Rwanda: WHO says slow, complex diagnostic tests challenge efforts to contain Ebola

Kigali, Rwanda (PANA) -  Efforts to contain the Ebola outbreaks in West Africa are currently hampered by cumbersome, slow and complex diagnostic tests that impose a number of additional logistical challenges, including requirements for a high level of laboratory bio-safety and staff expertise in using sophisticated machines, according to the World Health Organization (WHO)'s situation assessment released Tuesday in Geneva, Switzerland.

"The goal of interrupting chains of Ebola virus transmission depends heavily on laboratory support. This support is needed to confirm or discard suspected cases, guide triage and clinical decisions, aid contact tracing, and facilitate the early detection of cases in people with an exposure history," the UN agency said Tuesday, noting that its own goal of aggressive case detection and isolation likewise depends on laboratory support.

The standard molecular assays currently used in mobile and other laboratories supporting the Ebola response include the reverse-transcriptase polymerase chain reaction, or RT-PCR test.

According to WHO, the test, which involves a number of laborious procedures, provides very accurate results when performed by trained staff.

Each test requires a full tube of blood, takes from 2 to 6 hours, and costs around $100. These requirements are difficult to meet in resource-constrained West African settings, thus severely limiting testing capacity.

Further in its situation assessment, WHO noted that the time lost transporting patient samples over bad roads to West Africa’s limited number of laboratories means that anxious patients and their families may need to wait several days for test results.

"Lost time means that infected people may remain in the community, with a severe risk of unknowingly transmitting the virus to others.

"Moreover, in the absence of rapid laboratory support, people with other common infectious diseases, such as malaria and dengue, that have similar early symptoms may be unjustifiably held in an Ebola 'transit' centre as a precautionary measure. If they did not have Ebola when entering the centre, they may unfortunately get it there.

"Apart from posing a severe risk to families and communities, undiagnosed and unmanaged patients contribute to the cyclical transmission pattern currently being seen, whereby cases begin to fall as control measures take effect, only to spike again as new chains of transmission are ignited," the UN agency said.

Perhaps most importantly, a recent research study, based on the management of more than 700 Ebola patients in Monrovia, Liberia, strongly suggested that clinical decisions guided by results from rapid point-of-care diagnostic tests could significantly improve treatment outcomes.
-0- PANA TWA/AR 18Nov2014

18 november 2014 17:56:50

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