The University of Maryland health center said Friday that it has learned of 22 confirmed cases of students with Adenovirus. In four cases, tests showed the presence of Adenovirus 7, which can cause more severe illness than other strains.

The death of one Maryland student has been linked to an Adenovirus infection.

According to the health center, the 22 confirmed cases include a number of students who had were sick earlier in November, but have since recovered.

In a statement issued Friday, the health center distinguished between Adenoviruses that cause colds and are widely found at this season, and a more dangerous strain, known as Adenovirus 7. It said that strain turned up in four specimens sent for testing.

Adenovirus 7 , the statement said, may cause more severe illness particularly for patients with chronic medical problems, or with immune systems compromised by illness, or by medicine.

For them, the health center said, “it is vitally important” not to ignore flu-like symptoms and to visit a physician within 48 hours of developing the symptoms.

In describing flu-like symptoms, the announcement listed high fever and cough/sore throat and vomiting/diarrhea.