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The doctor reminded him that this test shows if a person has an infection. It is used both to diagnose individuals who are experiencing symptoms and to identify asymptomatic cases.
If this test method were chosen, the objective could be to determine the proportion of asymptomatic people infected with COVID-19 in the country.
“We know that a large proportion of infected people have no symptoms, but are vectors of the infection. These individuals would not be among those infected with the current testing strategy. Random tests allow an objective determination of morbidity in one country, and such tests have been performed in other countries, such as Iceland, “said Beinort.
The example of Iceland has been widely reported in the international media. According to the USA Today website, this country has tested up to 10 percent. populations The country has a total population of 364,134.
“By studying asymptomatic cases in the population, we will not get a higher percentage of positive results than by studying on purpose. In Iceland, for example, about 13% of people who were attacked because they had symptoms and were suspected of having coronaviruses. tests had a positive value.
Among those who were randomized, there were about 0.6 percent who tested positive, “said Beinort.
The researcher taught that knowing the morbidity level of COVID-19 in Lithuania would help decision-makers to plan the work of the health care system, resources, and make decisions about quarantine mitigation.
“Random testing is a very powerful tool for predicting the course of an epidemic, the only tool for statistical analysis and to see the true prevalence of active infection. It is also a good method of detecting early outbreaks, which requires the participation of appropriate laboratories, logistics resources and people, “said Beinort.
It would be even more useful to repeat the investigation
The doctor speculated that in Lithuania COVID-19 currently has less than 0.1% activity. people. He did not want to speculate on how many people would need to be investigated to obtain reliable results.
“I cannot comment on the number, it depends on the statistical reliability chosen, the suspicion of prevalence, and these decisions are the responsibility of epidemiologists.” Without a doubt, by investigating more people, we will obtain more reliable results, but it depends on resources, ”said T. Beinort.
According to him, the individuals for the study should be selected at random.
“Targeted tests do not provide information about the prevalence of the virus in society, but they do provide prevalence in the target group of people tested,” said Beinort.
At the same time, the researcher emphasized that a single prevalence study is useful, but it would be even more useful to study people in a certain sample every day in Lithuania or in regions with high risk of transmission.
“This is how we will follow the changing rhythm of the disease, which is the most valuable information in managing the epidemic. Based on mathematical models from ETH Zurich and the University of Lucerne, we would see the full spread of the epidemic about 7 days earlier than now. Consequently, decisions about case control, quarantine or release could be made safer and faster, and the life of the country could return to normal with less fear, “said Beinort.
There is a great lack of research on immunity indicators in Europe
According to the scientist, there is another possible way to evaluate the public: seroepidemiological tests, which evaluate the formation of IgG or IgA antibodies (indicates that he is sick or vaccinated), IgM (indicates that the infection is recent).
He clarified that he was not referring here to the well-known rapid tests, but to laboratory tests called ELISA.
ELISA is a classic antibody test in laboratory medicine that shows how many antibodies have been formed. Rapid tests show whether antibodies have been formed. The validation of ELISA and 9 rapid tests by the University of Oxford has shown that the ELISA method is sensitive and specific, but none of the 9 rapid tests tested showed sensitivity or specificity to be used in society (…) ELISA tests Certificates were not recently introduced. Two weeks ago, there was only one company in Europe that had CE marked ELISA tests. Today, there are probably more of them already. However, this is a product that everyone wants and the queues are long. The United States does not release strategically important reagents from the country at all, “Beinort said.
At the same time, the researcher saw another gap in that strategy, if applied.
“It is interesting to know how many people have had COVID-19, but such a test requires a very good serological test that would give an extremely small proportion of false positive responses.” Otherwise, we will greatly overestimate the number of survivors. Also, without knowing whether antibody formation means protective immunity, today we could not use the results of seroepidemiological research to make decisions, “said T. Beinort.
There are still many questions about the development of immunity.
When asked if COVID-19 would lead to immunity, the researcher said they would like to know more than is currently known.
“According to data released by Chinese hospitals on April 29, IgG antibodies eventually developed in everyone who required hospitalization. In a previous post, 30 percent. People with COVID-19 developed little or no antibody. This trend was more visible in younger individuals. People who are in a milder form may not develop an antibody response, “said Beinort.
At the same time, the doctor stressed that the issue of the development of immunity is complex. Immunity itself is divided into innate and humoral, and antibodies are only part of the humoral, albeit simply detectable, immune response to infection.
“We still don’t know which part of the immune system, memory T cells or B cells, gives us maximum immunity to the virus, if it does. The ideal vaccine should form T and B cell memory,” he said. Beinort.
He was skeptical of rumors that the recurrence of the coronavirus could be a reactivation of the virus. The young scientist was more likely to believe it was a test error or a new case of infection.
“It is likely that a false negative response was received before receiving a positive test again. We know that PCR tests also have a certain frequency of false negative results. Virus sequencing studies of patients would answer the question of whether it’s a reinfection, ”said Beinort.
Beinort is currently working as a doctor at Cambridge University Hospital. He has a degree in biochemistry from the University of Cambridge and a degree in medicine from the University of Oxford. At the same time, the young specialist investigates, lectures and exercises for medical students and doctors.
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