Sen. Jeanne Shaheen asks for aggressive response to Zika virus

The letter was sent Wednesday to the secretaries of state, health and human services and homeland security, urging them to quickly notify Congress of what resources they need to mount a defense.

"As the Zika virus spreads, the federal government needs to have a plan in place," Shaheen said. "Congress must also demonstrate that it understands the breadth and depth of this virus and be ready to assist in this effort. By planning ahead and marshalling federal resources, we can help prevent a major outbreak of Zika in the United States."

The virus, first detected in 1947, caused mild disease for decades. It's now in more than 20 countries, spread by the Aedes mosquito. In recent days, the virus has been discovered in Americans who have traveled to countries where Zika has been found.

Shaheen notes American public health and military personnel "performed heroically" to stop the spread of the Ebola virus in West Africa. While the Zika virus doesn't yet require the same resources, she encourages coordinated efforts with the same urgency.

"Within our own borders, U.S. Customs and Border Protection should enhance monitoring at ports of entry for mosquito infestations in cargo and for individuals demonstrating symptoms of the virus," she wrote. "The Department of Health and Human Services should also work with state and local public health officials and frontline health care providers to ensure they have the most up to date information about the virus, how to test for it, and how it could impact at-risk groups."