<b> </b>Investigating an unusual rise in blood-borne coagulase-negative Staphylococci in a tertiary health facility, Southwest Nigeria

Introduction: The clinical significance of coagulase-negative staphylococci (CoNS) is becoming increasingly concerning in healthcare settings, with dire consequences such as mortality. We investigated an unusual increase in blood-borne CoNS among patients in a private tertiary health facility in Southwest Nigeria and described mitigation strategies. Methods: CoNS bacteraemia descriptive analysis was conducted among inpatients between April 2022 and June 2022. Blood cultures were processed with an automated system. Phenotypic and molecular analyses (using 16S rDNA) of CoNS were performed according to established guidelines. We implemented the multimodal infection prevention and control (IPC) approach recommended by the World Health Organisation. Results: Eighty-two blood cultures (non-duplicate samples) were requested during the period. Of these, 30 (36.5%) were culture-positive, and 10 were CoNS (10/30, 33.3%).The cumulative incidence of CoNS bacteraemia was 12 cases per 100 patients over 90 days, compared to 1-2% in previous months. Staphylococcus haemolyticus (4/10, 40%), Staphylococcus hominis (3/10, 30%), Staphylococcus epidermidis (2/10, 20%), and Staphylococcus saccharolyticus (1/10, 10%) were identified. All isolates were resistant to ciprofloxacin, trimethoprim-sulfamethoxazole, and cefoxitin (methicillin-resistant surrogate marker), while they were susceptible to vancomycin and linezolid. All the isolates fell into the S. epidermidis and S. haemolyticus clusters in phylogenetic studies. The rates returned to baseline following the implementation of the IPC strategies. Conclusion: The unusual surge in CoNS incidence at the hospital resulted from multidrug-resistant clusters of S. haemolyticus and S. epidermidis, which were addressed by the implementation of multimodal IPC strategies.