Workers with the Puerto Rico Health Department and the Centers for Disease Control and Prevention review Zika-related data in San Juan, Puerto Rico, in February. (Danica Coto/AP)

As many as 50 pregnant women in Puerto Rico are becoming infected with Zika every day, top U.S. health officials said Wednesday as they urged the U.S. territory to strongly consider aerial spraying to prevent further spread of the mosquito-borne virus.

The warning came as Puerto Rico debates whether to fumigate with the insecticide Naled, a proposal that has sparked protests in the U.S. territory over concerns about its impact on human health and wildlife.

Tom Frieden, director of the Centers for Disease Control and Prevention, said aerial spraying is the island’s best defense to fight a virus that can cause microcephaly, a rare defect in which babies are born with abnormally small heads and brain damage.

He said the island lacks an integrated mosquito-control program.

“If any part of the continental U.S. had the kind of spread of Zika that Puerto Rico has now, they would have sprayed months ago,” he said. “This is more a question of neglect than anything else. . . . If we wait until children with microcephaly are born, it will be too late. That’s the problem.”

An Aedes aegypti mosquito is shown at the Laboratory of Entomology and Ecology of the Dengue Branch of the Centers for Disease Control and Prevention in San Juan, Puerto Rico, in March. (Alvin Baez/Reuters)

Puerto Rico government officials are still debating the issue, with legislators holding public hearings amid a growing number of protests.

In May, Puerto Rico reported the first microcephaly case acquired on U.S. soil. It involved a fetus that a woman turned over to U.S. health officials who found it tested positive for Zika.

A total of 339 pregnant women in Puerto Rico have been diagnosed with Zika.

Overall, Puerto Rico has reported nearly 2,400 Zika cases, 44 hospitalizations and one death. In addition, 16 people have been diagnosed with a temporary paralysis condition known as Guillain-Barre that has been linked to Zika infections.

Gina McCarthy, administrator for the Environmental Protection Agency, told the AP that Puerto Rico needs to seriously consider aerial spraying.

“It can be done safely and effectively and is perhaps the most important tool we can use right now to change the trajectory,” she said.