Symptoms
Flu symptoms with sudden onset:
- Fever, chills
- Muscle, joint and headache
- Weakness, fatigue
- Sore throat
- Dry irritating cough
- Especially in young children also digestive problems such as nausea, vomiting and diarrhea
- Other complaints (see flu)
Complications
The course is usually benign, mild to moderate, and self-limiting. Rarely, however, a severe and life-threatening course is possible. The most important complication is pneumonia, which has been observed primarily in children and young adults. Other possible complications include bacterial superinfection, sepsis, renal failure, inflammation of the myocardium, encephalitis, and cardiovascular disease. High-risk groups include children <2 years of age, people with chronic medical conditions, pregnant women, and the elderly.
Causes
It is an infection with an influenza A virus of subtype H1N1 (A/California/7/2009 (H1N1)-like virus). The new virus contains genetic components of influenza viruses from pigs, humans, and birds.
Transmission
From human to human, or from the environment to humans:
- In closer contact with infected people (kissing, shaking hands).
- Via hands: hands can be contaminated directly by droplets or by contaminated objects or surfaces.
- Contact with objects and surfaces.
- Via airborne droplets expelled by coughing, sneezing or spitting.
Duration of contagiousness
From the first day before the onset of symptoms until 7 or more days after the person becomes ill. If a person is ill for more than 7 days, he or she should be considered to continue to be contagious until symptoms have subsided. Children with influenza are known to remain contagious for a significantly longer time than adults (up to 21 days in preschoolers). The incubation period for influenza infections is usually short (1-4 days, up to 8 days).
Diagnosis
Under medical treatment. Diagnosis based on symptoms alone is unreliable because numerous viruses can cause influenza-like illness. Differential diagnoses include the common cold and other flu viruses, for example.
Vaccination
Vaccine was supplied beginning in late October 2009 and was available in many countries as of November 2009 (Celtura, Pandemrix, and Focetria; Focetria is out of stock). The 2010 seasonal influenza vaccine also protects against swine flu; see Influenza Vaccination.
Prevention
Hand hygiene: hands should be washed regularly and thoroughly with soap and water. In everyday life, no special hand disinfectant is necessary for this purpose. Regular hand washing has been shown to reduce infection. In the event of an acute illness, it is advisable to stay at home to reduce the risk of transmission to others. People should not return to everyday life until one day after the symptoms have subsided. Sick people who belong to a risk group (e.g. pregnant women, children, chronically ill) should contact their doctor. The doctor should also be contacted if complications occur and if the course of the disease is severe. The Federal Office of Public Health advises coughing or sneezing into a paper tissue. If none is available, cough or sneeze into the crook of the arm. Hygiene masks should be worn in special situations (e.g., major local outbreak, direct contact with ill persons, examination of patients). Chemoprophylaxis: Chemoprophylaxis with neuraminidase inhibitors (oseltamivir, zanamivir) is possible but is not usually recommended.
Nonpharmacologic therapy.
- Bed rest, avoidance of exertion
- Ensure adequate hydration, e.g. hot tea.
- Fever treatment with cooling compresses, lukewarm water or a bath.
Drug therapy
Treatment of acute symptoms: See under the article Flu. The symptoms of uncomplicated swine flu can be treated in exactly the same way as those of normal flu. For severe symptoms and in high-risk groups, it should be treated by a physician. Painkillers such as paracetamol or ibuprofen help against fever, headache, sore throat and aching limbs. Acetylsalicylic acid in children is not recommended (Reye syndrome).For coughs, cough suppressants can be taken. Finally, numerous other conventional and alternative medical remedies are available. Neuraminidase inhibitors:
- Oseltamivir (Tamiflu).
- Zanamivir (Relenza)
- Peramivir (Rapivap)
Neuraminidase inhibitors act causally against the multiplication of influenza viruses. Therapy should be initiated as early as possible, within 48 hours after the onset of illness. They inhibit the neuraminidases of influenza type A and B viruses. These enzymes are essential for the release of newly formed viruses from infected cells and thus for the further spread of infectious viruses in the organism. Animation M2 channel inhibitors: viruses are resistant to amantadine (PK-Merz, Symmetrel) and rimantadine (not commercially available). The drugs are ineffective and should not be used.
