ID Flashcards
The following is the general “criteria” for what?
- Fever >38.3degC (100.9F)
- At least 3wks duration
- No dx after 3 outpt visits or 3 days of hospitalization
Fever of unknown origin
What are the 3 MC etiologies of Fever of Unknown Origin (FUO)?
- Infection
- Malignancy
- Connective Tissue Disease
What is the #1 MC malignancy to cause FUO (fever of unknown origin)?
Lymphoma, especially non-hodgkins
What is the main site of colonization of staphylococcal infections?
Nose
Is staph aureus coagulase negative or positive
positive
(Staph epidermidis and staph saprophyticus are both coag neg)
- Which staphylococcal strain is a frequent skin contaminant of blood cultures?
- What do you do to confirm whether a contaminant or a true cause of bacteremia?
- Staph epidermidis
- May have to draw from 2 sites
Which bacteria causes infections of:
- Urine catheters
- IV lines
- Prosthetic joints/heart valves
- Dialysis catheters
Staph epidermidis
Which staphylococcal strain is coagulase negative and is a leading cause of UTIs?
Staphylococcus saprophyticus
What is the etiology of TSS?
Staph aureus
Clinical presentation of what?
- Abrupt onset high fever
- Vomiting & watery diarrhea
- Sore throat, myalgias, h/a
- Hypotension with kidney and heart failure
- Diffuse macular erythematous rash and nonpurulent conjunctivitis
- Desquamation, esp. of palms & soles (late finding)

TSS
Lab findings in TSS are consistent with what?
shock and organ failure
What is empiric antibiotic tx for TSS?
Clindamycin + Vanco
(Also needs rapid rehydration–> 3L)
What condition is caused by Staph aureus and is primarily in neonates 3-15 days old?
Staph Scalded Skin Syndrome (SSSS)
Clinical presentation of which condition?
- Prodrome: fever, irritability
- Erythematous patches with large superficial fragile blisters
- When blisters rupture, skin appears red and scalded
- Nikolsky sign (only the first layer)

Staph Scalded Skin Syndrome (SSSS)
Diagnosis of what?
- Clinical with cultures
- Skin biopsy shows intraepidermal cleavage without necrosis**
Staph Scalded Skin Syndrome (SSSS)
What type of abx should be used to tx SSSS? If there is no response, what 2 meds should you consider?
- Penicillinase-resistant beta-lactam agents (Nafcillin)
- If no response, consider MRSA & tx with vancomycin
Etiology of Anthrax?
Bacillus anthracis
T/F: there has been bioterrorism w/ anthrax spores
True
Hallmark of what condition?
- Painless eschar with extensive surrounding edema
(will be on exam)

Cutaneous clinical syndrome of Anthrax
What causes:
- hemorrhagic mediastinitis
- occasionally necrotizing pneumonia
- Bacteremia
Inhalation clinical syndrome of Anthrax (the most dangerous form)
Which clinical syndrome has a prodrome including sxs like hemoptysis and dyspnea and can resultmin death within days
INHALATION clinical syndrome of Anthrax
What is seen on CXR of the inhaled form of Anthrax?
(will be on exam)
Widened mediastinum

What is the GI form of Anthrax from?
consumptom of undercooked, infected meat from animals infected with anthrax
Which infectious disease causes:
- Necrotic ulcers surrounded by extensive edema of infected intestinal segment and adjacent mesentery
- Can cause GI hemmorrhage
GI tract clinical syndrome of Anthrax
How do you tx anthrax if it is systemic w/ meningitis?
- Report/consult public health department
- Cipro + meropenem + Linezolid
- Antitoxin
- etc.
How do you tx Anthrax that is systemic WITHOUT meningitis?
- Report/consult public health department
- Cipro + Clinda
- Antitoxin
- etc.
How do you treat cutaneous Anthrax?
- Report/consult public health department
- _Ciprofloxacin**_
- Antitoxin
- etc.
***definitely know abx- will be on exam***
Which type of anthrax has the highest mortality rate? (cutaneou, injection, GI, inhalation or anthrax meningitis)
- Anthrax meningitis- even with treatment, mortality is 100%
- Inhalation is also very deadly with mortality rate of 45%
What is post-exposure prophylaxis for patients exposed to aerosolized B. anthracis (anthrax)?
Start Cipro w/in 48hrs- treat for 60 days
+
3 dose series of Anthrax vaccine
What is usually transmitted by the infected saliva of a bat, raccoon or skunk?
Rabies (caused by rhabdovirus)
Which infectious disease?
- Virus travels in nerves to the brain, multiplies in brain, then travels along efferent nerves to salivary glands
- Forms cytoplasmic inclusion bodies – site of viral transcription & replication
Rabies
What infectious disease causes percussion myoedema (mounding of the muscle at the percussion site)?
Rabies
What are the two types of CNS presentations of Rabies? What do both forms progress to?
•“furious” – encephalitic
•“dumb” – paralytic
*both forms progress to coma, ANS dysfunction, death
“Furious” (encephalitic) or “dumb” (paralytic) form of rabies?
- MC
- paranoia, terror
- Hydrophobia
- unquenchable thirst
- oversalivating
- Death by cardiac arrest
Furious (Encephalitic) rabies
“Furious” (encephalitic) or “dumb” (paralytic) form of rabies?
- gradual coma
- NO hydrophobia
- paralysis
- muscle weakness and loss of sensation
- death
Paralytic rabies
(this is less dramatic and usually longer course than furious rabies)
How do you diagnose rabies? (4)
- test animal if possible
- PCR of saliva
- viral culture of saliva
- Full thickness skin biopsy from posterior region of neck at hairline
How do you prevent rabies? (this is the main tx)
Immunize household pets and ppl w/ signifcant animal exposure
What is PEP and PrEP for rabies?
PEP= Human rabies immune globulin, Rabies vaccine
PrEP= Human diploid cell vaccine
Which infectious disease?
- Aedes mosquito
- Sexual, vertical or blood transmission
- Sxs: Acute onset fever, maculopapular pruritic rash, nonpurulent conjunctivitis, arthralgias
- most are asymptomatic
Zika

How do you dx Zika virus?
- Viral RNA or IgM
- real-time RT-PCR of blood or urine for Zika virus RNA
When is it important to test someone for Zika virus even if they are asymptomatic?
Test asymptomatic pregnant women for IgM 2-12 weeks after:
- travel to endemic area OR
- sex w/ person with confirmed Zika
If you have a pregnant woman with Zika virus, what is the management?
Ultrasounds every 3-4wks looking for:
- Congenital microcephaly
- Also may see arthrogryposis (club foot) and spontaneous abortions
What are 3 complications of Zika virus?
- Guillain-Barré syndrome
- Myelitis
- Meningoencephalitis
What is tx for Zika virus?
rest
symptomatic tx
How do you prevent zika virus? (4)
- Mosquito control
- Avoidance of travel to affected areas when pregnant
- Abstinence from sexual intercourse or barrier protection
- No blood donations
Which infectious disease is due to Water reservoir contamination and transmission is never person-to-person
Legionella
What are 5 risk factors for Legionella?
(you can be exposed without getting sick)
- smoking
- chronic lung disease
- older age
- transplant recipient
- biologic therapy
Which infectious disease has a cough that is initially mild and slightly productive and then develops blood-streaked sputum (rarely gross hemoptysis)
Legionella
What is seen on CXR for legionella?
•Patchy unilobar infiltrate that progresses to consolidation
•Pleural effusions common
The following lab findings are seen in which infectious disease?
- Renal/hepatic dysfunction
- Thrombocytopenia
- Leukocytosis
- Hypophosphatemia
- Hyponatremia
- Hematuria/proteinuria
- Elevated serum ferritin
Legionella
what form of legionella is more mild and has the following:
•Fever, malaise, chills, fatigue, h/a
•No respiratory complaints
•Self-limited
Pontiac fever
How do you diagnose Legionella?
sputum culture
Urinary antigen tests
How do you tx legionella?
Azithromycin or clarithromycin or levofloxacin x10-14days
No isolation needed
How do you tx pontiac fever?
symptomatic tx
Which infectious disease blocks release of acetylcholine at the neuromuscular junction
Botulism
How do alduts typically get botulism? infants?
Adults= canned, smoked or vacuum-packed food
Infants= honey
Clinical presentation of which infectious disease?
- Descending weakness
- NO fever
- Visual- blurred vision, diplopia, nystagmus, ptosis
- urinary retention & constipation
- _***Paralysis may progress to respiratory failure***_
Botulism
How do you dx botulism?
Clinical dx
Toxin in serum, stool, etc
How do you tx Botulism?
- Equine serum heptavalent botulism antitoxin w/in 24 hrs
- intubation
- IV fluids
Which infectious disease has a gray membrane covering tonsils & pharynx?
Diphtheria

The exotoxin from Coryneybacterium diphtheriae causes what 2 things?
Myocarditis
neuropathy
What are the 2 complications of Diphtheria?
•Myocarditis complication – arrhythmias, heart block, heart failure
•Neuropathy complication – diplopia, slurred speech, dysphagia
How do you dx diphtheria?
Clinical dx
confirmed w/ culture and + toxin assay
How do you treat diphtheria? (4)
- Diphtheria equine antitoxin
- Penicillin or erythromycin x14 days
- Remove membrane by laryngoscopy
- ISOLATION until neg culture x3
What is PEP for diphtheria?
Booster + penicillin or erythromycin
Pathology of which infectious disease?
- Retrograde axonal transport within motor neuron
-
Blocks neurotransmission, inactivating inhibitory neurotransmission causing:
- increased muscle tone
- painful spasms
- widespread autonomic instability
Tetanus
Which infectious disease?
- Trismus (“lock jaw”)
- tonic/spastic muscle contraction in 1 EXTREMITY OR BODY REGION
- intermittent intense spasms
Tetanus
The following is a later finding of which infectious disease?
- profuse sweating
- cardiac arrhythmias
- labile HTN or hypotension
- fever
- profuse sweating
- cardiac arrhythmias
- labile HTN or hypotension
- fever
How do you dx tetanus?
clinical dx in setting of tetanus prone injury and hasn’t had tetanus booster in last 5 yrs
How do you tx tetanus? (7 most important)
- ICU
- Metronidazole
- Tetanus immune globin
- Tetanus immunization x3
- Benzos
- airway management
- neuromuscular blocking agents
What causes lyme dz?
Borrelia Burgdorferi
transmitted by deer tick and blacklegged tick
Which disease has a bimodal distribution (5-10 and 35-55)
Lyme disease
For someone to get lyme disease: ticks need to feed for ___ to ___ hours to transmit infection
24-36 hours
Presentation of which disease?
- Erythema migrans (target lesion) 1 week after bite
- Viral like illness (myalgias, headache, fatigue,etc)

Lyme Disease
How do you dx early lyme?
clinical diagnosis
How do you dx late lyme? (intermittent or persistent arthritis, subtle encephalopathy, polyneuropathy)
Clinical dx + lab evidence
How do you tx Lyme Disease? Alternative tx for pregnant women?
Doxycycline x10-14 days
Amoxicillin for pregnant/lactating women
What are the complications of Lyme Disease in pregnancy?
•spontaneous abortion, still birth, preterm birth
What are 3 things that people with chronic lyme complain of?
- fatigue
- Arthralgias
- Memory impairment
T/F: the following is some of the diagnostic for chronic lyme disease:
- H/o lyme treatment
- onset of nonspecific sxs (fatigue, arhtralgias, memory disturbances, etc) w/in 6 months
True
Criteria that must be met for you to give prophylactic antibioticcs for lyme disease:
- Tick attached for at least ____ hours
- Prophylaxis within ____ hours of the time the tick was removed
- More than 20% of ticks in the area are known to be infected with B burgdorferi
- No contraindication to the use of doxycycline
- Tick attached for at least 36 hours
- Prophylaxis within 72 hours of the time the tick was removed
What causes rocky mountain spotted fever?
Rickettsia rickettsia
(tick borne illness)
Which infectious disease:
- MC men, <10y/o and 40-64y/o
- Fever, severe h/a, malaiase, myalgias, arthralgias
-
Rash on day 3-5: blanching erythematous rash w/ macules–> petechiae
- rash starts on ankles/wrists–> trunk–> palms/soles

Rocky mountain spotted fever
Which infectious disease?
•Normal WBC count with immature bands
- Thrombocytopenia
- Hyponatremia
- Elevated LFTs
Rocky Mountain Spotted Fever
How do you dx Rocky mountain spotted fever?
•Serologic testing with IFA (indirect fluorescent antibody) for R. rickettsia antigen
How do you tx Rocky Mountain Spotted fever?
Doxycycline w/in 5 days of onset
Complications of which infectious disease?
- Renal failure
- Sepsis
- Encephalitis
- Noncardiogenic pulmonary edema
- ARDS
- Cardiac arrhythmias
- Coagulopathy/DIC
- GI bleeding
- Skin necrosis
Rocky Mountain Spotted Fever
Which infectious disease?
- 90-95% serum positive
- Transmitted through intimate contact w/ saliva
- Persists asymptomatically for life, reactivation uncommon
- Associated w/ B cell lymphomas, etc
Epstein Barr Virus (EBV)
The following is classic sxs of which disease?
- tonsillitis/pharyngitis, cervical LAD, fever
- Nausea, vomiting, anorexia (mild hepatitis in 90%)
- Splenomegaly (50-60%)
- Resolves in 1-2wks; fatigue persists x months
Infectious mononucleosis caused by EBV
Treatment of infective mononucleosis caused by EBV with ______ results in a morbiliform rash
Ampicillin
What is a good marker of acute infection of infectious mononucleosis (caused by EBV)
IgM and IgG antibodies against viral capsid antigen (VCA)
Infectious mono caused by EBV:
Early presence of what excludes acute infeciton?
IgG antibodies to EBV nuclear antigen (EBNA)
*this indicates latent infection
What are the top 3 complications of infectious mononucleosis caused by Epstein Barr Virus?
- Pneumonia
- Hepatitis
- Myocarditis
What are the 2 main treatments of infectious mononucleosis caused by EBV?
- Supportive care- NO ABX (Amox)
- Sports restrictions- no contact b/c of splenomegaly
What is the MC presentation of Cytomegalovirus?
CMV mono
The following is caused by what virus?
- Transmission: sex, close contact (daycare), blood, perinatal
- usually asymptomatic but sxs in transplant pt
Cytomegalovirus
T/F: CMV can be vertically transmitted and is associated w/ syndrome of congenital CMV in newborns
True
How do you dx CMV?
Quantitative DNA PCR
How do you tx cytomegalovirus
strong antivirals (ex: ganciclovir)
Which disease?
- Caused by cat feces or eating poorly cooked contaminated meat
Toxoplasmosis
Which disease is usually asymptomatic in immunocompetent patients but can have:
- b/l symmetrical nontender cervical or occipital adenopathy
- Chorioretinitis – visual loss or floaters

Toxoplasmosis
Which 4 things can be vertically transmitted? (TORCH)
T- Toxoplasmosis
O- Other (Syphilis)
R- Rubella
C- CMV
H- Herpes
Which disease can cause encephalitis with multiple necrotizing brain lesions in immunocompromised pts
Toxoplasmosis
(this is the most concerning presentation)
Toxoplasmosis in pregnancy can cause what 3 things
- Spontaneous abortion
- still-birth
- neonatal disease (neurologic & ophthalmic disorders)
How do you dx Toxoplasmosis
Serology- ELISA
Although most pts with Toxoplasmosis don’t need treatment, If someone has severe/prolonged infection, or are immunocompromized/pregnant?
- Pyrimethamine + sulfadiazine OR pyrimethamine + clindamycin + leucovorin
- Tx minimum of 2-4 weeks
- Ophthalmology
What is prophylactic treatment of Toxoplasmosis?
Trimethoprim- sulfamethoxazole
Which disease?
- Pigeon dung
- transmitted by inhalation
- usually asymptomatic
- Immunocomp- progressive lung disease and dissemination
Cryptococcosis
Presentation of what?
- Nodules, widespread infiltrates leading to respiratory failure
- Dissemination:
- CNS - Meningitis, AMS, CN abnormality
- Skin – papules, plaques, abscesses, sinus tracts
- MSK – osteolytic lesions

Cryptococcosis - presentation above is seen in immunodeficient patients
What 4 things are used to dx Cryptococcosis?
•Respiratory secretion or pleural fluid culture
- LP with CSF analysis
- MRI
- Antigen testing
How do you treat Cryptococcosis?
- Amphotericin B x 14 days
- Follow with fluconazole x 8 weeks
Which disease?
- Unilateral vesicular eruption in a dermatomal distribution
- old people (>50)
VZV- Herpes Zoster

How do you dx VZV
clinical diagnosis
When would you treat VZV and what would you tx with?
Acyclovir w/in 72 hrs of onset
>72 hrs if still getting new lesions
if immunocompromised
How would you tx a pt w/ VZV with mild pain
NSAIDs and acetaminophen
How would you tx a pt w/ VZV with mod-severe pain
Stronger opioid (Oxycodone, morphine)
The following are complications of what?
•Postherpetic neuralgia (90d of pain)
- Ocular complications – uveitis, keratitis
- Aseptic meningitis
- Encephalitis
•Herpes zoster oticus (Ramsay Hunt syndrome)- facial palsy w/ vesicles in ear
•Myelitis
VZV
When do you give the Herpes Zoster Vaccine?
50+