Methods: Published reports of mucormycosis during 1994-2015 were accessed via Medline, Embase, and Global Health. English and Spanish reports of laboratory-confirmed invasive mucormycosis with defined dates of suspected exposure(s) and symptom onset (or laboratory diagnosis) were included. For patients with single exposures, incubation period was calculated as time from exposure to onset (or to diagnosis date if onset unknown); for patients with repeat exposures the maximal incubation was calculated using the first exposure. Analyses were stratified by exposure type (percutaneous, ingestion, and inhalation). Of 5558 citations, 188 met inclusion criteria.
Results: The 188 citations described 219 mucormycosis cases. Of these, 202 (92%) had percutaneous exposures, including trauma (45%), surgery (25%), and dental procedures (5%). Median age of patients was 40 (interquartile range [IQR] 22–55) years; 35% were women; 33% died. Underlying conditions were reported for 61% of percutaneous exposure cases, most commonly corticosteroid use (30%) and diabetes (26%). The median incubation period for 168 patients with single percutaneous exposures was 8 (IQR: 5–16) days and did not change with restriction to cases with known symptom onset date or with inclusion of maximal incubations for patients with repeat exposures. Fatal cases had a non-significantly shorter incubation period than non-fatal cases (7 vs. 10 days, p=0.08). Of 40 patients with data available, the median time from symptom onset to diagnosis was 12 (IQR: 7–23) days.
Fewer reports described ingestion (15, 7%) or inhalational (2, 1%) exposures, with median incubations of 6 and 2 days, respectively. Twelve ingestion exposures were in neonates with gastrointestinal mucormycosis exposed to enteral feedings or nasogastric tubes.
Conclusion: The typical incubation period for cutaneous mucormycosis is 1 to 2 weeks and there are often delays in diagnosis. These findings can help guide clinical suspicion for these severe infections. Limited data are available to evaluate the incubation periods following non-percutaneous exposures.
R. M. Smith,
R. K. Mody, None