Chapter 23: ID II - Bacterial Infections Flashcards
If antibiotics are needed post-op, when should they be d/c
within 24 hrs
Which antibiotic is preferred for perioperative cardiac or vascular surgeries to prevent MSSA and streptococci infections. What is the alternative if the patient has an allergy
Include timing
Cefazolin - infuse 60 min before incision
Clindamycin or vanco if BL allergy - infuse 120 min before incision
The prophylactic antibiotic regimen in colorectal surgeries needs to cover skin flora plus broad gram-____ and ____ organisms found in the gut
Which drugs are used
Broad gram-negative
Anaerobic
Cefotetan, cefoxitin, ampicillin/sulbactam, ertapenem
OR
metronidazole + (cefazolin or ceftriaxone)
Which antibiotic is preferred for perioperative hip fracture repairs or total joint replacement surgeries to prevent MSSA and streptococci infections. What is the alternative if the patient has an allergy
Cefazolin
Clindamycin or vanco if BL allergy
Classic symptoms of meningitis
How is it diagnosed
fever, HA, nuchal rigidity (stiff neck), and altered mental status
lumbar puncture
The risk of meningitis is caused by which bacteria
Streptococcus pneumoniae, Neisseria meningitidis and H. infuenzae
Which pathogen is prevalent in select patient groups that puts them at risk for meningitis and what additional treatment is required for it
Listeria monocytogenes
ampicillin
Which drug can be given 15-20 minutes prior to or with the first antibiotic dose for meningitis to prevent neurological complications
Dexamethasone
Which groups should receive ampicillin for Listeria monocytogenes in meningitis
neonates
Age > 50 years
Immunocompromised
Meningitis treatment for neonates (< 1 month old)
Ampicillin (for Listeria coverage)
+
CefoTAXime or Gentamicin
(no ceftriaxone) - can cause biliary sludging & kernicterus
Meningitis treatment age 1 month to 50 years
Ceftriaxone or cefotaxime
+
Vanco
Meningitis treatment for age > 50 years or immunocompromised
Ampicillin (for Listeria coverage) \+ Ceftriaxone or cefotaxime \+ Vanco
Observation of non-severe acute otitis media without antibiotics for __-__ hours (mild otalgia < 48 hours or temp < 102.2F) and what other factors can be considered
48-72 hrs and
- Age 6-23 months: symptoms in one ear only
- Age >/= 2 years: symptoms in one or both ears
After 48-72 hours of observation, what is the first line treatment option for acute otitis media, including the dose
ALTERNATIVE if patient has a non-severe PCN allergy
-High-dose amoxicillin (80-90 mg/kg/day) in 2 divided doses
OR
-Augmentin 90 mg/kg/day of amoxicillin in 2 divided doses (can be considered in pts who have received amoxicillin in the past 30 days)
-Remember to use the formulation with the LEAST amount of clavulanate to decrease the risk of diarrhea (Augmentin ES-600 is a common formulation)
OR
-Ceftriaxone IM for 1-3 days (if vomiting or unable to tolerate oral)
NON-SEVERE PCN ALLERGY: Cephalosporin (first or second generation; Cefdinir, Cefuroxime, Cefpodoxime, Ceftriaxone)
Which bug causes pharyngitis
S. pyogenes
Criteria for anti-infective treatment of influenza
Treatment options and duration
< 48 hours since symptom onset
- Oseltamivir x 5 days
- Baloxavir x 1 dose
- Zanamivir inhalation x 5 days
Criteria for anti-infective treatment of pharyngitis
Positive rapid antigen diagnostic test
Criteria for anti-infective treatment of sinusitis
> 10 days of symptoms
OR
> > /= 3 days of severe symptoms
Which bug is responsible for causing whooping cough
Bordetella Pertussis
Bronchitis caused by bordatella pertussis is treated with
A macrolide
Antibiotics for 5-7 days should be used in COPD exacerbations if which criteria are met & what is the preferred antibiotic
-All 3 of the following: ↑ dyspnea, ↑ sputum volume and ↑ sputum purulence
-↑ sputum purulence + 1 additional symptom
-Mechanically ventilated
Preferred abx: Augmentin
Most bacterial cases of pneumonia are caused by which bugs
S. pneumoniae
H. influenzae
M. pneumoniae
Duration of treatment for CAP
5-7 days
If patient does NOT have comorbidities (chronic heart, lung, liver or renal disease; DM; alcoholism; malignancy or asplenia) & has no RF for MRSA or PsA (prior resp isolation of either pathogen or hospitalization with receipt of parenteral abx in the past 90 days), what is the empiric regimen for CAP
-Amoxicillin 1 gram TID OR -Doxycycline OR -Macrolide (azithromycin or clarithromycin) if local pneumococcal resistance is < 25%
If patient DOES have comorbidities (chronic heart, lung, liver or renal disease; DM; alcoholism; malignancy or asplenia) & has no RF for MRSA or PsA (prior resp isolation of either pathogen or hospitalization with receipt of parenteral abx in the past 90 days), what is the empiric regimen for CAP
-BL + macrolide + doxy (Augmentin or cephalosporin (e.g., cefpodoxime, cefdinir, cefuroxime)
PLUS
-Macrolide or doxycycline
-respiratory quinolone monotherapy (moxi, levo, gemi)
Non-severe (typically non-ICU care required) treatment of inpatient CAP
BL (ceftriaxone or cefotaxime) + macrolide or Unasyn
OR
Respiratory quinolone monotherapy (moxi, levo, gemi)
Severe (typically ICU care required) treatment of inpatient CAP
BL + macrolide
OR
BL + resp quinolone (do NOT use quinolone monotherapy)
In CAP treatment, if there are RF for MRSA, add coverage with:
In CAP treatment, if there are RF for PsA, add coverage with:
vanco or linezolid
Zosyn, cefepime, meropenem or aztreonam
HAP has an onset > __ hours after hospital admission
VAP occurs > __ hours after the start of mechanical ventillation
48 hours
48 hours
Which pathogens are common in HAP & VAP
nosocomial
The risk for MRSA and MDR Gram-negative rods, including PsA is increased in select cases
How to select empiric regimen for HAP/VAP
- Choose 1 abx to cover PsA and MSSA if low risk for MRSA or MDR pathogens (cefepime or Zosyn)
- Choose 2 abx, one for MRSA and one for PsA if risk for MRSA but low risk for MDR pathogens (cefepime + vanco or meropenem + linezolid)
- Choose 3 antibiotics, one for MRSA and 2 for PsA if risk for both MRSA and MDR pathogens (e.g., IV antibiotics within the past 90 days (Zosyn + cipro + vanco or cefepime + gentamycin + linezolid)
What is latent TB & how is it diagnosed
What is active pulmonary TB
The immune system contains the infection and the patient lacks symptoms
Diagnosed: tuberculin skin test (TST) aka PPD test
It is transmitted by aerosolized droplets and is highly contagious.
Presents with cough/hemoptysis, fever and night sweats
Hospitalized pts are isolated in a single negative-pressure room
A false positive TB test can occur in those who have received which vaccine
BCG vaccine
What is a positive TST result in patients with no risk factors
What is a positive TST result in patients who reside in “high-risk” congregate settings (e.g., prison inmates, healthcare workers)
What is a positive TST result in patients with significant immunosuppression
> /= 15 mm induration
> /= 10 mm induration
> /= 5 mm induration
How is latent TB treated
- INH or rifapentine weekly x 12 weeks via directly observed therapy (DOT) - DO NOT USE THIS REGIMEN IN PREGNANT WOMEN
- Rifampin x 4 months (children and HIV-neg adults)
- Isoniazid with rifampin x 3 months (all ages and HIV+)
- Alternative: INH x 6 mo or 9 mo - treatment of choice for pregnant women
A positive TST is likely with active TB, but the diagnosis must be confirmed with
sputum culture
M. tuberculosis (MTB) is an acid-fast bacilli and can be detected using a(n)
AFB stain (note: MTB is a slow-growing organism)
The preferred intensive phase treatment for active TB consists of which drugs and how long is therapy
In the continuation phase of active TB, what are the drugs used and how long is treatment
RIPE: -Rifampin -Isoniazid -Pyrazinamide -Ethambutol 2 months
Rifampin and Isoniazid x 4 months
Rifampin SE
↑ LFTs, hemolytic anemia (positive Coombs test), flu-like sx, Orange-red discoloration of sputum, urine, sweat, tears, teeth, can stain contact lenses and clothing
-Rifabutin can replace rifampin in some cases d/t DDI
What can be used to decrease the risk of isoniazid-associated peripheral neuropathy (include dose)
Pyridoxine 25-50 mg
Isoniazid BW
Hepatitis
Isoniazid SE
↑ LFTs, hemolytic anemia (positive Coombs test), DILE
Pyrazinamide CI
acute gout
Pyrazinamide SE
↑ LFTs, hyperuricemia/gout
Ethambutol SE
↑ LFTs, optic neuritis (dose-related), confusion, hallucinations
Major drug interactions with rifampin
Potent PgP and 3A4 inducer
-Protease inhibitors
-Warfarin (very large ↓ in INR)
-Oral contraceptives (decreases efficacy)
DO NOT USE RIFAMPIN WITH apixaban and rivaroxaban
What are the 3 most common bugs that can cause infective endocarditis
Staphylococci
Streptococci
Enterococci
Which drug is added to infective endocarditis treatment for synergy, when the infection is more difficult to eradicate
Gentamicin
When gentamicin is used for synergy in infective endocarditis, traditional dosing is typically used to target peak levels of __-__ mcg/mL and trough levels of < __ mcg/mL
3-4
<1
Adult ppx regimens for infective endocarditis after dental procedures if no PCN allergy and in PCN allergy (including dose)
No PCN allergy:
-Amoxicillin 2 grams 30-60 min before dental procedure
PCN allergy:
-Clindamycin 600 mg
azithromycin or clarithromycin 500 mg
DOC for spontaneous bacterial peritonitis (SBP) and duration of treatment
Ceftriaxone for 5-7 days
What are the most likely pathogens of secondary peritonitis
Streptococci
enteric Gram-negatives
anaerobes (B. fragilis)
Purulent SSTIs include
Superficial SSTIs include
Subcutaneous tissue SSTIs include
abcesses
impetigo (honey-colored crusts), furuncles, and carbuncles
Cellulitis
Treatment of impetigo
Topical mupirocin (Bactroban) If numerous lesions, use Keflex to cover MSSA
Treatment of folliculitis/furuncles/carbuncles
- Cephalexin
- If non-responsive, change to a drug with CA-MSSA coverage (Doxy or Bactrim)
Mild cellulitis treatment
Keflex
Mild to moderate purulent abscess treatment
Severe purulent SSTI treatment
Bactrim or doxy
(commonly caused by CA-MRSA)
Severe: Need MRSA coverage: vanco, linezolid or dapto
Necrotizing fasciitis treatment
vanco + BL
UTIs that occur in the lower urinary tract are called
Symptoms?
UTIs that occur in the kidneys are called
Symptoms?
cystitis
- Urgency and frequency including nocturia
- Dysuria
- Suprapubic heaviness
- Hematuria
pyelonephritis
-Flank pain
Drugs of choice for acute uncomplicated cystitis with dose
Nitrofurantoin (Macrobid) 100 mg PO BID with food x 5 days (CI if CrCl < 60 mL/min)
OR
Bactrim DS 1 tab PO BID x 3 days
Can add phenazopyridine (Pyridium) to relieve dysuria for max 2 days
Drugs of choice for acute uncomplicated cystitis for pregnant women
Keflex, Amoxicillin
Treat asymptomatic pregnant women!!!
Treatment for acute uncomplicated pyelonephritis
- If local quinolone resistance is < / = 10%: cipro or levo
- If local quinolone resistance is > 10%: ceftriaxone, Bactrim, or BL
Complicated UTI treatment
Use a carbapenem if ESBL-producing
How should Pyridium be taken
with 8 oz of water with or immediately following food to minimize stomach upset
Pyridium can cause
red-orange coloring of urine and other body fluids; contact lenses/clothes can be stained
Which bugs can cause traveler’s diarrhea
Bacterial - E. coli, Campylobacter jejuni, Shigella spp, and Salmonella
Viral - rotavirus
Treatment of choice in TD if dysentery is present
Treatment of choice in TD if dysentery is not present
Azithromycin - DO NOT USE LOPERAMIDE IN DYSENTERY
Quinolones or rifaximin
How is the first episode of C. diff treated (non-severe or severe)
VAN 125 mg PO QID x 10 days
OR
FDX 200 mg PO BID x 10 days
if above tx are not available and episode is non-severe use Metronidazole 500 mg PO TID x 10 days
How is fulminant/complicated C. diff treated
fuliminant = severe or sudden in onset
VAN 500 mg PO/NG/PR QID + metronidazole 500 mg IV Q8H
How is the 1st recurrence (or 2nd episode) of C. diff treated if metronidazole was used for the initial episode
What about if vanco was used in the initial episode?
VAN 125 mg PO QID x 10 days
FDX 200 mg PO BID x 10 days
How are subsequent episodes (more than 2) of C. diff treated
VAN tapered and pulsed regimen OR VAN 125 mg PO QID x 10 days then rifaximin 400 mg TID x 20 days OR FDX 200 mg PO BID x 10 days OR fecal microbiota transplant
Symptoms of chlamydia & gonorrhea
genital discharge or no symptoms
Syphilis symptoms & DOC for primary, secondary or early latent syphilis and dose & alternative
Painless, smooth genital sores (chancre)
Penicillin G benzathine (Bicillin L-A) 2.4 million units IM x 1
Alternative: doxy
HPV symptoms
genital warts or no symptoms
Pregnant patients with syphilis who are allergic to PCN should be treated with
Desensitize and treat with DOC (Bicillin L-A)
This is also recommended in HIV+ pts
DOC for late latent syphilis and dose
Penicillin G benzathine (Bicillin L-A) 2.4 million units IM weekly x 3 weeks
Gonorrhea treatment and dose
UPDATED PER CDC: Ceftriaxone (higher dose)
< 150 kg: 500 mg IM x 1
≥ 150 kg: 1 gram IM x 1
Old guideline (per book): Ceftriaxone 250 mg IM x 1 plus Azithromycin 1 g PO x 1 or doxy
Note: monotherapy is not recommended for treatment
Chlamydia DOC and dose
Azithromycin 1 gram PO x 1 or doxy
Bacterial vaginosis symptoms
Trichomoniasis symptoms
clear, white or gray vaginal discharge that has a fishy odor and pH > 4.5 with little to no pain
yellow/green frothy vaginal discharge, soreness, and pain with intercourse
DOC for Bacterial vaginosis
DOC for Trichomoniasis & dose
Metronidazole or Metronidazole 0.75% gel
Metronidazole 2 g PO x 1
Genital warts (HPV) DOC
Imiquimod cream (also approved for superficial basal cell carcinoma)
Treatment for Rocky Mountain Spotted Fever
Doxycycline (also DOC for peds)
Treatment for Lyme disease & how does disease present
Which bugs are responsible
Doxycycline
Bullseye rash (round, red), achy joints, fever
Borella burgdorferi and Borrelia mayonii, spread by ticks
How to diagnose Lyme disease
EIA
Which tests are done to diagnose syphilis
RPR and VDLR
