Infectious Disease Flashcards
Common causes of PNA in Neonates
GBS
E. coli
Listeria
Common causes of PNA in Children (6w-18y)
Viruses S. pneumoniae Mycoplasma Chlamydia pneumoniae S. aureus
Common causes of PNA in Adults (18-40)
Mycoplasma
S. pneumoniae
Viruses
C. pneumoniae
Common causes of PNA in Adults (40-65)
S. pneumoniae H. flu Mycoplasma Viruses Anaerobes
Common causes of PNA in Elderly (65+)
S. pneumoniae H. flu Viruses S. aureus GNRs Anaerobes
Causes of PNA: Atypical
Mycoplasma
Legionella
Chlamydophila (chlamydia)
Causes of PNA: Nosocomial
GNRs
Staph (MRSA)
Anaerobes
Pseudomonas (intubated pts)
Causes of PNA: Immunocompromised
Staph Gram + rods Fungi virus PCP Mycobacteria
Causes of PNA: Aspiration
Anaerobes
Causes of PNA: Alcoholics/IV drugs
S. pneumo
Klebsiella
Staph
Causes of PNA: Cystic Fibrosis
Staph (under 20)
Pseudomonas (over 20)
Burkholderia
mycobacteria
Causes of PNA: COPD
H flu
Moraxella catarrhalis
S pneumo
Causes of PNA: Post-viral
Staph
S pneumo
H flu
Causes of PNA: Neonates
GBS
E. coli
Listeria
Causes of PNA: Recurrent
Obstruction, bronchogenic carcinoma, lymphoma, Wegener’s, immunodef., unusual organisms (nocardia, coxiella, aspergillus, pseudomonas)
Treatment of PNA: CAP
Macrolide (Azithromycin, Erythromycin) or Doxycycline
[S. pneumo, mycoplasma, chlamydia, h flu, viral]
Treatment of PNA: with comorbid disease
COPD, HF, CKD, DM, Liver
>65, or recent ABx (in 3 mo)
Fluoroquinolone (levofloxacin, moxyflocacin)
or Betalactam + macrolide (Ceft/Azith)
[S pneumo, H flu, E. coli, enterobacter, klebs, s aureus, legionella, virus]
Treatment of PNA: CAP req hospitalization
CURB-65
Fluoroquinolone (levo)
or antipneumococcal betalactam + macrolide (Ceft/Azith)
[S pneumo, h flu, anaerobes, E. coli, klebs, legionella, chlamydia]
Treatment of PNA: CAP req ICU
Antipneumococcal beta-lactam
+ either azythromycin or fluoroquinolone
Treatment of PNA: HCAP
cefepime or imepenem/meropenem
+ gentamycin or levofloxacin
Extended spec Cephalosporin
or carbapeneme with antipseudomonal
-Add aminoglycoside or fluoroquinolone for resistant organisms
[GNRs (pseudomonas, acinetobacter), s aureus, legionella, mixed]
Treatment of PNA: critically ill
Add vancomycin or linezolid, broaden gram neg coverage
[MRSA]
Rx for TB: agents
RIPE for treatment
Rifampin {orange body fluids}
INH {peripheral neuropathy, hepatitis}
Pyrazinamide
Ethambutol {optic neuritits}
Rx for TB: duration
Active: 4 drug x2 mo; then INH + rifampin x4 mo
–Give Vitamin B6, pyridoxine, to prevent INH peripheral neuropathy
Latent: INH x 9 mo (or 6 mo, or rifampin x4 mo)
Causes of acute sinusitis
++viruses
strep pneumoniae
H flu
m catarrhalis
bacterial = rare, has purulent nasal discharge, symptoms > 10 days
Complications of sinusitis
Meningitis Frontal bone osteomyelitis Cavernous sinus thrombosis abscess Orbital cellulitis (post-septal)
Rx for sinusitis
Acute: amox/clav x10 days (or azith, bactrim, 2nd gen ceph)
Chronic: same Abx for LONGER: 3-6 wks
Pt from Nevada, Arizona, New Mexico, California, Texas (mexico) with respiratory complaints?
also Rx?
Coccidioidomycosis
Rx: PO fluconazole or itraconazole
IV amphotericin B if severe
HIV+, pregnant, filipino, black from SW state?
Increased risk for disseminated Coccidioidomycosis
fever, myalgias, chills, cough, coryza, but rapid flu negative?
Still think flu, rapid flu test has low sensitivity
PCR assays, DFA and viral culture more definitive
Rx for influenza
symptomatic
oseltamivir or zanamivir IF WITHIN 2 DAYS OF ONSET can reduce duration of illness by 1-3 days
Causes of Meningitis by Age: Newborn
GBS
E. coli/ GNRs
Listeria
Causes of Meningitis by Age: Children (6mo-6y)
S. pneumo
N. meningitidis
H flu type b
Enterovirus
Causes of Meningitis by Age: 6y-60y
N. meningitidis (#1 in teens)
S pneumoniae
Enteroviruses
HSV
Causes of Meningitis by Age: >60
S pneumoniae
GNRs
Listeria
N meningitidis
Empiric Rx for Meningitis by Age: Neonate
Ampicillin
+ cefotaxime
or gentamicin
[GBS, E coli, Listeria]
Empiric Rx for Meningitis by Age: 1mo-3mo
Vancomycin IV
+ Ceftriaxone
or Cefotaxime
[pneumococci, meningococci, h flu]
Empiric Rx for Meningitis by Age: 3mo - adult
Vancomycin IV
+ Ceftriaxone
or Cefotaxime
[pneumococci, meningococci]
Empiric Rx for Meningitis by Age: >60, ETOH, Chronic Illness
Ampicillin
+ vancomycin
+ cefotaxime
or ceftriaxone
[pneumococci, gram neg bacilli, listeria, meningococci]
Rx for contacts of meningococcal meningitis
RIFAMPIN, CIPROFLOXACIN or ceftriaxone
Dexamethasone in meningitis?
Reduce neurologic complications of S PNEUMO meningitis if given 15-20 MIN BEFORE ABX
Complications of meningitis
SENSORINEURAL HEARING LOSS mental impairment seizures increased ICP empyema abscess focal neuro deficits, coma, death hyponatremia
RBC in CSF, no history of trauma?
highly suggestive of HSV encephalitis
CNS Infection key words:
Photophobia, nuchal rigidity
meningitis
CNS infection key words:
Focal neurologic deficits
brain abscess
CNS infection key words:
Confusion, mental status changes
Encephalitis
HSV Encephalitis:
Dx & Rx?
PCR highly sensative and specific
CT or MRI shows TEMPORAL LOBE SIGNAL
Rx with IV Acyclovir asap
CMV encephalitis Rx?
IV Ganciclovir +/- foscarnet
Brain abscess imaging?
Ring-enhancing lesion
If hematogenous spread, multiple abscess at Grey-white junciton in middle cerebral distribution
Fever, confusion, dull constant headache, no relief with nsaids, papilledema, CN III and CN VI palsy?
indicative of brain abscess
Fever, headache, focal neurological deficit?
Triad for Brain Abscess
present in 50% of cases
Rx for brain abscess?
IV Abx and surgical drainage (no surgery if less than 2 cm)
CD4 ~ 500
also ppx?
Herpes Simplex Herpes Zoster Vaginal candidiasis Hairy leukoplakia Kaposi Sarcoma TB and bact. infections
Bactrim (50?)
CD4 less than 200
also ppx?
PCP Toxo Cryptococcosis Coccidioidomycosis Cryptosporidiosis
Bactrim double strength (100?)
CD4 less than 50
also ppx?
Disseminated MAC
Histoplasmosis
CMV retinitis
CNS lymphoma
Azithromycin
Side effects: Protease Inhibitors
hyperglycemia
hyperlipidemia
lipodystrophy
Side effects: Thiazides
Hyperglycemia Hypertriglyceridemia Hypercalcemia Hyponatremia Hypokalemia Hypomagnesemia
Side effects: Nucleoside RTIs
Bone marrow suppression
neuropathy
lactic acidosis?
Side effects: Indinavir
crystal-induced nephropathy
nephrolithiasis
Side effects: Didanosine
pancreatitis
Side effects: Abacavir
hypersensitivity
Side effects: Nevirapine
liver failure
Side effects: Efavirenz
vivid dreams, hallucinations
Pizza pie retinopathy, floaters and visual field changes, association with retinal detachment
CMV retinitis
CD4 less than 50
Bloody diarrhea, abdominal pain, CD4 less than 50
CMV colitis
Systems CMV manifests in AIDS?
Retinitis (retinal detachment)
GI & hepatobiliary (bloody diarrhea)
pneumonitiis (coufh, sparse sputum, high mortality)
CNS (polyradiculopathy, transverse myelitis, encephalitis)
Rx for CMV infection?
Ganciclovir or valganciclovir +/- foscarnet
Fever, weakness
elevated Alk Phos and LDH
HIV not on HAART
biopsy shows foamy macrophages with acid-fast bacilli
MAC, disseminated if CD4 less than 50
multiple hypodense ring-enhancing mass lesions on CT/MRI
Toxoplasmosis encephalitis
Rx is high dose PO pyrimethamine + sulfadiazine and leucovorin (folic acid analog prevents heme toxicity) for 4-8 weeks
Bactrim as prophylaxis if CD4 less than 100
Ring-enhancing lesions in AIDs
Toxoplasmosis
CNS lymphoma
(abscess?)
Chlamydia Rx in pregnancy?
Azithromycin or Amoxicillin
Chlamydia Rx
Doxycycline x7days or azithromycin
Reiter Syndrome?
Complication of Chlamydia
urethritis, conjunctivitis, arthritis
Fitz-Hugh-Curtis Syndrome?
complication of chlamydia
perihepatic inflammation and fibrosis
Hemorrhagic, painful pustules on erythematous base
Monoarticular septic arthritis
Tenosynovitis
also Rx?
Disseminated gonorrhea
Ceftriaxone IM and Azithromycin PO
Rx syphilis
Benzathine PCN IM
or Tetracycline/doxycycline x14 days in PCN allergy
Rx syphilis in pregnancy
Benzathine PCN
If allergic, desensitize and rx with PCN
Headache, fever, chills, myalgias, just started PCN for rash on palms and soles
Jarisch-Herxheimer reaction, from release of endotoxins from killed syphilis organisms (treponema pallidum)
Common UTI bugs
SEEKS PP
Serratia E COLI Enterobacter Klebsiella Staph saprophyticus Pseudomonas Proteus mirabilis
Beefy red genital ulcer with rolled edge of granulation tissue
Painless
Granulomatous ulcers
also Rx?
Klebsiella Granulomatis
aka
Granuloma inguinale
Rx Doxy/Azith
Painful papule or pustule on genitals
irregular, deep, necrotic
1-2 cm
Inguinal lymphadenopathy
also Rx?
Haemophilus ducreyi (“do cry”)
Rx Azith or Ceftri
Rx uncomplicated UTI
PO bactrim, fluoroquin x3 days or nitrofurantoin x5
Rx complicated UTI
obstruction, men, renal txplant, catheters, instruments
PO bactrim, or fluoro or nitro x7-14 days
Rx UTI in pregnancy
AMOXICILLIN 3-7 days
or nitrofurantoin or oral cephalsporin
treat asympto and sympto, to prevent pyelonephritis
Rx pyelonephritis
Fluoroquinolones
if severe, admit, 3rd/4th gen cephs, carbapenems, beta/lactamase inhibs
Rx pyelonephritis in pregnancy
Admit, 3rd gen cephalosporin
SIRS criteria
Temp 38
RR >20
HR >90
WBCs 12000
Deadliest form of malaria?
Plasmodium falciparum (falchion)
others
P vivax, P ovale, P malariae
Dx of malaria?
Giemsa- or Wright-stained thick and thin blood films
or rapid antigen, fluorescent antibody, or PCR if available
Rx for malaria?
Chloroquine PO
+ Primaquine for P vivax & P ovale or Unknown to eradicate hypnozoites in liver
If severe, IV Quinidine
Malaria prophylaxis?
Atovaquone-proguanil and mefloquine
first line for chloroquine-resistant malaria
Young adult, fever, fatigue, sore throat, posterior cervical lymph nodes, complains of facial droop, blurred vision, and numbness/weakness spreading up his legs
CNS infection, complication of EBV Infectious Mononucleosis
can be meningitis, encephalitis, CN palsies (VII), optic neuritis, transverse myelitis, or Guillain-Barre syndrome
Young adult male, fever, fatigue, sore throat, posterior cervical lymph nodes, develops RUQ pain, jaundice, confusion, and abnormal LFTs
Fulminant hepatic necrosis, complicatino of EBV Infecitous mononucleosis
Most common cause of Fever of Unknown Origin
Infection and cancer ~ 60%
Autoimmune disease ~15%
in elderly, rheumatic dz is 1/3 of cases
Rx for Fever of Unknown Origin with negative work-up
Stop unnecessary medications
No empiric ABx indicated
Good prognosis, most resolve in months to years
Rx for Neutropenic Fever
Empiric Antipseudomonal agent (cefepime, piperacilin-tazobactam)
If persists >72 hours, start antifungal Rx
Headache, fever, chills, myalgias, confusion
travel to louisiana, camping
Leukopenia, thrombocytopenia
Elevated LFTs
Ehrlichiosis from lone star tick
Rx Doxycycline
Rash uncommon
Headache, fever, malaise, macular rash on wrists and ankles that spreads to body as petechial/purpuric rash
Rocky Mountain Spotted Fever
rickettsia reckettsii
small vessel vasculitis
Rx Doxycycline or chloamphenicol for pregnancy
Injected conjunctiva, eye pain, discharge, gram stain shows gram - intracellular diplococci
EMERGENCY! Neisseria gonorrhoeae infection
Corneal involvement can perforate and cause blindness
IM or IV Ceftriaxone, admit if complicated
Copious watery eye discharge, severe ocular irritation, preauricular lymphadenopathy
Adenovirus
contagious, but self-limited
Neonate with mucopurulent conjunctivitis
Chlamydia trachomatis
Rx Azithromycin, tetracycline, or erythromycin x3-4 weeks
PE feature of Infective Endocarditis
FROM JANE
Fever Roth Spots (retinal hemorrhage) Osler nodes (tender nodules on finger/toe) Murmur (mitral valve) Janeway lesions (periph. hemorrhage) Anemia Nail hemorrhage (splinter) Emboli (focal neuro deficit?)
Causes of acute endocarditis
S aureus (IV drug, prosthetic valve)
S pneumoniae
N gonorrhoeae
Causes of subacute endocarditis
Viridans strep (native valve, dental procedures) Enterococcus (UTIs) S epidermidis (prosthetic valve) S bovis (GI insult, malignancy) Fungi
Causes of marantic endocarditis
Cancer
Metasteses seed valves, emboli cause cerebral infarct
poor prognosis
Causes of culture negative endocarditis
HACEK Haemophilus Actinobacillus Cardiobacterium Eikenella Kingella
also coxiella, brucella, bartonella
Endocarditis and SLE
Libman-sacks endocarditis
antibodies to the valve
Rx endocarditis
IV vancomycin + gentamicin, then tailor
hunter or rancher presents with pruritic papule, becomes ulcer, develops black eschar a week later
also Rx?
Cutaneous anthrax (bacillus anthracis, gram +)
Rx Ciprofloxacin or doxycycline plus 1-2 additional Abx for 14 days
Sheep rancher with fever, hypoxia, hypotension, cough, SOB, CXR shows widened mediastinum and pleural effusions
also Rx?
Pulmonary anthrax causing hemorrhagic mediastinitis
Cipro/doxy plus 1-2 additional ABx for 14 days
Osteomyelitis in otherwise healthy?
Staph aureus
Osteomyelitis in IV drug user
S aureus or pseudomonas
Osteomyelitis in Sickle Cell disease
Salmonella (no spleen, capsulated organism)
Osteomyelitis in Hip replacement
S epidermitis
Osteomyelitis in foot puncture wound
pseudomonas
Chronic osteomyelitis
S aureus, psudomonas, enterobacteriaceae
Osteomyelitis in diabetic
polymicrobial, pseudomonas, s aureus, strep, anaerobes
Risk factors for osteomyelitis
peripheral vascular disease diabetes penetrating injury chronic decubitus ulcer IV drugs (vertebral)
Rx for diabetic with osteomyelitis
target g+ and anaerobes
vancomycin and clindamycin
Rx Toxoplasmosis encephalitis
pyrimethamine
+ sulfadiazine
+ leucovorin
Rx is high dose PO pyrimethamine + sulfadiazine and leucovorin (folic acid analog prevents heme toxicity) for 4-8 weeks
Most common cause of PNA in CF child (under 20)
Staph aureus
Most common cause of PNA in CF adult (over 20)
Pseudomonas aeruginosa
22 yo male, fever, sore throat, malaise
cervical and axillary lymphadenopathy
Hepatosplenomegaly
Jaundice
What am I? Complication?
Infectious Mononucleosis
Autoimmune hemolytic anemia (EBV ab’s cross react with RBCs and Platelets)
Most common cause of sepsis in child with sickle cell?
Strep pneumo DESPITE VACCINATION (other serotypes)
hence PCN ppx
Classic triad of congenital rubella
deafness, cataracts, cardiac defects (PDA, VSD)
