Bacterial-associated bloodstream infections among hospitalized patients in Lagos, Nigeria

Bacterial-associated bloodstream infections (BSIs) pose a significant health challenge, particularly in low- and middle-income countries where diagnostic delays and antimicrobial resistance exacerbate outcomes. This study investigated the prevalence, clinical correlates, bacterial aetiology, and resistance profiles of BSIs among hospitalised febrile patients in Lagos, Nigeria.

A total of 2,940 blood samples were collected from febrile inpatients across five healthcare centres between 2018 and 2023. Standard microbiological techniques and mass spectrometry were employed for bacterial identification. Antimicrobial susceptibility testing was performed following CLSI guidelines. Statistical analyses included chi-square tests, regression modelling, and correlation analysis.

Of the 2,940 samples, 307 (10.44%) were culture-positive, with gram-negative bacteria accounting for 91.8% of isolates. Proteus spp., Escherichia coli, and Klebsiella spp. were the most prevalent pathogens. Septicaemia, bradycardia, and extreme age groups (0-10, ≥ 41 years) were significantly associated with BSIs (p < 0.0001). Multidrug resistance was highest in P. vulgaris (32.7%) and E. coli (27.9%). A strong correlation (R = 0.76) was observed between clinical diagnosis and culture positivity.

The findings reveal a high burden of gram-negative bloodstream infections predominantly caused by Proteus spp., E. coli, and Klebsiella spp., with significant multidrug resistance, particularly in P. vulgaris and E. coli, and strong associations with septicaemia, bradycardia, extreme age groups, and clinical diagnoses.