Invasive Mold Infections in Solid Organ Transplant Recipients

Table 3

Diagnosis of invasive mold infection among solid organ transplant recipients.

	Aspergillosis	Scedosporium	Fusariosis	Mucormycosis	Phaeohyphomycosis
Pathogen detection
Microscopy techniques [130]
Color	Hyaline	Hyaline	Hyaline	Hyaline	Brown
Size	3–8 microns wide	3–8 microns wide	3–8 microns wide	5–15 microns wide	Variable
Septation	Yes (no adventitious forms)	Yes (+/−adventitious forms: yeast-like structures)	Yes (+/−adventitious forms: yeast-like structures)	No or pseudoseptation	Yes
Branching	Dichotomous acute angle (45°)	Dichotomous acute angle (45°)	Dichotomous acute/right angle	Irregularly right angle	Variable
Culture [3, 57, 125]	Among 128 IA in SOT: All samples: Sens: 91.4%; Sputum or BAL: PVP: 58%^**; Blood culture: limited utility	Among 23 SOT: No positive blood culture; In HSCT: Blood culture Sens: 50%	Among  : blood culture Sens: 41%–60%	Blood culture: limited utility; Culture of CSF and urine often negative for kidney or CNS infection	Blood culture: limited utility
PCR [72, 126, 131, 132]	Among HSCT: Blood: Sens 0.88, Spe 0.75 (0.87 if 2 consecutive positive samples). High NPV; Among lung SOT: BAL: Sens 100%, Spe 88% (pan-Aspergillus PCR)	Insufficient data	Insufficient data	Moderately supported. Fresh material is preferred over paraffin-embedded tissue because formalin damages DNA.	Insufficient data
Beta-D-glucan assay [133, 134]	Among SOT: Sens: 66%; Spe: 44%	NA	Few data but case report with positive results	Negative	Few data but case report with positive results
Galactomannan Ag [70, 135, 136]	Among SOT; Serum/BAL: Sens: 22%/81.8%; Spe: 84%/95.8%	NA	In HSCT: Sens 83% & Spe 67%; Positive before the diagnosis in 73% at a median of 10 days	Negative	Cross reactivity in some cases Not recommended
Identification species by molecular method [72, 126, 132, 137]	Required in 10% of cases because of cryptic species with particular antifungal resistance pattern	Marginally recommended	Marginally recommended	Recommended to establish epidemiological knowledge (and in case of healthcare-associated mucormycosis and outbreaks)	Recommended especially for unusual or newly described pathogens.
Antifungal susceptibility testing to guide treatment [72, 126, 132]	Not recommended in routine in area of low frequency of resistance.	Marginally recommended	Marginally recommended	Moderately recommended	Strongly recommended for deep infections

Ag: antigen; AMB: amphotericin B; BAL: bronchoalveolar lavage; FC: flucytosine; ITC: itraconazole; HM: patients with hematological malignancies; IMI: invasive mold infection; NA: not available; NVP: negative predictive value; PCZ: posaconazole; PVP: predictive positive value; Sens: sensitivity; Spe: specificity; SOT: solid organ transplant recipients; VCZ: voriconazole; no specific data among SOT except for invasive aspergillosis; ^**lower PVP in lung transplant recipients.