Large Outbreaks of Fungal and Bacterial Bloodstream Infections in a Neonatal Unit, South Africa, 2012–2016

Abstract

Candidemia is a major cause of healthcare-associated infections. We describe a large outbreak of Candida krusei bloodstream infections among infants in Gauteng Province, South Africa, during a 4-month period; a series of candidemia and bacteremia outbreaks in the neonatal unit followed. We detected cases by using enhanced laboratory surveillance and audited hospital wards by environmental sampling and epidemiologic studies. During July–October 2014, among 589 patients, 48 unique cases of C. krusei candidemia occurred (8.2% incidence). Risk factors for candidemia on multivariable analyses were necrotizing enterocolitis, birthweight <1,500 g, receipt of parenteral nutrition, and receipt of blood transfusion. Despite initial interventions, outbreaks of bloodstream infection caused by C. krusei, rarer fungal species, and bacterial pathogens continued in the neonatal unit through July 29, 2016. Multiple factors contributed to these outbreaks; the most functional response is to fortify infection prevention and control.

Prolonged Outbreak of Candida krusei Candidemia in Paediatric Ward of Tertiary Care Hospital

“…These risk factors along with total parenteral nutrition and central venous catheter are previously reported in neonatal C. krusei candidemia cases [19,20]. The use of fluconazole prophylaxis is reported as a risk factor for the majority of C. krusei outbreaks though this practice is not prevalent in our hospital [18,19]. The overall inhospital mortality rate (22.9%, n = 17) among C. krusei infected patients was lower than C. tropicalis (42.9%) candidemia patients which may be attributed to its lower virulence potential as described previously [21].…”

“…In their study from a single centre, they found contaminated intravenous multi-electrolyte dextrose infusate bottle (different brands) as the source in first two outbreaks and a suction apparatus in the third outbreak [11,12]. A large outbreak of C. krusei candidemia (n = 48, 8.2% incidence) was reported by van Schalkwyk et al [18] among infants of Gauteng Province in South Africa over a period of 4 months in 2014. Subsequently, another large outbreak of 41 cases of C. krusei was reported in April-July 2015 although source could not be traced in both these outbreaks.…”

“…A sudden upsurge in the number of C. krusei candidemia cases to 44.09% in the year 2014 as compared to 4.93% in 2012 prompted us to perform epidemiological investigation. The majority of the cases were neonates (79.3%) who are an established risk group for developing candidemia due to their weak immune system and fragile skin/gut barrier [18]. The previously described outbreaks of C. krusei candidemia are either from neonates or from haematology oncology wards (Table 3).…”

“…Hautala et al [13] and Ricardo et al [30] from Europe could isolate the related strains of outbreak from sink traps and surfaces, respectively. Several recurrent outbreaks of C. krusei candidemia have been reported in neonatal ICUs due to contaminated environmental sources from India and South Africa [11,12,18] . In their study from a single centre, they found contaminated intravenous multi-electrolyte dextrose infusate bottle (different brands) as the source in first two outbreaks and a suction apparatus in the third outbreak [11,12].…”

“…Fluorescent amplified fragment length polymorphism (FAFLP) technique was carried out to evaluate the clonality of the clinical and environmental isolates from various sources [9,17]. Clonality is defined as the isolates having its origin from the single source/cell and has low degree of genetic exchange due to asexual reproduction [18]. C. albicans and C. tropicalis were used as an out-group, and C. krusei ATCC 6258 was used as control.…”