Researchers Race for Rapid Field Tests to Isolate Ebola Patients

Aug 18, 2014 5:15 am ET

(For more news on the Ebola outbreak see EXT7 <GO>.)

Aug. 16 (Bloomberg) -- It took three days recently for a New York City hospital to determine that a patient with Ebola- like symptoms didn’t have the deadly virus.

Now, as the disease rages in West Africa, researchers are closing in on the development of new devices that will allow medical workers to get results in hours or minutes, taking the determination out of the laboratory and into the field.

The laptop-sized devices include tiny silicon microchips imprinted with antibodies that bind with the Ebola virus, making it immediately identifiable. With current technology, blood from suspected Ebola victims must undergo complex genetic testing at a laboratory to confirm the diagnosis.

“We now have the basic architecture” to build the devices to test, said John Connor, a Boston University microbiologist working with one of several federal grants aimed at improving Ebola testing. “We’re working as fast as we can to make it a reality.”

Conner said he hopes to start testing on humans by 2016.

Such a device could be particularly useful in Africa at a time when travel is difficult and laboratory time is extremely limited, potentially helping doctors more quickly isolate just the patients with Ebola, as opposed to anyone with treatable diseases that have similar initial symptoms, including malaria, Lassa fever and even the flu.

Similar Symptoms

“Most of these viral diseases have the same symptoms,” said Doug Simpson, chief executive officer of Corgenix Medical Corp., which in June was awarded a $2.9 million, three-year grant to develop a faster, cheaper Ebola test. “Waiting until they show up and they’ve been bleeding for days and they’ve infected all their family is what’s leading to the epidemic.”

The Ebola outbreak centered in the West African countries of Liberia, Guinea and Sierra Leone has killed 1,145 of 2,127 stricken with the disease as of Aug. 13, according to the World Health Organization. Of those, 712 deaths and 1,310 cases have been confirmed with laboratory results.

In the U.S., blood samples from suspected cases are sent to the Centers for Disease Control and Prevention, where testing can take 24 hours to 48 hours. The Atlanta-based CDC said last week that about six suspected cases have been tested and subsequently ruled out.

The New York case involved Mount Sinai Hospital, which kept a patient in isolation for three days awaiting test results from a CDC laboratory. The man, who traveled in West Africa before arriving in New York, showed up at the Mount Sinai emergency room with a high fever and stomach pain, the hospital said. Ebola was ruled out on Aug. 6.

Slow Process

In Africa, patients generally are first diagnosed based on symptoms, then confirmed by a lab. The process is too slow to effectively control the outbreak because patients become more and more contagious as their symptoms worsen and the virus is spread through bodily fluids, often to family members caring for the sick.

Current methods for testing “are not easy to take to the point of need,” Boston University’s Connor said.

Connor is developing a small, portable Ebola test that could be deployed to field hospitals and doctors visiting patients. The test uses a silicon chip, 1-centimeter square, that has been imprinted with antibodies that bind with the Ebola virus. A sensor identifies when the virus is present.

The device could eventually be reduced to the size of a DVD player, he said in a telephone interview.

Multiple Pathogens

Researchers are also working on diagnostics to test for multiple pathogens at once, focused on those rated as posing the highest risk to public health by the National Institute of Allergy and Infectious Diseases.

“The goal is to develop on-chip technology to detect these diseases quickly and specifically,” said Holger Schmidt, director of the W.M. Keck Center for Nanoscale Optofluidics, at the University of California at Santa Cruz. “So within a couple of minutes you should be able to distinguish between Ebola, Marburg and Lassa fever.”

While many of the approaches are promising, none of the research is yet “ready for prime-time,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

“It would be very helpful and prevent some spread from the health-care workers if we had a point-of-care diagnostic,” Fauci said in a telephone interview.

‘In Your Lap’

While people could be isolated more quickly, it would not be as useful in situations where someone very sick, vomiting and bleeding, arrives at a hospital, he said, because the first instinct of the health-care workers would be to take care of the person, and not necessarily to isolate them.

“It’s too late, they already landed in your lap,” Fauci said.

The U.S. has the resources to isolate potential patients as they appear. That’s not the case in Africa, where clinics may be dealing with dozens of ill people at once. Malaria, influenza and Lassa fever are all common in some countries, said Ian Lipkin, an epidemiologist at the Columbia University Mailman School of Public Health.

“We need to be able to triage people, we can’t afford to put everyone in containment,” Lipkin said by phone. “It’s just not feasible.”

While the test from Broomfield, Colorado-based Corgenix may not help in the current outbreak, it could be available for the next one, Simpson, the CEO, said. The diagnostic would function like a home pregnancy test, with a rapid initial result confirmed with more certainty later in a lab.

Village Screening

“The health-care worker can go into the village and screen them for the virus,” Simpson said. “You need the laboratory setting for the ultimate diagnosis.”

Another company, closely held Lucigen Corp. of Middleton, Wisconsin, may seek emergency approval for its diagnostic in which a sample can be placed in a test tube, heated, then transferred onto a test strip or other device to confirm the infection’s presence. “This is much faster than the other molecular diagnostics,” said Yogesh Chander, the lead researcher on the project.

The company has a $1.7 million grant from the National Institute of Allergy and Infectious Diseases. It’s gathering data to support a possible emergency authorization use, said Hemanth Shenoi, the company’s director of business development.

“We believe this outbreak can be controlled,” Chander said.

--With assistance from Caroline Chen in New York.