4. Viral gastroenteritis
Some viruses can cause vomiting and/or diarrhoea which can appear to be food poisoning - although the virus is actually caught from infected people in the same way a cold can be passed from person to person. These are often referred to as Norovirus or viral gastrointestinal infections.
This, strictly speaking, is not food poisoning. These are usually quite severe bouts of illness, but recovery is normally within 48 hours. After that time a person may still be a little weak for a day or so from loss of fluids and lack of food.
Viral infection is very common in environments where many people get together, so residential homes, hotels, leisure and entertainments venues are all places where many people can become infected from just one person suffering from the illness. It is also common for ill people to infect others who live with them.
Violent vomiting and diarrhoea generate tiny droplets of infected fluid which land on objects and surfaces. The viruses in these droplets can survive for several days and can be picked up on other peoples hands and transferred to their mouths, passing the illness on. It is important to regularly disinfect surfaces in homes where people have been ill, especially where hands touch, so door handles, tap handles and switches. It is sensible to use disposable cloths and not to move from room to room with the same cloth.