At least 18 people across Norway have fallen ill with a rare strain of Salmonella, according to the Norwegian Institute of Public Health. The strain, Salmonella Coeln, infected three children and 15 adults. Each year for the past 10 years, Norway has seen zero to three cases of illness from this particular strain. Norwegian health authorities are currently investigating the cause of the outbreak. Norwegian counties where patients fell ill include Buskerud, Oslo, Rogaland, Akershus, Nordland, Oppland, Troms, Vestfold, Hordaland, Vest-Agder and Østfold.