Portable System Uses Light to Diagnose Bacterial Infections Faster

PAD system

Caption: PAD system. Left, four optical testing cubes (blue and white) stacked on the electronic base station (white with initials); right, a smartphone with a special app to receive test results transmitted by the electronic base station.
Credit: Park et al. Sci. Adv. 2016

Every year, hundreds of thousands of Americans acquire potentially life-threatening bacterial infections while in the hospital, nursing home, or other health-care settings [1]. Such infections can be caused by a variety of bacteria, which may respond quite differently to different antibiotics. To match a patient with the most appropriate antibiotic therapy, it’s crucial to determine as quickly as possible what type of bacteria is causing his or her infection. In an effort to improve that process, an NIH-funded team is working to develop a point-of-care system and smartphone app aimed at diagnosing bacterial infections in a faster, more cost-effective manner.

The portable new system, described recently in the journal Science Advances, uses a novel light-based method for detecting telltale genetic sequences from bacteria in bodily fluids, such as blood, urine, or drainage from a skin abscess. Testing takes place within small, optical cubes that, when placed on an electronic base station, deliver test results within a couple of hours via a simple readout sent directly to a smartphone [2]. When the system was tested on clinical samples from a small number of hospitalized patients, researchers found that not only did it diagnose bacterial infections about as accurately and more swiftly than current methods, but it was also cheaper. This new system can potentially also be used to test for the presence of antibiotic-resistant bacteria and contamination of medical devices.

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Shining Light on Ebola Virus for Faster Diagnosis

Optofluidic analysis system

Caption: A rapid Ebola detection system consisting of a microfluidic chip (left) and an optofluidic chip (right), connected by a curved tube (center).
Credit: Joshua Parks, University of California, Santa Cruz

Many lessons were learned during last year’s devastating outbreak of Ebola virus disease in West Africa. A big one is that field clinics operating in remote settings desperately need a simple, rapid, and accurate test that can tell doctors on the spot—with just a drop of blood—whether or not a person has an active Ebola infection.

A number of point-of-care tests are under development, and it’s exciting to see them moving in the right direction to fill this critical need [1]. As a recent example, a paper published in Nature Scientific Reports by a team of NIH-supported researchers and colleagues shows early success in rapid Ebola detection with an automated lab on a chip [2]. The hybrid system, which combines microfluidics for sample preparation with optofluidics for viral detection, identifies Ebola at concentrations that are typically seen in the bloodstream of an infected person. It also distinguishes between Ebola and the related Marburg and Sudan viruses, suggesting it could be used to detect other infectious diseases.

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Enlisting mHealth in the Fight Against River Blindness

CellScope Loa

When it comes to devising new ways to provide state-of-the art medical care to people living in remote areas of the world, smartphones truly are helping scientists get smarter. For example, an NIH-supported team working in Central Africa recently turned an iPhone into a low-cost video microscope capable of quickly testing to see if people infected with a parasitic worm called Loa loa can safely receive a drug intended to protect them from a different, potentially blinding parasitic disease.

As shown in the video above, the iPhone’s camera scans a drop of a person’s blood for the movement of L. loa worms. Customized software then processes the motion to count the worms (see the dark circles) in the blood sample and arrive at an estimate of the body’s total worm load. The higher the worm load, the greater the risk of developing serious side effects from a drug treatment for river blindness, also known as onchocerciasis.

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New Strategies in Battle Against Antibiotic Resistance

Klebsiella pneumoniae Bacteria

Caption: Colorized scanning-electron micrograph showing carbapenem-resistant Klebsiella pneumoniae interacting with a human white blood cell.
Credit: National Institute of Allergy and Infectious Diseases, NIH

Over the past year, the problem of antibiotic resistance has received considerable attention, with concerns being raised by scientists, clinicians, public health officials, and many others around the globe. These bacteria are found not only in hospitals, but in a wide range of community settings. In the United States alone, antibiotic-resistant bacteria cause roughly 2 million infections per year, and 23,000 deaths [1].

In light of such daunting statistics, the need for action at the highest levels is clear, as is demonstrated by an Executive Order issued today by the President. Fighting antibiotic resistance is both a public health and national security priority. The White House has joined together with leaders from government, academia, and public health to create a multi-pronged approach to combat antibiotic resistance. Two high-level reports released today—the White House’s National Strategy for Combating Antibiotic-Resistant Bacteria (CARB) and the complementary President’s Council of Advisors on Science and Technology (PCAST) Report to the President on Combating Antibiotic Resistance—outline a series of bold steps aimed at addressing this growing public health threat.

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