Nearly one in seven positive blood cultures at a major tertiary hospital in Mogadishu was flagged as contaminated, according to a six-year retrospective analysis of laboratory records published in BMC Infectious Diseases. The study, conducted at Recep Tayyip Erdoğan (Ex-Digfeer) Hospital, examined all blood culture records collected between January 2020 and December 2025 and offers one of the first detailed pictures of blood culture contamination in Somalia, where published data on the problem have been scarce.
The researchers analyzed 8,238 blood culture records, treating each laboratory record as the unit of analysis and taking contamination classifications directly from the hospital’s laboratory system. Microbial growth appeared in 2,645 cultures, or 32.11 percent, while 5,593 cultures, or 67.89 percent, showed no growth. Of the positive cultures, 2,263, or 85.56 percent, were classified as true positives, and 382, or 14.44 percent, were classified as contaminated. Expressed against all blood cultures drawn, the overall contamination rate was 4.64 percent.
Contamination was not evenly distributed across the hospital. The highest rate among all cultures was recorded in the hemodialysis department, at 12.89 percent (95 percent CI: 9.13–17.90), followed by the emergency, outpatient, and ancillary departments, each at 9.11 percent (95 percent CI: 6.90–11.94). The lowest rates appeared in critical care settings: 1.22 percent in general intensive care (95 percent CI: 0.66–2.23), 1.68 percent in adult emergency intensive care (95 percent CI: 1.09–2.58), and 1.83 percent in neonatal intensive care units (95 percent CI: 1.28–2.61). The authors suggest targeted interventions particularly in hemodialysis, emergency, and pediatric departments.
The departmental differences held up statistically. A Monte Carlo exact test, used to handle sparse groups, showed significant variation across departments (p < 0.001), and the variation remained evident in an exploratory logistic regression adjusted for year, age group, and sex (global p < 0.001). The authors emphasized that these inferential results are exploratory because repeated patient records could not be linked, meaning the analysis could not account for multiple cultures from the same patient over time.
Throughout the study period, coagulase-negative staphylococci were the predominant contaminants.
The clinical stakes of contamination are considerable. False-positive blood cultures can lead to unnecessary antimicrobial use, additional laboratory work, increased healthcare costs, and prolonged hospitalization, as the study’s background notes.
The study’s design has limitations worth keeping in view. It was retrospective and laboratory-based, relying on contamination classifications already recorded in the laboratory system rather than on independent re-adjudication. Because patient records could not be linked, the regression findings are exploratory rather than definitive, and the observational design cannot establish why contamination rates differ so sharply between departments.
Even so, the marked departmental variation points to practical opportunities. The authors suggest targeted interventions in hemodialysis, emergency, and pediatric departments, alongside strengthened blood culture collection practices, staff training, and quality monitoring programs. Such measures, they argue, may help reduce contamination and improve diagnostic accuracy in a setting where reliable blood culture results are critical for guiding antimicrobial therapy.
As one of the few multi-year assessments of blood culture quality from Somalia, the analysis provides a baseline against which future improvements can be measured, and it highlights how routine laboratory data, even with methodological constraints, can reveal actionable patterns in patient safety.
Subject of Research: Blood culture contamination rates and microbial patterns in a Somali tertiary hospital
Article Title: Blood culture contamination and microbial patterns in a tertiary hospital: a six-year retrospective analysis, 2020–2025
Article References: Mohamud, R. Y. H., Orhan, Z., Mohamed, N. A., Osman, A. M., Hassan, M. Y., Doğan, S., Mohamud, S. M., Yusuf, Z. A., Mohamed, M. M., Hussein, S. A., & Omar, M. A. (2026). Blood culture contamination and microbial patterns in a tertiary hospital: a six-year retrospective analysis, 2020–2025. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14747-9
Image Credits: AI Generated
DOI: 10.1186/s12879-026-14747-9
Keywords: blood culture, contamination, Somalia, tertiary hospital, coagulase-negative staphylococci, clinical microbiology, hemodialysis, patient safety, antimicrobial use, retrospective study, Blood, culture
News Source: Ophelia Keating. (October 30, 2026). Blood Culture Contamination Hits 4.6 Percent in Six-Year Mogadishu Hospital Review. Scienmag.
