Despite Level 5 restrictions since last December, Covid-19 daily case numbers are still hovering around 500-700 and the challenge is how to drive them lower and then keep the numbers low. Intensive widespread Covid-19 PCR testing with follow-up contact tracing is the answer.
Ireland’s community testing rate, currently about 18,000 per day, is ranked a lowly 17 out of 29 compared with our EU counterparts and is a tenth that of Denmark, which has the highest test rates in the EU. The introduction of temporary walk-in testing in some areas last month was a welcome initiative, but the finding that up to 4.3 per cent of asymptomatic walk-ins were Covid positive underlines the need to do more extensive testing in the population.
Countries that have successfully contained the spread of Covid-19 (Australia, New Zealand, Taiwan, China, Vietnam, Iceland, Japan, South Korea) have all used lockdowns in combination with intensive PCR testing and follow-up tracing. For testing to be of benefit, it must be fast.
In recent weeks, Denmark's case notification and positivity rates have reduced dramatically and lockdown has been eased substantially
Once an individual requires a test, it should ideally be carried out that day and the result available later in the day or at the latest by lunchtime the following day, so that self-isolation advice is reinforced and contact tracing can get under way immediately. Although vaccination will help counter Covid-19, the rollout is slow and it may not be a panacea. Putting all our eggs in the vaccination basket is unwise.
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The logistics challenges of intensive community testing and their solutions are exemplified by various practices in other countries. Using US and European PCR machines, 11 million people were tested over a five-day period in Qingdao, China, in October after an outbreak involving three people – with the mass testing, nine other people were found to be positive, a positivity rate of 0.0001%. Lockdown was avoided.
UK test and trace in 2020 has been severely criticised but since a former Swissport UK chief, with extensive aviation passenger and baggage logistics experience, was appointed as a director, there has been steady improvement. US president Joe Biden’s current push against Covid-19 involves the establishment of a National Pandemic Testing Board, modelled on Franklin D Roosevelt’s War Production Board.
Highest test rates
Since the new year, Denmark has had the highest community PCR testing rates among EU states. In recent weeks, while many EU countries faced the threat of static or increasing case numbers, Denmark’s case notification and positivity rates have reduced dramatically and lockdown has been eased substantially.
Currently throughout Denmark (population 5.8 million) up to 180,000 PCR tests in the community are carried out each day – a test rate nine to 10 times that in Ireland. There are 165 community-based PCR test centres throughout the country, and no Dane has to travel more than 20km for a test.
In a deteriorating pandemic, there is a race against time to identify those infected and protect those who aren't
All the community samples are analysed in either a laboratory in Aarhus or Copenhagen, run by a special agency, TestCenter Danmark. The laboratories work in three shifts a day and TestCenter Danmark has established a unit focused solely on ensuring a supply of materials and reagents.
To enhance productivity and automation, these laboratories use large numbers of a single model PCR machine, the BioRad CFX, and 96. 80 per cent of people are tested within 24 hours of a request and 80 per cent of results are available within 24 hours.
When local test centres’ swabbing capacity becomes overwhelmed due to a surge in cases, mobile testing units are deployed. Mobile testing stations are particularly useful for quickly testing large numbers in schools, colleges, universities, construction sites, factories and so on. In addition to the usual groups, such as healthcare, care home and meat factory workers, testing is offered to all Danes, and asymptomatic testing is encouraged.
The Danish Health Authority plans to expand testing further such that, by May, 500,000-700,000 tests – both PCR and antigen – will be carried out daily, which means 40-50 per cent of the population will be tested each week. High-intensity PCR testing is the bedrock of Denmark’s testing strategy, and the exact role of antigen testing remains to be fully defined.
Easing restrictions
Testing with follow-up contact tracing should be made more readily available in order that restrictions can be quickly and successfully eased. With increased community testing, initially case numbers will increase so policy decisions in those circumstances should be not be made solely on the basis of absolute case numbers, but on indicators such as hospital admission rates, death rates, overall positive percentage, age of positive cases and proportion of asymptomatic cases.
Targeted testing of specified populations such as in a school, factory, town, city, district or county may need to be undertaken in certain circumstances. Even if case numbers remain low, the test-and-trace system, like a fire brigade, needs to be able to respond quickly and comprehensively at short notice.
In a deteriorating pandemic, there is a race against time to identify those infected and protect those who aren’t. We, in Ireland, along with most other European and American countries, have lost this race on three occasions in the past year. Ireland can win this race in 2021 with intensive, well-directed testing and effective contact tracing.
Luke O’Donnell is past president of the European Board of Gastroenterology and Hepatology and previously worked as a physician at Mayo University Hospital and St Bartholomew’s Hospital, London