Table 1. Typical organisms after renal transplant by time period (3-6).

Time after transplant	Likely organisms	Typical presentation	Diagnosis	Treatment
First month	Streptococcus pneumoniae, Neisseria meningitidis, Listeria monocytogenes, Haemophilus influenza	Nonspecific; ranging from headache, fever, meningismus, altered mental status	CSF with neutrophilic predominance, decreased glucose, elevated protein	Empiric treatment including ceftriaxone, vancomycin, ampicillin, narrowing therapy after culture results
	Aspergillus fumigatus	Nonspecific; seen with comorbid respiratory disease	Antigen or antibody present in CSF, branching hyphae visualized in CSF	Antifungals including voriconazole, amphotericin
	Candida species	Disseminated fungemia with CNS symptoms	Pseudohyphae visualized in CSF, PCR, positive culture	Fluconazole
				Amphotericin can be considered in severely ill or neutropenic patients
1–6 months	Mycobacterium tuberculosis	Non-specific; consider in patients from endemic areas, travel or exposure history, or history of latent infection	CSF Acid Fast Bacteria stain may miss the diagnosis. Interferon-Gamma Release Assay as screen. Decreased glucose, leukocytosis with lymphocytic predominance, increased protein, and increased adenosine deaminase	Multiple drug therapy including isoniazid, rifampin, ethambutol, pyrazinamide
	Cytomegalovirus	Non-specific, but may include symptoms of retinitis, GI manifestations	CSF PCR	Ganciclovir, foscarnet
	Varicella Zoster Virus	Encephalitis, headache, altered mental status, seizure. May or may not have skin manifestations	PCR of CSF, may require multiple samples to rule out as it can initially be negative	Intravenous acyclovir with appropriate hydration. Can consider valacyclovir prophylaxis after infection fully treated to prevent reactivation
6 months and beyond	Cryptococcus neoformans	Nonspecific; fever, headache	CSF PCR, antigen, culture	Amphotericin, flucytosine. Will need continued treatment with fluconazole for life even after CSF culture negative. Poor prognosis
	Toxoplasma gondii	Altered mental status, seizure, focal neuro signs	Serum toxoplasma IgG, supportive imaging findings include ring-enhancing lesions	Pyrimethamine with leucovorin
				Prophylaxis can include Trimethoprim-Sulfamethoxazole or pyrimethamine with leucovorin if cannot tolerate TMP-SMX
	JC virus	AMS, seizure, focal neuro signs	CSF PCR	No treatment. Consider reducing immunosuppression. Poor prognosis

CNS, central nervous system; GI, gastrointestinal; CSF, cerebrospinal fluid; PCR, polymerase chain reaction.