Ch 13. Infections and III Flashcards
Encapsulated organisms (7)
Some Nasty Killers Have Some Capsule Protection 1. Streptococcus pneumoniae 2. Neisseria meningitidis 3. Klebsiella pnemoniae 4. Haemophilus influenzae 5. Salmonella typhi 6. Cryptococcus neoformans 7. Pseudomanas aeruginosa
HIV infections at CD4 levels 200-500 (2) and less than 200 (4) and less than 50 (2)
- 200-500 = oral candidiasis, TB, ITP, hairy leukoplakia, Kaposi sarcoma
- <200 = PCP pneumonia, TB, toxoplasmosis, cryptosporidiosis, esophageal candidiasis, Cryptococcus, histoplasmosis, progressive multifocal leukoencephalopathy
3. <50 = MAC, CMV (retinitis)
PCP pneumonia symptoms, treatment (2)
- PCP (Pneumocystis jirovecii) symptoms=non-productive cough, fever, profound SOBOE
- Rx. TMP-SMX and steroids if PaO2 <70
Dx. Bronch + lavage
How long does it take for the ELISA HIV antibody test to become positive? (1)
- 28 days (1 month) “HIV routine serology”
What is the earlier HIV screening test? (1)
- P24 antigen or HIV viral RNA PCR “HIV rapid assay”
* Exposure within 1 month, call the virologist for high suspicion *
What is the HIV acute retroviral syndrome? (1)
- Acute exposure (75% of people get it): fever, lymphadenopathy, malaise, lasts weeks
HIV diarrhea DDx (4)
- Secondary to HIV medication side-effects
- Normal bacteria that cause diarrhea (SSEYC)
- Cryptosporidium
- Malignancy (lymphoma, bowel Ca)
5. C Diff
How do you measure a CD4 count? (1)
- Take the CD3+4+ count and times by 1000 CD3+4+ of 0.025 is a CD4 count of 25.
DDx HIV pneumonia (3)
- Your normal pneumonia’s (Strep pneumo, H flu, M catarrhalis)
2. TB
3. PCP (CD4 <200)
What defines AIDS? (2)
- CD4 <200 (lymphocyte surrogate <1.0) or
2. HIV+ and AIDS-defining illness (ex. opportunistic infection)
What is the risk of contracting HBV, HCV, HIV from a needle stick injury contaminated with blood from aknown positive source?(3)
1.Rule of 3s: HBV, HCV, HIV: 1/3, 1/30, 1/300 risk of acquiring blood-borne infection. high HBV risk is assuming unvaccinated host. Risk if vaccinated is veryyyy low.
What is the recommended antibiotic treatment for pneumonia in the following settings:
- Outpatient (healthy, immunocompetent)
- Outpatient (comorbidities and or antibiotics in last 3 mo)
- Inpatient (Ward)
- Inpatient (ICU)
- Outpatient (healthy, immunocompetent):
Doxyclycline 100mg PO BID Or Clarithoromycin 1g BID
- Tetracyclines cover: Gram + (strep, staph), Gram - (H. flu), Atypicals (mycoplasma, chlamydophila) - Outpatient (comorbidities and/or antibiotics in last 3 months): Levofloxacin 750 for 5 days
OR Amoxicillin + Doxyclycline
-Levofloxacin adds pseudomonal coverage - Inpatient (ward)
Ceftriaxone + Azithro (can consider antiviral if appropriate)
-Ceftriaxone provides broader gram negative coverage while also having strong staph/strep coverage. - Inpatient (ICU)
PipTazo + Vancomycin(can consider antiviral if appropriate)
- Vanco providing MRSA coverage
PO and IV Antibiotic to treat MRSA (4+3)
MRSA antibiotics:
-PO: Doxy, Septra, Clinda, Linezolid
-IV: Vancomycin, Daptomycin, Linezolid
PO and IV Antibiotic to treat pseudomonas (1+4)
Pseudomonas antibiotics:
-PO: cipro
-IV: Carbapenems (imipenem, meropenem), Ceftazamine/Cefepime, PipTaz, Aminoglycosides (Tobramycin, Gentamicin)
DDx of cellulitis (6)
Cellulitis = red warm painful. Also fever, streaking lymphangitis, regional lymphadenopathy
*Itchy, bilateral, not improving with AB’s, or in a risky location (groin, genitals, joint) think of other Dx
1. Stasis dermatitis – bilateral red legs above medial malleolus. * redness resolves with a passive leg raise 1-2 mins
2. Peripheral arterial disease
3. DVT/thrombophlebitis – use Well’s. Only 1% of DVT’s have concomitant cellulitis
4. Septic arthritis – can they move the joint? Is there a large POCUS effusion?
5. Gout – looks like gout.
6. Flexor tenosynovitis – passive extension of the finger is ++ painful. Tracks up the tendon.
7. Bee sting – cellulitis after a wasp sting is uncommon and delayed days after the sting.
8. Erythema migrans (Lyme disease)
9. Necrotizing fasciitis – very sick, very rapid, extreme pain, gas
Antibiotic treatment for cellulitis (2).
When to reassess (1)
- Cephalexin (Keflex) PO x 5 days
- Doxycycline (if a true severe allergy to Penicillin or cephalosporins). Or levofloxacin.
1. Reassess at 48-72 hours. Consider treatment failure if no improvement in pain or heat or redness progresses
*Do not empirically cover for MRSA (TMP-SMX) – it doesn’t work and doesn’t have Strep coverage
Non-purulent = Strep. Purulent = staph. But still use Keflex.
Which cellulitis patients need IV antibiotics (3)
- Immunocompromised (not diabetes – they still get PO)
- Systemic signs (SIRS)
3. Hemodynamic instability - Altered mental status
- Consider in high BMI
Antibiotics for abscess (1)?
- Consider doxy (95% coverage MRSA), esp for recurrent abscess. It will decrease 7% recurrence. NNT 14.
Which abscess need packing (3)
- Large abscess >5cm
- Abscess in groin or axilla
- Diabetic foot
*Just a very small wick. Patient can take it out in 2 days.
What is the rate of true penicillin allergy? (1)
Cross reactivity to cephalosporins? (1)
- A “true” penicillin allergy is <10%
- The cross-reactivity in true allergy is <10%.
This means penicillin allergy is <1% to cephalosporins. Only avoid if true severe anaphylaxis.
Signs and symptoms of necrotizing fasciitis (8)
- SICK (SIRS criteria, fever, sepsis)
- Rapidly spreading
3. Pain out of proportion to clinical findings
4. Skin necrosis
5. Blisters/bullae
6. Tense edema
7. Palpable crepitus/gas on US
8. Local hypo-esthesia (can’t feel)
NecFas = 30% mortality.
Rx. PipTazo + Vanco + Early surgical debridement
Type 1=polymicrobial (Fournier’s gangrene)
Type 2=GAStrep. Often preceding by minor trauma even without skin tear.
TB Risk factors (9)
- Immigrant status
- HIV/immunocompromised
3. Homeless - Alcoholic
5. IVDU - First Nations
7. Elderly
8. Healthcare worker - Known TB contact
Symptoms of TB (2)
Pneumonia and B symptoms
1. Pneumonia: fever, cough, dyspnea, pleuritic CP, hemoptysis
2. B symptoms: night sweats, fatigue, weight loss
TB X-ray findings (5)
*Acute TB infection can look like a normal every-day pneumonia.
Re-activation TB looks like:
1. Upper lobe consolidation
2. Mediastinal lymphadenopathy
3. Cavitation
4. Miliary TB is the diffuse, fine granules. Often immunocompromised patient. SICK.
5. Latent TB can present with a calcified lymph node called a Ghon complex
Complications of TB (6)
- Pneumonia
- Empyema
- Sepsis (military TB)
- Peritoneal TB
5. Hepatosplenomegaly
6. Prostatitis
7. Epididymitis/orchitis - Adrenal insufficiency
9. TB osteomyelitis
10. Meningitis
What are 4 TB meds. Complications (8)
RIPE 1. Rifampin - hepatitis 2. Isoniazid (INH) – hepatitiss. B6 deficiency. Peripheral neuropathy. Seizures 3. Pyrazinamide - hepatitis 4. Ethambutol – hepatitis.
Who is asplenic? (3)
- Trauma with splenectomy
- Sickle cell
3. ITP/TTP
How does prednisone work? When is somebody immunocompromised? (2)
- Inhibits cell mediated translocation across a membrane and into tissue, inhibiting macrophages
- Immunocompromised comes after >20mg per day, chronically
What is neutropenia? When do you treat neutropenia? Which antibiotic for febrile neutropenia? (3)
- Neutropenia <1.0
- Severe neutropenia <0.5 (profound <0.1). Treat with antibiotics when <0.5
3. AB’s = outpatient Clavulin + Cipro, Inpatient = PipTazo, HIGH RISK = PipTazo + Vanco
Oncological emergencies (10)
- Metastatic disease (intracranial met)
- SVC syndrome
3. NVD dehydration - Horner’s syndrome
- Airway obstruction
- Malignanct PCE
7. Spinal cord compression - Vertebral compression fracture
- Bowel obstruction
- Tumor lysis syndrome
11. Hyperviscosity syndrome
12. DVT/PE
13. Hypercalcemia, hyponatremia
Treatment of tumor lysis syndrome (2)
- Calcium for hypocalcemia
2. IV fluids
When is hematocrit and WBC a hyper viscosity problem? (1)
Treatment of hyperviscosity syndrome (2)
- Hyperviscosity: Hematocrit >60, WBC>100
1. IV fluids
2. PLEX - +/- phlebotomy
Treatment of hypercalcemia (3)
- IV fluids
- Bisphosphonate
- Dialysis if you can’t give them fluids
IVDU complications (6)
- Skin/soft tissue abscess or cellulitis
- Spine or bone osteomyelitis/transverse myelitis/septic arthritis/AVN
3. Endocarditis – staph aureus, strep viridans, Rx ceftriaxone + vanco - Pneumonia
5. Meningitis/encephalitis
6. Cotton fever
7. Endopthalmitis - HIV/hepatitis
Transplant rejection symptoms (3)
- Pain to graft site
- General malaise (fever, hypertension/hypotension, tachycardia, unwell)
- Signs of organ failure (renal – 20% increase Cr, liver – increase ALT/AST/ALP/Bili, Lung – cough, chest pain, hypoxia, CXR infiltrates)
*Do a drug level (tacrolimus, cyclosporin)
*Consider bacterial, viral, fungal, parasitic infections
DDx fever in the return traveler? (5)
- Consult CDC website to learn what is endemic in the place of travel.
1. Malaria malaria malaria
2. MERS – fever, cough, SOB, NVD. Beware pneumonia and ARDS.
3. Dengue -
4. Chikungunya – fever, joint swelling/arthralgia, NVD, maculopapular rash, HA, extreme fatigue
5. Zika virus – fever, rash, HA, conjunctivitis, arthralgia. Beware pregnancy complications.
Treatment of chlamydia? Gonorrhea? HSV? Syphilis? (4)
- C = Azithro,
- G = Ceftriax 250mg IM, or Cefixime 500mg PO 7 days
- HSV = Valacyclovir 1g PO TID
- Syphilis = Pen G 2.4million units IM
DDx of genital ulcers (4)
- Herpes (HSV)
- Syphilis (chancre)
3. Chancroid (painful genital ulcer and lymphadenopathy) - Lymphogranuloma venereum (impressive unilateral groin lymphadenopathy)
- Granuloma inguinale (painless genital ulcer and lymphadenopathy)
Difference between primary, secondary, and tertiary syphilis (3)?
- Primary syphilis – painless chancre (2-6weeks after exposure)
- Secondary syphilis – maculopapular rash, fever, lymphadenopathy. Hands and soles
3. Tertiary syphilis - years after. CNS or aorta or cardiac or gummas or anywhere.
How do you test for syphilis (2)?
- EIA = screening test
- Reflexively confirmed with the RPR confirmatory test
* R for reflexively done.
DDx rash on hands and feet (5)
- Hand foot and mouth disease (Coxsackie)
2. Secondary syphilis
3. Rocky Mountain Spotted Fever - Bacterial endocarditis (Janeway lesions)
- Kawasaki disease
Maybe: Measles, Toxic shock syndrome
Which HPV subtypes cause cervical cancer and genital warts (1)
- HPV 16 and 18 (vaccine = Gardasil)
Signs/Symptoms of Staph Toxic Shock Syndrome, Streptococcal Toxic Shock Syndrome (2)
- Staph Toxic Shock Syndrome – fever, diffuse rash, hypotension, multi-organ involvement (renal, liver, neuro etc)
Rx. PipTazo Vanco - Strep Toxic Shock Syndrome - fever, diffuse rash, hypotension, multi-organ involvement
Rx. PipTazo Vanco
Treatment or erysipelas (1)
- Keflex. Treat the same as cellulitis
Clinical diagnosis of influenza (3)
- Fever
- Aches/myalgia
- Cough
* Often Dx’d DURING influenza season. Makes sense.
Which influenza patients get treatment? (3)
- Dx within the first 48hours
- Admitted patients (treat anyone sick enough to get admitted)
- High risk of complications (<2 or >65years, cardioresp comorbidity, immunocompromised, pregnant, morbid obesity)
Rx. Oseltamivir (Tamiflu) 75mg PO BID 5 days
Hallmark of HSV encephalitis (2)
- Acute fever and
- Encephalitis (cranial nerves, focal neuro findings, seizures, altered mental status/behavior
Rx. Valacyclovir 1g PO TID, or acyclovir 10mg/kg IV Q8H
Non-ulcerative genital STI’s (5)
- Chlamydia
- Gonorrhea
- Trichomonas
- HPV
- Syphilis (2,3)
Painful (2) and painless (2) genital STI’s
- HSV – painful
- Chancroid, caused by Hemophilus ducreyi – painful
- Syphilis – painless
- Lymphogranularum venerum, caused by Chlamydia trachomatis – painless (groin)
Four infections that cause vaginitis (4)
- BV – itchy, foul smelling. Rx Flagyl
- Yeast – cheese curds like, itchy. Rx Canesten, Fluconazole 150mg PO x1
- Trichomonas – frothy discharge. Rx Flagyl
- C,G (PID) – more cervicitis. Rx Cefixime + Azithro
- Physiologic
- Atrophic vaginitis. Rx Vagifem
Treatment options for gonorrhea (2) and chlamydia (2)
- Gonorrhea = Ceftriaxone 250mg IM, or Cefixime 800mg PO x1
- Chlamydia = Azithro 1g, or Doxy 100mg PO BID x7days
* Only do a test of cure in pregnancy. Only remove IUD if it is within the first month of insertion
Toxin mediated diarrhea versus infectious diarrhea (2)
- Toxin mediated = abrupt onset. Staph (eggs/mayo), B. cereus (fried rice), E.coli (Travellers diarrhea), Scromboid (dark fish tuna – histamine), Ciguatera – neuro tingling
- Infectious diarrhea = gradual onset, fevers. Salmonella, Shigella, Campylobacter, Yersennia, EHEC. These all get AB’s.
When are antibiotics CONTRAINDICATED in diarrhea? (1)
- When you suspect HUS – no antibiotics.
Overcrowding situation (refugee camp): several patients with profuse diarrhea. Bug (1), treatment (1)?
- Cholera
2. Oral rehydration salts + Doxycycline
Clinical signs/symptoms of botulism (4)
Spore forming organism in soil. Blocks Acetylcholine release at the NMJ leading to paralysis
**Think about botulism in wounds (IVDU) and infants
1. Diplopia
2. Droopy eyes (ptosis)
3. Dilated pupils
4. Dysphonia
5. Dysarthria
6. Symmetric descending muscular weakness (proximal > distal). Can involve the diaphragm
Rx. Supportive care.
Atraumatic paralysis / neuromuscular weakness DDx (4)
- Guillain-Barre – distal weakness, +/- parastesia. CSF high protein
- Tick paralysis – usually ascending, +tick
- Botulism – descending paralysis. Wound or infant. Bulbar findings.
- Myasthenia gravis – muscle weakness, often eyes, face, swallowing. Droopy eyelids.
What is Waterhouse-Friderichsen syndrome (1)?
- Rapid hypotension and adrenal hemorrhage from meningiococcemia infection
* Recognize this petechial/purpuric rash early. Rx ceftriaxone.
* *Chemoprophylaxis for close contacts only (Ceftriaxone). Vaccinate.
Clinical manifestations of tetanus (1)
- Tetanus = muscle spasm, lockjaw, tingling to wound site
Immunocompromised patient (ex HIV) with odynophagia (1)
- Treat empirically for esophageal candidiasis
Severe fungal infections (3)
- Candida – can give you candidiasis, vaginitis, but also disseminated.
- Cryptococcus (from soil – meningitis and Cryptococcus pneumonia)
- Histoplasmosis – US Southwest Ohio/Mississippi, caves, bat poop. Pneumonia, disseminated.
Parasitic disease associated with cat faces (1)
- Toxoplasmosis – CAT POOP, raw pork. Can give you ring enhancing CNS lesions. And congenital infections.
* This is why pregnant women should not change litter boxes
Fever in a return traveler is ________ until proven otherwise (1) Dx? (1) Rx? (3)
- Malaria
- Dx: thick and thin blood smear x3 (12-24 hours apart)
- Rx. Chloroquine. Falciparum needs IV Quinine and beware hypoglycemia!
Malaria species: P. falciparum (worst), P vivax, P ovale
Symptoms: anemia, HA, chills, lethargy, abdominal pain, diarrhea, hypoglycemia
Falciparum gives you cerebral malaria. Very bad.
Lyme disease stages (3)
- Erythema migrans – bulls eye rash 7-10 days after bite from Ixodes tick, B. Borgdorferi infection
- Early disseminated (days to weeks) – CNS Bell’s Palsy bilateral, MSK myalgia, cardiac heart blocks
- Late persistent (weeks to months) – chronic joint pain, encephalopathy.
Dx. ELISA antibody test (may need a repeat test if very early)
Rx. Doxycycline 14 days
Rocky Mountain Spotted Fever signs/symptoms (2)
*Also tick-borne disease in Eastern US
1. Rash starting on palms/soles/wrists/ankles and then goes inwards
2. Flu-like illness w/ malaise, unwell, fevers, +/- myocarditis, neuro Sx, DIC
Rx. Doxycycline
DDx of exudative pharyngitis (3)
- Viral pharyngitis
- Strep pharyngitis
- Mono/EBV (fever, posterior lymphadenopathy, pharyngitis) – 90% will get a rash if given Amoxil! 50% get splenomegaly.
Croup pathogen (1), treatment (1), soft tissue neck Xray finding (1)
- Pathogen = PIV
- Treatment = Dexamethasone, cool mist
- Xray finding in croup = Steeple sign
Hutchinson sign (1), Ramsay-Hunt syndrome (1)
- Hutchinson sign = vesicle on tip of nose. Predicts herpes opthalmicus. Fluorescein the eye!
- Ramsay-Hunt yndrome = zoster oticus with Bell’s Palsy. Veiscles in ear + ear pain.
Animals high risk for rabies (4)
Treatment of rabies (1)
- Bats, skunks, foxes, raccoons, coyotes, NOT rodents, RARELY dogs/cats
Rx. Rabies immunoglobulin + vaccine (day 0, 3, 7, 14)
Signs/symptoms Roseola (2)
- Fever fever fever (40celcius) THEN
2. Pink maculopapular rash when fever resolves
Bilogical warfare agents (4)
- Anthrax – powder in envelopes.
- Smallpox
- Plague – Yerssenia pestis
- Botulism
- When is measles infective? (1)
- How effective is the vaccine? (1)
- Is there post-exposure prophylaxis for measles?
- Infective: 4 days prior to rash, up to 5 days after rash. Airborne transmission, in the air for 2 hours (N95).
Incubation period is 10-14 days! - Vaccine is 90-95% effective. 2 doses 97% effective.
- PEP: measles vaccine if given within 72hours of exposure is effective. IgG possible if patient immunocompromised.
