Zika Update: Hundreds of Babies in Puerto Rico Could be Born with Birth Defects

Hundreds of pregnant women are at risk of having babies with severe birth defects as number of people infected with Zika in Puerto Rico increases at an alarming rate, the Centers for Disease Control and Prevention (CDC) said.

According to the latest data, infection rates are continuously rising and will eventually affect one-quarter of the U.S. territory's 3.5 million people.

Current estimates also show that 1 percent to 13 percent of babies born to women infected with Zika during pregnancy will have birth defects such as microcephaly, a condition where babies are born with abnormally shrunken heads.

"In coming months, thousands of pregnant women in Puerto Rico will catch Zika," CDC director Thomas Frieden said in a press release published on The Washington Post.

"This could lead to dozens or hundreds of infants being born with microcephaly in the coming year," Frieden added.

The data came from blood donation testing results from blood centers in Puerto Rico. According to the data, the percentage of blood donations testing positive for Zika has been increasing at 1.1 percent in the week ending June 11. This is the highest level since testing began in April 3, CDC said.

This percentage translates to a 2-percent infection rate each month and a 25-percent infection rate annually.

"These numbers are increasing faster than we had anticipated," Frieden said in an interview with The Washington Post.

About 32,000 babies are born in Puerto Rico each year, and the projected increase in Zika infection rate would put thousands of women at risk before giving birth, CDC said.

The estimate of the number of birth-defect cases was based on a recent study in Brazil, which found that women who were infected in the first trimester faced a 13-percent risk of giving birth to infants with Zika-related birth defects.

According to the Puerto Rico health department, the island territory has 1,726 confirmed cases of Zika, including 191 pregnant women. So far, only one case of microcephaly has been reported to date.