A new molecular test called 'Prove-it' had accurate and rapid detection of most common causes of sepsis, researchers found.

The test, which detects more than 50 species of bacteria, had a sensitivity of 94.7 per cent and a specificity of 98.8 per cent, Vanya Gant, PhD, of University College London Hospital, and colleagues reported online in The Lancet. Calling the study a major progress, they said further study was needed before application of the test.

The test would allow improved clinical outcomes. Currently, blood culture is the gold standard for identification of bacteria from patients with sepsis. It takes one to three days to become positive. An additional day or two might be required for identification of bacteria and their antibiotic sensitivity patterns. In order to cut this extra time, new diagnostic tests that can identify bacterial species rapidly and accurately are needed.

A total of 3,318 blood samples were collected in an observational study, with 2,107 positive blood-cultures. The 'Prove-it' sepsis assay had a clinical sensitivity of 95 percent and the specificity was of 99 percent. The assay was 18 hours faster than the conventional method.

In an associated note, Dr Shin Lin, Stanford University School of Medicine, Stanford, CA, USA, and Dr Samuel Yang, Department of Emergency Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA inquire: "Will resolving these scenarios 18 hours earlier than usual translate into demonstrable clinical benefit commensurate to the cost of undertaking the additional test?"

Some shortcomings of the assay were that use of this method for bacterial identification from blood was restricted to research applications, owing to the cost, using different technology, difficulties with variable DNA extraction efficiency, potential contamination by amplified PCR products, and performance. Cost-effectiveness will be assessed in a future study.