Pessimistic Forecasts From Scientists: Fight Against Coronavirus May Continue In Second Half Of Summer

Predictions from the COVID-19 mathematical model developed by Vytautas Magnus University three weeks ago showed that despite relaxed quarantine conditions, we had to approach the minimum number of infections detected per day in late May.

In the last days of May and the first days of June, we were already able to receive good news when no new cases were detected during the day. We expected such a pandemic scenario before further reducing quarantine requirements.

FIG. 1. Simulation results after the first stage of quarantine mitigation.

The beginning of May did not predict anything unexpected. As predicted, with a few thousand tests per day, the number of positive cases began to gradually decrease. During the first week of May, the average number of cases per day ranged from 5 to 6, and on May 7, a record number of cases was even recorded. Only three positive cases of the COVID-19 test were detected that day. The changes started unexpectedly when May 9. The number of detected cases increased to 35. And although most of the cases were registered in the so-called virus outbreaks (15 cases in the Antaviliai care home and 10 cases in the Vilnius City Clinical Hospital), it was stopped the number of other cases not directly related to the outbreaks. Here is a graph of the cases registered in May.

FIG. 2. Prepared according to data from the National Center for Public Health

“Lithuania is often pleased that the curve of identified cases is flat. If it is meant that this curve is more or less parallel to the x axis, i. and. Basically it doesn’t go up or down, so rejoicing is nothing. The non-increasing number of cases detected in the midst of a pandemic could certainly have pleased us, but now that curve should be going down. Its balance of the same number of cases detected per day indicates that the virus withdrawal has stopped.

Of course, the situation is improved by the fact that most of the cases detected are localized virus outbreaks, but the number of outbreaks does not decrease and there is no complete guarantee that, for example, infected workers will not unknowingly infect others out of the outbreak. “Says Juozas Augutis, professor at the Department of Mathematics and Statistics, VMU School of Informatics, the head of the research group that created the probabilistic simulation model.

With the opening of national borders, the international movement of people begins. Unfortunately, the threat of imported infections is also recurring. We are already counting the first such cases in Lithuania. But there is greater concern about fighting the pandemic in the country.

According to the professor, an understandable and reasonable desire, first of all in the service business, to return to normal life as soon as possible. No matter how creative we are, it is impossible to completely change life, business or creativity remotely, not to mention the huge economic losses the state suffers. Summer is approaching, the rest period, cultural events, the end of the school year and other holidays.

“During those few months of virus siege, we are all used to hearing daily summaries of new infections and even deaths, and we are no longer as sensitive as we used to be.” We get together more and more frequently, visit more and more workplaces, forget about putting on a face mask or gloves, and sometimes move forward with quarantine requirements that are gradually loosened. It is true that in some places we also see greater caution, the concern of the communities for the safety of their members. For example, educational institutions, while being allowed to return to contact work forms, took these opportunities very seriously and considered them. Most of them still decided not to take risks and finish the school year remotely, “says J. Augutis.

Is such a precaution justified? Most now know that the nature of the pandemic is largely determined by the rate of transmission of R0 disease. It shows how much an average virus carrier can transmit to others during a period of illness. If this rate is less than one, the number of infections decreases over time. However, when the indicator rises above unity, a very rapid increase in the number of infections begins. We observed this situation in March.

According to prof. Juozas Augutis, the value of R0 depends on many circumstances, some of them are not related to our activities, but one of the most important measures that stops its growth is quarantine, more precisely, strict compliance with quarantine conditions. Before the introduction of quarantine in Lithuania, the R0 virus transmission coefficient ranged from 3 to 5. In mid-March, when the volume of tests began to increase, the power of this coefficient was also seen. The number of infections has increased very rapidly from a few cases per day to 50-60 cases.

The introduction of sufficiently strict quarantine and public awareness have paid off. After about a month, the number of infections doubled, and despite the slight decrease in quarantine in the second half of April, the number of detected infections continued to decline. Therefore, the value of the coefficient R0 also decreased. In late April and early May, this value was approximately 0.3-0.4, depending on the number of cases detected.

Unfortunately, as already mentioned, the decline stopped in mid-May, and the number of new infections began to fluctuate around 10-12 cases per day. Even after the rejection of diseases in the foci, leaving 5-6 cases per day, we no longer have a downward trend. By entering the number of cases identified in the model, we can easily determine which value of the coefficient R0 corresponds to the situation of the last week.

“To model a situation like Lithuania’s last week, the value of the R0 coefficient had to increase to 0.7-0.8. This is already a sign that we are beginning to get closer to the unit area. As the coefficient increases, the end of the pandemic progresses, i. July-August “, warns the scientist.

He notes that relief from quarantine conditions is inevitable and that more responsibility for managing the pandemic will fall on our shoulders. Increasingly, we will have to decide for ourselves how to behave, how to protect ourselves and those around us. We must not forget that the virus is unequally dangerous for different people, so every action we take should be in the public interest. Humanity is expected to gain collective immunity one day with or without a vaccine. Until we have it, we can only resist a pandemic through collective efforts.

The model was prepared by researchers from the Vytautas Magnus University: Professor in the Department of Mathematics and Statistics, Rector of the Juozas Augutis University and PhD student in the Department of Applied Informatics Justinas Dainauskas and Rokas Krivaitis. The developed probabilistic simulation model, available online, allows the user to interactively change the parameters and immediately view the modeled predictions. For example, adjust quarantine conditions and duration, consider the number of tests. This model can be tested here: https://covid19.vdu.lt/

The university also introduced the international social initiative “Together at a distance”, which requires contact with the people who need it most and not using the harmful term “social distance”, replacing it with a more precise one: “physical distance”. This is expected to draw attention to the most vulnerable people after a pandemic: the elderly, the unmarried, those with mental health problems or those who need care.

The initiators are VMU and Global Initiative in Psychiatry (FGIP). Almost 50 international organizations from around the world have already joined the initiative.