Table 5.

Laboratory Diagnosis of Pericarditis and Myocarditis

Etiologic Agentsa	Diagnostic Procedures	Optimum Specimens	Transport Issues and Optimal Transport Time
Bacteria	Gram stain Aerobic bacterial cultureb	Pericardial fluid or pericardium biopsy	Sterile container or blood culture vial (pericardial fluid only), RT, immediately
	Blood cultures (see I-a above)
Fungi	Calcofluor-KOH stain Fungal culture	Pericardial fluid or pericardium biopsy	Sterile container, RT, 2 h
	Blood cultures (see Section I-A)
Mycobacteria	Acid-fast smear AFB culture	Pericardial fluid or pericardium biopsyc	Sterile container, RT, 2 h
	Blood cultures (see Section I-A)
Viruses
Coxsackie B virus  Coxsackie A virus  Echovirus  Polio virus  Adenovirus  HIV  Mumps virus  Cytomegalovirus  Other viruses	Virus-specific serology	Acute and convalescent sera	Clot tube, RT, 2 h
	Virus-specific NAAT (may be first choice if test is available)	Pericardial fluid or pericardium biopsy	Closed container, RT, 2 h
	Virus culture (culture not productive for all virus types)	Pericardial fluid or pericardium biopsy	Virus transport device, on ice, immediately
	Histopathologic examination	Pericardial fluid or pericardium biopsy	Place in formalin and transport to histopathology laboratory for processing.
Parasitesd
Trypanosoma cruzi  Trichinella spiralis  Toxoplasma gondii	Parasite-specific serology	Acute and convalescent sera	Clot tube, RT, 2 h
	Blood smeare	5 mL of peripheral blood	EDTA tube, RT
	Histopathologic examination Toxoplasma NAAT	Endomyocardial biopsy or surgical specimen	Consultation with the laboratory is recommended. For histopathology, place in formalin and transport to histopathology laboratory for processing.

Abbreviations: AFB, acid-fast bacilli; EDTA, ethylenediaminetetraacetic acid; HIV, human immunodeficiency virus; KOH, potassium hydroxide; NAAT, nucleic acid amplification test; RT, room temperature.

^aOther infectious causes of pericarditis and myocarditis include rickettsiae (Rickettsia rickettsii, Coxiella burnetii), chlamydiae, Borrelia burgdorferi, Treponema pallidum, Nocardia spp, Tropheryma whipplei, Legionella pneumophila, Actinomyces spp, Entamoeba histolytica, Ehrlichia spp, Toxocara canis, Schistosoma, and Mycoplasma spp.

^bIf aerobic bacteria are suspected. If anaerobes are suspected, then the culture should consist of both a routine aerobic and anaerobic culture.

^cPericardial tissue is superior to pericardial fluid for the culture recovery of Mycobacterium spp.

^dIf parasites other than T. cruzi, T. gondii, or T. spiralis are suspected, consult the Centers for Disease Control and Prevention Parasitic Consultation Service (http://dpd.cdc.gov/dpdx/HTML/Contactus.htm).

^eBlood smears may be useful in detection of infection caused by Trypanosoma spp.