Nucleic acid amplification / Nanosphere Verigene:
This testing process takes between 1 to 2 hours. It is multiplex technology, which means that you can know an organism ID and select resistance genes at the same time. You can also “escalate or de-escalate therapy for Staphylococcus.” Drawbacks? It’s an add-on product, so it doesn’t replace any current technology being used for organism ID or susceptibility. Dr. Nagel added that, with this product, there is also “diminished sensitivity and specificity directly from specimens.”
Accelerate is “one of the newer technologies that’s coming out, which is pretty novel, kind of outside-the-box thinking.” It’s also the only product to offer “rapid organism ID, [minimal inhibitory concentration] MICs, and sensitivities” which tracks the growing curve, division rate, time/effect curve, and gages expected patterns. “If we’re talking S. aureus
, you would know the organism ID in 20 minutes and then the MIC and susceptibilities about 7 hours later.” However, it’s not capable of handling a large number of samples, because there are not too many antibiotics on panel. Therefore, compared with other technologies, it’s slower in detecting methicillin-resistance.
“[With these tools], you’re going to get data quicker, [there’s] improved time to optimal therapy, [you’re] reducing length of stay, [and] reducing mortality. But, I think one of the things that we’re facing now is [the question of] how [to] manage the patient as a whole, and how [to] incorporate rapid diagnostics into that scenario,” Dr. Nagel said.
Even with early targeted therapy brought on by early detection, morbidity and mortality “remains significant.” Therefore, improvements need to be made in other areas, such as: surgical management, antibiotic regimens, medical management, and identification of complicated bacteremia, among others.
Dr. Nagel stressed that patient care should be in compliance with performance measures that are listed in the Infectious Diseases Society of America (IDSA) guidelines. At his facility, Dr. Nagel and his team have come up with a collaborative approach to improving outcomes for those with S. aureus
bacteremia. For example, for one part of their approach they “have a process where if we have [gram-positive Cocci] GPC in clusters, we have a pharmacist receive a real-time alert 24/7, and so, if patients aren’t on the right therapy we can get them on the right therapy.” They also provide ID consultations to all of [their] patients. “I think the data is overwhelmingly positive for patients having good outcomes from ID consultations,” he added. They also ensure that other measures are being met, for example, is the patient receiving therapy for the right duration? The researchers even created cards to give out to ID fellows that provided guidance on treatment duration and how to handle somewhat controversial issues. The results? Compliance to guidelines significantly improved—going from 56% up to 84%.
“Rapid diagnostics can dramatically improve time to organism identification and detection of some resistance genes. Developing a process to facilitate timely antibiotic changes following rapid diagnostics is essential, and then developing a comprehensive approach can optimize [patient] outcomes,” Dr. Nagel concluded.
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