Over 30 people have been infected with salmonella in the Bergen area in Norway, reports the local newspaper Bergens Tidende. They are suffering from nausea and diarrhoea. The epidemic could be the biggest of its kind in the world. Those infected all come from outlying districts, and have been in contact with hedgehogs. Salmonella with hedgehogs as the source is extremely rare.It has only happened once before, also in Norway, in 1996 when 28 people were infected outside Moss, near the Oslo Fjord, a long way from the present outbreak. At that time everyone was surprised that hedgehogs were the cause of the infection.However, now the Norwegian National Health Institute suspects that the same basic bacterium has been active for several years, and that the original source of infection is seagulls flying along the western coast of Norway.It appears that the infection has moved from Herøy parish, where 54 people were ill last winter, to Bergen. DNA tests show that the bacterium is the same type in both places. This is important, since there are more than 2,500 different salmonella bacteria. A dead seagull was found in the drinking water in Herøy, infected with the same bacterium as the one causing the current outbreak.How the seagulls infected the hedgehogs is anyone's guess. But, if seagulls are the cause, it will be very difficult to eradicate it, said consultant doctor Jørgen Lassen to Aftenposten, the national evening paper.Nobody living in flats in the city of Bergen has been infected, just people who live out in the country where hedgehogs are around. Direct contact with the animals, or their excrement, which is brought into the house by people or pets, is probably the reason for the epidemic.