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Flashcards in Infectious Disease Deck (27)
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1
Q

Candidiasis

A

MC: vulvovaginal

  • other: balanitis, mucocutaneous, mastitis, esophagitis, oropharyngeal
  • RF: denture wearers, immunocompromised, children

Sxs: itching, discharge

  • dyspareunia, dysuria, vaginal irritation
  • vulvar erythema, swelling, and vaginal erythema
  • white, curd-like but may be watery

Dx:

  • wet prep: budding yeast, hyphae, pseudohyphae; no WBCs
  • pH < 4.5

Mgmt:
- Azoles

2
Q

Chlamydia

A

Intracellular bacteria
MC reportable, bacterial STI
Dangerous in women: 40% w/untreated disease will develop PID/infertility/ectopic preg

Sxs:

  • asx (F 80%, M 50%)
  • common cause of NGU, dysuria in men; urethritis in women
  • discharge*
  • diffuse pelvic pain, dyspareunia
  • post-coital bleeding, friable cervix, red, inflamed, mucopurulent
  • dysuria
  • may have mild pelvic pain on exam

Dx:

  • wet mount w/>10 WBC/hpf
  • +LE on UA w/neg nitrates
  • NAAT for G/C**
  • routine annual screening for women < 25

Mgmt:

  • Azithro 1g x1 OR doxy 100mg BID x7d OR levofloxacin 500mg qd x7d
  • abstain from sex x7d
  • test for cure/reinfection 3 mo later
  • treat all partners in past 3 mo
3
Q

Cholera general

A

Inflammatory type diarrhea*

  • GNB (costal waters)
  • ingestion of bacteria colonizes SI and produces toxin modulating CFTR
  • increased secretion, loss of Na/H20 into SI

Requires large infecting dose

RF: raw/undercooked shellfish (oysters*)

  • poor sanitation
  • contaminated H2O
  • natural disasters

Sxs:

  • endemic: asx, mild “non-inflammatory” diarrhea
  • epidemic: severe, dehydrating, life-threatening inflammatory diarrhea (electrolyte abnormality, hypovolemic shock)
  • vomiting early, painless diarrhea w/out tenesmus (rice water stool*)
  • severe cholera gravis: lose 1L+/hr, can die w/in 12hr from SCD d/t electrolyte abnormality
4
Q

Cholera dx/tx

A

Dx:

  • dark-field microscopy* = comma-shaped darting bacteria*
  • green –> yellow +
  • stool culture

Mgmt:

  • early, aggressive fluid replacement
  • IV cholera saline (Dhaka solution) - more K and bicarb
  • start ORS concurrent to IV or w/in 3-4hr of stabilization
  • Doxy (adults), azithro (peds)
  • supplemental zinc
5
Q

Diphtheria

A

Et: corynebacterium diphtheria; respiratory droplet spread

Sxs:

  • early: ST, mild, fever, hoarseness, malaise
  • obstructive membrane* forms in nasopharynx or laryngotracheal area restricting breathing/swallowing*
  • “bullneck”

Complication:

  • inflammation of heart (arrhythmia)
  • nerves (paralysis)

Dx: swab/culture throat

Mgmt:

  • tx based on clinical presentation
  • antitoxin w/in 48hr
  • PCN G IM/IV or Erythromycin x 10d
  • isolation, DTap/Tdap
  • tx close contacts
6
Q

Gonococcal infections

A

Neisseria gonorrhea (GN diplococci)

  • short incubation 2-14d
  • causes active PID

Disseminated disease:

  • skin (erythematous, purple nodules)
  • pharynx
  • eyes
  • liver
  • joints

Sxs: more than chlamydia, but may be asx

  • heavy mucopurulent d/c
  • post-coital bleeding, pelvic pain, dysuria (mc men)
  • Bartholin gland cyst: infected, accumulates pus

Dx:

  • wet mount w/>10 WBC/hpf
  • +LE on UA w/neg nitrates
  • NAAT for G/C**
  • routine annual screening for women < 25

Mgmt:
- ceftriaxone 125mg IM x1 AND Azithro 1g PO

7
Q

Helminth infestation

A

Ingesting eggs
child itches butt at night
use tape to check for worms and view them at night

Tx: albendazole 400mg PO x1, repeat in 2wk

8
Q

Toxoplasmosis

A

Parasite spread through eating oocytes and contact with cat feces

Sxs:

  • mostly asx
  • HIV: organ failure, encephalitis, chorioretinitis
  • blurry vision, slurred speech, HA, unsteady gait, confusion

Dx: + serology

Mgmt:

  • sulfadiazine and pyrimethamine
  • must give prophylaxis to HIV pt (Bactrim)
9
Q

Lyme disease

A

Et: borrelia burgdorferi (transmitted by ixodes scapularis)

Sxs:

  • constitutional
  • erythema migrans (bullseye)

untreated:
- neuroborreliosis triad: lymphocytic meningitis, CN palsies, radiculoneuritis
- cardiac: AV block, pericarditis, palpitations

persistent:
- chronic arthritis
- shooting pain/numbness, tingling

Dx:

  • screening EIA assay
  • confirm with WB if +
  • CSF studies, lyme pcr

Mgmt: Doxy
- <8y or pregnant: amoxicillin

10
Q

RMSF general

A

MC rickettsial disease in the U.S.

Et: rickettsia rickettsii

  • obligate intracellular gram neg coccobacilli
  • transmission: american dog tick (Dermacentor variabilis)
  • April-Sept

Location:

  • SE atlantic coast
  • midwest

Pathogenesis:

  • organism in tick are dormant (need 1-2d of attachment)
  • activated by warm blood meal
  • released into saliva of tick
  • prolonged exposure for transmission (24-48hr)
  • spreads through lymphatic system to cause vasculitis affecting all organs

Manifestations:

  • MC affects skin, adrenals
  • 7d incubation
  • presents w/fever, chills, HA, malaise
  • rash (95%) w/in 1st week: initial, blanching 1-4mm macular lesions (petechial)
  • extremities to trunk
  • the larger the blood vessels the high mortality rate
  • may occur on palms/soles*
11
Q

RMSF dx/tx

A

Dx:

  • CBC, LFTs: leukopenia, thrombocytopenia, inc transaminases
  • serology: IgM/IgG confirmation
  • generally not positive for 7-10d
  • skin biopsy if + rash

Complications:

  • life-threatening complications arise from widespread vasculitis; usually in pt w/out rash d/t delayed dx/tx
  • encephalitis
  • noncardiogenic pulmonary edema, ARDS
  • cardiac arrhythmias
  • coagulopathies
  • GI bleeding
  • Skin necrosis

Mgmt: Doxycycline 100mg PO bid x 7-10d (even kids, preg)

12
Q

CMV infection

A

Congenital acquired: blood disorders, deafness, microcephaly, fetal death
- asx in mothers typically

IgG/IgM specific ab for CMV if pt is exposed or if there are fetal growth complications

Mgmt:
- no tx or immunization available

Prophylaxis:

  • pregnant women should avoid contact w/urine or saliva of young children
  • hand hygiene after handling secretions from children
13
Q

EBV infections

A

Sxs:

  • malaise, HA, low grade fever to high grade
  • progress to tonsillitis +/- pharyngitis
  • posterior cervical LAD = mono
  • white exudates, severe fatigue FIRST
  • palatal petechiae, periorbital/palpebral edema, maculopapular or morbilliform rashes
  • splenomegaly

Dx: monospot finger prick (may take 1-2wk to be positive)
- blood test: peripheral blood lymphocytes + positive heterophile ab test

Mgmt:

  • sx tx: rest, APAP, Ibu
  • fluids
  • stay out of contact sports x 6-8wk
14
Q

HPV infections

A
  • Genital: condylomata acuminate
  • Cervical CA

Sxs: mostly asx, subclinical or unrecognized

Dx: clinical
- confirmed w/bx if needed

Mgmt:

  • podophyllin resin
  • tri/bichloracetic acid
  • cryotherapy
  • surgical excision
15
Q

Syphilis background

A

Et: treponema pallidum

  • corkscrew spirochete
  • doubles q 24hr

Sexual transmission only when mucocutaneous syphilitic lesions are present
- MC: MSM (HIV)

Pt: 20-40yo
- MC AA

Occurs in overlapping stages classified according to symptoms and time since initial infection

Tx:

  • depends on infection stage, CNS involvement
  • serologic testing should be repeated 6 and 12 months after initial tx (f/u mandatory)

Reportable infection

16
Q

Primary active infection (syphilis)

A

Localized infection representing recent infection

Sxs:

  • ** Chancre ***
  • firm, round, small, painless, may be asx
  • well circumscribed, may look like punch biopsy

Appears at spot where T. pallidum enters body w/resultant dermatologic response

More common in genital location

Lasts 3-6wk before healing on its own

17
Q

Secondary active infection (syphilis)

A

Systemic or disseminated infection

Wks-few months (2-6mo)
Pt w/untreated infection may develop systemic illness
+/- preceding chancre (chancre often asx)

Derm:

  1. Generalized rash
    * MC manifestation of secondary syphilis
    - rusty/brown colored, consider w/any widespread rash
    - palms/soles commonly involved**
    - mucosal lesion, alopecia possible

Faint, erythematous macules over upper torso/flanks -> lesions infiltrated and darker, often w/scale, darker the pt skin -> palms, soles

  1. Condyloma lata
    - large, raised, gray/white lesions, involving warm, moist areas such as mucous membranes in mouth and perineum
    - lesions occur most often in areas close to primary chancre
    - highly infectious

Other:
* LAD - epitrochlear nodes

18
Q

Primary / Secondary syphilis active infection TX

A

** Benzathine Penicillin G 2.4 mu X1

Ceftriaxone (if MP rash) or doxycycline (if allergy)

PCN Tx of syphilis may induce Jarisch-Herxheimer Rxn

  • acute onset fever, rash, myalgia, HA, hypotension
  • T. pallidum lacks endotoxin - rxn results from release of large amounts of treponemal lipoprotein that stimulate production of inflammatory mediators
19
Q

Tertiary syphilis infection

A

Progression of systemic or disseminated infection - refer

Months-Years later - progressed from secondary syphilis or late latent syphilis
- can occur any time after initial infection

  1. Infiltrative tumors (gummas)
    - small, rubbery granulomas w/necrotic center and inflamed, fibrous capsule
    - may be hard to discriminate from secondary syphilis
  2. CV involvement (Aortitis)
    - chronic infiltration of aortic wall causing clotting
    - wall starts to separate d/t inflammation
  3. Neurosyphilis: may occur any stage of infection
    - eye, ear, brain, spinal cord
    Early (more common)
    - CN dysfunction, chronic meningitis, CVA, acute AMS, auditory or ophthalmic abnormalities*
    Late
    - 10-30y after infection - emotional lability, memory deficit, psychosis (dementia in younger pt*)
    - sensory ataxia of LE
20
Q

Latent infection

A

“no symptoms syphilis”

  • untreated and became latent
  • may be diagnosed in asx pt by serologic testing
  1. Early latent syphilis
    - <1yr w/out sxs of primary or secondary
  2. Late latent syphilis
    - >1yr w/out sxs may progress to tertiary

Mgmt:

  • early: same as primary and secondary (PCN)
  • late: benzathine PCN G x 3
21
Q

Congenital syphilis

A

infected pregnant woman to fetus

  • fetal infection can occur during any trimester of pregnancy
  • routinely test in first tri

2/3 infants are asx at birth

transmission can occur during any stage of syphilis

Early lesions (children <4y) more common

  • fever, rash, HSM
  • neurosyphilis: bulging fontanelle, seizures, CN palsies

Late lesions (children >4y)

  • interstitial keratitis (looks like cataract)
  • bone, teeth involvement
22
Q

Syphilis diagnosis

A
  1. sexual exposure history
  2. clinical sxs
  3. diagnostic tests
    - direct methods (minimal use in routine practice)
    - indirect methods (serologies mc)

Definitive diagnosis
- both nontrep and trep tests are reactive

H/o treat syphilis

  • newly acquired syphilis infection is dx if quant testing on an RPR test reveals >4x increase in titer w/in 6mo**
  • serofast - retain a low titer (<1:8) reactive nontrep tests despite successful tx
  • reactive trep test in a person with h/o treated syphilis should not be used alone to dx newly acquired syphilis
23
Q

Syphilis direct methods dx

A

evidence of inflammation that seems consistent w/syphilis

Early syphilis

  • darkfield microscopy: visualization of spirochete from moist lesion (e.g. chancre)
  • most don’t have access to darkfield microscopy
24
Q

Nontreponemal serologic tests

A

Screening test

  • VDRL
  • RPR
  • positive nontrep tests reported as titer of antibody (e.g. 1:32 - represents detection of antibody in serum diluted 32-fold)
  • higher the titer, the more disease activity

False (+): pregnancy

False (-): early syphilis (presence of chancre before ab generation)

RPR - quant test and ab titers monitored to assess tx response

25
Q

Specific treponemal serologic tests

A

Confirmatory - qualitative only, reported as reactive or nonreactive

  • TP-PA
  • TP-EIA - new choice and better s/s than RPR
Detect abs (IgM, IgG) to specific antigenic components of T. pallidum 
- appear earlier than nontrep abs

Most patients who have reactive trep tests will have reactive tests for remainder of their lives, regardless of treatment or disease activity

26
Q

Dx CNS syphilis

A

May occur at any stage

CSF exam if:

  1. clinical evidence of neuro involvement observed
  2. setting of symptomatic late syphilis
  3. treatment failure (RPR not improving by 6mo) - may be in CNS now

Lumbar puncture: send for CSF VDRL

27
Q

Syphilis serofast state

A
  • rates depend on syphilis stage, pretreatment titer, point at which response is assessed

Nontrep abs decline (often adequately) after tx but fail to completely revert to NONREACTIVE: 20-40% of pts

May represent 1 of 3 situations:

  1. persistent low-grade infection
  2. variable host ab response to infection
  3. tissue injury due to nonsyphilitic inflammatory condition