Gram Positive Infections Flashcards
are Group B Streptococcal Infections gram positive or gram negative?
positive
Group B Streptococcal Infections
Where are these bacteria usually found?
normal vaginal flora
Group B Streptococcal Infections
why do we test pregnant women for this?
- to see if it’s present (normal vagina flora, but want to know potential for infection)
- don’t want to pass bacteria to baby during delivery
Group B Streptococcal Infections
what do we do if a pregnant women tests pos?
abx treatment for weeks prior to birth
Group B Streptococcal Infections
why do we treat pregnant women prophylactically?
can spread to baby during birth & the bacteria is much more serious in newborns.
Group B Streptococcal Infections
What infections can this lead to?
3 most common, 3 less common
Most Common: septic abortion, endometritis, peripartum infection
Less Common: cellulitis, bacteremia, endocarditis
Group B Streptococcal Infections
Treatment
Penicillin
Vancomycin
Group B Streptococcal Infections
Can lead to what in neonates?
3 not so great things
- bacteremia
- sepsis
- meningitis
Strep Viridans
Are strep viridans hemolytic?
No- they are nonhemolytic
Strep Viridans
Where are strep viridans typically found?
normal oral flora
Strep Viridans
What do strep viridans most commonly cause?
native valve endocarditis
Group D streptococci
Group D streptococci
which bacteria is group D?
Streptococcus gallolyticus
Group D streptococci
what 2 things do people who become ill from this usually have?
GI cancer or cirrhosis
Group D streptococci
what is secondary to this infection?
endocarditis
Group A Streptococcal Infection Types
4 categories
- Non-invasive Infections
- Exotoxin Mediated Disease
- Non-supportive Immune Related Sequalae
- Invasive Infections
Group A Streptococcal Infection
Example of non-invasive infection
Bullous Impetigo
covered in Derm not ID
Group A Streptococcal Infection
Example of Exotoxin mediated disease
Scarlet Fever
Group A Streptococcal Infection
Example of Non-suppurative immune related sequalae
Rheumatic Fever
Group A Streptococcal Infection
Examples of Invasive Infections
4
Cellulitis (covered in Derm not ID)
Abscess
Bacteremia
Infective Endocarditis
Scarlet Fever
AKA
strep throat
Scarlet Fever
people with this have often recently been ______
exposed to someone with strep throat
Scarlet Fever
signs
5 things
- Exudative pharyngitis
- Bright red exanthem
- Flushed face
- Circumoral pallor
- Tongue coated with enlarged red papillae
Scarlet Fever
sx
7 things
- abrupt onset of fever
- sore throat
- headache
- chills
- nausea
- myalgias
- malaise
Scarlet Fever
what causes rash to develop?
group A beta-hemolytic streptococci toxin causes rash
Scarlet Fever
Physiology of rash occuring from toxin exposure
- local production of inflammatory mediators and alteration in cutaneous cytokines
- Dilation of blood vessels leads to characteristic scarlet color
Scarlet Fever
Evolution of “Strawberry Tongue”
- Day 1/2: tongue heavily coated with white membrane through which you can see edematous red papillae protrude
- Day 3/4/5: white membrane sloughs off, revealing shiny red tongue with prominent papillae
Scarlet Fever
Rash Characteristics
- diffusely erythematous w/ find red papules (sandpaper consistency)
- greatest in groin and axillae
- blanches (touch it and it goes away, then returns when no touch)
Scarlet Fever
how could texture of rash be described?
PPP
sandpaper
Scarlet Fever
How long after onset of fever does rash occur?
12-48 hrs
Scarlet Fever
How does rash change over course of illness?
- 12 to 48 hrs: onset, appears on neck
- travels to trunk/extremities
- 2 to 5 days: fades leaving desquamation, peeling occurs
Scarlet Fever
Timeline
Untreated: fever peaks by 2nd day, afebrile by days 5-7
Treated: fever abates 12-24 hrs after abx initiation
Scarlet Fever
Dx
- primarily a clinical diagnosis
- test: rapid strep test or throat culture
Scarlet Fever
when to do culture vs rapid test?
if rapid test was negative but you still suspect strep, send off for culture.
Strep Throat
do not treat until you have ?
positive test result
Scarlet Fever
Treatment
3 options, give med, route, dosage, and duration
Treat strep pharyngitis
* Pen VK 500mg PO 2-3x daily for 10 days
* Amoxicillin (tastes better) 500 mg PO 2x daily for 10 days
* PCN G benzathine 1.2 million units IM x 1 (expensive, not readily available)
Scarlet Fever
when to use PCN shot vs amox series?
worried about non-compliance, kids refuse meds, recurrent infections (indicating non-complicance)
Acute Rheumatic Fever
Define
autoimmune inflammatory process that develops after beta-hemolytic streptococcal pharyngitis
perivascular granulomatous rxn with valvulitis
Acute Rheumatic Fever
Epidemiology
- Most common in developing countries
- 250,000 deaths worldwide/year
- Peak incidence between ages 5-15
- Predisposition to recurrence
Acute Rheumatic Fever
Complication
Rheumatic heart disease
Acute Rheumatic Fever
Molecularly mimics which other disease?
Scarlet Fever
* immune response aimed at strep antigens
* recognizes human tissue especially on endothelial cells on heart valves
Acute Rheumatic Fever
Clinical Presentation
sx onset after what?, % of people with groups of presentations
- Typically sx onset is 2-3 wks after strep throat infection
- Variable presentation
- Carditis 50-70%
- Arthritis 35-66%
- Chorea 10-30%
- SubQ nodules 0-10%
- Erythema marginatum < 6%
Acute Rheumatic Fever
what presentation are we most worried about?
it’s the most common
cardiac complications
Acute Rheumatic Fever
Diagnosing
5 things
- Troat culture
- ASO titer
- ESR
- CRP
- Echo
no specific diagnostic tests
Acute Rheumatic Fever
what does the Jones criteria help a provider determine?
when/whether to treat for strep
Acute Rheumatic Fever
Treatment
med, dosage, duration, freq
Treat group A strep infection
* Pen VK 500mg PO 2-3x daily for 10 days
* Amoxicillin (tastes better) 500 mg PO 2x daily for 10 days
* PCN G benzathine 1.2 million units IM x 1 (expensive, not readily available)
Acute Rheumatic Fever
Symptomatic Tx
1 med, 1 action
Salicylates (ex: Aspirin)
Bed rest for carditis
Acute Rheumatic Fever
Continuous abx prophylaxis for years
what med/dosage/freq
PCN G benzathine 1.2 mil units IM every 3-4 wks
Acute Rheumatic Fever
Education to provide
risk of infective endocarditis- sx watch
emphasize oral hygiene
Acute Rheumatic Fever
what percentage of people with rheumatic heart disease have a history of rheumatic fever?
60%
Acute Rheumatic Fever
Describe chronic rheumatic heart disease
- rigid and deformed valve cusps
- fusion of the commissures
- shortening and fusion of the chordae tendinae
Acute Rheumatic Fever
What can Rheumatic Fever lead to in the long term?
more specific than rheumatic heart disease
valvular stenosis and/or regurgitation
Infective Endocarditis
Describe endocarditis
inflammatory process of the valvular or endocardial surface of the heart
Infective Endocarditis
Clinical Findings
5 (1 sx, 1 condition, 1 test result, 2 signs)
- Fever
- Pre-existing organic heart lesion
- pos blood cultures
- Evidence of vegetation on ECG
- Evidence of systemic emboli
Infective Endocarditis
Microbiology
3 bacteria, 1 other
- Staphylococcus
- Strep viridans
- Enterococcus
- Fungal
Infective Endocarditis
Which gender is IE more common in?
males
Infective Endocarditis
Which bacteria is most common for IE in IV drug users?
S. aureus
> 60% of cases
Infective Endocarditis
Which valves are typically impacted in the general population?
left sided valves (mitral/bicuspid & aortic)
Infective Endocarditis
Which valves for IV drug users?
Right sided valves, especially tricuspid
Infective Endocarditis
The rate of ____ is higher for IE in IV drug users
recurrence
Infective Endocarditis
Cardiac Predispositions
6 things
- valvular heart disease
- congenital heart disease
- prosthetic valve
- history of IE
- pacemakers
- hypertrophic cardiomyopathy
Infective Endocarditis
Most Common Clinical Findings
2 (1 sx, 1 sign)
Fever (90%)
New/changed murmur (85%)
Infective Endocarditis
Additional Clinical Findings
11 sx
chills/night sweats
anorexia, wt loss
arthralgias, myalgias
malaise
dyspnea, cough, pleuritic pain
splenomegaly
Infective Endocarditis
Uncommon findings
but pathognomonic!
janeway lesions
osler nodes
roth spots
Infective Endocarditis
Janeway lesions
nontender erythematous macules on the palms and soles
Infective Endocarditis
Osler nodes
tender subQ violaceous nodules mostly on the pads of the fingers and toes, which may also occur on the thenar and hypothenar eminences
Infective Endocarditis
Roth spots
exudative, edematous hemorrhagic lesions of the retina with pale centers
Infective Endocarditis
Components of a Diagnosis
Blood cultures
ECG
CXR
Chest CT
Infective Endocarditis
use cation with what diagnostic procedure?
cardiac catheterization
Infective Endocarditis
What would an echo show?
which valves are impacted
Infective Endocarditis
What would the CXR show?
cardiac abnormalities
Infective Endocarditis
What would a chest CT show?
may show emboli
Infective Endocarditis
What criteria help determine if someone has IE?
Duke Criteria
Infective Endocarditis
Duke Criteria thresholds for dx
- 2+ major criteria
- 1 major & 3+ minor
- 5+ minor