Infectious Disease Flashcards
Skin or Soft tissue infection
What are two ways osteomyelitis can be spread?
Hematogenous and contiguous spread
Viruses
What does cytopathology show in CMV?
Owl Eyes
STD
(T/F) Viral shedding occurs in HSV even in the absence of lesions
True
Bacteria
What are gram negative coccobacilli (2)?
H influenza and Bordetella (Pertussis)
Antibacterial
What are two fifth generation cephalosporins and what are each good at covering?
Ceftaroline - MRSA
Ceftolozone - Pseudomonas
How does reactivated TB typically present?
Subacute illness over weeks/months with fever/night sweats/weight loss/cough
What is metronidazole used to cover?
Anaerobic infections below the diaphragm
What test should be ordered before starting Dapsone?
G6PD deficiency
What are six antibiotics that cover MRSA?
Vancomycin
Daptomycin
Linezolid
Clindamycin - community MRSA
Fluoroquinolones
TMP-SMX
Name three big shapes of gram positive bacteria?
- Cocci - Staph/Strep
- Branching filaments - Actinomyces/Nocardia
- Bacilli (rod)- Listeria/Bacillus/Clostridium
What are five diseases that cause genital ulcers?
Which are painful?
- HSV - painful
- Syphilis - Painless
- Haemophilus ducreyi (chancroid)- Painful
- Lymphogranuloma venereum - painless
- Granuloma inguinale - painless
Painful ones start with H for Hurt
What are gram negative dipplococci?
Neisseria meningitidis
Neisseria gonorrhoeae
What generations of cephalosporins cover anaerobes?
2nd and fifth generation
Treatment for ebola?
Supportive care
Treatment for Smallpox?
Supportive care
Define multi-drug resistant TB?
TB that is resistant to INH and/or rifampin
What are three side effects of Vancomycin treatment?
- Red-man syndrome
- Ototoxicity
- Nephrotoxicity
What virus causes temporal lobe encephalitis and what are the EEG findings?
HSV encephalitis.
You will see 2-3 mm HZ highly characteristic slow wave complexes on EEG
What are the major symptoms of a brain abscess? What is the size cutoff for brain abscesses that require drainage?
Severe headache. Other symptoms such as neck stiffness, fever may not always be present.
Abscess greater than 2.5 cm should be excised or drained.
When should necrotizing fasciitis be suspected in patients?
If a patient has skin inflammation with hemodynamic instability, rapid progression, pain out of proportion to exam, physical exam with necrosis, bullae, crepitus, it is important to consider a deeper tissue infection like necrotizing fasciitis and to obtain urgent surgical consultation.
When should necrotizing fasciitis be suspected in patients?
If a patient has skin inflammation with hemodynamic instability, rapid progression, pain out of proportion to exam, physical exam with necrosis, bullae, crepitus, it is important to consider a deeper tissue infection like necrotizing fasciitis and to obtain urgent surgical consultation.
Urinary Tract Inections
What three groups of patients should receive treatment for asymptomatic bacteruria?
- Pregnant patients
- Patients undergoing invasive urinary urological procedures
- Renal transplant patients/immunocompromised patients
Gastrointestinal Infections
What kind of foods is Bacillus cereus associated with?
Starchy/fried foods
What are three types of gram positive bacilli?
Listeria
Clostridium
Bacillus
What is a unique side effect of imipenem?
Decreases seizure threshold
When should vancomycin not be used?
When MIC is greater than 2
What are the gram negative bacilli?
SSEKP
Shigella
Salmonella
E coli
Pseudomonas
Klebsiella
What are some causes of encephalitis and how does it present?
Causes - HSV, Arbovirus (West Nile and St. Louis), Lyme disease
Symptoms - Confusion/AMS are most prominent findings. Fever/headache/focal neurological deficits are other findings
What is chemoprophylaxis for Neisseria Meningitidis and who should receive treatment?
Rifampin/Ciprofloxacin/Rocephin
Give to household contacts, salivary contacts, or healthcare providers who have had direct contact with an infected patient’s oral and respiratory secretions without a mask
T/F - All patients with tick bite should be treated with prophylactic and empiric antibiotics
False
What is the PPD cutoff in HIV patients and what are next steps if cutoff is met?
PPD > 5 mm. If PPD positive, check for active infection and if active infection is ruled out, then treat as latent TB (INH for 9 months or rifampin for 4 months)
What are two branching filament gram positive organisms and how do you treat each?
(Aerobic) Norcadia - TMP-SMX
SNAP
(Anaerobic) Actinomyces - Penicillins
What are four groups of beta lactam antibiotics?
- Penicillins
- Cephalosporins
- Monobactams
- Carbapenems
What are gram negative curved rods?
H pylori
Vibrio
Camplyobacter Jejuni
What types of bacteria can cause infections in DM patients?
Polymicrobial infections
Anaerobic infections
Gram positive and gram negative bacteria
Endocarditis
How many blood cultures should be obtained in patients with suspected endocarditis?
Three sets of blood cultures taken at least one hour apart before antibiotics
Anti-bacterial agents
What kind of organisms is vancomycin used to treat?
Gram positive organisms
MRSA
What is treatment for latent TB?
INH + vitamin B6 for 9 months
Rifampin for 4 months
What is treatment for CMV?
Valganciclovir
What are next steps in a patient with a positive PPD?
Rule out active infection with a CXR/symptoms
If no active infection, treat as latent TB
How are post-exposure HIV patients treated?
Treated with two nucleoside analogs (tenofovir/emtricitabine) + integrase inhibitor (raltegravir) for a month
How is scabies treated?
Treat with permethrin cream. Ivermectin is first line only in crusted scabies. Wash clothing and linens in hot water. Place other items in airtight plastic bags for several days.
Can interferon gamma release assay distinguish between active or latent TB
No
What does E coli 0157:H7 cause?
5-10% of patients can have hemolytic uremic syndrome (uremia/hemolytic anemia/thrombocytopenia)
What are some uses of clindamycin? (3)
What is a major side effect of clindamycin?
Clindamycin covers MRSA, decreases toxin production by Strep pyogenes and Staph aureus, and treats anaerobic infections above the diaphragm
Side effect - C diff
What antibiotics can be used to treat CAP empirically?
Cephalosporins (Rocephin)+ Macrolides (azithromycin)
Respiratory Fluroquinolones (Levofloxacin)
HIV
When should be rifabutin be used over rifampin in TB patients and why?
Use rifabutin over rifampin in HIV patients with TB because rifabutin has fewer drug-drug interactions with ARTs
What part of the lung does primary TB affect? What does it form?
The lower lobes of the lung. Forms Ghon Complex. “Started from the bottom now we here”
What part of the lung does secondary TB affect?
Secondary TB is reactivated latent TB. It affects the upper lobes.
Do entamoeba histolytica liver abscess require treatment?
No
How is HSV encephalitis diagnosed?
PCR of CSF after LP
What are atypical causes of CAP? (3)
Chlamydia
Mycoplasma
Legionella
Endocarditis
What two bacteria cause endocarditis or bacteremia and warrant colonoscopy/EGD?
Strep bovis
Clostridium septicum
What strains of HPV do HPV vaccines protect against? Who should get this vaccine?
6, 11, 16, and18 . Males and females 9-26 years of age should get the HPV vaccine.
When is candidiasis infection always treated? What is used for treatment in these cases?
When should fluconazole be used in these cases?
Treat in candidemia (blood cultures showing candidasis infection). Use echinocandin if patients are moderately/severely ill or neutropenic or if there is a possibility of fluconazole resistant organism.
Use fluconazole if candidemia is caused by UTIs or CNS infection
What are penicillins great for treating? What did bacteria develop against penicillin?
Penicillins are great for treating gram positive (ie skin flora). Bacteria developed penicillinase to counteract penicillins.
What are three penicillinase resistant pencillins?
Methicillin/Oxaficillin/Naficillin
What are gram positive cocci that are catalase positive? What is their morphology on microscopy?
Staphylococcus. Clusters or grapes of Staph
What is an example of a monobactam?
Aztreonam
What do monobactams cover? What do they not cover?
Monobactams cover gram negative organisms and pseudomonas.
Does not cover anaerobes
What is treatment for HSV and VZV encephalitis?
IV acyclovir (oral does not penetrate CSF)
How does CNS toxoplasmosis and CNS lymphoma typically present on MRI in HIV patients?
Toxoplasmosis is usually multiple ring enhancing lesion. CNS lymphoma is usually a single ring enhancing lesion.
T/F - Can tuberculin skin testing determine between active or latent TB?
No
T/F BCG vaccine may cause false positive TB skin tests?
True
Should BCG vaccination status should be taken into account when interpreting Tuberculin skin tests?
No. If a patient is from endemic country or is at risk for TB, CDC recommends interpreting Tuberculin Skin Tests as you would for someone who did not get BCG
In cellulitis patients, when should Staph Aureus be considered part of the etiology?
When you see pustules, abscesses, or purulent drainage.
How does primary TB present?
Primary infection is usually asymptomatic. 90% of patients who are immunocompetent control the infection and develop clinically silent latent infection.
How does active TB present?
Symptoms of active infection include cough, hemoptysis, weight loss, fever, and night sweats
How do post-splenectomy patients with encapsulated bacterial infection present?
Viral prodrome followed by abrupt deterioration and shock
What should be done in all patients with non-tunneled CRBSI?
Remove non-tunneled catheters if CRBSI is confirmed.
When should TEE be done in CRBSI?
Perform TEE in cases of Staph Aureus CRBSI
Endocaritis
What are physical exam signs associated with endocarditis?
Fever and regurgitant murmurs are most common. Petechiae is common as well.
- Splinter hemorrhages
- Roth spots - retinal hemorrhages
- Osler nodes - painful nodes on palms/feet
- Janeway lesions - non-tender nodules on palms/soles
- Conjunctival hemorrhages
Doxycycline can treat all tick-borne illnesses except what?
Babesia
What do echinocandins end in?
- Fungin
What are two lung manifestations of MAC?
Bronchiectasis and upper lobe cavitary lesions
What form of TB is transmittable (active or latent)?
Active TB is transmissible
How does pelvic inflammatory disease present?
Purulent endocervical drainage
Fever, lower abdominal pain that is bilateral.
Cervical motion tenderness and adnexal tenderness
What is Fitz-Hugh Curtis syndrome and what does it indicate?
RUQ pain from perihepatitis seen in pelvic inflammatory disease
Endocarditis
What are five indications for surgery during active endocarditis?
- Prosthetic valve endocarditis
- Fungal endocarditis
- Perivalvular extension - new conduction abnormalities, myocardial abscess, persistent bacteremia despite antibiotics)
- Vegetative burden - size > 10 mm or recurrent embolic events despite antibiotics
- Refractory CHF
When are stool cultures considered in patients with diarrhea? (3)
Stool cultures are generally low yield, although they may be considered in patients with:
- Fever
- Bloody diarrhea
- Diarrhea lasting longer than 72 hours
How does bacterial vaginosis present?
White discharge/white non-inflammatory coating
How does bacterial vaginosis appear on microscopy? (3)
- Clue cells on microscopy.
- Vaginal pH > 4.5
- Positive whiff test (fishy odor with addition of 10% KOH
Treatment for bacterial vaginosis?
7 day course of metronidazole BID
How is chlamydia diagnosed and how is treated?
Diagnosis is via NAAT of urine in men. Women need cervical swab. Treatment is azithromycin/doxycycline
What does acid-fast stain show in patients with suspected TB?
Just shows acid-fast bacilli which can be various strains of mycobacteria.
Acid-fast stain is not sensitive nor specific for mycobacterium TB.
When does arbovirus (West Nile) encephalitis present?
Summer and fall
WHEN does HSV encephalitis present?
Typically winter and spring
How does West Nile encephalitis present?
Encephalitis and acute asymmetric flaccid paralysis that may progress to respiratory failure
How does Creutzfeldt-Jakob prion disease present?
Rapidly progressive dementia, myoclonus, ataxia, and spasticity
What is treatment for pregnant women with UTIs? (4)
MS
Seven day course of amoxicillin-clavulanate, nitrofurantoin, cefpodoxime, or cefixime.