Similar to avian influenza, they generally belong to the influenza viruses circulating in the animal world and the human population.

Swine flu virus is an altered H1N1 virus (A/H1N1), which can also be transmitted from person to person.

H and N stand for the most important proteins, called haemagglutinin (H) and neuraminidase (N), which are numbered consecutively according to their occurrence. The most well-known virus type in recent years is H5N1 – avian influenza (bird flu).

According to the estimate of the Robert Koch Institute (RKI), the patients in the USA who contracted the disease had no contact with pigs, and in Mexico only limited contact. It therefore cannot be ruled out that individual cases of influenza can be brought in by travellers.

Symptoms in humans:
The symptoms of swine flu in humans are similar to the symptoms of seasonal human influenza: fever, tiredness, lack of appetite, and cough. Some people who were infected with swine flu viruses reported a running nose, sore throat, nausea, vomiting and diarrhoea.