It's very kind of you to consider the contagious factor! Scarlet fever is a bacteria that is spread by inhaling the droplets of an infected person (released for example, during coughing), by sharing utensils or other personal items, or by direct contact with an infected person.Effective hand washing is a great prevention tool.carlet fever is a bacteria that is spread by inhaling the droplets of an infected person (released for example, during coughing), by sharing utensils or other personal items, or by direct contact with an infected person.