Polymer Innovation Helps Fight HAIs

A hospital is probably the least likely place you’d get some kind of infection, right? And if you do get an infection, wouldn’t you think there’s no better place to catch it than a hospital, where you should be able to get a speedy diagnosis and cure? Actually, as nearly any medical professional will tell you, hospitals are one of the places you’re most likely to develop an infection, and getting it diagnosed, treated and cured can prove difficult.

The high toll of HAIs

Hospital-acquireshutterstock_104336624d/health-care associated infections (HAIs) affect hundreds of millions of patients worldwide every year, according to the World Health Organization. In fact, seven out of every 100 hospital patients in developed countries and 10 out of every 100 in developing countries will acquire at least one HAI, the WHO says. In the U.S., about 75,000 hospital patients with HAIs died during 2011, according to the most recent data available from the Centers for Disease Control and Prevention.

Health-care settings are germ stewpots, making your risk of acquiring an infection while hospitalized higher than it might be if you weren’t in hospital. What’s more, because of the sheer range of infectious agents you might be exposed to while in the hospital, diagnosing the exact pathogen causing your infection can be difficult — especially if your doctor has to send your samples to a lab for analysis.

Traditional testing methods involve the need to take specimen cultures from the patient and submit them to a lab that has specialized testing equipment and personnel trained in testing for a particular pathogen. The process can take days to yield results on which a doctor can base a diagnosis. Genetic testing that IDs bacteria by mapping their nucleic acid sequences is just as complex and time-consuming.

It seems like the world could use a better, faster way to identify the pathogens responsible for HAIs.

Faster analysis through polymer science

A team of investigators at Massachusetts General Hospital (MGH) apparently agree.

“Health-care-associated infections are a major problem that affects more than 600,000 patients each year, more than 10 percent of whom will die, and incurs more $100 billion in related costs,” Dr. Ralph Weissleder, Ph.D., director of the MGH Center for Systems Biology, said in a news release announcing the team’s development of an alternative polymer science-based testing method. “Rapid and efficient diagnosis of the pathogen is a critical first step in choosing the appropriate antibiotic regimen, and this system could provide that information in a physician’s office in less than two hours.”

The MGH researchers call their brainchild PAD (Polarization Anisotropy Diagnostics). The device extracts bacterial RNA from a sample in a small, disposable plastic cartridge. The RNA is subjected to polymerase chain reaction amplification, then loaded into a 2-centimeter plastic cube where optical components detect target RNAs based on the sample’s “response to a light signal of sequence-specific detection probes,” MGH says. The optical cube is then placed on an electronic base station that transmits data developed from the analysis to a smartphone or computer, where health-care professionals can review the information.

Researchers tested the accuracy and efficacy of the prototype by using the PAD system to test samples from nine patients. They also tested samples through conventional microbiology cultures and then compared results from the two methods. The results were identical. The difference? Time and cost.

The PAD system churned out results in less than two hours, while the traditional testing method took three to five days. What’s more, researchers anticipate the cost of PAD testing should not exceed $2. Anyone who’s ever had a blood test and received an explanation of benefits from an insurance company is well aware traditional testing methods are far costlier.