Swine flu

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Dr. med. Mira Seidel is a freelance writer for the medical team.

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Swine flu (New Influenza A / H1N1, New Flu) is caused by a variant of the influenza A virus H1N1. Originating in Mexico, the new influenza pathogen triggered a pandemic in 2009 and 2010. Fortunately, it was mild. Compared to seasonal flu, swine flu has additional symptoms such as nausea, vomiting and diarrhea. In addition, the disease predominantly affects young, healthy adults. Read more about swine flu here!

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. J09J10

Swine flu: description

Swine flu was first detected in April 2009. Doctors also speak of New Influenza A / H1N1 or New Flu. Just a few years ago, the term "swine flu" triggered concerned reactions in the population, while it is now rarely discussed. Many people are not even aware that around a third of the influenza viruses circulating today are swine flu viruses.

The causative agent of swine flu is a type A / H1N1 flu virus, which was unknown until 2009. Like the causative agents of common seasonal flu, the new virus can jump from person to person.

The swine flu initially occurred on a massive scale in Mexico. On June 11, 2008, the World Health Organization (WHO) declared the highest pandemic level 6. On August 10, 2010, the pandemic was declared over as it was no longer a health emergency. However, this does not mean that the H1N1 virus is gone. Years after the pandemic, the virus can continue to circulate and cause infections. Just as no pandemic can be foreseen, neither can one predict how a virus will behave after a pandemic. The WHO therefore prescribes a vaccination against the swine flu virus even after the pandemic.

Swine flu: parallels to seasonal flu

Like seasonal flu, swine flu is transmitted by droplet infection, i.e. when you cough or sneeze. The symptoms are similar, except that swine flu patients also have more gastrointestinal problems.

In contrast to seasonal flu, swine flu does not occur more frequently in winter, but rather in summer. It also affects young, healthy people unusually often. Serious viral pneumonia can also develop as a complication. This is precisely why every swine flu illness must be taken seriously and treated.

Swine flu: incubation period and risk of infection

From infection to the outbreak of swine flu (incubation period) it generally takes one to three, sometimes four days. Infected swine flu viruses can already be passed on during the incubation period, i.e. even if no symptoms of the disease have yet been shown. After the first symptoms appear, infected swine flu viruses are eliminated for three to five days, possibly for up to seven days. In young children, experts assume that they shed more viruses than adults and also for a longer period of time.

The chronically ill and people who have a lot of professional contact with other people have an increased risk of contracting swine flu. These include, for example, medical staff, teachers and kindergarten staff.

Swine flu: symptoms

You can read everything you need to know about the typical signs of swine flu in the article Swine Flu Symptoms.

Swine flu: causes and risk factors

Swine flu is triggered by a type A / H1N1 flu virus. The H1N1 virus was first detected in pigs in 1930. However, this pathogen was not dangerous to animals and infection was not fatal. It has happened that people who have had contact with affected pigs have become infected with this virus. However, transmission from person to person was not possible.

However, the pathogen has evolved and changed (it mutated) over the years. He now has genes from influenza viruses from pigs, birds and humans. Such mixed viruses can develop when a host is infected with several influenza viruses at the same time. Pigs in particular are considered to be classic "mixing vessels" because they can be infected with both swine influenza viruses and those from birds and humans. The modified swine flu virus can therefore now be transmitted from person to person. The majority of those infected with swine flu and those who died during the pandemic were under 60 years of age.

H1N1 virus variants have been circulating since the so-called "Spanish flu" in 1918. Some elderly patients have already become infected with these virus variants, which are similar to swine flu, and have developed a certain level of immune protection. This explains why many young people in particular have swine flu - a clear difference to seasonal flu, which mainly affects the elderly.

Swine flu: multiplication of the virus

A virus can only multiply with the help of living cells, for example from humans or animals (host). The swine flu virus preferentially attacks the respiratory tract and nests in a cell there. It forces the cell to produce countless new viruses that either look for new neighboring host cells or a new host such as humans or animals.

By the way: It is not the target of the virus, but a side effect of the infection that the host's immune system is weakened by the virus.

Swine flu: risk factors

As with normal flu, A / H1N1 also leaps over via droplet infection, for example by coughing and sneezing directly. It is very likely that you can also become infected with swine flu if you touch surfaces (such as doorknobs, cutlery, etc.) to which virus-containing secretions are stuck (smear infection). If you then touch your face, the viruses get through your hand into your mouth, nose or eyes and from there on into the body.

Swine flu: examinations and diagnosis

If you suspect swine flu, you should first call a family doctor and tell him your suspicion over the phone. In this way, precautionary measures against the contagious swine flu virus can be taken in the practice before your visit in order to protect other patients and staff. The swine flu is not an emergency situation, so a trip to the emergency room of the nearest hospital is not necessary.

It is difficult to tell whether you have swine flu based on clinical symptoms alone. The direct detection of the swine flu virus (influenza A / H1N1) in sample material from the patient's respiratory tract provides certainty.

The doctor must take a swab from the pharynx or nasal mucosa as soon as possible after the onset of the disease and send the sample to a laboratory for a detailed examination. The viruses are grown in laboratory vessels (culture). As a rule, this may only be done in specialized laboratories. This also applies to the other tests that are necessary to determine the subgroup (subtype) of the influenza viruses.

Swine flu: treatment

Swine flu is often mild. In most cases, treating the symptoms is enough. The doctor will usually discharge you home unless you have a chronic illness or pregnancy. If you have confirmed swine flu, you must remain in quarantine, whether you are in the hospital or at home, because the disease is extremely contagious. So it is important to avoid any contact with your partner, family and fellow human beings.

Only after seven days, when the swine flu has been treated, one is no longer considered to be contagious. To be on the safe side, protective measures should be observed even after the swine flu has been overcome.

Swine flu: rest, sleep, and fluids

In the case of swine flu, it is particularly important to allow the body plenty of rest and sleep. Any additional activity or sport weakens the body unnecessarily. In addition, you should drink as much fluids as possible in the form of water or tea - the symptoms of sweating, diarrhea and vomiting cause a lot of fluids and electrolytes to be lost. Home remedies can help with the symptoms (e.g. calf wraps for a fever).

Swine flu: medication

Since swine flu is a viral and not a bacterial infection, antibiotics will not help. However, if a bacterial infection (e.g. bacterial bronchitis) occurs as a result of the viral disease, treatment with antibiotics makes sense.

The Robert Koch Institute (RKI) recommends therapy with special flu remedies, especially if patients are chronically ill, for example. Two drugs are available for this case, one with the active ingredient oseltamivir and one with the active ingredient zanamivir.

Both active ingredients belong to the group of so-called neuraminidase inhibitors. They block a certain enzyme on the surface of the virus, which, among other things, enables them to penetrate the human mucous membrane cells. The increase is stopped in this way. The virus inhibitors (antivirals or antivirals) must, however, be taken within 48 hours (maximum 72 hours) after the first symptoms appear. Otherwise the viruses have already multiplied too much in the body - the neuraminidase inhibitors then no longer work.

Swine flu: flu drugs ineffective?

The two drugs used in swine flu are controversial. Researchers from the Cochrane Collaboration and the British Medical Journal have shown that these virus inhibitors are actually unsuitable for fighting swine flu. While the duration of the symptoms of flu can be reduced by about half a day, it will not prevent the serious complications of flu.

Instead, the drugs would induce vomiting, nausea, and abdominal pain. Other side effects can be psychiatric disorders. According to the package insert, these can range from hallucinations, confusion and abnormal behavior to mysterious suicides.

Swine flu: disease course and prognosis

The 2009 pandemic turned out to be less bad than initially feared. In some cases, however, the course of the swine flu was also very serious or even fatal. At least 18,449 people worldwide died from the 2009/2010 swine flu pandemic, in Germany it was 253. Up to 85 percent of those affected were younger than 65 years.

Children under four years of age, pregnant women and people with previous chronic illnesses such as respiratory diseases, cardiovascular diseases, diabetes, immune deficiency and kidney and liver diseases are particularly prone to a severe or even fatal course of swine flu.

So far, the virus has not mutated into an even more deadly form, nor has it developed any drug resistance. The swine flu vaccine has so far proven effective against the viruses in circulation.

Recently published studies have shown that 20 to 40 percent of the population has been infected with the H1N1 virus in the past and, as a result, now has some level of immunity.

Swine flu: general protective measures

There are a few simple steps you can take to protect yourself against swine flu or seasonal flu. The main aim is to prevent virus-contaminated secretion from getting into your own airways and eyes:

• Wash your hands frequently, especially after coming into contact with people, before eating, or when you have come into contact with objects that may have been used by infected people. This also includes door handles in public spaces and handrails in public transport.
• Avoid direct contact with potentially ill people.
• Touch your eyes, nose or mouth as rarely as possible, as they are the entry points for the pathogens.
• Avoid getting coughed or sneezed on.
• Avoid shaking hands.

In addition, there are some tips for patients to prevent the virus from being passed on:

• Ordinary paper respirators offer little protection to healthy people. It is better if patients wear them to prevent them from spreading large amounts of virus-containing secretions and thus infecting other people.
• Sick people should use disposable handkerchiefs and dispose of them safely.
• Those who are already sick should stay at home for at least a week. On the one hand, it prevents infecting others. On the other hand, the patient saves himself from catching secondary infections as a result of his weakened immune system.

Swine flu: vaccination

The greatest protection against infection with any type of influenza is an influenza vaccination. A swine flu vaccination has been available since October 2009 - primarily for particularly vulnerable groups. These include, for example, people with previous illnesses, medical staff, fire brigade, police, correctional officers, pregnant women, people with an increased risk of infection such as schoolchildren, kindergarten children and their family members, as well as teachers and kindergarten staff.

Since the first cases of swine flu did not occur until the spring of 2009, the Robert Koch Institute recommended a separate swine flu vaccination in addition to the normal flu vaccination for the 2009/2010 season. In August 2010, the Standing Vaccination Commission (STIKO) at the Robert Koch Institute withdrew the recommendation for a separate swine flu vaccination. The annual "normal" flu vaccine now also offers protection against swine flu.

Swine Flu Vaccine: Cause of Sleeping Sickness?

Some European studies suggest that the swine flu vaccination may have caused sleeping sickness (narcolepsy) in some cases. In Finland, 60 children between the ages of four and 19 were diagnosed with sleeping sickness during the swine flu pandemic. 52 of them had received the special swine flu vaccine used at the time. In the same year, 29 cases of narcolepsy were diagnosed in Germany. The causal connection is not yet entirely clear. Studies have shown, however, that a small part of the vaccine resembles a part of the neurotransmitter hypocretin, which regulates the sleep rhythm in the brain. According to researchers, a lack of hypocretin can trigger narcolepsy. In people with a corresponding genetic predisposition, the immune system now seems to confuse hypocretin with the swine flu viruses in the vaccine and also attack the messenger substance.

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