Sandbox endocarditis2

Epidemiological features	Common Microorganism(s)
Injection drug use	S aureus, including community-acquired oxacillin-resistant strains Coagulase-negative staphylococci β-Hemolytic streptococci Fungi Aerobic Gram-negative bacilli, including Pseudomonas aeruginosa
Indwelling cardiovascular medical devices	S aureus Coagulase-negative staphylococci Fungi Aerobic Gram-negative bacilli Corynebacterium sp
Genitourinary disorders Genitourinary infection Genitourinary manipulation pregnancy Delivery Abortion	Enterococcus sp Group B streptococci (S agalactiae) Listeria monocytogenes Aerobic Gram-negative bacilli Neisseria gonorrhoeae
Chronic skin disorders	S aureus β-Hemolytic streptococci
Poor dental health, dental procedures	Viridans group streptococci “Nutritionally variant streptococci” Abiotrophia defectiva Granulicatella sp Gemella sp HACEK organisms
Alcoholism, cirrhosis	Bartonella sp Aeromonas sp Listeria sp S pneumoniae β-Hemolytic streptococci
Burn patients	S aureus Aerobic Gram-negative bacilli, including Pseudomonas aeruginosa Fungi
Diabetes mellitus	S aureus β-Hemolytic streptococci S pneumoniae
Early (1 y) prosthetic valve placement	Coagulase-negative staphylococci S aureus Aerobic Gram-negative bacilli Fungi Corynebacterium sp Legionella sp
Late (>1 y) prosthetic valve placement	Coagulase-negative staphylococci S aureus Viridans group streptococci Enterococcus species Fungi Corynebacterium sp
Dog–cat exposure	Bartonella sp Pasteurella sp Capnocytophaga sp
Contact with contaminated milk Contact with infected farm animals	Brucella sp Coxiella burnetii Erysipelothrix sp
Homeless, body lice	*Bartonella sp
AIDS	Salmonella sp S pneumoniae S aureus
Pneumonia, meningitis	S pneumoniae
Solid organ transplant	S aureus Aspergillus fumigatus Enterococcus sp Candida sp
Gastrointestinal lesions	S bovis Enterococcus sp Clostridium septicum

Empirical Antibiotic Therapy

• Although antibiotic therapy for subacute disease can be delayed till the result of blood culture, the rapid progression of acute cases necessitate the start of empirical treatment antibiotic therapy once the blood cultures have been collected.

• Empirical therapy is needed for all likely pathogens, certain antibiotic agents, including aminoglycosides, is preferably avoided for its toxic effects.

• Clinical course of infection beside the epidemiological features should be considered upon selecting empirical treatment regimen.

Regimen	Dosage and Route	Duration(weeks)
	Native valve
Ampicillin sulbactam	12 g per 24 h IV in 4 equally divided doses	4–6 weeks
	plus
Gentamicin sulfate	3 mg per kg per 24 h IV/IM in 3 equally divided doses	4–6 weeks
	or
Vancomycin	30 mg per kg per 24 h IV in 2 equally divided doses	4–6 weeks
	plus
Gentamicin sulfate	3 mg per kg per 24 h IV/IM in 3 equally divided doses	4–6 weeks
	plus
Ciprofloxacin	1000 mg per 24 h PO or 800 mg per 24 h IV in 2 equally divided doses	4–6 weeks
	→Pediatric dose: Ampicillin sulbactam 300 mg per kg per 24 h IV in 4–6 equally divided doses Gentamicin 3 mg per kg per 24 h IV/IM in 3 equally divided doses Vancomycin 40 mg per kg per 24 h in 2 or 3 equally divided doses Ciprofloxacin 20–30 mg per kg per 24 h IV/PO in 2 equally divided doses
	Prosthetic valve (early, ≤ 1y, , mostly Oxacillin resistent)
Vancomycin	30 mg per kg per 24 h IV in 2 equally divided doses	6 weeks
	plus
Gentamicin sulfate	3 mg per kg per 24 h IV/IM in 3 equally divided doses	2 weeks
	plus
Cefepime	6 g per 24 h IV in 3 equally divided doses	6 weeks
	plus
Rifampin	900 mg per 24 h PO/IV in 3 equally divided doses	6 weeks
	→Pediatric dose: Vancomycin 40 mg per kg per 24 h IV in 2 or 3equally divided doses Gentamicin 3 mg per kg per 24 h IV/IM in 3 equally divided doses Cefepime 150 mg per kg per 24 h IV in 3 equally divided doses Rifampin 20 mg per kg per 24 h PO/IV in 3 equally divided doses
	Prosthetic valve (late—greater than 1 y, mostly Oxacillin sensitive) Same regimens as listed above for native valve endocarditis
	Suspected Bartonella, culture negative
Ceftriaxone sodium	2 g per 24 h IV/IM in 1 dose	6 weeks
	plus
Gentamicin sulfate	3 mg per kg per 24 h IV/IM in 3 equally divided doses	2 weeks
	with/without
Doxycycline	200 mg per kg per 24 h IV/PO in 2 equally divided doses	6 weeks
	Documented Bartonella, culture positive
Doxycycline	200 mg per 24 h IV or PO in 2 equally divided doses	6 weeks
	plus
Gentamicin sulfate	3 mg per kg per 24 h IV/IM in 3 equally divided doses	2 weeks
	→Pediatric dose: Ceftriaxone 100 mg per kg per 24 h IV/IM once daily Gentamicin 3 mg per kg per 24 h IV/IM in 3 equally divided doses Doxycycline 2–4 mg per kg per 24 h IV/PO in 2 equally divided doses Rifampin 20 mg per kg per 24 h PO/IV in 2 equally divided doses

Epidemiological features	Common Microorganism(s)
Injection drug use	S aureus, including community-acquired oxacillin-resistant strains Coagulase-negative staphylococci β-Hemolytic streptococci Fungi Aerobic Gram-negative bacilli, including Pseudomonas aeruginosa

Treatment Based Upon Infectious Agent

Penicillin-Susceptible Strep Viridans and Other Nonenterococcal Streptococci

Penicillin G

• If Minimum inhibitory concentration [MIC] <0.2 µg/ml.
• Dose: 12–18 million units I.V. daily in divided doses q. 4 hour for 4 weeks.

Penicillin G + Gentamicin

• Dose: Penicillin G, 12–18 million units I.V. daily in divided doses q. 4 hour for 4 weeks plus gentamicin, 3 mg/kg I.M. or I.V. daily in divided doses q. 8 hour for 2 weeks (peak serum concentration should be ~ 3 µg/ml and trough concentrations < 1 µg/ml).

Ceftriaxone

• Dose: 2 g I.V. daily as a single dose for 2 weeks.