Table 2. Illustrates extensive workup that was done on CSF and blood samples to elucidate the etiology of the patient’s encephalitis.

Ab - antibodies; CSF - cerebrospinal fluid; IgM - immunoglobulin M; IgG - immunoglobulin G; IGRA - interferon-gamma release assays; PCR - polymerase chain reaction; PRNT - plaque reduction neutralization test; VDRL - venereal disease research laboratory

Pathogen/Test	CSF	Blood
Gram stain	Negative	-
Cultures	Negative	Negative
Herpes simplex virus I and II PCR	Negative	-
Varicella zoster virus PCR	Negative	-
Cytomegalovirus PCR	Negative	-
Human parechovirus PCR	Negative	-
Human Herpesvirus 6 PCR	Negative	-
Epstein Barr virus PCR	Negative	-
Enterovirus 71 PCR	Negative	-
Adenovirus PCR	Negative	-
LCM virus IgM and IgG	Negative	-
West Nile virus IgM and IgG Ab	Negative	Negative
Jamestown Canyon virus IgM Ab	IgM positive, PRNT positive	-
St. Louis Encephalitis virus IgM and IgG Ab	Negative	-
Calif (LaCrosse) encephalitis virus IgM and IgG	Negative	-
West equine encephalitis virus IgM and IgG Ab	Negative	-
Human immunodeficiency virus PCR	-	Negative
East Equine Encephalitis Virus IgM and IgG Ab	Negative	-
Powassan virus IgM, IgG, PRNT	Negative	Negative
Escherichia Coli K1 PCR	Negative	-
Neisseria meningitidis PCR	Negative	-
Borrelia burgdorferi PCR, IgM, IgG Ab	Negative	Negative
Leptospirosis spp IgM and IgG	Negative	Negative
IGRA	-	Negative
Listeria monocytogenes PCR	Negative	Negative
Ehrlichia eauclairensis PCR	-	Negative
Ehrlichia chaffensis IgM and IgG	-	Negative
Anaplasma phagocytophilum IgG	-	Negative
Anaplasma phagocytophilum IgM	-	Negative
Anaplasma phagocytophilum PCR	-	Negative
Borrelia miyamotoi PCR	-	Negative
Streptococcus pneumoniae PCR	Negative	-
Streptococcus agalactiae PCR	Negative	Negative
Haemophilus influenza PCR	Negative	Negative
VDRL	-	Negative
Babesia microti PCR, IgG	-	Negative
Cryptococcus neoformans/gattii PCR	Negative	-