Infectious Disease Flashcards
(32 cards)
M. tuberculosis treatment
2 months of 4 med regimen, 4 months of 2 med regimen for active TB.
Rifampin, INH, pyrazinamide, ethambutol –> INH, rifampin
10-20% patients have mild, subclinical hepatic injury with mild LFT elevations (~ <100 IU/L) and prognosis excellent.
Risk of developing more ominous hepatotoxicity in those who:
1) Drink ETOH daily
2) Have pre-existing liver disease
3) are 50 or older
Those with positive PPD but normal CXR (non-active dz, in latent primary phase) need 9 months INH monotx. Those starting INH should ALWAYS start with vitamin B6 to prevent deficiency (stomatitis, glossitis, cheliosis, sideroblastic anemia, peripheral neuropathy).
After any treatment, need to isolate until negative AFB (can also r/o with CXR those those on 9 mo ppx for primary disease).
Malaria treatment
Atovaquone-proguanil, doxycycline, or mefloquine for chloroquine-resistant areas.
Mefloquine started 2 weeks prior to travel, continued during stay, and d/c 4 weeks after returning. Neuropsych side effects.
Areas without Chloroquine resistance include Central America and Carribean.
Primaquine administered to those with P. vivax to eliminate dormant hepatic hypnozoites (eg in India high prevalence of falciparum and vivax).
Infectious mononucleosis
Common clinical features: fever, exudative tonsilitis/pharyngitis, hepatosplenomegaly, rash after amoxicillin
Complications: acute airway obstruction, splenic rupture, autoimmune hemolytic anemia/thrombocytopenia (due to cross-reactivity of EBV-induced Ab against RBCs and platelets)
Anemia can lead to turbulent blood flow from low viscosity to cause cardiac murmur.
EBV dormancy in B cells leads to increased risk fo recurrence and B-cell lymphoma
Commonly transmitted STIs in those <25 with new/multiple sexual partners, substance abuse, or MSM
- Neisseria
- Chlamydia
- HIV
- Syphilis
- Hep B
TB - those indicated to treat
> =5mm PPD: HIV+, recent TB contact, CXR changes c/w previously healed TB, transplant recipient, other immunosuppressed
> =10mm Recent immigrants (<5 years) from endemic area, IVDU, residents/employees of high risk settings, higher risk for TB reactivation (eg DM, leukemia, ESRD), children <4
> =15mm all of the above + healthy individuals
Disseminated gonococcal infection/gonococcemia
Classic triad of:
1) Polyarthralgia
2) Tenosynovitis
3) Painless vesiculopustular skin lesions
Common abx good for anaerobic coverage includes:
1) Metronidazole (Flagyl) + amoxicillin
2) Amoxicillin-clavulanate
3) Clindamycin
Many anaerboes produce beta-lactamases and would need to use beta-lactam like amoxicillin with a beta-lactamase inhibitor.
Enthesitis is
Inflammation at site of tendon insertion into bone.
A/w seronegative spondylarthropathies like ankylosing spondylitis, psoriatic arthritis, and reactive arthritis.
Treatment of uncomplicated and complicated cystitis in non-pregnant women? Pyelo?
Uncomplicated cystitis: nitrofurantoin, TMP-SMX, or fosfomycin; fluoroquinolones only if above cannot be used
Complicated cystitis: fluoronoquinolones; extended broad-spectrum abx (eg amp + genta) for more severe cases; obtain urine cx prior to therapy
Pyelo: Outpatient = fluoroquinolones (cipro, levo); inpatient IV abx fluoro or aminoglycoside +/- amp
HCV management
Despite introduction of direct-acting antiviral agents (eg sofosbuvir-velpatasvir), HCV management continues to involve strategies to prevent further liver management:
ETOH avoidance
HepA/B vaccination
Dumping syndrome
Complication of gastric bypass where consumption of high carb meal, which are highly osmotically active, can lead to abrupt transfer of fluid from circulatory system into intestines, leading to symptoms of:
- Abd pain, N/V
- Hypotension, tachycardia a/w diaphoresis, lightheadedness, syncope
Erlichiosis - HME and HGA
HME: Transmitted by lone star tick of southeastern and south central U.S. (vs. Lyme usually in NE part of U.S.)
HGA: Ixodes scapularis, same as Lyme and babeisiosis
Clinical manifestations: flu-like illness, neuro symptoms, RASH IS UNCOMMON (“RMSF w/o spots”)
Lab findings: leukopenia (followed by left shift), thrombocytopenia, elevated LFTs and LDH
Dx: intracytoplasmic morulae in monocytes, PCR
Tx: empiric doxycycline while awaiting test results
Necrotizing (malignant) otitis externa
Usually in elderly with DM, most commonly due to Pseudomonas.
Severe ear pain worse at night and with chewing (spread to TMJ)–> granulation tissue in external auditory canal with purulent discharge and elevated ESR. +/- Deficits of CN VII, X, and XI
Treat with IV anti-pseudomonal abx (eg ciprofloxacin)
+/- surgical debridement for those not responding to medical tx
AIDs-related diarrhea, infectious etiologies
Cryptosporidium, MAC (if CD4 < 50), microsporidia, Giardia, Isospora –> O&P, stool examination for cx, C. diff antigen, acid fast stain for cryptosporidium
T. cruzi
“Chagas Disease”
Kissing bug’s feces
Endemic in Latin America
Commonly megacolon/esophagus and cardiac disease (dilated cardiomyopathy)
CSF findings for cryptococcal meningoencephalitis
Treatment
Usually develops in setting of HIV with CD4 < 100/uL
High opening pressure
Low glucose, high protein
WBC < 50/uL with mononuclear predominance
Transparent capsule on Indian ink
Initial treatment with amphotericin B and flucytosine, maintenance with fluconazole (can cross BBB, unlike itraconazole which therefore would not be useful with CNS infections)
Rabies PEP
1) High risk wild animals (eg bat, raccoon, skunk, fox, coyote) - Start PEP if animal unavailable. If available, euthanize and test and start PEP if positive.
2) Low risk wild animals (eg squirrel, chipmunk, mouse/rat, rabbit) - No PEP
3) Pet (eg dog, cat, gerbil, ferret) - If available for quarantine, observe x 10 days and no PEP if healthy. If unavailable start PEP.
4) Livestock or unknown wild animal - contact public health dept
Ramsay Hunt Syndrome
aka herpes zoster osticus
Reactivation of VZV in geniculate ganglion with subsequent spread to CNVIII. 2 defining manifestations are:
1) painful erythematous vesicular rash on auditory canal or auricle
2) Ipsilateral facial palsy
Systemic symptoms are rare.
Lyme disease treatment
Doxycycline drug of choice in most.
Amoxicillin for children < 8 and pregnant women because permanent tooth discoloration and skeletal problems in exposed children and fetuses.
PPSV23 and PCV13 vaccine
PPSV23 alone for those 19-64 with chronic heart, lung or liver disease, DM, current smokers, ETOH. Sequential PCV 13 + PPSV23 in high risk patients 19-64(eg CSF leaks, sickle cell, immunocompromised, CKD).
Those =>65 sequential PCV13 + PPSV23
Occupational HIV PEP
Initiate urgently, preferably within first few hours x 28 days
=> 3 drug regimen recommended: w/ 2 NRTIs (eg tenofovir, emtricitabine) + 1 integrase inhibitor (eg ralteravir), protease ihibitor, OR non-NNRTI
HIV testing immediately to establish baseline serologic status and repeated at 6 weeks, 3 months, and 6 months. DO NOT wait for initial results to come back before initiating PEP.
HSV keratitis
Frequent cause of corneal blindness in US.
Symptoms of pain, photophobia, blurred vision, tearing, and redness. Recurrences precipitated by sun, outdoor occupation, fever, immunodeficiency.
Corneal vesicles and dendritic ulcers characteristic.
Tx: oral or topical antiviral
PJP treatment (not ppx)
Bactrim, TMP-dapsone, clinda-primaquine, or atovaquonte +/- corticosteroids
Given the fulminant course and high mortality in HIV-uninfected patients with moderate to severe PCP, we suggest the use of glucocorticoid therapy in HIV-uninfected patients with PCP who, while breathing room air, have an arterial blood gas measurement that shows a partial pressure of oxygen ≤70 mmHg or an alveolar-arterial (A-a) oxygen gradient ≥35 mmHg, or hypoxemia on pulse oximetry.
Adjunctive glucocorticoids are recommended in HIV-infected patients with moderate or severe PCP because their use improves clinical outcomes and mortality without increasing the risk of other opportunistic infections.
Babesiosis
Tick-borne protozoal endemic to NE U.S. transmitted via Ixodes scapularis (also transmits Borrelia and Anaplasma, making co-infection possible). Peak prevalence is July and August.
Infection often mild/asx but the immunocompromised, > 50, s/p splenectomy higher risk for severe illness.
Symptoms include fevers, chills, malaise, weakness, anemia with intravascular hemolysis. Thrombocytopenia and mild HSM may occur.
Dx with peripheral smear: “Maltese cross.”
Tx: Atovaquone + azithro x 7-10 days or quinine + clinda.
