CDC has issued an updated guidance and information to prevent Zika virus transmission and health effects surrounding updated interim guidance for healthcare providers caring for pregnant women with possible exposure to Zika virus; and updated interim guidance for the prevention of sexually transmitted Zika virus.
CDC updates its interim guidance related to Zika virus transmission and related health effects based on the accumulating evidence, expert opinion, and knowledge about the risk associated with other viral infections. CDC will continue to update this guidance as new information becomes available.
Updated interim guidance for healthcare providers caring for pregnant women with possible exposure to Zika virus
Because the diagnosis of Zika infection can be complicated, the updated guidance expands the timeframe, up to 14 days, that testing for Zika virus particles in the blood of pregnant women can be offered. This expansion will provide a definite diagnosis for more pregnant women infected with for Zika virus.
Many people infected with Zika virus won’t have symptoms or will only have mild symptoms. Up until now, scientists thought that if a person becomes sick after being infected with Zika, the virus stays in the person’s blood for about a week after symptoms started. So the first week of illness was thought to be the best time to find evidence of the virus in blood using a Zika-specific test. But not everyone will see a health care provider while they are sick with Zika and many will not have symptoms. For those who visited a health care provider more than a week after symptoms started, that is, after the virus has cleared from the blood, and those who were possibly exposed to Zika but never developed symptoms, healthcare providers could order a different test to look for evidence that the body is fighting a virus in the family of viruses that includes Zika. The results of the latter test are more difficult to interpret because the body’s reaction to Zika virus can resemble the reaction to similar viruses; therefore, this test may not provide a definite diagnosis.
New information has indicated that some infected pregnant women can have evidence of Zika virus in their blood for longer than the previously recommended seven-day window for testing after symptoms begin, and that even pregnant women without symptoms can have evidence of the virus in their blood and urine. Therefore, the updated guidance expands the Zika-specific blood testing for a longer period, up to 14 days, in pregnant women with symptoms and advises that pregnant women with possible Zika exposure but no symptoms receive this testing as well. In addition, if pregnant women visit their healthcare provider after the 14 day testing window and test positive with the less-specific test, the Zika-specific blood testing can now be offered potentially to provide a definite diagnosis for pregnant women with Zika virus infection. Expanding the use of the Zika-specific test could provide more women with Zika virus infection a definite diagnosis and help direct medical evaluation and care. In addition, the CDC’s new guidance includes recommendations to help healthcare providers better care for their pregnant patients with confirmed or possible Zika infection.
Updated recommendations for the prevention of sexually transmitted Zika virus to include the possibility of sexual transmission from an infected woman
This expanded guidance is based on a recently reported case of female-to-male sexual transmission in New York City and limited human and non-human primate data indicating Zika virus RNA can be detected in vaginal secretions. It expands CDC’s definition of sexual exposure to Zika to include sex without a barrier method (including male or female condoms, among other methods) with any person-- male or female-- who has traveled to or lives in an area with Zika. The updated recommendations for pregnant couples include pregnant women with female sex partners who are potentially infected with Zika. They also give advice for potentially infected women about how to reduce their risk of sexually transmitting the virus to partners.
Although transmission of Zika from a woman to her sex partners is believed to be uncommon and (as with the majority of Zika infections) unlikely to result serious side effects, it could present a risk for pregnant women with female sex partners who may be infected with Zika. For this reason, CDC recommends that all pregnant women with sex partners (male or female) who live in or traveled to an area with Zika use condoms during sex or abstain from sex for the remainder of their pregnancy. All other couples in which a partner (male or female) has been in an area with Zika can also reduce the risk of sexual transmission by using condoms or abstaining from sex. Sex includes vaginal, anal and oral sex, and may also include the sharing of sex toys. Health care providers should test all pregnant women who may have been exposed to Zika sexually. Health care providers should also test any patients for Zika if they develop symptoms of Zika and report potential sexual exposure to a partner who lives in or traveled to an area with Zika. CDC encourages local and state health department to report potential cases of sexually transmitted Zika virus infection.
CDC will continue to update its guidance related to Zika virus transmission and related health effects based on the accumulating evidence, expert opinion, and knowledge about the risk associated with other viral infections.