Number of pregnant women in U.S. with Zika virus triples
The number of pregnant women in the United States infected with Zika virus is suddenly tripling, due to a change in how the government is counting cases.
Previously, officials had reported how many pregnant women had both Zika symptoms and positive blood tests. In a change announced Friday, the Centers for Disease Control and Prevention will count all women who tested positive -- regardless of whether they showed symptoms.
There are now 157 pregnant women infected with Zika in the 50 states, up from 48 cases last week. Another 122 pregnant women with Zika have been reported in U.S. territories including Puerto Rico.
But those numbers may still underestimate the true extent of the problem.
"Only pregnant women who are tested for Zika virus infection are included, thereby potentially underestimating the prevalence of infection and outcomes among all pregnant women," the CDC said in the report. Some states are also not included in the current report, so there may be missed cases. The CDC said it's critical for local health care providers to report possible cases in pregnant women to health department officials.
President Obama received a briefing on the Zika virus today and called on Congress to approve funding to help fight the disease.
Zika can cause a birth defect called microcephaly, in which babies are born with unusually small heads, and other serious brain abnormalities. Recently published reports indicate that some pregnant women with laboratory evidence of a recent Zika infection but without symptoms have delivered infants with these defects.
The agency had counted only those who had suffered symptoms in part over concerns that one type of blood test is too prone to giving a false positive test result if a woman was infected with a different but similar virus.
So far all of the cases reported in the U.S. have been linked to travel in Latin America or other regions where Zika is more widespread, or to sexual contact with someone who traveled. But health officials say mosquitoes are likely to start spreading the virus within the United States this spring or summer.
"If we have people who are infected here, who have the Zika virus here, it's only a matter of time before we have local spread," said CBS News medical contributor Dr. Holly Phillips. "They get bitten by a mosquito, the mosquito then carries the Zika virus and can spread it to someone here within the United States locally."
Because Zika can also be spread through sex, couples are advised to use condoms and postpone pregnancy if they may have been exposed to the virus. "The CDC says... for women who have been possibly exposed, they should hold off on pregnancy for eight weeks," Phillips said.
President Obama has requested $1.9 billion in funding to combat the Zika virus in the U.S., but so far the House and Senate have favored smaller spending packages.
The funding would help pay for local mosquito eradication efforts and essential medical research. "One of the priorities of funding is to develop a fast and accurate test that can be widely available," Phillips said.