Cuddle grandma or keep your distance? - Tips to protect against colds and flu during the Christmas season (stern+)

Cold, flu and corona - Cuddle grandma or keep your distance? How to get through the Christmas season in good health

As always, we pick Grandma up for lunch on Christmas Day. On Christmas Eve we are alone with the children. Do we want to go to mass again? In any case, we're going to the in-laws on the second day of Christmas. Advent looked very different two years ago. And the year before that, we sat all alone in the living room and tested ourselves for corona every morning ...

This or something similar is currently being planned in millions of households in this country. But perhaps everything is already well planned. The family gets together to admire the presents under the Christmas tree and enjoy a Christmas goose. By New Year's Eve at the latest, however, we want to dive into our circle of friends, dance and drink, hug each other with our best wishes as the clock ticks down to twelve. But wasn't there something?

It's not just presents and mulled wine that are in season. A glance at the streets, trains and buses or the crowds at Christmas markets and department stores gives the impression that everything is back to the way it used to be. Of course we want to forget the pandemic. But GP surgeries can hardly keep up with all the people who are currently seeking help because of an "ILI". In international medical terminology, this is the name given to all symptomatically similar illnesses caused by a flu-like infection: ILI -"influenza like illness". The Robert Koch Institute in Berlin, which is also responsible for such infections, summarizes the situation during the autumn and winter season in weekly reports. And these show that the figure for acute respiratory illnesses is well above average: a good seven million people have been infected nationwide. Around a quarter have already contacted their own practice about this or rushed straight to reception - with or presumably without a mask. So it's not just in the waiting room that the risk of encountering swarms of pathogens is high - all in search of new victims.

Everyone is sniffling and coughing, but the real flu wave is yet to come

However, the actual flu season, the time of influenza or "real flu", has not even started yet, as the current data shows. Rhino cold viruses, of which there are dozens, and Sars-CoV-2 - i.e. corona - are currently dominating the field. RSV, the "respiratory syncytial virus", is also on the rise, posing a particular threat to young children. Influenza, however, hardly plays a role. Last year, on the other hand, everything started very early in the post-pandemic phase. However, in normal times, the actual flu season doesn't start until around the turn of the year. It seems to be the same this year. In other words, exactly when everyone meets up and gets together over the holidays. However, just because the influenza numbers will presumably also rise at that time does not mean that the other pathogens will immediately clear the field. You can also be infected with more than one virus. So if in doubt, should you stay at home? Better to celebrate alone or in a very small group, if you feel like it at all? But if my nose is just blocked and not running like a few days before, am I really still contagious? Or can grandma be cuddled again?

If you want to be on the safe side and protect your loved ones as much as possible, you ultimately only have one option: as much distance as possible, preferably with house walls in between. After all, neither coronavirus nor the flu or one of the many rhino cold viruses can be dangerous via email, chat or a traditional festive card - unless the letter carrier or postwoman delivers the greetings personally and exhales. If you still want to celebrate together - and most people probably do - you now have relatively simple, pandemic-related means of checking your own status fairly accurately: rapid tests from the supermarket, drugstore or pharmacy. Such antigen tests are not only available for coronavirus, but also in combination for the two basic influenza types A and B, as well as for RSV.

Although this covers important pathogens, it by no means covers all pathogens that can cause "colds", i.e. flu-like infections. So is it enough to at least look out for symptoms in yourself? The rule of thumb for these viruses is that the time I can infect others roughly corresponds to the duration of my own illness. Unfortunately, this is not the whole truth. Let's look at a few details and start with corona, because this pathogen and we have become accustomed to each other in recent years and some considerations also apply to other "holiday viruses".

Why this year is different

We have indeed adapted: The Sars-CoV-2 virus no longer triggers such a large number of serious illnesses as it did at the beginning of the pandemic, even in intensive care units. One of the most important reasons is that we - the potential "hosts" - have acquired solid basic immunity through vaccinations and surviving infections. This provides security. However, the broad immunity in the population still does not protect against infection, but "only" against its more serious consequences. Anyone can therefore become infected. The rule known from the pandemic that the probability of a severe course of Covid-19 increases with people's age and any previous illnesses also continues to apply. Caution when meeting others is therefore not just a question of politeness: Grandma is in her mid-eighties and has asthma. Aunt Frida has been living with high sugar levels for years. Anyone who brings such pre-existing conditions to the party still risks severe symptoms if infected with the coronavirus, despite possible vaccinations and perhaps recovery. This does not necessarily have to be fatal. But the often diverse symptoms associated with the still poorly understood "long Covid" are not just talk or imagination. That much is now clear. And even younger and healthy people can catch it and be paralyzed for a long time. Corona infection is therefore always associated with a risk.

One of the early findings for the then still new virus was the time of infectivity: around one day before the first symptoms appeared - if the virus became noticeable at all. Even today, viruses can still be spread by infected people who do not show any signs of illness. Aching limbs and headaches, plus a high temperature or even a fever (over 38 degrees) can of course still follow during the incubation period of a few days. A quick test shortly before the celebrations is certainly not a bad idea. And if there are symptoms? Then you probably don't feel like celebrating anyway. But even if you feel comparatively well again, the risk of infection for others is not yet zero.

A recent study of almost one hundred patients, in which not only the usual tests were carried out, but the swabs were also examined virologically in detail, showed that adults with mild symptoms were still shedding viable virus ten to fourteen days after the onset of symptoms. The decisive measure of the risk of infection was not the protein of the virus that is normally checked in the rapid tests, i.e. the "spike" for the docking of the pathogen to the host cells. More important was the detection of a protein called N ("nucleocapsid"), which originates from the genetic material envelope of the pathogen. If someone tested positive for this protein, they were also excreting "viable" virus. Sars-CoV-2 could therefore be obtained in a "culture" from a nasal swab and spread to cells. During this time, there is also a risk of infection for others. However, no one is infectious at the push of a button or not at all. The concentration of excreted viruses rises rapidly at first, but falls relatively quickly as the Covid-19 disease progresses. It is therefore also at its highest shortly before the outbreak and in the first five days or so afterwards. This is also in line with the current medical recommendations formulated by the Robert Koch Institute, for example. As a rule of thumb, two weeks after the onset of your own illness is a sensible - albeit not guaranteed - time to be able to mingle with others again after Covid-19.

Every year again: the classic flu

The fact that your own symptoms are a certain measure of infectiousness also applies to influenza. About a week after the first symptoms appear, there is usually no longer a great risk of infection for others. However, the range can vary. For example, children or people with a weakened immune system can shed viruses for much longer. Influenza is also contagious even before it causes symptoms in a person. However, once symptoms are present, there are hardly any further infections after around three days under real-life conditions in a shared household because the virus concentration has already dropped significantly. At least that is the result of a study presented in 2015 by the World Health Organization in collaboration with the University of Hong Kong and the Pasteur Institute in Paris. At least among adults, age or possible treatment with the flu drug oseltamivir played no role in infectivity. The exact type of flu virus also made little difference to the question of how long someone can infect others. Surprisingly, however, another characteristic can cause an adult to shed virus for longer than usual: severe obesity. This was observed by a US team a few years ago during studies in Nicaragua. People with a BMI (body mass index) of more than 30 and who were therefore obese shed the virus for around 40 percent longer than their slimmer counterparts. This finding only applied to type A influenza, not type B. However, it can still make sense to plan an extra day for the infection phase when assessing your own risk just before the holidays. Together, this would be at least five or six days after the onset of influenza symptoms instead of the average three or four days.

In any case, you are on the safe side with the recommendation of the Federal Center for Health Education: keep your distance from others for a week from the first flu symptoms. For people with a functioning immune system, the same period applies to infections with the RSV virus - three to eight days. However, this virus can also be highly infectious even before the first symptoms of illness appear. The same time frame also applies as a rule of thumb for the many different rhinoviruses. However, there is one difference: these cold pathogens and RSV spread not only through droplets and aerosols, but also very well through smear infection. They may therefore "stick" to door handles, bus or train handrails or the handle of a shopping cart.

But once again as a warning: with all the viruses mentioned, there may be a high risk of infection for others even before they make themselves felt through a cold, cough or hoarseness. So if you want to meet particularly susceptible people with a clear risk of a severe course of the disease over the holidays, you should consider a quick test with a short lead time before your visit. And it's certainly not a good idea to get the last presents or groceries in the hustle and bustle on Christmas Eve or even the day before. However, with a bit of common sense, you can stay reasonably on the safe side and still avoid isolation. Of course, washing your hands thoroughly and wearing a mask are not prohibited even after the official end of the pandemic.