Protecting and testing—more to be learned from Ebola

As covered in The BMJ,1 problems with both supply chain and policy are hampering the response to the covid-19 pandemic. Unavailability of resources is partially understandable given the massive worldwide demand for personal protective equipment and testing materials. But against the background of our current “firefighting” mode, we seem to be ignoring past lessons in virus testing that could reduce risk to healthcare workers and increase the number of samples processed.

The NHS and other health organisations in major developed countries have followed the World Health Organization’s guidance on handling patient samples.234 These protocols transport the virus “live” in a cell preservation media that must be kept cool (2-8°C) and has a limited life due to degradation. NHS guidance requires these potentially infective samples to be handled as containment level 3 pathogens from the time they are sampled at the point of care through shipping to inactivation in the initial processing at analytical laboratories. This limits laboratory testing and increases risk to healthcare workers.

In past Ebola outbreaks (another RNA virus), methods were developed to enable samples taken at the point of care to be denatured by immersion of swabs in a chemical denaturant, which allowed subsequent processing by laboratories at containment level 2, a major reduction in risk in the analysis chain.5 This method, using high molarity guanidine thiocyanate solutions, was shown to effectively denature both Ebola (with 0.1% Triton detergent) 6 and influenza A viruses7 and is compatible with high throughput processing.78

Using an inactivating storage buffer would not only reduce risk but also increase the speed and number of laboratories able to process these samples.7 This method also stabilises the samples, reducing the need for cold shipping and improving sample consistency.8

We must be willing to try new ways of working in these extreme circumstances. Changes need to be expedited, and healthcare providers must be supported to use the allowances in the EU’s in vitro diagnostic regulations9 to make greater use of both physical resources and the experience of academics and healthcare staff in the UK.