Infectious Disease Flashcards
1
Q
Clindamycin coverage
A
- Most gram positive bacteria
- Some MRSA
- NOT active against Enterococcus (Gram + cocci)
2
Q
1st generation cephalosporins
A
- Cephalexin (PO) and cefazolin (IV)
- Good Staph and Strep coverage (NO MRSA)
- Good activity against PEcK gram negative bacteria (Proteus, E. Coli, Klebsiella)
3
Q
Enterococcus coverage
A
- Ampicillin
- Vancomycin
- Linezolid
- NO clindamycin OR cephalosporins!
4
Q
2nd generation cephalosporins
A
- Cefaclor, cefuroxime, cefotetan, cefoxitin
- NO good coverage for gram positive bacteria - better for gran negative coverage
- Coverage for HEN PEcK bacteria (Haemophilis influenza, Enterobacteri, Neisseria, Proteus, E. Coli, Klebsiella)
5
Q
3rd generation cephalosporins
A
- Ceftriaxone, cefotaxime, ceftazidime, cefpodoxime
- Not good gram positive coverage - HOWEVER, ceftriaxone has great Strep coverage (i.e. when treating meningitis, treat with Vancomycin ONLY for possible Strep resistant to ceftriaxone)
- Better gram negative coverage
- Use for hospital-acquired gram-negative infections and CNS infections
- Ceftazidime is great for Pseudomonas!
6
Q
4th generation cephalosporins
A
- Cefepime
- Extended spectrum -> gram positive just as good as 1st generation + broader gram negative coverage.
- Good CNS penetration.
- More resistant to beta-lactamases.
7
Q
Macrolides
A
- Azithromycin, clarithromycin, erythromycin
- Common side effect = increased GI motility (sometimes use erythromycin for diabetic gastroparesis).
8
Q
Carbapenems
A
- Imipenem
- Use for extended-spectrum beta-lactamase (ESBL) producing organisms (i.e. ENTEROBACTER, gram negative)
9
Q
Albendazole and Pyrantel Pamoate
A
- Worm infections
- For pinworms (Enterobius), give one dose and repeat after 2 weeks if recurs. For all other worm infections, multiple doses required.
10
Q
Metronidazole
A
- Tx parasite and anaerobic infections
- Often used for intra-abdominal infections
- GET BCG = Giardia, Entamoeba, Trichomonas, Bacteroides, Clostridium, Gardnerella
- If breastfeeding, stop breastfeeding for 24 hours after treating with Metronidazole.
11
Q
Enterococcus faecalis
A
- Gram-positive diplococcus (can look similar to strep)
- Sepsis, NEC
- Tx with ampicillin, vancomycin or linezolid
12
Q
Listeria Monocytogenes
A
- Gram-positive diptheroid (rod)
- Look for history of NODULES on PLACENTA or mild maternal fever + viral symptoms.
- Treat with ampicillin
13
Q
Neonatal sepsis antibiotics
A
- Ampicillin covers GBS, enterococcus and listeria
- Gentamicin covers some gram negatives
14
Q
Clostridium tetani
A
- Gram positive anaerobe
- Common hx of puncture wound
- Uncontrollable muscle spasms and contractions. Locked jaw, arched back.
- Treat with debridement of infected tissue, TIG + metronidazole or penicillin
15
Q
Clostridium botulinum
A
- Gram positive
- Common presentation: child < 6 months with progressive DESCENDING weakness (i.e. progressive ptosis and poor suck to urinary retention). Progresses quickly (within hours).
- Toxin inhibits release of acetylcholine
- Tx with supportive care or antitoxin (if available)
16
Q
Corynebacterium diphtheriae
A
- Gram-positive rod
- Low fever + URI symptoms -> pseudomembrane forms on tonsils and pharynx. Can also cause motor and sensory problems as well as areflexia.
- Tx with erythromycin or penicillin G.
17
Q
Streptococcus
A
- Gram-positive cocci in pairs & chains.
- Alpha-hemolytic = S. viridans and S. pneumoniae
- Beta-hemolytic = S. agalactiae (GBS) and S. pyogenes (GAS)
18
Q
Peritonsillar abscess
A
- Unilateral tonsillar swelling -> deviated uvula, trismus, “hot-potato voice”, drooling.
- Usually caused by GAS
- Tx with IV antibiotics with anaerobic coverage (clindamycin, ampicillin-sulbactam), though once drainaged and patient can swallow, treat with Augmentin.
19
Q
Retropharyngeal abscess
A
- Usually presents in child < 6 years old
- Fever, lymphadenopathy, odynophagia, difficulty swallowing, drooling, HYPEREXTENSION of neck
- Usually 2/2 GAS
- Lateral neck XR reveals widening of retropharyngeal space
20
Q
Occult bacteremia
A
- S. pneumo is most common cause.
- If S. pneumo bacteremia is found incidentally and patient is asymptomatic, NO NEED to treat!
21
Q
Pneumonia
A
- S. pneumo most common cause.
- If patient has CF, S. aureus or Pseudomonas aeruginosa
22
Q
GBS Sepsis
A
- Early = within first 3 days of life. Usually 2/2 GBS PNA.
- Late = >3 days - 90 days. More focal infections - most concerning is meningitis, but also cellulitis and osteomyelitis.
- Treat with penicillin G.
23
Q
GBS screening and prophylaxis
A
- Screening occurs at 35 - 37 weeks gestation
- Prophylaxis = penicillin at least 4 hours prior to delivery.
- Give prophylaxis if Mom previously had a baby with GBS disease, evidence of GBS (i.e. UTI or screening) OR if status is unknown & < 37 weeks, ROM > 18 hours, intrapartum fever, rapid test positive.
- DO NOT treat if delivery by C/S with intact membranes, previous + screening or UTI (only focus on current pregnancy results) UNLESS previous baby with GBS, or screening cultures negative.
24
Q
Early discharge in GBS positive Mom
A
- Term (> 37 weeks)
- Asymptomatic
- Mom receive adequate intrapartum prophylaxis
25
Blood culture positive for S. aureus
- Gram positive organisms in clusters
| - Prolonged IV antibiotics and ECHOCARDIOGRAM
26
Coagulase-negative Staph
- Staph epidermidis
27
Blood culture positive for coagulase-negative Staph
- Treat with vancomycin
- Extremely resistant to common antibiotics
- Final culture may reveal MRSA
28
Secondary bacterial periotonitis and VP shunt infections
- Assume methicillin-resistant S. epidermidis
| - Treat with vancomycin pending culture results
29
Strep bacteria causing endocarditis
Viridans >> mutans or bovis
30
Rocky Mountain Spotted Fever
- Rikettsia rickettsii
- Most common tick-borne illness
- S/S: Thrombocytopenia, petechiae, headache, lethargy, altered mentation, muscle pain, rash that starts and palms/soles/wrists and spreads centrally
- Treat with doxycycline
- Ehrlichiosis presents similarly BUT may have associated liver dysfunction and possible leukopenia/lymphopenia - tx is the same w/ doxycycline
31
Enterobacter
- Usually hospital-acquired, leading to urinary tract or respiratory tract infections
- May treat with cephalosporins, though commonly ESBL and requires imipenem
32
Cat Scratch Disease
- Bartonella henselae
- Draining and tender lymphadenopathy and possible history of cat/dog exposure
- NO NEED to treat unless immunocompromised or has severe symptoms (i.e. HSM).
- Tx with macrolides, cephalosporins, doxycycline or Bactrim
33
Citrobacter Freundii
- Brain abscess (think Freundii = Freud - a psych/brain doc!)
- Can be hospital-acquired, especially in neonates
34
Chlamydia trachomatis
- Urethitis, conjunctivitis, PID, staccato cough in neonates, lymphogranuloma venereum
- Most common STD
- Obligate intracellular anaerobe (look for intracytoplasmic inclusions)
- Dx with PCR of cells, secretions or urine
- Tx with azitromycin x 1. May tx with doxycycline x 7 days, though if recurrence, tx failure or noncompliance, tx with azithromycin, eryth, levo, oflox x 7 days.
35
Lymphogranuloma venereum
- STD
- Starts with small, nontender papules or shallow ulcers that resolve --> tender unilateral inguinal lymph node appears and can rupture (relieving pain), then can drain for months
36
Chlamydia pneumoniae
- Atypical pneumonia
- Often < 2 months
- Tachypnea, STACCATO cough +/- eye discharge, may be afebrile
- Tx with doxycycline or macrolide
37
Chlamydia psittaci
- Bird exposure + atypical PNA
| - Tx with doxycycline or macrolide
38
Gram stain characteristics of H. flu
- Pleomorphic organisms
| - Tx with ceftriaxone
39
Bordatella pertussis
- Paroxysmal cough
- High WBC
- Dx with PCR or culture with NP swab
- Tx with erythromycin, clarithromycin or azith (especially for children < 1 month)
- ALL contacts (even if immunized) should be given prophylaxis
40
Pseudomonas
- Can cause skin infections, PNA, OE, UTI, osteomyelitis, sepsis, other
- Tx with ceftazidime, cefepime, ticarcillin, carbenicillin, piperacillin, gentamycin, tobramycin
41
Treatment of unstable or ICU patient with fungemia
- Amphotericin B
| - If liver disease - tx with liposomal amphotericin
42
Cryptococcus
- Hx bird exposure or travel to NORTHWESTERN US
- PNA or meningitis
- Dx with india ink staining
- For meningitis or disseminated infection, tx with amphotericin, then may switch to fluconazole.
- For isolated PNA, treat with fluconazole
43
Blastomycosis
- Broad-based, budding yeast, usually found near water
- PNA or flu-like illness, skin lesions
- Treat with azoles (itraconazole)
- Key point: used to be caused Chicago disease and solution was to move sewage from drinking water
44
Coccidioidomycosis
- AKA Valley Fever can present with PNA or flu-like symptoms
- PNA may have pulmonary nodules
- Hx living or travel to western UC (AZ, CA, TX)
- Tx with amphotericin or azoles (fluconazole or ketoconazole)
45
Histoplasmosis
- Flu-like illness
- Most clear infection without intervention
- Calcifications on CXR (may look like tuberculosis), pulmonary fibrosis, HSM, mediastinal/hilar calcifications
- Hx exposure to bird droppings or travel to OHIO (OHIO-plasmosis) or Mississippi
46
Fungal infections caused by exposure to exposure to birds
- Cryptococcus
| - Histoplasmosis
47
Allergic Bronchopulmonary Aspergillosis (ABPA)
- May occur in immunocompetent patients
- Hypersensitivity reaction
- Particularly in patients with asthma or CF
- Eosinophilia and lung infiltrates
- Tx with itraconazole and steroids. If disseminated, tx with amphotericin. May required long-term steroids.
48
Mycobacterium tuberculosis
- BACTERIA (not fungus)
- Acid-fast staining used because does not allow for gram staining
- Prolonged illness, fever, cough, chills, night sweats, weight loss, immigrant status, travel to endemic area, hilar adenopathy, apical infiltrate, pleural effusion, supraclavicular lymphadenopathy
- Dx with AFB smears of sputum/secretions, + PPD or + Quantiferon Gold
49
PPD interpretation
< 5 mm = negative. If induration present and < 5 mm, consider atypical mycobacteria.
5-10 mm = Positive IF X-ray findings present, hx close contact with patient with TB or immunocompromised
> 10 mm = positive IF risk factor
>15 mm = positive for lowest-risk patients with zero RFs
50
Treatment after +PPD
- Normal CXR = isoniazid for 9 months
| - Positive CXR = 3 or 4 drug therapy (RIP or RIPE = rifampin, isoniazid, pyrazinamide, ethambutol)
51
Newborn with +PPD Mom
- Mom asymptomatic and negative CXR = check baby's PPD q3 months. If PPD positive, tx INH x 1 year if CXR negative. If CXR positive, tx with 4 drug therapy.
- Mom with active disease OR positive CXR = consider baby positive and tx with 3 or 4 drug therapy
52
Treatment for older children with ACTIVE TB in household contacts
- PPD and CXR negative = INH x 12 weeks
- +PPD and CXR negative = INH x 9 months
- +PPD and +CXR = 3-4 drug therapy
53
Tx for TB meningitis
- 3-4 drug therapy + steroids + streptomycin
54
Assess for infectivity
- DO NOT get a CXR
| - Obtain sputum samples or gastric aspirates for AFB smear
55
Arbovirus encephalitis
- S/S of encephalitis (confusion, lethargy) + mention of mosquitoes (California, STL)
- Dx with virus-specific ACUTE AND CONVALESCENT antibitody titers
56
TORCH infections
- Toxoplasma
- Other (varicella, syphilis)
- Rubella
- CMV
- HSV
57
Toxoplasma Gondii
- Protozoan
- Transmitted via cat litter
- Classic triad = diffuse intracerebral calcifications (“RING-ENHANCING LESIONS”) + hydrocephalus + unilateral/bilateral chorioretinitis
- may also see addnopathy, thrombocytopenia, HSM, jaundice or Blueberry Muffin Syndrome
58
Diagnosis of Toxoplasma
IgM tiger or immunofluorescence
59
Treatment of Toxoplasma
- Sulfadiazine OR pyrimethamine
60
Long-term effects of Toxoplasma in neonate
Even if child is normal at birth, may later develop seizures, cognitive issues and/or deafness
61
MRI findings in Toxoplasma vs CMV
- Toxoplasma = diffuse ring-enhancing lesions
| - CMV = periventricular, non-enhancing lesions
