Gregory Korte

USA TODAY

WASHINGTON — President Obama told Congress not to leave town before passing a Zika funding bill amid new reports that 279 pregnant women from the United States and its territories have shown signs of infection from the Zika virus.

"Here's the upshot: This is something that is solvable. This is not something we need to panic about. But this is something we have to take seriously," Obama said. "Congress needs to get me a bill. They should not be going off on recess before this is done."

Obama spoke after meeting with his top public safety advisers in the Oval Office Friday. He said scientists are still learning about the scope and effects of the virus, which can cause severe birth defects and miscarriages in pregnant women.

The Centers for Disease Control and Prevention said Friday that 157 pregnant women in the continental United States — and 122 in its territories — have tested positive for the virus,

Less than a half-dozen of those women have reported adverse outcomes, but most are still pregnant and it's not yet known whether those numbers will increase over time, said Dr. Margaret Honein, chief of the CDC's Birth Defects Branch.

The new numbers are as of May 12 and, for the first time, count women who have tested positive for Zika even if they haven't shown symptoms, so they're not comparable to previously reported numbers. Previously, just 47 pregnant women in the continental United States, and 65 in the territories, were reported to have Zika symptoms.

"I think it’s a combination of both — both increasing numbers of pregnant women with a Zika infection, and also a recent change in how we’re reporting out the numbers on a weekly basis," Honein said.

In all, 544 cases of Zika have been reported in the continental United States. But because pregnant women are most closely monitored for the disease, that might be the best indicator of how quickly the disease is spreading. As of Wednesday, none of the cases in the mainland were caused by local mosquitoes, and instead involved people who had recently traveled to Zika-prone areas. There are also 10 confirmed cases of sexual transmission, but the CDC would not say how many of them involved pregnant women.

Even more concerning, Obama said, in Puerto Rico, where the virus is quickly spreading through mosquitoes.

"This is not something we can build a wall to prevent. Mosquitoes don't go through customs," Obama said.

Obama met with Vice President Biden, Secretary of Health and Human Services Sylvia Burwell, Director of National Institute of Allergy and Infectious Diseases Anthony Fauci and Director of the Centers for Disease Control and Prevention Tom Frieden.

Senate approves $1.1 billion to fight Zika virus

The meeting comes as Congress debates how much emergency funding to approve for Zika response before going on recess after Memorial Day, when the summer season heats up and mosquitoes become more active. The Senate has approved $1.1 billion; the House has approved $622 million. The White House has threatened to veto the House bill if it's sent to the president's desk. Obama said Friday the problem with the House bill is that it "robs Peter to pay Paul."

The White House has asked for $1.9 billion.

"We didn't just choose $1.9 billion from the top of our heads. This was based on a public health assessment of all the work that needs to be done," Obama said.

That work includes vaccine development — "You don't get a vaccine overnight," Obama said — and mosquito eradication. "That's a tough piece of business, because we've been using insecticides for a long time that have become less and less effective," he said.

And Obama said that cost is modest in comparison to the human and financial toll of caring for the babies born with smaller heads because of microcephaly, a birth defect linked to Zika.

"If I'm a young family right now, or thinking about starting a family, this is a piece of insurance I'd want to have," he said.