Workload and clinical significance of the isolation of zygomycetes in a tertiary general hospital

Abstract

Several reports of increases in invasive zygomycosis (IZ) at individual institutions across the USA and Europe have contributed to a generalized concept that IZ is an increasing problem and the overestimation of the clinical significance of the isolation of zygomycetes in microbiology departments. We assessed the workload and clinical significance of zygomycetes isolates recovered from clinical samples in our institution over a 19-year period (1988-2006). We retrospectively reviewed the charts of those patients from who isolates of zygomycetes were obtained and calculated the workload of its isolation, the incidence of IZ during this period and the positive predictive value (PPV) of a positive culture. Zygomycetes were recovered from 210 samples (176 patients), i.e., 0.086/1,000 clinical samples processed and 6.3/1,000 samples submitted for fungal isolation. Zygomycetes represented 0.6% of the total fungi recovered. The mean incidence of the disease was 1.2 cases/100,000 admissions (range 0-20). Only 16 of the samples which grew zygomycetes (7.6%) were from infected patients. The workload generated by zygomycetes in our institution and the PPV for IZ of their isolation in our laboratory were very low and the disease was not found to have significantly increased in recent years in our institution. Data from specific institutions cannot be generalized.

Increasing incidence of mucormycosis in a large Spanish hospital from 2007 to 2015: Epidemiology and microbiological characterization of the isolates

“…We previously reported 12 patients diagnosed from 1988 to 2006 and estimated an incidence of 1.2 cases/100,000 admissions at our institution [14]. This finding is in line with that reported in a multicenter study conducted in Spain in 2005 (0.62 cases/100,000 admissions) [20].…”

“…Our series includes cases collected as recently as 2015, and half of the patients had hematological disorders. A high proportion of patients had skin and soft tissue involvement (52%), and a lower percentage of diabetes mellitus and rhino-cerebral involvement than in previous reports [1, 21, 22], including one from our institution [14]. …”

“…Categorical variables were described and compared using the chi-square or Fisher exact test. The incidence of the infection was calculated and compared with that reported previously from 1988 to 2006 using standard binomial methods [14]. …”

Quantifying guideline adherence in mucormycosis management using the EQUAL score

“…In this retrospective study at the University Hospital of Cologne, Germany, the overall mucormycosis incidence rate was 0.06/1000 admissions. This concurs with the reported general incidence of mucormycosis in Europe ranging from 0.006 to 0.2/1000 admissions …”

Increasing Incidence of Zygomycosis (Mucormycosis), France, 1997–2006

“…First, diagnosing zygomycosis is not easy. As recently underlined ( 25 ), a culture positive with a zygomycete does not always mean infection; many gastrointestinal cases reported in the PMSI may be false-positive cases resulting from laboratory contamination. The unusual distribution of clinical presentations found in our study and the fact that one third of clinical information was missing favor this hypothesis.…”