Bacterial Infections
Conditions
Keywords
blood culture, diagnostics
Brief summary
Diagnosis of bloodstream infections (BSI) is done by sampling blood in blood culture bottles that are checked for growth in the microbiology laboratory. In LRS, microbiology laboratories are however scarce, and BSI cannot be diagnosed, resulting in overuse of antibiotics which fuels AMR. For diagnosis of BSI, so-called manual blood culture (equipment-free) systems are used in LRS, with daily visual inspection for growth. Compared to automates, manual systems are less sensitive, and growth is slower; in addition, training and experience are needed before laboratory staff is competent to detect growth when inspecting the blood culture bottles. A simplified blood culture system could enable expanded use of blood cultures in LRS and would thus improve BSI treatment. Ongoing research at the Institute of Tropical Medicine, in collaboration with Ghent University has resulted in a novel, simple, cheap, open-access and robust blood culture system, the Bactinsight blood culture system. This system consists of two modules. Firstly, a portable, battery-operated measurement device (turbidimeter), which monitors and detects bacterial growth in blood culture bottles based on the turbidity of the culture medium caused by bacterial growth. Secondly, optimized blood culture bottles have been developed. A second step in blood cultures is the identification of the causing organism. Researchers at LETI (Grenoble, France) have developed a lensfree microscope, which simplifies and expedites identification of the causative organisms, improving patient's diagnosis and more directed antibiotic treatment. The lensfree microscope is an additional module for the Bactinsight blood culture system. In SIMBLE, the Bactinsight blood culture system will be evaluated against reference systems in two phases. During the optimization phase in Belgium, the performance of Bactinsight turbidimeter + lensfree microscope will be tested in a reference hospital laboratory. In parallel, an in vitro laboratory evaluation of the Bactinsight blood culture system (turbidimeter + blood culture bottles + lensfree microscope) will be done using spiked blood cultures. In the field-testing phase, the ease-of-use, acceptability, adoptability and performance of Bactinsight blood culture system will be evaluated in three hospitals in Benin and Burkina Faso. The blood culture bottles used for this study will be manufactured in a production facility in Benin, that will be installed at the start of the project.
Interventions
DIAGNOSTIC_TESTBactInsight blood culture system
A battery-operated measurement device (turbidimeter), which monitors and detects bacterial growth in blood culture bottles based on the turbidity of the culture medium caused by bacterial growth, in combination with optimized blood culture bottles.
Sponsors
Reactivos para Diagnóstico, S.L.
University Ghent
Université Libre de Bruxelles
Commissariat A L'energie Atomique
Centre Hospitalier Universitaire Yalgado Ouédraogo
Centre National Hospitalier et Universitaire de Pneumo-Phtisiologie de Cotonou
European and Developing Countries Clinical Trials Partnership (EDCTP)
Institute of Tropical Medicine, Belgium
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
15 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* With indications for blood culture sampling and for whom collection of a blood culture sample is part of standard clinical practice * Willing and able to provide written informed consent (assent for minors)
Exclusion criteria
* none
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time-to-actionable result | Within 8 days | The paired Wilcoxon signed rank test will be used to compare the location of the distribution of time-to-actionable result measurements between the two groups for those with a positive blood culture result. * BactInsight versus manual system: Time-to-actionable result is compared between both groups with the Wilcoxon signed rank test at the 5% significance level. * BactInsight versus automated system: The non-inferiority margin equals 12 hours. Non-inferiority is shown if the upper limit of the two-sided 95% confidence interval for the median of the differences from the Wilcoxon signed rank test is lower than 12h i.e. 12 is excluded from the non-parametric confidence interval. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Time-to-detection | Within 8 days | The paired Wilcoxon signed rank test will be used to compare the location of the distribution of time-to-detection measurements between the two groups for those with a positive blood culture result. |
| Yield | 2 years | The McNemar's test will be used to compare the yield between the BactInsight system and the manual reference system at the 5% significance level in order to detect if there is a statistically significant difference between the paired binary data in terms of proportions. o The difference in yield between the BactInsight system and the automated system will be compared to a non-inferiority margin of 15%. Non-inferiority is shown if the lower limit of the two-sided 95% confidence interval is larger than -0.15 i.e. if -0.15 is excluded from the confidence interval. A non-inferiority margin of 15% was chosen as reasonable based on clinical and practical arguments. |
| Diagnostic performance | 2 years | Sensitivity and specificity will be calculated for the BactInsight system compared to the composite reference standard, based on the combined result from the components tests i.e. the BactInsight and reference system in use. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Yield - Antibiotic use | 2 years | Test whether yield differs in case of antibiotic use (yes/no) within 48 hours prior to blood culture sampling: Pearson Chi-square test (or Fisher exact test in case of small sample size). |
| Yield - V blood sampled | 2 years | Test whether yield differs with different volumes of blood sampled (e.g. 5-8 ml; 8-10 ml; 10-15 ml): Pearson Chi-square test (or Fisher exact test in case of small sample size). |
Countries
Benin
Outcome results
None listed