Bringing Ebola tests up to speed
DAKAR, 20 November 2014 (IRIN) - Ebola in West Africa is believed to have erupted almost a year ago in southern Guinea, but was confirmed by the French Pasteur Institute only in March 2014, by which time it had killed 60 people and was suspected to have crossed the border into Liberia and Sierra Leone.
While it now takes just a few hours to diagnose Ebola, the rate and scale of the outbreak (in which more than 14,000 cases have been reported so far in West Africa, Europe and the US) still outpace the hours-long tests, necessitating even quicker diagnoses.
Currently in West Africa, samples have to be transported to a laboratory where the commonly used test takes 4-6 hours between set-up and results. Poor roads, and lack of electricity and properly functioning health systems are some of the obstacles to timely diagnoses.
"Getting specimens to the lab can take days and getting the result to clinicians and patients can also take several days. So the time between taking samples and receiving the result can be as long as four days," Margaret Harris, a spokesperson with the World Health Organization (WHO), told IRIN.
WHO on 18 November called for rapid diagnostic kits to overcome the complex and lengthy lab tests. Safe and easy-to-use kits would help quickly isolate Ebola patients from others who present with similar early symptoms but have other ailments.
Last month, the agency invited submissions from researchers and firms working on Ebola diagnostics and is now assessing the first five of the 16 project documents received. Key specifications for an ideal kit, WHO says, include the ability to be used in a remote clinic with no laboratory; having test procedures of less than three steps; able to give results in less than 30 minutes; and needing no other biosafety requirements beyond wearing personal protective gear.
Working on it
One of the devices under development is "EbolaCheck", an A4-size battery-powered portable kit able to give results as accurate as lab tests. The kit, being developed by the Westminster Genomic Services Unit at the University of Westminster, can take eight samples at a time and produce results in 40 minutes or less, if there is a high concentration of Ebola virus in the specimen.
A total of 10 devices will be manufactured and the first three will be deployed in the field by May 2015, said Sterghios Moschos, director of the Westminster Genomic Services unit. A lab version of EbolaCheck that can test 96 samples at a time is also being developed.
The portable devices require just a droplet of blood, not a tube-full, as is currently the case for lab tests. It has a simple traffic-light system where a red glow means Ebola-positive and green the contrary. A retractable finger-prick needle is used to ensure safety.
Moschos told IRIN the objective is to "get a diagnostic kit that is cheap enough, fast enough and safe enough to work in West Africa and give an answer to the people as soon as possible when they present symptoms…
"The mortality rate of the disease is such that many people have died by the time the results are available."
The 12-month University of Westminster project also aims to develop diagnostic devices able to detect the Ebola virus in saliva and urine. "We need to establish criteria, because they don't exist yet, of what level of virus in saliva or urine gives a true positive of the disease versus blood, because at the end of the day it's much easier and much safer to collect urine or saliva than it is to collect blood," Moschos explained.
Handling the Ebola virus is an extremely hazardous operation and requires the taking of strict precautions. Medical personnel are among the most at risk of exposure to the virus if proper safety procedures are not adhered to. Currently there are no rapid diagnosis devices being used in the field in West Africa.
"The safety question is a big one because these [kits] will be testing potentially highly infectious fluids and will need to be used only by people with full personal protection and expert in infection prevention and control. So no matter how good and quick they are, that's a big limitation," stressed Harris of WHO.
Several rapid detection kits are being developed by various manufacturers. According to WHO, they are technically readily achievable, should be cheaper than the current diagnosis devices and face no "significant technical hurdles".
Asked whether the development of the devices is coming too late after more than 5,000 Ebola deaths, Moschos said: "I don't think that a good field-deployable, economical and reliable system is going to come any time late in the day. This is not the first outbreak of Ebola, but it certainly is the first to last this long…
"If you look at what happened this time around, the outbreak started in December  and it took until March to confirm it."
Theme (s): Ebola Crisis, Health & Nutrition,
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