Aspergillosis: Likelihood Ratios

Introduction: Invasive infection by the Aspergillus fungus, typically in neutropenic patients.

Differential Diagnoses include: Lymphoma

The likelihood ratios of findings for Aspergillosis are listed below. See the left navigation bar to change the display.

Pre-Test Probability (Prevalence): %.	Post-Test Probability (Predictive Value): %.	Switch to display mode.
Note that calculating probabilities from more than one** finding is inherently inaccurate because findings are not independent. (For example, using two positive findings that share a common pathogenesis is likely to overestimate the true probability.)

Good Positive and Negative Likelihood Ratios
Finding	Result	+LR	-LR
[ + ] Chest CT	+ 0 -	2.7	0.1
finding: pulmonary nodules (sensitivity and specificity from different studies) Differential Diagnosis: Lymphoma Study: Mycoses. 2002 Oct;45(8):287-94. PMID: 12572717 Haematologica. 2000 Jul;85(7):745-52. PMID: 10897127 Clin Infect Dis. 2007 Feb 1;44(3):373-9. PMID: 17205443
[ + ] Serum galactomannan assay	+ 0 -	6.5	0.3
the sensitivity ranged from 61 to 71 percent with a specificity of 89 to 93 percent Study: Diagnosis of invasive aspergillosis using a galactomannan assay: a meta-analysis. Pfeiffer CD; Fine JP; Safdar N Clin Infect Dis. 2006 May 15;42(10):1417-727. Epub 2006 Apr 14. PMID 16619154
[ + ] Serum Beta-D-glucan	+ 0 -	5.2	0.3
Component of the fungal cell wall. This study evaluated dx of invasive fungal infections, not specifically Aspergillus. The test is nonspecific and includes all fungi, including PCP (which was excluded from this study). Study: PMID 21367728

Good Positive Likelihood Ratio
Finding	Result	+LR	-LR
[ + ] Chest CT	+ 0 -	22	0.6
For findings of 'halo sign' or 'air crescent' sign. Another study gave sensitivity for halo sign at 61%. Study: Haematologica. 2000 Jul;85(7):745-52. PMID: 10897127 Clin Infect Dis. 2007 Feb 1;44(3):373-9. PMID: 17205443
[ + ] Latex Agglutination	+ 0 -	6.3	0.6
Study: Haematologica. 2000 Jul;85(7):745-52. PMID: 10897127