Multiresistant superbug appears in Australia

Healthcare facilities should be concerned by the recent appearance of the multiresistant superbug Candida auris in Australia. Without care, we could face a post-antibiotic era where once-simple infections will be untreatable.

Antimicrobial resistance is a well-documented global health and security threat^1-3. For the most part when we think of antimicrobial resistance we typically think of bacterial organisms such as MRSA (multiresistant Staphylococcus aureus) or Golden Staph, and VRE (vancomycin resistance enterococcus). Few of us think about resistance in other kinds of microorganisms.

In recent months, a newly recognised multidrug-resistant organism emerged in Australia⁴, this time the fungus Candida auris (C. auris), which presents as major public health concern. A male aged 70 years was recently identified as the first reported case in Victoria, and was thought to have acquired the organisms during hospitalisation in the UK.⁴

First reported cases

Reports of cases of drug-resistant C. auris first emerged internationally in 2009, beginning with outbreaks in hospitalised patients in Japan and South Korea. In Japan, the organism was isolated from the external ear canal of a female 70 years, and in patients (n=15) including three paediatric cases with chronic otitis media, respectively.⁵ In 2011 in South Korea, reports from 1996–2009 revealed a high case mortality with the deaths of two of three patients with nosocomial candidaemia.⁶

By 2016, C. auris strains had caused outbreaks in five continents⁷ with alerts issued by the Center for Disease Control and Prevention (CDC), European Centre for Disease Control (ECDC) and Public Health England (PHE). In 2017, cases were reported in the Middle East and Canada. In these and other international settings C. auris has spread quickly in healthcare settings, including hospitals and aged-care institutions, particularly in the intensive care populations.

Clinical features of C. auris

The clinical features of C. auris are similar to that of other Candida species. Colonisation of the skin, urine, sputum, enteral feeding tubes, drainage or intravascular clinical devices can be asymptomatic. Infection with C. auris results in sepsis or clinical syndromes such as otitis media, pericarditis, peritonitis, osteomyelitis, meningitis, wound and urinary catheter-associated infections as well as intravascular line-associated fungaemia which spread to the blood stream.

Sepsis due to C. auris has a reported case mortality rate of 30% to 60%, most cases with fungaemia.⁴ Patients most at risk for becoming colonised or infected with C. auris have co-morbidities such as immunosuppression, diabetes mellitus, recent surgery (especially abdominal) or age (prematurity).

Clinical-based risk factors include recent/current prescription of anti-fungals or broad-spectrum antibiotics, central venous line, urinary catheter, a stay in the intensive care unit (ICU) or neuroscience ICU, or prolonged hospital stay. Most important is a history of recent hospitalisation overseas, especially in India, Pakistan, South Africa, Venezuela, Columbia, Kuwait, the United Kingdom (UK) or the United States of America (USA).⁴

Transmission of C. auris is by person-to-person contact and environmental contact with contaminated surfaces or medical equipment such as thermometers (auxiliary).⁴ C. auris can live on surfaces for several weeks, for example a hospital study found C. auris persisted on dry mattresses and linen for up to seven days and remained viable on plastic for up to 14 days.

Of most concern is that the organism in these outbreaks is significantly multidrug resistant and difficult to identify with standard laboratory methods. Confirmed isolates of C. auris should be sent to specialist laboratories for further testing.⁴ Treatment of systemic infections is difficult, with isolates showing resistance to three commonly used classes of anti-fungal medications, that is, azoles (fluconazole, voriconazole), polyenes (amphotericin B) and echinocandins (caspofungin). The optimal drug regimen is unknown, and infections may be untreatable.^4,8

Managing outbreaks

Outbreaks require an aggressive infection control response as C. auris is persistent in the environment and can colonise patients and staff⁹. In the UK by the end of July 2017, over 200 patients from 20 separate NHS Trusts and independent healthcare providers had been detected to have C. auris, and another 35 hospitals received patients with known C. auris. Despite candidaemias comprising 25% of the infections, there were no deaths.

From April 2015 to August 2017, three large outbreaks occurred in intensive care units in England. Despite exemplary infection control measures, these outbreaks proved difficult to stop. For example, during the first outbreak in England at the Royal Brompton Hospital, environmental surveillance revealed contamination of the floor, radiators, windowsills, equipment monitors and keypads, trollies and an air sample. The ICU was closed and cleaning/disinfection was achieved with sodium hypochlorite products and hydrogen peroxide vapour.^10,11

Guidelines from Public Health England recommend isolation of colonised or infected patients during all admissions.^12,13 Also, broad containment and prevention measures in terminal cleaning of patient rooms, clearing colonisation of body sites using chlorhexidine washes, decontamination of the environment using disinfectants and hand hygiene.^9,14

A timely reminder

While this is far from the first documented emergence of antimicrobial resistance in non-bacterial organisms, it is a timely reminder of the growing pace and breadth of the spread of resistance and the ease with which it spreads globally.

Without sustained behaviour change to reduce our use of antibiotics, coupled with a comprehensive range of other One Health measures, we will soon experience the post-antibiotic era where once-simple infections will be untreatable, resulting in significant global morbidity and mortality.

*Professor Ramon Shaban is Clinical Chair and Professor of Infection Prevention and Control at the University of Sydney and Western Sydney Local Health District, within the Susan Wakil School of Nursing and Midwifery and the Marie Bashir Institute for Infectious Diseases and Biosecurity.

^Julie Potter is a Senior Research Officer at the University of Sydney and Western Sydney Local Health District, within the Susan Wakil School of Nursing and Midwifery and the Marie Bashir Institute for Infectious Diseases and Biosecurity.

References

1. O’Neill J. Tackling drug-resistant infections globally: Final report and recommendations of the Review on Antimicrobial Resistance. In: Government of the United Kingdom & Wellcome Trust; 2016.
2. Rump B, Timen A, Hulscher M, Marcel V. Ethics of infection control measures for carriers of antimicrobial drug-resistant organisms. Emerging Infectious Diseases. 2018;24(9):1609-1616.
3. Shaban R, Cruickshank M, Cristiansen K, the Antimicrobial Resistance Standing Committee. National surveillance and reporting of antimicrobial resistance and antibiotic usage for human health in Australia. In: Antimicrobial Resistance Standing Committee AHPPC, ed. Canberra 2013.
4. Chief Health Officer (Communicable Disease). Candida auris case detected in Victoria. In: Health and Human Services, ed. Victoria: Communicable Disease Epidemiology and Surveillance; 2018.
5. Satoh K, Makimura K, Hasumi Y, Nishiyama Y, Uchida K, Yamaguchi H. Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital. Microbiology and Immunology. 2009;53(1):41-44.
6. Kim MN, Shin JH, Sung H, et al. Candida haemulonii and closely related species at 5 university hospitals in Korea: identification, antifungal susceptibility, and clinical features. Clinical Infectious Diseases. 2009;48(6):e57-61.
7. Chowdhary A, Sharma C, Meis JF. Candida auris: A rapidly emerging cause of hospital-acquired multidrug-resistant fungal infections globally. PLoS Pathog. 2017;13(5):e1006290.
8. Warris A. Candida auris, what do paediatricians need to know? Arch Dis Child. 2018; In press.
9. Beardsley J, Halliday C, Chen S, Sorrell T. Responding to the emergence of antifungal drug resistance: perspectives from the bench to bedside. Future Microbiology. 2018.
10. Schelenz S, Hagen F, Rhodes JL, et al. First hospital outbreak of the globally emerging Candida auris in a European hospital. Antimicrob Resist Infect Control. 2016;5:35.
11. Public Health England (PHE). Guidance for the laboratory investigation, management and infection prevention and control for cases of Candida auris. 2017; 2.0:https://www.gov.uk/government/publications/candida-auris-laboratory-investigation-management-and-infection-prevention-and-control. Accessed 14 August, 2018.
12. European Centre for Disease Prevention and Control. Candida auris in healthcare settings - Europe - first update, 23 April 2018. 2018; https://ecdc.europa.eu/sites/portal/files/documents/RRA-Candida-auris-European-Union-countries-first-update.pdf. Accessed 14 August 2018, 2018.
13. Jeffery-Smith A, Taori SK, Schelenz S, et al. Candida auris: a Review of the Literature. Clinical Microbiology Reviews. 2018;31(1).
14. Biswal M, Rudramurthy SM, Jain N, et al. Controlling a possible outbreak of Candida auris infection: lessons learnt from multiple interventions. J Hosp Infect. 2017;97(4):363-370.

Image credit: ©stock.adobe.com/au/Trueffelpix