“Bacillus cereus” Outbreak in a Tertiary Hospital in Manila, Philippines

Abstract

AIM: This investigation aimed to describe Bacillus cereus (B. cereus) outbreak. BACKGROUND: B. cereus is often considered a contaminant in blood cultures. However, B. cereus can cause severe infections among hospitalized immunocompromised patients. A series of B. cereus infections were documented between February 9, 2023 until August 1, 2024 at Makati Medical Center. METHODS: An outbreak investigation was conducted on March 20, 2024. Patient profiles were reviewed to determine possible risk factors to guide further outbreak investigation interventions. RESULTS: There were a total of 12 cases. The median age of cases was 66.5 years old. Majority (9 or 75%) were females, 7 or 58% were on chronic hemodialysis. 11 or 92% had a central line. B. cereus was isolated from the blood in 8 or 66% of the cases all of whom had a central line. 7 or 58% underwent a surgical procedure during admission. Among 8 (67%) of cases, B. cereus was isolated from blood or other specimens after 48 hours from admission. Only 4 (33%) had gastrointestinal symptoms. Two cases expired. Central line associated bloodstream infection prevention measures were reinforced in patient care areas. Sampling of dialysate fluid in the dialysis unit did not reveal the organism. CONCLUSIONS: Patients with a central line and undergoing hemodialysis comprise majority of cases with B. cereus infection. Breach in infection control measures can predispose patients infections. Early identification and outbreak investigation can determine common patient profiles that guide effective interventions.

Keywords

• Bacillus cereus
• outbreak investigation
• central line associated bloodstream infection
• dialysis
• hospital acquired infection