A nationwide review of public-sector laboratory records identified 426 patients with culture-confirmed Wickerhamomyces anomalus from January 1, 2022 through April 29, 2024. Case counts were low and stable before April 2023 (about 2–3 cases per facility per month), but 346/426 (81%) of detections occurred during May–November 2023, indicating a marked temporal cluster. Cases were reported across seven of nine provinces; Gauteng Province contributed the largest number (180/426, 42%). The most frequent specimen types were urine (207/426, 49%) and blood (77/426, 18%). The observed increase did not coincide with introduction of the Vitek MS identification system at laboratories, based on laboratory-reported timelines.
Clinical data were available for 52 of the 426 case-patients. Median age was 23 years (IQR 0–47); 63% were male. Among 51 patients with specimen-level detail, isolates came most commonly from urine (26, 51%), tracheal aspirate (13, 26%), peritoneal dialysis fluid (6, 12%), and blood (4, 8%). Among 37 patients with procedure data, 62% underwent urinary catheterization and 32% underwent endotracheal intubation; procedures were not mutually exclusive.
Clinicians judged positive cultures as contamination in 20 of 48 patients (42%) and clinically relevant in 28 (58%), with reported syndromes including urinary tract infection (15, 31%), lower respiratory tract infection (8, 17%), and bloodstream infection (2, 4%). Objective clinical evidence of invasive fungal disease—such as documented sepsis or consistent inflammatory biomarker elevations—was absent or incompletely documented in most reviewed records. Antifungal therapy was recorded for 10 of 44 patients with treatment data. Only five patients had W. anomalus recovered on subsequent cultures. Among 50 patients with known disposition, 30 (60%) were discharged, 6 (12%) remained hospitalized, and 14 (28%) died; the supplied data were insufficient to attribute deaths to W. anomalus infection.
Investigators obtained clinical isolates and unopened sealed sachets of a sterile lubricating gel (Lubri-A sterile lubricating jelly, manufacturer listed in the source). Subcultures were grown on chromogenic agar and incubated at 35–37°C. Species identification was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF; MALDI BioTyper). Of 86 isolates tested, 85 (99%) were confirmed as W. anomalus; one isolate was Candida albicans and excluded from W. anomalus analyses. Sealed gel sachets uniformly yielded heavy fungal growth.
Seventeen clinical isolates and 11 gel isolates underwent antifungal susceptibility testing using the Sensititre YeastOne method, interpreted against CLSI M57S epidemiologic cutoff values. Fluconazole MIC50 was 2 μg/mL for both clinical and gel isolates; 94% of clinical isolates and 82% of gel isolates had fluconazole MICs <2 μg/mL and were classified as wild-type. Other azole and micafungin MICs were at or below epidemiologic cutoffs. Amphotericin B MICs were <1 μg/mL for most isolates (88% of clinical, 82% of gel isolates); a minority had MICs >1 μg/mL. Flucytosine MICs were 0.06 μg/mL for all 17 clinical isolates, whereas 9 of 11 (82%) gel isolates had flucytosine MICs >64 μg/mL.
Whole-genome sequencing was performed on isolates using the Illumina NextSeq platform and analyzed via a fungal phylogenomics pipeline. Quality control and read trimming steps were performed and filtered reads aligned to a reference W. anomalus strain. High-confidence single-nucleotide polymorphisms (allele frequency >0.85) were annotated and used for distance matrix generation and phylogenetic reconstruction with IQ-TREE and 1,000 bootstrap replicates. The supplied text indicates the phylogenetic dataset included 95 genome sequences, of which 72 (76%) were current outbreak isolates. Additional genomic clustering and interpretation details appear in figures and appendices of the original article; those specifics were not fully reported in the supplied excerpt.
Investigators recovered W. anomalus from unopened sealed sachets of a sterile lubricating gel that was used during ultrasound-guided central venous catheter placement and other procedures. Gel batches produced heavy fungal growth and yielded isolates that were genomically and microbiologically consistent with the clinical isolates examined. These findings implicated contaminated sterile lubricating gel as the likely source of widespread laboratory detections and pseudo-infections.
Following identification of contaminated product batches, a nationwide product recall was implemented. The abstract and main text report that the recall corresponded with a decline in reported W. anomalus cases. The supplied text does not include the detailed timeline or quantitative post-recall surveillance data within the excerpt provided.
The provided source text documents key epidemiologic, microbiologic, and genomic methods and the association with contaminated sterile lubricating gel. However, the supplied excerpt is truncated before full presentation of phylogenetic clustering results and additional genomic analyses; precise SNP distances, cluster definitions, and some downstream interpretations were not reported in the text provided here. Clinical attribution of morbidity and mortality to W. anomalus could not be established from available clinical records in the supplied material.