WASHINGTON – A dozen new Zika cases are raising worries that the virus may be more easily contracted through unprotected sex than originally believed.
The Centers for Disease Control and Prevention reported Friday that they’re investigating 12 cases where the women’s only known exposure to the Zika virus was through sex with a male partner who had traveled to areas where Zika was active.
Now other researchers are assessing that information and reaching alarming conclusions about how Zika is spread.
“This is very serious business,” said Paul Roepe, co-director of the Center for Infectious Disease at Georgetown University.
Zika has not spread via mosquitoes in the United States, as it has elsewhere, Roepe pointed out. That makes unprotected sex the only known way that the disease has been transmitted in this country – something researchers would never have expected just a few months ago.
“The issue of sexual transmission may turn out to be the most serious consequence for pregnant women living in the continental United States at this point in time,” Roepe said.
Each of the men involved in the 12 known sexually transmitted cases had traveled to countries where the Zika virus is active and eventually came down with symptoms of the disease. CDC epidemiologist Paul Mead said the men were not using condoms at the time.
The cases were reported in the three weeks after health officials in Dallas confirmed that a woman there had contracted the virus after having sex with a man who recently returned from Venezuela. That was on Feb. 4. The next day, the CDC issued new advice to pregnant women to practice safe sex if their partners had traveled to or lived in Zika-affected areas.
The worry about sex comes as health officials are showing growing concern about the effect of Zika on unborn children. On Thursday, the CDC began posting a public service announcement on video monitors in the U.S. Customs and Border Protection area at Miami International Airport, warning pregnant passengers to see a doctor if they’ve been to one of the more than 30 countries and territories where Zika is present.
Sexual transmission had been thought to be relatively rare until last week, with only two suspected cases reported worldwide in at least six years. But the CDC finding of 12 such cases out of 105 infections reported in the United States suggests a far greater role for unprotected sex than previously suspected.
Federal officials said of those 12 cases, two have been confirmed as having been transmitted during sex, four are thought likely to have resulted from unprotected sex, and six are still under investigation.
In two additional cases, researchers think sex was not the cause, but they have yet to determine how the disease was transmitted.
Citing concern for the patients’ privacy, the Atlanta-based federal health agency said it would not reveal the states in which the infected men and women live. However, the Oregon Health Authority reported last week its first case of the Zika virus that was spread by sexual transmission.
Florida health officials said Tuesday that none of the 44 cases recorded in the state was sexually transmitted nor the result of a mosquito bite. All the cases are said to be travel related.
The news of sexual transmission of Zika comes as evidence mounts that the virus presents far greater risks than the rash and low-grade fever that typically mark its onset, especially to the unborn children of women who contract the disease during the first trimester of pregnancy.
Of the nine pregnant women in the United States who’ve tested positive for Zika, the CDC said six women had experienced symptoms of Zika in the first trimester. One gave birth to a baby with microcephaly, a birth defect characterized by a smaller-than-normal head and neurological disorders. Two had miscarriages; two others had abortions. The sixth woman is still pregnant with no known complications.
Of the two women who were exposed to Zika during the second trimester of pregnancy, one delivered a healthy baby and the other has yet to give birth. The woman who was exposed during the third trimester delivered a healthy baby, the CDC said.
CDC director Tom Frieden told Congress last week that the CDC is reiterating its recommendation that men who live or travel to an affected area abstain from unprotected sex or properly use condoms during sex. That’s especially true if their partner is pregnant because of the potential effect on the fetus.
Frieden said that while epidemiologists have yet to conclude that Zika causes microcephaly, there is a clear association between the condition and the virus. He said it is also likely that Zika is associated with another neurological disorder, Guillain-Barre Syndrome, which induces temporary paralysis that in some instances can be fatal.
“I think most epidemiologists would say it’s certainly related,” Frieden said.
Zika was first recorded to have landed in the Americas last May. It was first detected in Brazil, where it is believed to have infected hundreds of thousands of people as it began its march across the Americas. The U.S. cases have been detected in 24 states and the District of Columbia, Puerto Rico and the U.S. Virgin Islands. With 44 cases, Florida has had the most of any state, including 19 in Miami-Dade and six in Broward County.
The Florida Department of Health reported seven new Zika cases this week, including one in Broward County and five in Miami-Dade County. Among the state’s confirmed Zika infections are four pregnant women, health department said. It did not say where the pregnant women live for privacy reasons.
President Barack Obama has asked Congress for more than $1.8 billion in emergency funding to fight Zika domestically and internationally. The money would be used for testing and surveillance to help control any potential outbreak. It would also be put toward finding a vaccine.
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