Bayesian evaluation of sensitivity and specificity of blood culture media and hypoglycemia in sepsis-suspected calves

Mathilde Laetitia Pas; Filip Boyen; Donatienne Castelain; Laurens Chantillon; Dominique Paepe; Frederik Pille; Bart Pardon; Jade Bokma

doi:10.1111/jvim.17040

Bayesian evaluation of sensitivity and specificity of blood culture media and hypoglycemia in sepsis-suspected calves

J Vet Intern Med. 2024 Mar 25. doi: 10.1111/jvim.17040. Online ahead of print.

Authors

Mathilde Laetitia Pas¹, Filip Boyen², Donatienne Castelain¹, Laurens Chantillon¹, Dominique Paepe³, Frederik Pille⁴, Bart Pardon¹, Jade Bokma¹

Affiliations

¹ Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
² Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
³ Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
⁴ Department of Large Animal Surgery, Anaesthesia and Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.

PMID: 38526076
DOI: 10.1111/jvim.17040

Abstract

Background: Sepsis is a life-threatening condition for which critically important antimicrobials are often indicated. The value of blood culture for sepsis is indisputable, but appropriate guidelines on sampling and interpretation are currently lacking in cattle.

Objective: Compare the diagnostic accuracy of 2 blood culture media (pediatric plus [PP] and plus aerobic [PA]) and hypoglycemia for bacteremia detection. Estimate the contamination risk of blood cultures in critically ill calves.

Animals: One hundred twenty-six critically ill calves, 0 to 114 days.

Methods: Retrospective cross-sectional study in which the performance of PP, PA and hypoglycemia to diagnose sepsis was assessed using a Bayesian latent class model. A Cox proportional hazards model was used to compare time to positivity (TTP). Potential contamination was descriptively analyzed. Isolates were considered relevant when they were; member of the Enterobacterales, isolated from both blood cultures vials, or well-known, significant bovine pathogens.

Results: The sensitivities for PP, PA, and hypoglycemia were higher when excluding assumed contaminants; 68.7% (95% credibility interval = 30.5%-93.7%), 87.5% (47.0%-99.5%), and 61.3% (49.7%-72.4%), respectively. Specificity was estimated at 95.1% (82.2%-99.7%), 94.2% (80.7%-99.7%), and 72.4% (64.6%-79.6%), respectively. Out of 121 interpretable samples, 14.9% grew a presumed contaminant in PA, PP, or both. There was no significant difference in the TTP between PA and PP.

Conclusions and clinical importance: PA and PP appear to outperform hypoglycemia as diagnostic tests for sepsis. PA seems most sensitive, but a larger sample size is required to verify this. Accuracy increased greatly after excluding assumed contaminants. The type of culture did not influence TTP or the contamination rate.

Keywords: contamination; hemoculture; rational antimicrobial use; sepsis; volume.

Abstract

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