With the aim of mass population testing, governments and health agencies are in a rush to buy large quantities of laboratory and portable (non-laboratory) rapid testing kits for COVID-19.
Diagnostic testing is rightfully being held up as the key to slowing the spread of the coronavirus pandemic. It reveals invaluable information about how the virus is spreading and allows authorities to more accurately forecast future spread. Using this data, governments can take informed steps to implement targeted interventions and better protect public health. The approach has already been shown to have an impact during this outbreak in areas such as Hong Kong, Taiwan, Singapore and South Korea, and has been endorsed by the World Health Organisation director-general, who urged countries to step up testing, saying they “cannot fight a fire blindfolded.”
The British government has announced the purchasing of 3.5 million rapid test kits, and other health agencies across the world, such as in Israel, are buying and using lab-based real-time PCR tests.
If we take a closer look at the science and technology behind some of the rapid testing kits, we can see that most of them are not specific nor sensitive enough to detect the novel coronavirus, and the laboratory PCR kits – the current frontline standard – don’t offer the turnaround we need (i.e. too slow), can only be performed in a lab by trained experts, and can be expensive.
Albeit useful, the most widely used tests are not entirely fit for purpose and offer little support to most governments’ mitigation strategies of ‘flattening the curve’. The approach required to control the outbreak of coronavirus is different to the strategies applied to contain other infectious disease outbreaks, such as ebola.
There are significant differences between the two viruses. The coronavirus is extremely infectious, spreads fast, and contrary to ebola, it can be easily transmitted through air droplets. The long incubation period of COVID-19 means a person can have the virus active in their system long before they start showing any symptoms and if they start showing symptoms at all.
Currently, there isn’t a mass-produced, affordable rapid test specific to coronavirus that shows whether someone has the active virus and is infectious.
In one of its latest statements, life-science giant Roche Diagnostics recommended that all governments use their available tests only for those showing clear symptoms due to the limited availability but also due to the lack of specific and affordable rapid tests on the market.
Let’s look at the available options.
Laboratory Real-time PCR (Polymerase Chain Reaction) Kits
These are highly accurate (some are 100%) but are considered slow with the fastest one giving results in 2 to 4 hours.
Interpreting the result requires more time, trained experts and special laboratory equipment, making them impractical for mass population testing.
In some critical cases, time to diagnosis can be extremely important and even life-saving.
A typical PCR test costs about £300.
Portable rapid test that look for specific immunoglobulin IGG & IGM Antibodies
This is the test kit that the British Government ordered a whopping 3.5 million of. Widespread and gaining popularity due to this crisis, these tests are based on the technology behind the home pregnancy test – lateral flow. These rapid lateral flow tests look for antibodies from a bodily fluid sample, most commonly blood or saliva.
Antibodies are produced when an immune response is triggered, i.e. they are produced by a person’s own immune system. Their mission is to find and destroy virus antigen proteins (genetic material).
These lateral flow antibody tests are portable, can be used at home, give results in about 15 minutes and cost around £5 / £10 making them extremely attractive to government agencies worldwide.
But they have considerable limitations
- Because these tests look for antibodies, they only show whether a person has recently had an infection, but not whether the virus is active in their system at the point of testing.
- For COVID-19, these tests are designed to identify immunoglobulin IgG and IgM antibodies post infection. However, these will only tell if a person has had a general “flu-like” infection, including pneumonia. These tests are not specific enough to detect coronavirus.
- For the above reasons, these tests are likely to produce false positive and false negative results.
- There are huge risks when these are being used by the mass public. Home use raises concerns of potential misinterpretation of the results. Would you trust a person knocking on your front door who claims they’ve just done a self-test that showed a negative result or that they are cured? Especially as recent data suggests some patients (maybe as much as 10%) in Wuhan are testing positive even after being successfully treated.
If a person experiences symptoms at this time of the year, it is increasingly likely they have contracted coronavirus since we’re nearing the end of seasonal flu. IgG / IgM tests still have an important role to play. They are crucial in understanding how COVID-19 spreads and, in hindsight, epidemiological data will be invaluable for research.
A novel virus requires a novel solution
Time for the better news! There are companies developing novel lateral flow rapid tests. One such company is Canadian Sona Nanotech developing a direct antigen test looking for the S1 spike protein of coronavirus. When the test is ready in 6 to 8 weeks, it is estimated to cost around $50 / £30.
Many of us have seen a close-up of the coronavirus, but for those that haven’t, here it is:
The red bits on the outer coating are called spikes, and each spike has an antigen protein attached at the end of it. This protein attaches to the cell and this is how the virus ‘installs’ its genetic material and infects the cells.
What makes a direct antigen test better?
First, let’s note one similarity. Both the direct antigen test and the immunoglobulin IgG / IgM tests are rapid lateral flow tests that deliver lab-quality results in 15 minutes at the point of use and at a fraction of the cost of a PCR. This makes them much more appropriate to deal with this crisis situation.
The difference between the direct antigen test and others, is that it is specific to coronavirus. Using a nasal swab sample, Sona’s test will look specifically for the S1 spike protein of the coronavirus even before an immune response has been triggered.
This means that the active virus will be detected even in seemingly healthy people showing no symptoms.
This test will tell if you’ve got the active virus in you now, and will tell you to isolate now. Not tomorrow, after having infected the people you live with, the salesperson in the shop, and who knows how many others!
This is the test that all governments are after
This test has no competition in situations where quick and accurate information is needed such as at airports, before boarding cruise ships, in the health service, going into work, etc.
Testing the healthy population is extremely important for monitoring and managing the spread of the virus in real time and gives valuable information to health authorities. It can help alleviate the burden on health systems and optimise the deployment of resources where they are most needed. It means we will be better informed and one step ahead than we currently are.
Imagine integrating real-time disease mapping with the right diagnostic test
We need to go beyond just testing; we need to capture the data from the point-of-use, manage it in the cloud and then geo-map test results visually. Only then we stand a chance of controlling the disease spread in real time and deploying resources fast and effectively.
To achieve this, we need to form consortiums between technology and science companies that together can deliver holistic solutions fit for the future, but also for the present.
There is no need to imagine any of this, because we’re already working on it. We’re integrating our data capture and disease mapping technology with Sona’s novel test as part of an international consortium which includes GE Healthcare.
Discussions are underway with Italy, Australia, Saudi Arabia and other governments to accelerate production and supply our test.
Cooperation is needed from regulatory bodies for fast tracking and emergency use authorisation of the tests. Accelerated mass production is needed to ensure timely supply. We need enhance collaboration between private sector companies and public institutions across the globe.
Harnessing digital technologies (such as smartphones) combined with the computational power of the cloud and integrated with the appropriate rapid diagnostic test is becoming the norm in fighting public health threats of a global scale.
The visual interpretation of epidemiological data in real-time is critical to the prevention, or at the very least mitigating the effects of this and future outbreaks.
In Bond Digital Health we know real-time data and disease mapping are powerful tools to help achieve this, and our solution is quickly becoming the norm. To quote Steve Jobs:
Those who are crazy enough to think they can change the world are usually the ones who do.
Watch this space.