[Burkholderia cepacia Outbreak: Hospital-acquired Infection Caused by Contamination of Foam Soap]

Burkholderia cepacia is an environmental bacterium that can cause nosocomial infections, particularly in immunocompromised patients. This study aimed to describe a hospital outbreak caused by B.cepacia. In our hospital, we observed an unusual increase in B.cepacia growth in blood culture samples, prompting the infection control team to initiate a retrospective investigation due to concerns about a potential outbreak. Since February 2023, we have detected a rise in B.cepacia isolations from specimens of patients hospitalized in the intensive care unit (ICU). As a result, we retrospectively reviewed patient data from the ICU with positive cultures in blood, tracheal aspirate, urine and other sterile body fluids between October 2022 and December 2023. The outbreak was defined as starting in February 2023 and ending in December 2023. During this period, we evaluated clinical data from infected patients, laboratory results and environmental samples (including medical devices and hygiene products). Bacteria isolated from patient and environmental samples were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS Microflex LT/SH Smart MS, Bruker Daltonics, USA). The genetic relatedness of B.cepacia isolates identified by MALDI-TOF MS was determined using 16S rRNA typing. To control the outbreak, contact isolation, enhanced hand hygiene protocols, environmental disinfection and discontinuation of foam soap use were implemented. Additionally, based on culture results, we performed de-escalation to reduce unnecessary use of broad-spectrum antibiotics. A total of 155 patients in the ICU were found to have B.cepacia growth, compared to only 13 patients in clinical wards. Among the patients with B.cepacia growth, 55.4% were diagnosed as B.cepacia infection. Of these, 78 (83.9%) had bloodstream infections, seven (7.5%) had ventilator-associated pneumonia, four (4.3%) had hospital-acquired pneumonia, three (3.2%) had urinary tract infections and one (1.1%) had peritonitis. Overall, 39.8% of patients died due to sepsis. Patients without a diagnosis of infection were considered colonized. We detected B.cepacia growth in 43.8% of foam soap samples used in the ICU. The bacterium was also isolated from unopened soap bottles, and 16S rRNA analysis showed that 23 strains isolated from patients and foam soaps were phylogenetically related. Colony counts of B.cepacia in foam soap cultures exceeded 1000 CFU/mL, surpassing the acceptable limits stated in the “Guidelines for the Safety Assessment of Cosmetic Products.” Trimethoprim-sulfamethoxazole was identified as the antibiotic with the highest susceptibility rate among our clinical isolates. We contacted the manufacturer of the foam soaps used in our hospital to identify and eliminate the source of the contamination. The outbreak lasted approximately 270 days, from February to November 2023. This outbreak highlights that despite its low virulence, B.cepacia can pose a serious threat to critically ill ICU patients and underscores the importance of microbiological monitoring of hospital-use products. The absence of adequate quality control procedures for commonly used hygiene products, such as foam soaps, can lead to nosocomial outbreaks associated with high morbidity and mortality. Therefore, strict adherence to infection control measures and regulatory standards is essential in the delivery of healthcare services.