A study has demonstrated the use of AdvanDX's PNA Fish test to reduce mortality by 42 per cent for patients with drug resistant hospital-acquired enterococcus faecium bloodstream infections (BSIs).
In addition, the study demonstrated that PNA Fish reduced the time to reporting of laboratory identification results for all enterococcal BSIs by 2.6 days and reduced time to appropriate antimicrobial therapy for E.faecium BSIs by 1.8 days.
The study was undertaken by clinicians at the University of Maryland Medical Center (UMMC) in Baltimore and published in the latest issue of Antimicrobial Agents and Chemotherapy.
Bloodstream infections due to enterococcus bacteria, predominantly enterococcus faecalis and E.faecium, are often acquired while patients are in the hospital and can lead to increased mortality, longer hospital stays and increased healthcare costs.
The infection is initially diagnosed when a culture of the patient's blood turns positive with Gram-positive cocci in pairs and chains (GPCPC), indicative of enterococci and/or streptococci.
As conventional laboratory identification methods can take 48 hours or longer and early antimicrobial therapy is crucial to ensure positive patient outcomes, physicians often prescribe broad-spectrum antibiotics such as vancomycin to cover the patient.
However, this may lead to the administration of inadequate or inappropriate antibiotic treatment as E.faecium is often resistant to both vancomycin (VRE - vancomycin-resistant enterococci) and penicillin-based drugs such as ampicillin, while E.faecalis is often susceptible to ampicillin.
PNA Fish delivers rapid, molecular identification of E.faecalis and other enterococci, including E.faecium, directly from GPCPC positive blood cultures in hours instead of days.
As a result, laboratories can provide faster information that enables clinicians to select effective antibiotic therapy sooner for patients afflicted with enterococcal bloodstream infections.
The study included 224 patients with hospital-acquired enterococcal bloodstream infections; 112 patients before the PNA Fish test was implemented (Pre-PNA Fish group) and 112 after implementation (PNA Fish group).
A treatment algorithm based on the rapid PNA Fish results was developed and implemented by the hospital's antimicrobial management team.
Patients with E.faecalis by PNA Fish were to be given ampicillin, while patients with other enterococci, including E.faecium, and at 'high risk' for VRE were to be given linezoid, a newer anti-VRE antibiotic.
At the end of the study, data on characteristics, therapy and outcomes between the Pre-PNA Fish and PNA Fish patients groups were compared.
More than 88 per cent of all E.faecium were resistant to vancomycin (VRE) and 100 per cent were resistant to ampicillin.
Initial empirical antimicrobial therapy for 84 per cent of patients with E.faecium BSIs was inadequate.
A 42 per cent reduction in 30-day mortality rates for patients with E.faecium occured in PNA Fish group.
PNA Fish sensitivity, specificity, positive predictive value and negative predictive value was shown to be 100 per cent compared to conventional methods.
'We are very excited to see the results from the University of Maryland Medical Center study,' said Dr Graeme Forrest, division of infectious diseases, University of Maryland Medical Center and lead author of the study.
'Not only do the results show that PNA Fish significantly speeds up species identification results from the lab, but also that using the results to tailor therapy at an earlier stage in bloodstream infections can significantly improve patient care and outcomes,' said Thais T Johansen, president and chief executive officer, AdvanDX.
'If we extrapolate the data to the rest of the country, PNA Fish could help ensure that all of the 18,000 patients with hospital-acquired enterococcal bloodstream infections receive effective antibiotic therapy as early as possible and help save close to 2,000 lives,' added Johansen.
