The state Department of Public Health issued a virus alert for the city of Danbury on Friday, saying it has seen a significant spike in cases.

Between Aug. 2-20, the city recorded at least 178 new cases, a sharp increase over the previous two-week period when only 40 new cases were recorded, the department said in a statement.

Much of the outbreak is related to recent domestic and international travel. Residents are urged to stay home if possible, avoid unnecessary outings and wear a mask when leaving home, according to the statement.

“This is a serious outbreak in Danbury and we really need an all hands on deck approach,” Acting DPH Commissioner Deidre S. Gifford said in the statement. “We need you to answer your phone if a contact tracer tries to get in touch.”