Infectious Disease Flashcards
You are called by the laboratory which reports gram-positive cocci in clusters growing from the blood culture bottles. What is the best next step in management?
a. Start Oxacillin
b. Start Erythromycin
c. Start Vancomycin
d. Start Doxycycline
e. Consult infectious diseases
f. Wait for speciation and sensitivity of the organism.
g. It is contamination; no treatment is needed
C. The best empiric therapy for gram-positive cocci growing from blood cultures is vancomycin
Which is not an adverse effect of Linezolid?
a. Thrombocytopenia
b. interaction with MAO inhibitors
c. causes CPK elevation
C
Should we use Tigecycline for MRSA in blood?
No.
Which is not an adverse effect of Daptomycin?
a. causes CPK elevation
b. thrombocytopenia
c. not effective in the lung
B
Give 4 medical management for minor MRSA infections.
TMP/SMX
Doxycycline
Clindamycin
Linezolid
Which of the following is the most accurate test for an infectious disease?
a. Protein level of fluid
b. Culture
c. IgM levels
d. IgG levels
e. Gram stain
f. Response to specific
B. Culture
Enumerate the bacteria covered by amoxicillin
(HELPS)
H. influenzae E. coli Listeria Proteus Salmonella
Enumerate 6 diseases in which Amoxicillin is the best initial therapy
- Otitis Media
- Dental infection and endocarditis prophylaxis
- Lyme disease limited to rash, joint, or seventh cranial nerve involvement
- UTI in pregnant women
- Listeria monocytogenes
- Enterococcal infections
Which of the following antibiotics will cover methicillin-resistant Staphylococcus aureus (MRSA)?
a. Nafcillin
b. Cefazolin
c. Piperacillin-Tazobactam
d. Ceftaroline
e. Azithromycin
D. The only cephalosporin that will cover MRSA is Ceftaroline.
MRSA drugs
Vancomycin Daptomycin Linezolid Tedizolid Oritavancin Dalbavancin Telavancin Ceftaroline
‘mycin’ ‘zolid’ ‘vancin’ ‘roline’
If the case describes a RASH to penicillin, what would you give?
Cephalosporins
If the case describes ANAPHYLAXIS from Penicillin, what would you use?
Non-beta-lactam antibiotic
Give 2 medications from the family of the Cepalosporins that cover Anaerobes
Cefotetan and Cefoxitin
Inc. risk in bleeding and has a disulfiramlike reaction with alcohol
What is the best initial therapy for Pelvic Inflammatory Disease (PID)?
Cefotetan or Cefoxitin combined with Doxycycline
Which of the following is most likely to be effective for Morganella or Citrobacter?
a. Tedizolid
b. Dalbavancin
c. Ertapenem
d. Oritavancin
e. Erythromycin
C. Ertapenem
Ertapenem is a carbapenem antibiotic. All carbapenems are highly active against gram-negative bacilli. Morganella and Citrobacter are gram-neg bacilli in the same family as E.Coli. Ertapenem covers most gram-negative rods and bacilli except Pseudomonas
A patient has a perforation of an abdominal portion of the bowel and leakage into the peritoneum. There is fever and hypotension. The report on the anaerobic bottle of blood cultures states that it is growing an organism. Which of the following is most appropriate to start while waiting for the speciation and sensitivity testing?
a. Aztreonam
b. Piperacillin/Tazobactam
c. Oxacillin
d. Cefepime
e. Doxycyline
f. Vancomycin
B. Piperacillin/Tazobactam is the only medication of those listed that covers anaerobes
A man is admitted with E. coli bacteremia.
Which of the following is the most appropriate therapy?
a. Vancomycin
b. Linezolid
c. Quinolones, aminoglycosides, carbapenem, piperacillin, ticarcillin, or aztreonam
d. Doxycycline
e. Clindamycin
f. Oxacillin
C. All of the agents listed under “gram-negative bacilli” could be the right answer.
You see a patient with fever, headache, neck stiffness, and photophobia. The patient is also confused, so a CT scan of the head is ordered. Ceftriaxone and vancomycin are administered. There is a delay of 12 hours in obtaining the lumbar puncture after a normal head CT. In the event that the antibiotics produce a false negative in culture, which of the following is most useful to identify a specific organism?
a. Gram stain
b. Glucose level
c. Latex agglutination antigen
d. Protein level
C. Latex agglutination antigens
They have the same specificity as a culture but less sensitivity. The advantage of the antigen test is that it wwill not become negative with a few doses of antibiotics. The other tests listed are neither as sensitive nor as specific.
Give 3 initial treatment for bacterial meningitis.
Ceftriaxone, Vancomycin, Steroids
A man comes to the emergency department with fever, severe headache, neck stiffness, and photophobia. On physical examination he is found to have weakness of his left arm and leg. What is the most appropriate next step in the management of this patient?
a. Ceftriaxone, vancomycin, and steroids
b. Head CT
c. Ceftriaxone
d. Neurology consultation
e. Steroids
A.
When there is a contraindication to an immediate LP, the most important step is to initiate treatment.
What is the most accurate test oh herpes encephalitis?
a. Brain biopsy
b. PCR of CSF
c. MRI
d. Viral culture of CSF
e. Tzanck prep
f. Serology for herpes (IgG, IgG)
B.
PCR is more accurate than a brain biopsy
A woman is admitted for herpes encephalitis confirmed by PCR. After 4 days of acyclovir her creatinine level begins to rise.
What is the most appropriate next step in management?
a. Stop acyclovir
b. Reduce the dose of acyclovir and hydrate
c. Switch to oral famciclovir or valacyclovir.
d. Switch to foscarnet
B. Oral medications such as famciclovir and valacyclovir are insufficient for herpes encephalitis. Although acyclovir may occasionally be renal toxic because the medication precipitates in the renal tubules, foscarnet has far more renal toxicity.
Why do we need to avoid Ceftriaxone in neonates?
They have impaired biliary metabolism
_______ is the first cephalosporin to cover MRSA.
Ceftaroline
Which of the following is the most accurate in determining the etiology of infectious diarrhea?
a. Recent history of eating chicken
b. Frequency of bowel movement
c. Blood in stool
d. Odor of stool
e. Recent interstate travel
C. Presence of blood in the stool
Listeria, MRSA, and Enterococcus are resistant to all forms of ________.
Cephalosporins
What can you prescribe for some negative gram-negative bacilli such as E. Coli, but NOT Pseudomonas as well as Osteomyelitis, Septic Arthritis, Endocarditis, Cellulitis
First Generation Cephalosporin
Cefazolin, Cephalexin, Cephadrine, Cefadroxyl
What can you give for respiratory infections such as bronchitis, otitis media, and sinusitus?
2nd Gen Cephalosporin
Cefuroxime, Loracarbef, Cefprozil, Cefaclor
What 3rd gen Cephalosporin is first line for pneumococcus, including partially insensitive organisms responsible for Meningitis, CAP, Gonorrhea, Lyme disease involving the heart or brain?
Ceftriaxone
What 3rd gen Cephalosporin is superior to Ceftriaxone in neonates and is also used for spontaneous bacterial peritonitis?
Cefotaxime
What 3rd gen Cephalosporin has pseudomonal coverage?
Ceftazidime
This is a 4th gen Cephalosporin that is used to treat neutropenia and Ventilator-associated pneumonia.
Cefepime
This is a 5th gen Cephalosporin that can treat gram-negative bacilli and MRSA but not Pseudomonas.
Ceftaroline
This is a group of drugs that cover gram-negative bacilli, including many that are resistant anaerobes, streptococci, and staphylococci. They are used to treat neutropenia and fever.
Carbapenems
_____ differs from the other carbapenems. It does not cover Pseudomonas.
Ertapenem
This is the only drug in the class of monobactams that is used exclusively for gram-negative bacilli including Pseudomonas. This has no cross-reaction to Penicillin
Aztreonam
This group of drugs is the best therapy for Community-acquired Pneumonia, including penicillin-resistant Pneumococcus.
What is the exception for this group of drugs?
Fluroquinolones
except Ciprofloxacin
What drug can you use for cystitis, pyelonephritis, and ventilator-associated pneumonia
Ciprofloxacin
_______ is a Fluroquinolone that can be used as a single agent for diverticulitis and does not need Metronidazole.
Moxifloxacin
What drug must be combined with Ciprofloxacin, Gemifloxacin, and Levofloxacin for Diverticulitits and GI infections for anaerobic coverage.
Metronidazole
What are adverse effects known from Fluroquinolones?
Bone growth abnormalities in children and pregnant women, Tendonitis and Achilles tendon rupture
This group of drugs can be used for gram-negative bacilli (bowel, urine, bacteremia) and is synergistic with beta-lactam antibiotics for enterococci and staphylocci. It has no effect against anaerobes, since they need oxygen to work.
Aminoglycosides (Gentamicin, Tobramycin, Amikacin)
What are 2 common adverse effects of Aminoglycosides
Nephrotoxic and Ototoxic
This drug is used for treatment of Chlamydia, Lyme disease that is limeted to rash, joint, or seventh cranial nerve palsy, Rickettssia, MRSA of skin and soft tissue (cellulitis), Primary and secondary syphilis in those allergic to penicillin, Borrelia, Ehrlichia, and Mycoplasma.
Doxycycline
What are the common adverse effects of Doxycycline?
Tooth discoloration (children) Fanconi syndrome (Type II RTA proximal)
This drug can be used in cystitis, pneumocystis pneumonia treatment and prophylaxis, MRSA of skin and soft tissue (cellulitis)
Trimethoprim/Sulfamethoxazole
Give adverse effects of Trimethoprim/Sulfamethoxazole.
Rash
Hemolysis with G6PD deficiency
Bone Marrow Suppression because it is a folate antagonist
What can you give for Oral (above the diaphragm) anaerobe infection?
Penicillin (G, VK, Ampicillin, Amoxicillin)
Clindamycin
What can you give for Abdominal anaerobic infection?
Metronidazole
Beta-lactam/lactamase combinations
Carbapenems
What is the MOST LIKELY DIAGNOSIS for a patient presenting with fever, headache, nausea, and vomiting that has an accompanied stiff neck, photophobia, and meningismus?
Meningitis
What is the MOST LIKELY DIAGNOSIS for a patient presenting with fever, headache, nausea, and vomiting that has an accompanied confusion?
Encephalitis
What is the MOST LIKELY DIAGNOSIS for a patient presenting with fever, headache, nausea, and vomiting that has an accompanied focal neurologic findings?
Abscess
What organism is most likely present in a patient with AIDS <100 CD4 cells/ul?
Cryptococcus
What organism is most likely present in a camper/hiker patient with target shaped rash, joint pain, facial palsy, and sometimes presence of tick?
Lyme disease
What organism is most likely present in a camper/hiker patient with rash that moves from arms/legs to trunk?
Rocky Mountain Spotted Fever (Ricketssia)
What organism is most likely present in an adolescent patient with petechial rash with symptoms of fever, headache, nausea and vomiting?
Neisseria
What is the best initial and most accurate test for Meningitis?
Lumbar Puncture
Lab results for a patient you suspect with Meningitis came back.
Cell count 1000s, neutrophils, Elevated Protein Level, Decreased Glucose Level, 50-70% positive in stain and 90% in culture
What is the most likely etiology?
Bacterial Meningitis
Lab results for a patient you suspect with Meningitis came back.
Cell count 10-100s, lymphocytes, Possibly elevated Protein Level, Possibly decreased Glucose Level, Negative in stain and culture
What is the most likely etiology?
Cryptococcus, Lyme, Ricketssia
Lab results for a patient you suspect with Meningitis came back.
Cell count 10-100s, lymphocytes, Markedly elevated Protein Level, Possibly decreased Glucose Level, Negative in stain and culture
What is the most likely etiology?
Tuberculosis
Lab results for a patient you suspect with Meningitis came back.
Cell count 10-100s, lymphocytes, usually normal Protein Level, usually normal Glucose Level, Negative in stain and culture
What is the most likely etiology?
Viral
When is a Head CT the best initial test for Meningitis?
If you suspect a space-occupying lesion that may cause herniation as evidence by symptoms like Papilledema, Seizures, Focal neurologic abnormalities, Confusion interfering with the neurologic exam
If there is a contraindication to immediate LP in a patient with meningitis, what is the best initial step in management?
Give Antibiotics
When is a bacterial antigen test indicated?
When the patient has received antibiotics prior to LP and the culture may be falsely negative
What is/are the most accurate diagnostic test for Meningeal Tuberculosis?
Acid fast stain and culture on 3 high-volume lumbar punctures. TB has the highest CSF protein level
What is/are the most accurate diagnostic test for Lyme and Rickettsia?
Specific serologic testing
ELISA
Western blot
PCR
What is/are the most accurate diagnostic test for Cryptococcus?
India ink is 60-70% sensitive
Cryptococcal antigen is more than 95% senistive and specific
Culture of fungus is 100% specific
Listeria is resistant to all _______ but sensitive to ______.
Cephalosporins; Penicillins
If the patient with Listeria has the following risk factors: Elderly, Neonates, Steroid use, AIDS or HIV, Immunocompromised including alcoholism, Pregnant, what medical management should you initiate?
Add Ampicillin to Ceftriaxone and Vancomycin
What should you give the relatives or those who come in close contact with a patient with Neisseria meningitidis?
Rifampicin, Ciprofloxacin, or Cefttiaxone
What is the most common neurologic deficit of untreated bacterial meningitis?
Eight cranial nerve deficit or deafness
What is the best initial treatment for Herpes Encaphalitis?
Acyclovir
What is used for Acyclovir-resistant Herpes?
Foscarnet
What would you perform for a patient presenting with symptoms of Influenza with the onset not longer than 48 hours?
Nasopharyngeal swab or wash
How would you treat Influenza with less than 48 hours of symptoms?
Oseltamivir, Zanamivir (these drugs treat both Influenza A and B)
Peramivir is the intravenous version
How would you treat Influenza with more than 48 hours symptoms?
Symptomatic treatment
Analgesics, rest, antipyretics, hydration
Patient came in with complaint of blood in stool. Upon history, there is ingestion of some kind of poultry. Lab shows WBC in stool. What is the most likely etiology?
Salmonella
This is the most common cause of blood in stool and is associated with GBS.
Campylobacter
What is the organism responsible for Hemolytic Uremic Syndrome (HUS)?
E. coli 0157:H7
What organism is the second most common association with HUS?
Shigella
Patient came in with complaint of blood in stool. Upon history, there is ingestion of shellfish and boarding a cruise ship. Lab shows WBC in stool. What is the most likely etiology?
Vibrio parahaemolyticus
Patient came in with complaint of blood in stool. Upon history and PE, there is ingestion of shellfish, history of liver disease and presence skin lesions. Lab shows WBC in stool. What is the most likely etiology?
Vibrio vulnificus
This organism has high affinity for iron, seen in hemochromatosis, and blood transfusions
Yersinia
Patient came in with complaint of blood in stool. Lab shows red and white cells.
Clostridium difficile
What is the best initial test for a patient with blood in stool?
Blood and/or fecal leukocytes
Lactoferrin is a BETTER answer than fecal leukocytes if it in one of the choices
What is the most accurate test for a patient with blood in stool?
Stool Cultrue
Patient came in with complaints of loose bowel movements. There are no blood in stool. There is a history of camping/hiking and drinking unfiltered fresh water. What is the most likely organism?
Giardia
Medical management for Giardia
Metronidazole, Tinidazole