How COVID-19 and Mechanical Ventilation Caused Israel’s Candida auris Surge

Since its emergence in the last decade, Candida auris has raised alarms as a drug-resistant fungal pathogen with significant mortality rates.

The US Centers for Disease Control and Prevention (CDC) list drug-resistant C auris as an urgent threat, due to its ability to cause severe disease and spread rapidly between hospitalized patients and nursing home residents.

A new study, published in the CDC’s latest issue of Emerging Infectious Diseases, conducted a nationwide assessment of C auris infections in Israel. Since January 2021, the study authors noted, the country’s C auris isolates have steadily risen, with many Israeli medical centers reporting C auris infections for the first time. With this survey, the investigators sought to evaluate clinical and microbiological characteristics and determine what drove this 2021-2022 epidemiologic change.

The nationwide, retrospective, observational study covered the January 1, 2014-May 22, 2022 period. Israeli medical facilities that reported at least 1 C auris clinical isolate were included in the study. Yeast isolates sent to the reference laboratory underwent DNA-sequence based identification, sequence typing, and antifungal susceptibility testing.

From each site, the investigators collected demographic and clinical data. Data included comorbidities (quantified using the Charlson comorbidity score), COVID-19 infection, prior exposure to antibacterial and antifungal drugs, infection with or carriage of drug-resistant organisms, and need for mechanical ventilation. Clinical outcomes were all-cause in-hospital death, length of hospitalization, length of stay in intensive care unit (ICU), and mechanical ventilation duration.

“C auris was considered a colonizer if growing from respiratory tract, skin, or rectal specimens,” wrote the study authors, “and potentially clinically significant if isolated from normally sterile specimens.”

During the 8-year study period, the investigators recorded 209 patient-specific C auris isolates. As anticipated, Israel’s first C auris infections were detected in May 2014 at a tertiary-level medical center in Tel Aviv. From May 2014-December 2020, 24 total C auris infections were reported from 7 hospitals.

The C auris incidence rate increased significantly in 2021, with 120 cases reported by 10 hospitals and 3 long-term care facilities (ie, nursing homes). This means there was a 30-fold increase in C auris cases in 2021. Of 185 patient-specific isolates identified in 2021, 92.9% (n = 172) occurred in 4 community hospitals.

Notably, the incidence of C auris infections in 2021 and 2022 were correlated with Israel’s COVID-19 surges. C auris cases peaked in January-March 2021, alongside the Alpha variant wave, in June-November 2021, matching the Delta wave, and in January-May 2022, matching the Omicron wave.

During the Alpha wave, 88.0% of C auris patients were coinfected with COVID-19. This decreased to 22% of patients during Delta and 6.2% during Omicron. Broken down by demographics, the C auris patients were 68.3% male and averaged 70 years of age. Of the 23.2% of patients who contracted COVID-19 before C auris, 73.1% had critical COVID-19.

The investigators concluded that COVID-19 and mechanical ventilation were the 2 main drivers of C auris healthcare-associated dissemination. C auris will undoubtedly continue to spread across multiple Israeli hospitals, even becoming endemic in some facilities. New guidelines addressing this public health threat were published by the Israeli Ministry of Health, and continued surveillance and infection control implementation may save both healthcare costs and patient lives.