosal surface (resp tract) then hematogenous spread to brain
i. Blood supplies CSF
b. Spread from para-meningeal focus (otitis media, sinusitis)
c. Penetrating head trauma
d. Anatomic defects in meninges
e. Previous neurosurgical procedures
47
predisposing factors of bact meningitis
* Head trauma
* CNS shunt
○ Tube to CSF for drainage
○ Tube allows biofilm
* Neurosurgical pt
○ Insult, bact introduced
* CSF fistula or leak
○ Entry of microorg
* Local infections
○ Sinusitis
○ Otitis media
○ Pharyngitis
* Immunosuppression
* Splenectomised pt
* Congenital defects
* Varies substantially by geographical region
○ African > high income countries
* M > F pt
* Children, immune not developed
48
1) presence of infection (Sx)
Symptoms
○ Fever chills (general infection)
○ Classic triad of sx
§ Headache, backache, neural (neck) rigidity
○ Mental status changes (irritability), photophobia
○ NV, anorexia, poor feeding habits (infant)
○ Petechiae, purpura (Neisseria meningitidis)
49
Physical signs, examination of meningitis
Kernig sign (back pain)
Brudzinski sign (reflex in knees and hips)
Bulging fontane (in infants, skull not fully fused)
50
diagnosis for meningitis
* History
* Blood cultures
○ +ve culture is 70-80% chance of bact meningitis
* Lumbar punctures
* General lab findings
○ WBC, CRP, procalcitonin
§ Signs of systemic infections (inflammation)
§ Non-specific for bacterial meningitis
* Radiology: brain imaging (CT/ MRI)
51
lab results
- WBC > 4 x10*9
- CRP <10, >40
- procalcitonin 0.5-1ug/L
52
when is brain imaging done for meningitis
○ Not required for diag. but done to differentiate diagnosis and complications (STROKE, other CNS condition)
○ Prior lumbar puncture
§ If pt have mass lesion
If done after: brain shift. Brain herniation during LP
53
LP for
Between L3-L4, Draw out fluid
○ Elevated Opening Pressure
○ CSF composition
○ CSF gram stain and culture (AST)
○ CSF PCR
§ Nucleic acid presence of specific bact
§Fast + small qty needed
54
glucose, ratio to blood
norm:
2.6-4.5
CSF: blood >0.66
bact:
Very low
CSF: blood <0.4
viral: Norm to slight low
55
protein
N ; <0.4 g/L
B: Raised >1.5g/L
V: Normal to mild raised
56
WBC
N: <5 cells/mm3
B: Raised (>100) cells/mm3
neutrophils = pleocytosis
V: Raised (5-1000) cells/mm3
lymphocytes (clear virus)
57
causative pathogens by age grp
neonates <1mn
Grp B streptococcus, streptococcus agalactiae
Birth canal if mother is strep colonised
Escherichia coli
Listeria monocytogenes
Immunocompromised
Ceftriaxone + ampicillin (listeria)
58
causative pathogens by age grp
Infants, children 1-23mn
Streptococcus pneumoniae
Neisseria meningitidis
Covered by vaccine, meningococcal
streptococcus agalactiae
Escherichia coli
Ceftriaxone + vancomycin
59
Children, adults 2-50yo
Streptococcus pneumoniae
Neisseria meningitidis
Ceftriaxone (strep pneumo) + vancomycin
60
Adults > 50 yo
Streptococcus pneumoniae
Neisseria meningitidis
Listeria monocytogenes
Immunocompromised
Aerobic gram neg bacilli
E coli, klebsiella species
Ceftriaxone + vancomycin + ampicillin (listeria)
61
Listeria monocytogenes is a____
* Gram +ve, intracellular rod bact
○ found in moist environ, soil, water
○ Food borne (replicates in refrigerator temp -- cold deli meats, unpasteurized dairy pdt)
* Infect young, old!
62
Neisseria meningitidis is a____
* Fastidious, encapsulated aerobic gram neg diplococcus
* Habitant of nasopharynx of healthy individual
-Coloniser --> invade
63
meningitis -- Streptococcus pneumoniae tx + duration
Penicillin susp
* Penicillin G, ampicillin
Penicillin resistant, cephalo susp
* ceftriaxone
Pen, cephalo resistant
* Vancomycin + rifampicin
10-14
64
Neisseria meningitidis tx + duration
Penicillin susp
* Penicillin G, ampicillin
Penicillin resistant, mild allergy (rash, no extensive, anaphy)
* ceftriaxone
5-7
65
Listeria monocytogenes tx + duration
Penicillin G, ampicillin
Penicillin allergy
* CMX
* Meropenem
○ Low cross react
>21
66
Grp B streptococcus, streptococcus agalactiae
tx + duration
Penicillin G, ampicillin
Penicillin allergy, mild:
* ceftriaxone
14-21
67
if culture neg for meningitis
Culture-negative:
* Treat with empiric Abx for at least 14 days
* Extended depending on condition of pt
68
meningitis adjunct therapy
CS ADJUNCT: beyond neonatal age (>6wks) H.Influenzae & strep pneumoniae meningitis
dexamethasone 10mg QDS 4days
ADV:
- Less hearing loss and other neurological sequelae in H.Influenzae & strep pneumoniae meningitis
- Decr mortality in strep pneumoniae meningitis
DISADV:
-Decr Abx penetration
- Decr inflammation, less leaky BBB, less conc of Abx in meninges
69
CS dose
Dexamethasone (adult dose) 10mg, every 6hrs. Up to 4 days
- If culture shows NOT H.Influenzae & strep pneumoniae meningitis
- Stop early
70
why admin timing
Administer 10-20mins before/ same time as 1st dose of Abx
○ So that prevent Abx cause more inflammation
○ Prep, prevent inflam
71
Monitor response for meningitis
* Therapeutic response
* Most pt will improve within 48hr
* NOT:
○ Brain imaging
§ to detect cerebrovascular complications
§ Stroke, brain abscess
* No need repeat microbiological test if pt improve clinically
* ADR
* Morbidity common in bact meningitis
* Focal neurological deficits
○ Hearing impairment, cognitive impairment, seizure
* Adults at high risk of LT neurological and neuroPSYCHOLOGICAL deficits
○ Impact daily life activities and QOL
72
considerations for choice of Abx for meningitis
1) Active against pathogen
2) Distribute to CSF, adequate CSF conc
a. High dose and IV admin (suff conc)
3) Does not aggravate CNS morbidity
a. No b-lactams, imipenem (ADR: seizure at high conc)
4) Dose adj if renal pt
a. No accumulate dose, risk seizure too
73
Chemoprophylaxis --- close contact
Neisseria meningitidis
* Risk of meningococcal disease incr 400-800x in indiv in close contact (HH members) / exposure to oral secretions
* RIFAMPICIN
* CIPROFLOXACIN: 500mg PO, 1 dose
○ Adult only
○ Children, <18yrs: affect bone, joint development, Risk arthropathy
* CEFTRIAXONE: 125-250mg IM, 1 dose
HiB vaccination
74
rifampicin prophylaxis dose
Adult: 600mg every 12h, 4dose
Child: 10mg/kg, every 12hr, 4 dose
Infant (<1mn), 5mg/kg every 12hr, 4 dose
75
lab results
- WBC > 4 x10*9
- CRP <10, >40
- procalcitonin 0.5-1ug/L
