Because fifth disease is most contagious before a person starts showing symptoms of a rash, and because it's most often found in children, the virus tends to spread through outbreaks at schools or in closed communities [source: Wisconsin Department of Health Services]. In the case of school outbreaks, anywhere from 10 to 60 percent of students may get the disease [source: Center for Disease Control].
The disease passes from person to person through secretions such as saliva, sometimes, for example, by drinking from the same cup [source: Center for Disease Control]. This can happen during an outbreak or simply by coming into contact with a single infected person.
Although fifth disease outbreaks can happen at any time of the year, they're most common in late winter or early spring. There's no specific reason for this, though it most likely happens because people don't go outside as often in the colder months and therefore spend more time with others in enclosed areas [source: Kid's Health].
Rumors exist that fifth disease can be contracted from pets, particularly dogs. Although dogs are susceptible to a parvovirus, it is not the same one that affects people. Canine parvovirus attacks the intestines, white blood cells and sometimes the heart of dogs. It cannot be passed to humans, and likewise, the human virus cannot be passed to animals [source: American Veterinary Medical Association].
Read on to find out how this childhood disease becomes more serious when caught by adults, particularly pregnant women.