New Rapid Ebola Test Shows Promise in African Clinics

Researchers say speedy detection would dramatically improve containment efforts

By Mary Elizabeth Dallas

Friday, June 26, 2015

FRIDAY, June 26, 2015 (HealthDay News) -- A new rapid-detection test that diagnoses Ebola within minutes could improve treatment of the deadly virus and help health care workers contain outbreaks, researchers say.

Harvard Medical School researchers found the rapid diagnostic test as sensitive as traditional lab tests that can take days to produce results. The findings suggest this diagnostic tool could be a potential game-changer in the fight against Ebola, the researchers said.

In the West African countries hardest hit by Ebola -- Guinea, Liberia and Sierra Leone -- more than 11,000 people have died from the virus since late 2013. Although experts say the worst is over, some new cases continue to surface.

In order to contain Ebola, it's critical for doctors to quickly differentiate between patients who are infected with the virus and patients with other illnesses that cause similar symptoms. Conventional lab tests require drawing blood and disposing unsafe needles and syringes. The blood must be transported to a lab, potentially exposing more people to the Ebola virus along the way. Results of these tests may not available for several days.

While patients await these tests results, they are confined to "holding" areas. This means people who don't actually have Ebola may be exposed to it, the researchers pointed out.

"Simplifying the process and speeding up diagnosis could have a major impact," study senior author Nira Pollock, associate medical director of the Infectious Diseases Diagnostic Laboratory at Boston Children's Hospital, said in a Harvard news release.

For the study, she and her colleagues put a promising rapid-detection test developed by Colorado-based Corgenix to use during the outbreak in Sierra Leone.

Local health workers were trained to perform the test, known as ReEBOV Antigen Rapid Test. At two treatment centers in Sierra Leone, 106 people suspected of having Ebola underwent both rapid-detection and conventional testing in February.

With the rapid-detection method, a finger-prick blood sample is applied to a treated strip. If the sample is positive for Ebola, a colored line appears on the strip.

The safety lancet has a spring-loaded mechanism that prevents health care workers from accidentally sticking themselves, according to the news release.

The rapid-detection test accurately diagnosed all confirmed cases of Ebola, the study published June 25 in The Lancet found.

The rapid test also had a specificity of 92 percent, which means it resulted in few false-positive results.

Missed cases of Ebola involved patients with very low levels of the virus. The study authors noted these cases were only detected using an alternative lab test that is not widely available.

They concluded that more research is needed to determine how rapid diagnostic tests would work for patients in the very early stages of the illness.

SOURCE: Harvard Medical School, news release, June 25, 2015

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