Presenting the initiative, British Prime Minister Boris Johnson said that tracing contacts “will change people’s lives.” With its large-scale use, the government is confident of removing a large part of the limitations imposed so far, allowing greater movement and the complete reopening of commercial and production activities. In the United Kingdom, nearly 270,000 coronavirus positive cases have so far been reported and over 37,500 people have died.
During an epidemic, contact tracking is useful for identifying people who may have been infected by an infected person. It is usually done by interviewing individuals who tested positive for coronavirus, with the aim of reconstructing which people they came into contact with, exposing them to the risk of infection. According to the World Health Organization, epidemiologists and several other experts, tracing is essential to identify new chains of contagions as soon as possible and stop them quickly.
The British government explained that today the contact tracking workers will start contacting people who have tested positive in the last 24 hours, through the test that involves taking saliva and mucus through a swab. The new positives will be interviewed to find out about the movements made in the last few days and about the people with whom they have been in close contact in the two days before the development of the symptoms and in the following seven.
By “close contacts” the government means people with whom they have shared the same spaces for more than 15 minutes or with whom they have been close to less than two meters; cohabitants and people with whom you have sex also fall into the category.
In the United Kingdom, those who develop symptoms compatible with COVID-19 must go into isolation for a week, while any cohabitants must isolate themselves for two weeks (because they may have been infected and have in turn become contagious, but without having yet developed the symptoms ). With the new rules, those who develop the symptoms will have to request the test via the swab, by logging on to the British Health Service (NHS) website or by requesting by phone.
Interviews and isolation
People who are negative will immediately be able to stop the isolation and so will their cohabitants. If, on the other hand, the test is successful, a tracking employee will contact the person who has tested positive to interview them, asking them for information on the movements made in the last few days and especially on the meetings they had. The interview can take place by telephone, via messages on the mobile phone or with a phone call.
Individuals who have come into contact with the positive person, before they know they are, will then be notified and asked to remain in solitary confinement for two weeks, regardless of how they feel. They can be subjected to the swab if they develop symptoms, a condition that would then lead to a new tracing of contacts to continue following the chain of infection and try to stop it as soon as possible.
Contact tracking is effective only if it is done promptly as soon as new positive cases are detected. Times are above all conditioned by the possibility of making tampons and obtaining results in less than 24 hours. As in many other countries, including Italy, also in the United Kingdom the laboratories that deal with the analysis of the swabs are under great stress and rarely manage to provide the result less than a day after the sampling. Johnson said the timeframe will be drastically reduced, but many observers have commented with great skepticism on the British Prime Minister’s statements considering the announced target unlikely.
To strengthen the activities related to the tracking of contacts, the United Kingdom has also started experimenting with an application that should allow to receive notifications if you have come into contact with people who have then discovered that they are positive for coronavirus. A test on a small number of people has been launched on the Isle of Wight, and the government is confident that it will be able to release an early version of the system within the next month. Many other countries have started the development of similar solutions – experimentation for the Immuni app has just started in Italy – but to date there is insufficient data to evaluate its effectiveness and usefulness.
Test, trace, isolate
For several months now, the WHO has been advising above all to perform as many tests as possible, quickly isolate the infected and carry out an intense contact tracking activity to shorten the chains of the infections. The countries that have applied these indications with greater rigor have obtained appreciable results, although still difficult to estimate considering that the greatest slowdown in the spread of the epidemic has been favored by restrictive measures.