Twelve cases of Zika virus have been identified in Maryland, a top state health official said Friday.
The emerging tropical disease can cause serious birth defects.
Dr. Howard M. Haft, the state's deputy secretary for public health services, spoke during a news conference called by Gov. Larry Hogan. Officials also discussed what the state is doing to prevent a wider outbreak of the mosquito-borne disease in Maryland.
Haft said the state's 12 cases all involved people who had traveled to areas where Zika is prevalent, including South America, Central America and the Caribbean.
The disease can be spread if a person is bitten by either of two mosquito species or through sexual relations with an infected person.
Hogan said the state is treating the spread of Zika, which had its first widespread outbreak last year in South America, as an emergency. He said the state's response would include stepped-up spraying, aggressive public health measures and education.
"Our state is taking every precaution when it comes to Zika. We are taking this issue very seriously," he said. "At this point, it seems to be manageable."
Officials said the state will conduct an educational campaign aimed at travelers at BWI-Thurgood Marshall Airport and the cruise terminal at the port of Baltimore.
Officials urged residents to inspect their properties for objects such as pots or children's toys that could hold standing water in which mosquitoes can breed. If residents find standing water, they should dump it out and turn the vessel over so it cannot catch rain.
The federal Centers for Disease Control and Prevention reported Wednesday that there have been 426 travel-related Zika cases in the United States, and 36 infected women were pregnant. Eight cases were transmitted sexually. One person contracted Guillain-Barre syndrome.
There have been no Zika deaths in the United States, but the CDC reported Friday that there was a death in Puerto Rico from a complication of the disease.