Flu on the rise

Between January 1 and 7, 2023, over 300,000 cases and suspected cases of the flu were reported in Poland, which amounts to over 40,000 average daily infections. The flu virus is on the rise, and the “season” of increased incidence is just beginning. Do we have anything to fear? Are we facing another epidemic? How can we recognize the symptoms of the flu and how should we respond to prevent the disease from developing in our bodies and to avoid infecting our family members or coworkers? 

As recently as last October, in an article published in the medical journal The Lancet, experts reported that the 2022/23 season could see a several-fold increase in the scale of the flu epidemic. An analysis of data currently published by the National Institute of Hygiene, as well as our own observations, seem to confirm these predictions. We are currently facing a significant increase in cases, and it may peak, as in previous years, around the turn of February and March. Why is this happening? Experts cite a lack of population immunity as one of the causes, stemming from the fact that over the past two years of the ongoing COVID-19 pandemic, most of us have adhered to the DDM principles—distancing, disinfection, and masks—to a greater extent than average. As a result, most of the population did not contract the flu and therefore did not develop a certain degree of herd immunity. We are therefore currently experiencing a so-called catch-up period, during which there is an increased rate of influenza virus infections.

Influenza – a widely known virus

The pandemic caused by the SARS-CoV-2 virus, which causes COVID-19, has made us all accustomed to rapid virus detection methods using tests. Testing has become more widespread, and a large portion of the population in Poland has had experience with it. It is therefore not surprising that with the arrival of the next fall-spring flu epidemic in the 2022/23 season, combo testing—which detects the flu virus, SARS-CoV-2, and RSV in a single test—is becoming increasingly popular. If the flu virus is detected (marked with the symbol A on the test), we ask ourselves: do we know what type of virus we’re dealing with?

Not everyone realizes that there are several different strains of so-called seasonal flu: Influenzavirus A, Influenzavirus B, and Influenzavirus C (among which sub-strains are further distinguished). The most common type, with the greatest ability to mutate, is type A, which is found in about 70% of patients during the flu season, and it is this type of flu that is detected in combo tests. It has the greatest potential to cause a pandemic because its strains are constantly mutating. This is precisely why it is necessary to develop a new vaccine every year that will be effective against new mutations of the influenza virus.

One of the fastest-mutating viruses

It is believed that the first mentions of the flu date back to the 5th century BCE, from Hippocrates of Kos, considered the father of medicine. The influenza virus was not isolated until 1933, although the first pandemic of this disease was recorded as early as the 16th century, and since then there have been reports of significant increases in cases occurring regularly every 40–50 years. Why, then, do influenza viruses with the potential to cause epidemics appear with almost constant frequency? Precisely because new strains of influenza emerge at regular intervals against which we have no immunity. In such cases, the risk of a pandemic increases significantly.

We are all familiar with the Spanish Flu—the 1918–19 epidemic that claimed an estimated 100 million lives, with 500 million people contracting the flu during that time. Following the Spanish Flu, approximately 50 years later, another flu strain—this time an Asian one—emerged. It spread across China, Singapore, Hong Kong, and the U.S. over a three-year period, claiming an estimated 2 million lives, and a mutation of this virus struck Hong Kong again 10 years later. In 1977, another dangerous strain (known as the Russian flu) emerged, killing over 700,000 people and primarily affecting young people. Why did these pandemics claim so many lives? One reason was the rapid emergence of mutations; another was the lack of access to antibiotics necessary for treating severe pneumonia caused by the initial flu infection. There was also a lack of effective disinfection and hygiene practices to limit the spread of the pathogen, and hand hygiene—pioneered by Dr. Semmelweis, a Swiss gynecologist—left much to be desired.

The virus isn’t so scary

A quick response to the first symptoms of the flu is usually a guarantee that we will avoid a prolonged illness. It is also important to distinguish the flu from a common cold. This plays a significant role not only for our own health but also for protecting the health of those around us—our family members or coworkers. Not everyone knows that a person infected with the flu virus can spread the virus to others as early as 1–6 days before symptoms appear and for several days after symptoms subside. Therefore, the sooner we recognize the symptoms, the faster we can deal with the infection and protect others from getting sick.

The flu is usually distinguished from the common cold by significantly more severe symptoms and a much more sudden onset. Symptoms may appear suddenly, including a fever of around 38°C, general weakness, chills, muscle and joint pain, and a sore, dry throat. The onset of the flu is often accompanied by a runny nose.

How to fight the flu? First and foremost, don’t ignore its symptoms; remember to take vitamin C, which strengthens blood vessels and hinders the virus’s spread. Let your body rest—time spent in bed or under a warm blanket is beneficial for recovery. If you have a fever, use fever-reducing medications and home remedies to bring down the fever—such as extracts from rose hips, raspberries, or lilac flowers. Above all, however, do not ignore the symptoms, and if they worsen, see a doctor. In the case of more severe symptoms and a diagnosis confirmed by tests, among other things, the doctor will prescribe antiviral medications that can prevent complications, which, in the case of the flu, are the most dangerous consequence of ignoring symptoms.

It’s also worth taking preventive measures—the best methods of prevention are vaccines and following basic hygiene rules, which have already become second nature to us during the COVID-19 pandemic. The flu virus spreads through respiratory droplets, but remember that frequent handwashing and the use of effective hand and surface disinfectants developed in professional laboratories will significantly reduce the risk of infection. It’s a good idea to always carry a small, portable hand sanitizer, such as MEDISEPT Hand Sanitizing Spray, and upon returning home—for example, from the store—it’s wise to wipe down the surfaces where you unpacked your groceries, as well as other frequently touched surfaces in the home, such as doorknobs and light switches, with a surface disinfectant.

Vaccinations are also a fundamental preventive measure. The first flu vaccine was developed in 1937, and just four years later, it was administered to humans. To this day, it remains the most effective method of preventing illness and post-flu complications. Since, as we mentioned, the flu is one of the most mutable viruses, a new vaccine is developed every year. Unfortunately, vaccination coverage in Poland is very low, ranging between 4–7%. It is difficult to compare this to the countries of so-called “old” Europe, where 70% of the population receives the flu vaccine. May the time come in Poland when people will want to get vaccinated, because the history of the flu and the recent COVID-19 pandemic shows that pathogens will not let up, and in an era of ever-increasing population mobility, the potential for the spread of viruses will only grow.