Those most likely to get infected are usually people who are in close contact with birds, such as poultry workers. The strains that can impact humans include A (H5N1) or A (H7N9), with H5N1 ...
Norovirus can come on suddenly as it has an incubation period of 12 to 48 hours. Symptoms include vomiting, diarrhoea, abdominal pain, a high temperature, headache and aches and pains.