What is parvovirus? Johns Hopkins doctor explains why it's a concern.

BALTIMORE -- In a new advisory, the CDC warns that parvovirus B19, also known as slapped cheek syndrome, is spreading just as students prepare to head back to school.

Children between the ages of 5 and 9 years old are at particular risk for contracting the disease. 

Symptoms are typically mild and mirror those of the common cold or influenza, but also include a facial rash on the cheek.

"The virus is spread very rapidly through respiratory droplets. School is going to be an opportunity for many different respiratory viruses to spread from person to person," said Dr. Amesh Adalja, senior scholar at the Johns Hopkins University Center for Health Security and infectious disease physician.

The virus can be severe in people who have sickle cell disease, are immunocompromised or are pregnant, according to the CDC.

"Your ability to make red blood cells shuts down if you have sickle cell and get infected with parvovirus. Pregnant women can have their fetus develop anemia and sometimes they can even have pregnancy loss," Dr. Adalja said.

The CDC's advisory comes after the virus spread in Europe over the summer, according to the European Centre for Disease Prevention and Control.

There is no specific treatment for the illness. Typical cold and flu remedies can be used for treating minor symptoms and usually, patients recover within a week.

Healthcare providers are encouraged to monitor their patients for any signs of the virus. People who are at particularly high risk should take more precautions.