StratiVirus or the battle against the pandemic

In order to ease up the restrictions imposed to control the Covid-19 pandemic, requires an effective testing strategy.
Regular testing is a vivid example of this, which can help rebuild the economy by reducing Covid-19 cases.

Effective strategies are still being developed in the fight against the pandemic, two of which are the following:

Random universal testing

One of the proposed testing strategies is randomized universal testing when the population is tested randomly.

Professor Paul Romer, Nobel Laureate in Economics of 2018, proposed the Romer 2020 strategy. He claims that by randomly testing 7% of the population daily, then isolating those with positive results, it will be possible to significantly reduce the disease curve.

If we take the United States, with a population of 300 million, as an example, testing will require about 20 million tests a day. And the UK, with a population of 60 million, will require about 8.5 million tests a day. One of the disadvantages of randomized testing is that asymptomatic cases are ignored in this strategy. Thus, random testing is not the best strategy.

Another testing strategy is targeted or stratified periodic testing.

It assumes that individuals within risk groups are tested at regular intervals, not less than once every 10 days, and, in case of available resources, at smaller intervals.

According to this strategy, the tests are performed on individuals in selected groups based on their likelihood of becoming infected or infecting others. The likelihood can be understood from their occupation, geography, and many other factors. Targeted periodic testing can reduce or even eliminate the spread of Covid-19 in these groups specifically.

The testing of health care workers is more obvious and urgent, but all other groups whose members are likely to be infected should not be neglected. These groups are the following:

• People who have a lot of contact with people (e.g. bus drivers or supermarket employees);
• Those at high risk of infection (e.g, prison guards and guardians);
• Those who do not have the opportunity to work from home (e.g. construction workers);
• Education staff and students

This is a more efficient use of limited testing resources than the current strategy.

The testing strategy should be implemented in all cases where the results will lead to specific actions, such as:

• Isolation of those with a positive test result,
• Searching for a connection after the incident is discovered,
• Quarantine of close ties
• Review of infection prevention and control practices
• Strategy change or revision

This strategy to reduce the further spread of coronavirus through mass testing is already in use in some US universities.

One of the universities, the University of Illinois, has so far conducted 25,000 PCR tests.

625 PCR tests are planned to be performed during 20 weeks. 2021 PCR tests to be performed in the second half of the year are expected not to exceed 12,000.

To enter the university, you need to submit 2 negative results with a difference of 3 days. And the test conditions are as follows:

• Take a test twice a week
• When entering a university, present a passport or a special application and enter only in case of a negative result
• If they have a high risk of infection, they should be tested at short intervals

The university has also performed antigen testing, which is more effective in terms of time. If it took days for the PCR test results, the antigen allowed the university to determine the condition of the students and staff in just a few weeks. Moreover, antigen tests are quite affordable compared to PCR.

As a result of the tests, it was possible to find out the number of infected people in a rather early period, to take appropriate measures.

Another example of regular testing is the University of Washington (30,000 students) whose student dormitory caused the outbreak.

The strategy, carried out in Fall, was the weekly targeted PCR testing; in case of a negative result, students were required to wear a mask inside and outside, to maintain a distance of 1.5 meters, and other restrictions.

And in order to return to university in the spring semester, students must pass a PCR test with a negative result.

Another example is Green Carolina State Agricultural and Technical University (the number of students in the dormitory where the outbreak was 8,000 ).

The university adopted the PCR testing strategy, during which only symptomatic students were tested, and the results were clear within 5–6 days. However, as early as September 28, the university began conducting antigen testing to achieve faster results.

In one week, 1000 students were tested by antigen-PCR methods, moreover, with the help of the antigen test, it was possible to send 160 students to immediate isolation.

Other universities that have passed regular testing are as follows:

• Wisconsin — Madison University
• University of Colorado Mesa
• Rice University, Houston

Thus, the testing strategy should be an effective way to reduce the spread of COVID-19 using low economic costs. Targeted regular testing will be effective if those who can work from home continue to do so, retirees are more vigilant, and anti-epidemic rules are maintained in public places. In this case, the areas that can not operate remotely can quickly and safely move to normal work.