Deadly superbug fungus found in Bangladesh's NICUs: icddr,b study

A significant public health threat has been identified in Bangladesh's neonatal intensive care units (NICUs), where the dangerous superbug fungus, Candida auris (C auris), is spreading among critically ill infants.

This finding comes from a recent study published in the journal Microbiology Spectrum today (9 November), conducted by researchers from the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), in collaboration with the Institute of Epidemiology, Disease Control & Research (IEDCR) and with technical support from the US Centers for Diseases Control and Prevention (CDC).

C auris is a type of fungus associated with Healthcare-Associated Infections (HAIs) that poses a major burden globally, particularly in low- and middle-income countries (LMICs), where it has become a leading cause of invasive candidiasis.

The fungus can persist asymptomatically on the skin, but in around 10% of cases, this colonisation progresses to a clinical infection, often by invading sterile areas like the bloodstream, at which point it becomes highly lethal. In LMICs, hospitalisation linked to C auris carries a crude mortality rate of approximately 70%. It is particularly threatening to those with weakened immune systems, critical illnesses, and preterm babies, making NICU infants an extremely high-risk group.

Due to its ability to survive long-term on surfaces, spread rapidly, and its frequent multidrug-resistant nature—leading the CDC to declare it an urgent antimicrobial-resistant threat in 2019—C auris has been dubbed a healthcare-associated "superbug".

Dr Fahmida Chowdhury, associate scientist and lead of AMR Research Unit at icddr,b, stressed the importance of the findings, saying, "This study provides important evidence of transmission of this superbug among critically ill and vulnerable patients in NICUs. This is a necessary first step for beginning to take preventive measures at the administrative and policy levels."

The study examined two tertiary-level hospitals in Dhaka.

Study findings

The researchers enrolled 374 patients admitted to the NICUs of one public and one private hospital between August 2021 and September 2022.

They tested the infants for C auris colonisation or bloodstream infection (BSI) at enrollment and during follow-up.

Overall, 32 patients (9%) were colonised with C auris, and 1 (0.3%) developed a BSI.

Among the colonised patients, 44% (14/32) were colonised at enrollment, and 56% (18/32) became colonised after enrollment.

Of the 14 patients colonised on admission, 13 had been transferred from another healthcare setting (like an obstetric ward), strengthening the conclusion that C auris persists and spreads primarily within hospitals.

Seven (22%) of the colonised patients, including the one with BSI, died.

While only 3 isolates demonstrated multidrug resistance, 82% were resistant to fluconazole, the standard first-line treatment for invasive fungal infections.

Interestingly, 81% of colonised cases were delivered by Caesarean section, with longer hospital stays potentially increasing the risk of exposure.

Recommendations

The authors recommend regular cleaning of hospital surfaces using effective chlorine-based disinfectants and improved hand hygiene among healthcare workers to curb the persistence and spread of infection within NICUs and other hospital settings.

They also emphasise the need for continuous surveillance of C auris infections in NICUs to enable the swift identification and isolation of colonised or infected neonates, thereby preventing further transmission and ensuring timely antifungal treatment.