Infectious Disease Flashcards
areas affected by meningitis
arachnoid, subarachnoid space and CSF
Most common bacterial pathogens of meningitis
Streptococcus pneumoniae
Neisseria meningitidis
Haemophilis influenzae
Most common fungal cause of meningtitis
cryptococcus
Classic triad of meningitis
fever, nuchal rigidity, change in mental status
Which pathogen that causes meningitis is associated with a petechial rash?
N. meningitidis
If any of the following are present what needs to be done before doing an LP: abnormal level of consciousness, h/o CNS dz, papilledema, focal neuro deficits?
head CT (if ICP is to high an LP will result in brainstem herniation)
What WBC level in CSF is considered diagnostic of meningitis?
> 1000 if PMNs make up 85%
What abx should be given empirically prior to lab results being back for meningitis?
2 G Rocephin (Ceftriaxone) IV
What are normal glucose levels of CSF?
50 - 80 mg/100 mL
What ages does bacterial meningitis occur more frequently in?
2 months - 2 years
What is suggestive of meningitis in a young child/infant?
Paradoxical irritability (crying worsens when being held)
Most common cause of encephalitis
viral infections
What is the difference between encephalitis and meninigitis?
Encephalitis has altered brain function and neurologic findings like personality changes, paralysis, hallucinations, altered smell, problems with speech
What additional cultures should you order with LP for suspected encephalitis?
PCR for HSV1, serology: IgM ab for West Nile virus, mumps, EBV
What is the treatment for encephalitis?
Acyclovir 10mg/kg IV q 8 h
Which pathogen is the most deadly cause of encephalitis?
HSV
What must you do on any red, hot, swollen joint?
arthrocentesis
What might not show in gram stain of joint fluid even when it’s the cause of septic arthritis?
gonococcal organisms (test for STDs)
What is the abx treatment for severe sepsis +/- shock?
Gentamicin or tobramycin or amikacin PLUS antipseudomonal cephalosporin like Cefepime
What abx should be added to treatment for bacteremia until cultures come back?
vanco
Leading cause of gram + bacteremia
s. aureus
What should the work-up for bacteremia include to rule out infective endocarditis and is the most sensitive test for infective endocarditis?
Transesophageal echo
Clinical syndrome from a dysregulated inflammatory response to an infection. Can have low urine output, anemia, low platelets, hyperglycemia, high LFTs, ect
sepsis/septicemia
Describe the three situations when superficial soft tissue infections are emergencies
Infection around the face and hand. Cellulitis in the presence of diabetes or PVD. Local infection with the presence of leukemia or HIV
Pathogen most commonly involved with impetigo that causes small vesicles which quickly rupture and form “honey-colored” crusts
strep
What is the drug of choice for all cellulitis, folliculitis, furnuclosis until MRSA is ruled out?
BACTRIM. Alternate=Clindamycin
Patients at high risk are those with previous valve damage, valve replacement or history of IV drug use. Subacute may present with anorexia, night sweats and weight loss
endocarditis
Nontender red or maroon macules or nodules on the palms and soles that are characteristic of endocarditis
janeway lesions
tender, erythematous nodules with opaque centers which appear on pulp of fingers/toes associated with endocarditis
osler nodes
pale oval areas surrounded by hemorrhage near optic disc characteristic of endocarditis
Roth spots
Increasing number of cases now seen from wound or sinus infections. A diffuse, blanching, macular erythema appears with signs of pan-mucosal inflammation. T > 102 with multiple organ failure
Toxic Shock Syndrome
Why are blood cultures negative with TSS?
cause is from toxin not the bacteria. need to find source to grow out culture
Occurs in all states, but South Atlantic, South Central, and Oklahoma most common. Usually during warm months.
Sudden onset fever, chills, malaise, myalgias, severe frontal headache
Rocky Mountain Spotted Fever
Where is the pink, macular rash that appears on the 5th day of RMSF located?
palms of hands and soles of feet spreading centrally
Treatment of choice for RMSF?
doxy (in kids use chloramphenicol)
Empiric treatment of lyme disease
Tetracycline 500mg QID X 30 days at minimum
potentially life threatening neuroparalytic syndrome. Usually ingested through the GI tract. Gram + rod shaped anerobes
botulism
How is the acute onset of botulism classically described?
bilateral cranial neuropathies associated with symmetric descending weakness
What abx may be helpful for wound botulism?
PCN G and metronidazole
Droplet transmission from person to person. Spreads most readily during cool, dry winter. Caused by variola
smallpox
How does smallpox rash differ from varicella?
most prominent on face and extremities (including palms and soles) in contrast to truncal distribution of varicella
Begins as a papule, progresses through a vesicular stage to a depressed black necrotic ulcer (eschar)
cutaneous anthrax
A brief prodrome resembling a “viral-like” illness, characterized by myalgia, fatigue, fever, with or without respiratory symptoms, followed by hypoxia and dyspnea, often with radiographic evidence of mediastinal widening
inhalational (pulmonary) anthrax
