Flu

Introduction

Influenza is an acute, febrile infectious disease. It is caused by viruses and occurs more frequently in winter. In everyday life, the term "flu" is often incorrectly used to refer to flu-like infections, colds or chills: However, these illnesses are usually viral infections that are much more harmless.
The course of the flu can vary greatly - from a mild course to a life-threatening flu illness. Flu can lead to complications that require hospitalisation and sometimes even result in death. For this reason, the Federal Office of Public Health recommends the flu vaccination for people with an increased risk of complications.

Influenza viruses circulate mainly in winter and cause an epidemic practically every year. According to the Federal Office of Public Health, influenza leads to 112,000 to 275,000 consultations with doctors every year. Complications also result in several thousand hospitalisations and several hundred deaths.

Symptoms

Flu symptoms appear suddenly and the flu is often severe. People who have been infected with flu viruses can transmit them to others, even if they do not yet feel ill. The incubation period is a few hours to three days. In the case of flu, several symptoms usually occur simultaneously and intensively. The typical signs of flu are

• Sudden onset of illness
• High fever up to over 40 degrees (also with chills)
• Pronounced feeling of illness throughout the body
• Pronounced pain such as headaches, aching limbs or back pain
• Cough, cold and sore throat

Course

In a typical flu, the first symptoms appear one to five days after infection with the virus. The first sign of flu is often a sudden high fever. In most cases, sufferers are fever-free again after around six days. However, other symptoms such as a cough, runny nose or a general feeling of weakness can last one to two weeks longer.
In most cases, the dangerous thing about flu is not the virus itself, but bacterial infections that follow the flu illness. The person affected is severely weakened by the flu, making it easier for the bacteria to enter the body and lead to further illnesses (e.g. inflammation of the lungs, brain or heart muscle).

The effects of such secondary bacterial infections in the case of flu depend heavily on the state of health of those affected. Young children, older people, women during pregnancy and people with weakened immune defences or chronic illnesses have a high risk of a severe course of flu with complications. In rare cases, these also affect younger, previously healthy people.

Causes

Flu is mainly transmitted by so-called influenza A and influenza B viruses. The virus enters the body via the mucous membranes of the respiratory tract, mouth or eyes. The virus is transmitted by droplet infection, i.e. through contact of the mucous membrane with droplets produced when infected persons sneeze, cough, speak or breathe. People also become infected through contact or smear infections (e.g. smeared nasal secretions, touching infected objects).

Diagnosis

Flu is diagnosed based on a physical examination and the information provided by the person affected. The doctor first determines whether the patient has a common cold or the flu. With flu, several symptoms occur simultaneously and more intensely than with a cold. A "real" case of flu can be diagnosed if at least two of the four criteria - sudden onset, fever, pain and cough - are met. If a flu epidemic is raging at the same time or the flu viruses are spreading significantly in a region, the probability that it is the flu increases.

In many cases, this information can also be obtained by a doctor without having to see the patient in person or examine them on-site. A doctor can diagnose flu very well via telemedicine and in many cases treat it over the phone or video. This is particularly useful as it prevents further infections through contact with other people in a doctor's surgery or on public transport and protects flu patients.

However, if the illness is unusually prolonged or if the respiratory illness has already been present for some time, it may be necessary to carry out further instrumental examinations.

Treatment

As a rule, the patient's symptomatic complaints are treated. Medication can alleviate unpleasant accompanying symptoms such as fever, chills or obstructed airways and strengthen the weakened cardiovascular system. An additional bacterial infection - for example, a sore throat, acute bronchitis, pneumonia or meningitis - can be treated with antibiotics.

Additional measures usually have a favourable effect on the course of the flu. As the body has lost a lot of fluid due to the fever, it is generally important to make up for the loss of fluid by drinking plenty of fluids. The body needs a lot of energy to fight the pathogens - for this reason, the sick person should allow themselves to rest and recover. Other flu symptoms can be alleviated with tried and tested household remedies: For example, calf compresses reduce fever, inhaling steam helps with a cold and gargling with a saline solution supports the healing of coughs and sore throats.

Antiviral medication to combat influenza viruses is usually only administered if the flu is severe or if the person affected belongs to a vulnerable patient group.

Prevention

The best way to prevent influenza is through a flu vaccination. As influenza viruses are constantly changing, the vaccination should be renewed or refreshed every year. The flu vaccination is best given before the start of the annual flu season - preferably from October to November.

Up to 90 per cent of people who are vaccinated are prevented from falling ill or the illness is attenuated and has fewer complications. A cold, on the other hand, cannot be prevented by a flu vaccination. A preventive flu vaccination is advisable for the following people:

• People over 60 years of age
• Pregnant women from the second trimester onwards
• Children, adolescents and adults with a chronic illness (e.g. lung, cardiovascular, liver and kidney diseases, metabolic diseases such as diabetes, chronic neurological diseases such as multiple sclerosis, immunodeficiency, HIV infection)
• Residents of retirement or nursing homes and their relatives
• People who are in contact with people who have an increased risk of a severe course of the disease
• People with an increased risk of infection (medical and nursing staff)

During a flu epidemic, the number of infections can be significantly reduced by taking simple hygiene measures: It is generally advisable for people who are ill not to cough or sneeze into their hands, but to use the crook of their arm or a tissue instead. In addition, those affected should avoid touching their nose, mouth or eyes with unwashed hands. Regular hand washing and avoiding shaking hands or physical contact in general helps to contain the spread of flu viruses.