Polyclonal Burkholderia cepacia Complex Outbreak in Peritoneal Dialysis Patients Caused by Contaminated Aqueous Chlorhexidine

Abstract

Whether Burkholderia cepacia complex should be an objectionable organism in antiseptic solutions with acceptable total bacterial counts is controversial. By using next-generation sequencing, we documented a polyclonal B. cepacia complex outbreak affecting peritoneal dialysis patients in Hong Kong that was caused by contaminated chlorhexidine solutions. Epidemiologic investigations at a manufacturing site identified a semiautomated packaging machine as the probable source of contamination in some of the brands. Use of whole-genome sequencing differentiated the isolates into 3 brand-specific clonal types. Changes in exit site care recommendations, rapid recall of affected products, and tightening of regulatory control for chlorhexidine-containing skin antiseptics could prevent future similar outbreaks. Environmental opportunistic pathogens, including B. cepacia complex, might be included in regular surveillance as indicator organisms for monitoring environmental contamination.

Keywords: B. cenocepacia; Burkholderia cepacia complex; Hong Kong. China; bacteria; chlorhexidine; epidemiology; genomic sequencing; manufacturers; nosocomial infections; outbreak; peritoneal dialysis; polyclonal; wound infection.

Figure 1

Epidemic curve and incidence rate of Burkholderia cepacia complex isolated from peritoneal dialysis patients, Hong Kong, China, January 2014–September 2019.

Figure 2

Semiautomated packing machine for aqueous chlorhexidine in brand B manufacturing site, Hong Kong, China, A) Mixing compartment (I), transfer tube from mixing compartment to dispensing end (II), area in which unused plastic packages are threaded (III), collection tray of newly packed 25 mL 0.05% aqueous chlorhexidine (IV). B) mixing compartment (I), unused plastic package (II), unused plastic package funneled to dispensing end (III), heat seal of 0.05% aqueous chlorhexidine into 25-mL packages (IV).

Figure 3

Maximum-likelihood phylogenetic tree of 80 Burkholderia cepacia complex isolates based on single-nucleotide polymorphisms, Hong Kong, China. A, B, and C indicate clusters. Scale bar indicates nucleotide substitutions per site.