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Flashcards in Infectious Diseases Deck (53):

Most common CAP vs Nosocomial pneumonia

CAP=Strep. Pneumo
Nosocomial=E. coli, Pseudo, and S. Aureus


Atypical pneumonia common bugs and signs

Mycoplasma pneumonia, Chlamydia pneumonia, Coxiela, legionella, influenza

Dry cough, headache, sore throat
Normal pulse with high fever


Legionella common demographics

Organ transplant recipeients, renal failure, patients with chronic lung disease, and smokers


Nursing home residents common infection

Psuedomonas predilection for upper lobes


CD4 count less than 500 infections

Tb, recurrent pneumonias, vaginal candidiasis, and herpes zoster


CD4 count less than 200 infections and prophylaxis

pneumocystis jirovecii, cryptococcis (treat with IV amphotericin B plus flucytosine and chronic suppression with fluconazole, frequent lumbar punctures), histoplasmosis, or cryptospordiosis

Prophylaxis with TMP-SMX for pneumocystis one double strength tablet daily
P02 less than 70 and A-a gradient more than 35 have poor prognosis and should be given prednisone before TMP-SMX


CD4 count less than 50 infections

Mycobacterium aviium intracellulare complex, disseminated histoplasmosis, CMV retinitis, colitis, adrenalitis, and esophagitis (IV ganciclovir, foooscarnet or cidofovir), CNS lymphoma (diagnose with stereotactic brain biopsy or with CSF for epstein barr virus)


MAC with CD4 count less than 50 treatment

Clarithromycin, ethambutol, and rifabutin for weeks

MAC prophylaxis-clarithromycin 500 mg twice daily
Azithromycin 1200 mg weekly

Don't need concomitant HAART therapy with prophylaxis once CD4 counts recover


CD4 count less than 100

Prophylaxis with daily dosing of TMP-SMX

toxoplasmosis (sulfadiazine and pyrimethamine)


CURB 65 guidelines

Uremia >20 BUN
RR >30
BP less than 90/60
More than 2= inpatient
More than 4=ICU


Outpatient younger than 60 with pneumonia bugs and treatment

S. pneumo, Mycoplasma, Chlamydia or legionella

Treatment: Macrolides (azithromycin or clarythromycin)
or doxycycline

For 5 days


Older than 60 or with comorbidiites outpatient pneumonia treatment

Fluroquinolone (levofloxacin, moxifloxacin)
Second or third cephalosporin
For 5 days


Co morbidities to consider for pneumonia

Heart disease, sickle cell, pulmonary disease, diabetes, alcoholic cirrhosis


Inpatient CAP treatment

Macrolides + cephalosporin
Or fluorquinolone


ICU CAP treatment

Cephalosprin + macrolide (IV)
Cephalsoprin + flluoroquinolone


Hospital acquired pneumonia (in hospital for >72 hours)

ceftazidime or cefepime


Ventilator associated pneumonia diagnosis and treatment

Diagnosis: new inflitrate on CXR, purlent secretion from endotracheal tube
Bronchoalveolar lavage

Treatment: 3 drugs
1. ceftazdimine/cefipime OR pipercillin/tazobactam OR carbapenem (Pseudo)
2. Aminoglycoside or fluoroquinolone (Pseudo)
3. Vanco or linezolid (gram +)


Lung abscess treatment

Postural drainage
Gram positive: ampicillin or amoxicillin/clavulanic acid, ampicillin/sulbactam, or Vanco
Anaerobes: clinda or metro
Gram negative: fluoroquinolone or ceftazidime

Continue until cavity is gone or until CXR have improved considerably


Results of PPD test results and treatment

Used for latent TB not active TB (active TB order a sputum culture)
Positive if >15 mm in patients with no risk factors

High risk (high prevelance areas, immigrants, health care workers, nursing home residents, close contact with TB, alcoholics, diabetics)=10 mm positive

HIV, steroid users, organ transplant, close contact with active TB, radiographic evidence of primary TB=5 mm is positive

Never have had a PPD test before do another test in 1-2 weeks

If positive use chest X ray to rule out active disease-if excluded use 9 months of isoniazid (even if have had BCG vaccine)


Treatment of TB

2 months of RIPE (or streptomycin) and then 4 months of INH and rifampin


Ages and treatment of suspected meningitis

less than 4 weeks: aminoglycoside
Infants (less than 3 mos): cefotzxime +ampicillin +vanco
3 mos to 50 years: ceftriaxone or cefotaxime + vanco
greater than 50: ceftriaxone or cefotaxime+vanco+ampicilin
Impaired cellular immunity: ceftazidime +ampicilin +vanco

Aseptic is supportive


Diagnosis and treatment of encephalitis

MRI of brain-T2 signal in frontotemporal region=HSV encephalitis
EEG=tempral lobe discharges

Treatment: HSV=acycylovir for 2-3 weeks
CMV=ganciclovir or foscarnet


Importance of HBeAg, HBsAg, anti-HBs, anti-HbC

HbeAg: indicates infectivity
HbsAg: earliest to arrive
anti-HBs-natural or vaccine induced immunity
Anti-HbC: present during window period


diagnosis of Hep C

PCR detects viral load


Diagnosis Treatment of botulism

Diagnosis: ID toxin in serum, stool or gastric contents (bioassay)

gastric lavage if within several hours

High suspicion=antitoxin

Wounds=penicillin and wound cleansing


Complicated UTI

extends beyond blader: pyelo, prostatits, urosepsis)

Risks: men, diabetes, pregnancy, RF, history of pyelo, obstruction, catheter, resistant organism, immunocompromised


Treatment of UTI

TMP/SMX (bactrim): 3 days
nitrofurantoin: 5-7 days
Fosfomycin: single dose
Ciprofloxacin: 3 days

Pregnant: ampicllin, amoxicciln or oral cephalosporins: 7-10 days

Men: same as uncomplicated but for 7 days

Recurrent: 2 more weeks of treatment and culture

2+ UTIs per year: TMP/SMx after sex or at first symptoms
or low dose TMP/SMX for 6 months

Phenzopyridine: urinary analgesic


Treatment of Pyelonephritis

TMP/SMX or fluroquinolone for 10-14 days
Single dose of ceftriaxone or gentamicn

Ill, elderly, pregnant, unable to tolerate orals, urosepsis
Hospitalize and give IV fluids
Ampicillin plus gentamicn or cipro-parenterally
Treat until patient is afebrile for 24 hrs then 14-21 day course
Urosepsis: IV antibiotics for 2-3 weeks

same organism: 6 week treatment
dif. organism: 2 week treatment


Treatment of acute and chronic prostatits

Acute: IV TMP/SMX if extremely ill
Mild: TMP/SMX or fluoroquinolone or doxycycline for 4-6 weeks

Chronic: fluroquinolone


HPV treatment

ticholracetic acid, podophyllin, inqiquimoid, surgery


Diagnosis and treatment of HSV

Tzanc smear is quickest test shows multinucleated giant cells
Culture of HSV is gold standard-swab base of ulcer
Elisa- minutes to hours
encephaltiis: PCR of CSF is gold standard, EEG prominent intermittent high amp with slower waves

oral or topical acyclovir for 7-10 days
Foscarnet for resistant or immunocompromised

Disseminated: hospitalize and parenteral acyclovir


When is syphilis not contagious?

late latent phase if serology has been positive for >1 year


Diagnosis and treatment of syphilis

Diagnosis: start with VDRL or RPR if positive then do a FTA-ABS
Test for HIV

Treatment: Benzathine penicillin (one dose IM)
if allergic doxycycline for 2 weeks

Latent or tertiary: penicclin 3 doses IM once per week


Chancroid diagnosis and treatment

haemphoilus ducreyi
Diagnosis: painful genital ulcer, unilateral tender inguinal lymphadenopathy
Rule out syphilis and HSV

Treatment: azithormycin or ceftriaxone (IM) (one dose)


Lymphogranuloma venereum

C. Trachomatis
Painless ulcer, tender inguinal lymphadenopathy, constitutinal symptoms

Can lead to perianal fissures, andretal stricture or elephantiasis of genitals

Diagnosis: serology-complement fixation, immunofluorescnce

Treatment: doxy for 21 days


Pediculosis Pubis

Pubic lice

diagnosis: examination of hair under the microscope

Treatment: permethrin 1% shampoo (Elmite)


Local trauma-
wounds. abscesses
Immersion in water
Acute sinusitis

trauma-Strep. pyogenes
wounds-S. aureus
immersion-pseudo, aeromonas hydrophila, Vibrio vulnificus
Sinusitis-H. influenza

Treatment: Oxacililn/nafcillin or cephalosporin-IV until infection improves
then 2 weeks of oral antibiotics



Cellulits confined to dermis and lymphatics
Caused by Strep. pyogenes

Fiery red, well demarcated, painful lesion
High fever and chills

Predisposing factors: lymphatic obstruction, local trauma, fungal infections, diabetes, alcoholism

Complications: sepsis, local spread to subQ tissues, necrotizing fasciitis

Treatment: IM or oral penicillin or erythromycin


Tetanus treatment

Admit to ICU and provide respiratory support
Diazepam for tetany
Neutralize unbound toxin with passive immunization-give single dose of tetanus immune globulin (if large wound and unknown tetanus status, >10 yrs since boster or less than 3 Td)
Provide active immunization with tetanus/diptheria toxoid
Thoroughly clean and debride wounds with tissue necrosis
Give metroniadzole or penicillin G

If have greater than 3 doses of Td do not have to provide passive or active immunity


Osteomyelitis diagnosis and treatment

ESR and CRP useful in monitoring response to therapy
Needle aspiration or bone biopsy: most direct and accurate means of diagnosis
MRI: most effective imaging study

Treatment: IV antibiotics for 4-6 weeks only after etiology is based on cultures
Penicillinase resistatn penicillin-oxacillin or 1st gen cephalosporin-cefazolin
Aminoglycoside and B-lactam Ab if possilbility of gram-

Surgical debridement


Organisms and acute infectious arthritis

S. Aureus-most common overall
Young sexually active-gonorrhea
sickle cell, immunodefiency, IV drug abuse-salmonella, pseudo


Diagnosis and treatment of acute infectious arthritis

Joint aspiration->50,000 WBC with 80% PMNs
PCR of fluid if gonorrhea suspected
Elevated ESR
Elevated CPR-mointoring clinical improvement
CT or MRI-sacroiliac or facet joints involved

Daily aspiration or surgical drainage
Healthy adult: (S. aureus)-Parenteral, oxacillin and cephazolin for 4 weeks

Immunocompromised or other gram-indications: parenteral ceftriaxone or aminoglycoside for 3-4 weeks
tazobactam+pipercillin if pseudo

Gonnorrhea: parenteral ceftriaxone until improvement then cipro for 3-10 days orally also doxy


Diagnosis and treatment of Lyme disease

Diagnosis: Clinical-treat empirically
IgM Abs peak 3-6 weeks after onset of symptoms
Serologic studies: ELISA (serum IgG and IgM) during first month of illness
Western blot

Localized disease 10 days of antibiotics
Early Lyme disease:
Oral doxcycline-21 days
Amoxicclin and cefuroxime if pregnant or less than 12

facial nerve palsy, arthritis, or cardiac disease (30-60 days) of antibiotic therapy

CNS: treat antibioticcs for 4 weeks


Treatment of Rocky Mountain spotted fever

Doxycycline for 7 days orally or IV if vomiting

CNS manifestations or pregnant: chloramphenicol


Treatment of malaria

Chloroquine phosphate unless resistance is suspected (pretty much everywhere)
Qunine sulfate and tetracycline or atovaquone-proguanil and mefloquine
P. faliciparum (no remission of fever) may require IV quinidine and doxycycline
P. Vivax and ovale may requrie primaquine phosphate for hypnozoites in liver
Prophylaxis: mefloquine or chloroquine if not going to resistant areas


Diagnosis and treatment of rabies

Diagnosis: virus or viral Ag in infected tissue
Serum Ab titers
Negri bodies histologically
PCR detection of virus RNA

Clean the wound thoroughly
Wild animal bites: find animal capture and destroy them and send to lab for immunofluorescen of brain tissue
Healthy dog or cat: capture animal and observe for 10 days

Known exposure
Passive immunization: Administer human rabies immunoglobulin into the wound and gluteal region
Active immunization: administer antirabies vaccine in three IM doses into deltoid or thigh over a 28 day period


HIV prophylaxis s/p needle stick

Tenofovir-emtricitabin, raltegravir for 4weeks
Serology: immediately, 6wk, 3m, 6m


Candidiasis Treatment

oropharyngeal candidiasis: clotrimazole troches five times per day
Nystatin mouthwas: three to five times per day
Oral ketoconazole or fluconazole

Vaginal: miconazole or clotrimazole

Cutaneous: oral nystatin powder

Systemic: amphotericin B or fluconazole or vorinconazole or caspfungin


Treatment for leptospirosis

oral: tetracycline or doxycycline if severe IV penicillin G


Diagnosis and treatment of cryptococcosis

Diagnosis: LP is essential if meningitis suspected
Latex agglutiation detects cryptococcal Ag in CSF
Tissue biopsy is characterized by lack of inflammatory response

Treatment: amphotericin B with flucytosine for approx. 2 weeks followed by oral fluconazole


Catheter related sepsis organisms

S. aureus and S. epidermidis


Precautions for neutropenic patients

Reverse isolation precuations: positive pressure room, masks, and strict handwashing


amount of time to wait after mono to play sports

3-4 weeks after symptoms onset