Globally, lately, there has been an increase in the number of cases of COVID-19. In our country, last week more than 80% more people fell ill than the previous week and 5 deaths were reported. COVID-19 does not follow normal seasonal patterns, but this “It’s not a surprise at all“, say the epidemiologists who explained why we are dealing with a significant increase in the number of cases of SARS-CoV-2.
Why do we have more cases of Covid-19 in the summer – Photo Archive
Every July for the past four years, epidemiologists at the U.S. Centers for Disease Control and Prevention (CDC) have observed a sharp increase in COVID-19 cases and hospitalizations, a phenomenon called “summer tide“.
This summer, the United States is experiencing a significant increase in cases in states such as Arizona, California, Hawaii and Nevada. Positive tests reached 15.6 percent in the week ending July 6, a 1 percent increase from the previous week, according to CDC data. Viral rates in sewage are also increasing. The same trend was seen in the United Kingdom, where positive tests rose from 4% in March to 14% in June, the BBC reports.
COVID-19 in Romania
And our country follows this trend, the National Institute of Public Health (INSP) reported an alarming increase in cases of COVID-19, with 1,256 new infections in the week of July 8-14, an increase of 82.3% compared to the previous week . Of these cases, 419 are reinfections, and five patients died, all with comorbidities.
It is serious that the official number of cases represents only the peak of the phenomenon, because only the severe forms reach the hospital.
“We know very well that what is counted does not represent the total number of infections. Even during the periods when all kinds of tests and checks were done, we did not get to know the real number of infections because there are many asymptomatic patients, or with mild symptoms, which do not lead people to go to the doctor and then they do not have who to register it, no one knows about the patient. Certainly the number of infected people is higher, but it continues to evolve with less severe clinical cases than in previous waves of the pandemic, and then the importance given to these infections is less.“, explained the vice-president of the Romanian Society of Epidemiology, Dr. Emilian Popovici, for “Adevărul”.
The holiday season and COVID-19
Environmental and behavioral factors, such as air conditioning and large gatherings, contribute to summer surges, especially since the disease has not yet entered a stable seasonal cycle.
The number of cases increases during the holiday season. The reason?
“Because people are starting to move more and more. And by moving, the number of contacts that each person who moves increases, and by increasing the number of contacts, the risk of infection increases. That’s basically what happens. People go in groups, by bus, by train, in restaurants, in various public places. They come from all areas. With them come viruses. After that, people leave their vacation spots and spread again to all areas. And with them, the virus. So what we were discussing practically also happens during that pandemic period, but on a much smaller scale, namely, the increase in the number of contacts and the increase in the number of infections.“, detailed Dr. Emilian Popovici.
Akiko Iwasaki, a professor of immunobiology at Yale University, suggests that the summertime wave of COVID-19 could be amplified by factors such as crowds at festivals and concerts, as well as heavy use of air conditioning, which dries out the air and makes it easier for the virus to spread. .
“An infected person, not necessarily with SARS-CoV-2, who coughs, sneezes and behind has an air conditioner, sure that instead of circulating 2-4 meters, as it generally goes after coughing or sneezing, the viral particle it will go a much longer distance because the jet of air takes viruses with it. This problem also exists in commercial spaces, in means of transport in the commune. But the biggest problem is travel. It is no surprise that infections increase during this time. People come from all directions in places where the number of people is concentrated, in restaurants, in various public places. After that, some of them, infected, go back home and spread the virus in a bunch of places, and then the number of illnesses increases. The increase in the number of trips, the increase in the number of contacts lead to an increase in the number of infections“, adds Emilian Popovici.
Even though COVID-19 does not follow normal seasonal patterns, and waves of infection can occur at any time of the year, new and evolved subvariants are playing an important role in the spread of the virus this summer. The constant identification and monitoring of these variants, the implementation of preventive measures and the implementation of vaccination campaigns are essential to control the spread and impact of COVID-19.
FLiRT subvariants, responsible for increasing the number of cases
The recent increase is attributed to the FLiRT subvariants of the Omicron strain, which have evolved to more effectively evade neutralizing antibodies. Specifically, these subvariants have mutations that allow them to evade the immune system and bind efficiently to the ACE2 receptor.
According to Shan-Lu Liu, who directs the Viruses and Emerging Pathogens Program at Ohio State University and who studied the FLiRT subvariants, these latest COVID-19 viruses managed to find a balance between escaping the immune system and being able to still bind of cells, which leads to many of the new cases.
Specialists recommend booster vaccination, especially for the elderly and immunosuppressed. The monovalent XBB.1.5 vaccine, which targets the Omicron XBB 1.5 subvariant, is available to combat these new mutations, but in other countries.
“In the case of Covid-19, I think many people simply don’t want or don’t think they need the vaccine, but this means that population immunity rises and falls almost in unison based on the frequency and intensity of previous recent waves”emphasizes Denis Nash, professor of epidemiology at the City University of New York, according to the cited source.
There is no information related to the existence of vaccines for the newest variants of Covid-19 in our country.
“Of course there are deaths and there will be more, unfortunately. There are people who have health problems, they have various chronic diseases, they have poor health and there, either it was COVID, or it was another virus with respiratory transmission, the same outcome was reached. It is important that people who are in poor health when they show signs of acute illness, respiratory infection, contact their family doctor because he will certainly follow the problem and will know when is the optimal time for admission or for assistance medical at a higher level, if necessary.”the Romanian epidemiologist recommends.
COVID-19 does not follow normal seasonal patterns
For researchers studying SARS-CoV-2, predicting the emergence of the next strains remains a challenge. Unlike common respiratory viruses such as influenza or respiratory syncytial virus (RSV), which have clear seasonal patterns, COVID-19 has not yet adopted such a cycle. It remains to be seen whether, after this summer outbreak, COVID-19 will become a seasonal virus, and if so, how long it will take for such a pattern to be established.
“This virus has earned its place in the panoply of viruses that affect the human species, it is already in the same place as the flu virus. The periodicity is in a way seasonal, because in the cold season infections increase, not always very significantly, but this also happens in the warm season, when we would expect them to decrease, if we compare with the flu virus, which in summer evolves absolutely sporadically. The Sars-CoV-2 virus does not respect the rule of other respiratory infections and increases the number of infections in the warm season, for the reasons I mentioned. Basically, it is already a virus affecting the human species and will remain so. While? We cannot say, tens, hundreds of years“, said the vice-president of the Romanian Society of Epidemiology.
