Fresh uncertainty over the UK’s contact tracing plans has thrown light on the difficulties of a successful track-and-trace system to tackle Covid-19. Prof John Ashton, a former regional director of public health and regional medical officer for the north-west of England, describes his experience of contact tracing at the early stages of the coronavirus crisis and highlights pitfalls the UK should avoid.
“In early February I was invited to Bahrain to examine the country’s preparedness for Covid-19. The first case, that of a religious pilgrim returning from a visit to holy sites in Iran, was diagnosed while I was in Bahrain on 24 February.
“The first thing I asked for was a tour around the island state to visit key places where the virus might make an entry: – air and sea ports, the road causeway with its heavily used link to Saudi Arabia, the main prison, public health laboratories and each of the hospital estates, as well as housing projects for migrant workers.
“Together with members of the Covid task force that had been set up in early February, I spoke to all those in leadership positions to seek out weaknesses in the chain of epidemic control and to assess the capacity for an effective public health response.
“Among other things we were exploring forensically for weak spots where the virus could get hold, replicate and spread. At this early stage we were able to identify that a lack of testing capacity was an issue, and in mid-February I was able to advise the crown prince, Salman bin Hamad Al Khalifa, and the Supreme Health Council to urgently order more supplies and equipment, a recommendation that was immediately acted on.
“The result is that although Bahrain has a population of under 2 million, the Bahrainis are doing far more testing now per head of population than say, Wales, which has double its population. In practical terms at Bahrain airport, where screening and triaging of all arriving passengers has been in place for three months, up to 1,000 passengers coming from affected parts of the world, or who might be manifesting early symptoms of infection, have been routinely tested for coronavirus.
“This has been followed up by a systematic approach to isolation, quarantine, contact tracing and treatment with a large measure of success. As of last week 6,000 tests were being carried out daily with 4,000 cases of diagnosed infection; at that time there had only been 8 deaths.
“With the Bahrain situation in mind together with my own long experience of public health in England, I see several pitfalls ahead for the contact tracing system in Britain unless things are put right urgently. One problem for instance is the use of test kits sent through the postal service. It should be remembered that the swabs needed to be taken from a person’s nose and throat are quite invasive. Mistakes can be made and there is the risk that an inadequate sample is taken, resulting in a false negative report.
“Another potential problem in the current recruitment system for contact tracing staff is the lack of local knowledge. Ideally the national contact tracing system should be decentralised and put into the hands of local public health specialists, who know their populations and are able to fully engage with them.
“My fear is that we recruit an army of people working in call centres who are hundreds of miles from an area they are dealing with. There are thousands of experienced environmental health officers together with currently furloughed local government civil servants out there who could be recruited into the call pool who have the detailed knowledge to engage with their local communities and ensure a high-quality test, track and trace service.”