Profile of Bacteria Isolated from Patients and Surfaces in the Hemodialysis Unit of Douala General Hospital: An Analysis of 411 Samples

Abstract

Background : Hemodialysis units are particularly exposed to nosocomial infections: bacteria originating from patients, healthcare workers, or surfaces can be transmitted from one station to another, leading to severe bloodstream infections. The objective of our study was to identify the bacteria isolated from samples collected from patients and surfaces in the hemodialysis unit of Douala General Hospital. Methods : We conducted a descriptive cross-sectional study within the unit, during which 411 samples were collected from patients and service surfaces. The microorganisms were identified using classical bacteriological methods (direct examination, culture) and the VITEK automated system (bioMérieux). Data were analyzed using R software. Results : Of the 411 samples analyzed, 257 were collected from surfaces within the unit, with 98.8% testing positive, while 154 of the 163 patient samples revealed bacterial growth. Door handles were the main sampling sites (34%), followed by tables, bed feet, and headboards. Overall, 577 bacterial isolates were identified: surfaces were heavily contaminated (470 isolates), dominated by Burkholderia cepacia (64.8% overall, including 50.8% of surface isolates) and environmental Gram-positive cocci such as Staphylococcus cohnii and S. xylosus . Among patient samples, fermentative Gram-negative bacilli ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis ) predominated in urine and blood cultures, while Pseudomonas aeruginosa and Acinetobacter baumannii remained major pathogens in bloodstream infections. Staphylococcus aureus was isolated from both patients and surfaces. Conclusion: Our results highlight a high level of surface contamination and a wide diversity of pathogens among patients in the hemodialysis unit of Douala General Hospital.