This article is more than 5 years old. Information may no longer be current.
CDC updates Zika testing guidance for pregnant women
Click Here to Manage Email Alerts
The CDC issued a health alert notice on Friday with updated guidance on the interpretation of Zika testing results for women who plan on becoming pregnant and live in or frequently travel to areas where the virus is circulating.
New data suggest that, for some patients, Zika antibodies may remain in the body for months after infection. Therefore, the CDC warned that Zika virus immunoglobulin M (IgM) ELISA assays, which are used to detect Zika antibodies or proteins, may not be able to determine the timing of the onset of the infection.
“Although IgM persistence could affect IgM test interpretation for all infected people, it would have the greatest effect on clinical management of pregnant women with a history of living in or traveling to areas with Zika virus transmission before conception,” the health advisory said. “Pregnant women who test positive for IgM antibody may have been infected with Zika virus and developed an IgM response before conception.”
The CDC recommends that health care professionals consider testing women who plan on becoming pregnant and may have been exposed to Zika for antibodies before pregnancy. However, the results should not be used to determine whether it is safe for a woman to become pregnant. Instead, the results can be used to establish baseline IgM results and can help determine whether a woman became infected during pregnancy.
“For example, if a woman has a negative result before pregnancy and a positive result when she is tested during pregnancy, it is more likely that the woman experienced an infection during pregnancy,” a press release said.
The CDC also recommends that health care professionals evaluating asymptomatic pregnant women with potential Zika exposure should:
- screen for signs of infection and promptly test women using nucleic acid testing (NAT) if they develop symptoms during pregnancy or if their sexual partner develops Zika;
- consider NAT testing at least once during each trimester, unless a previous test was positive;
- consider testing any specimens collected during amniocentesis for evidence of Zika virus; and
- counsel all pregnant women during each trimester on the limitations of Zika testing.
Although testing recommendations for symptomatic pregnant women remain unchanged, health care providers should be aware that a symptomatic pregnant woman who is IgM positive but NAT negative and had lived in or traveled to an area with Zika transmission does not necessarily have a recent infection, the CDC stated.
“Our guidance … is part of our continued effort to share data for public health action as quickly as possible,” Henry Walke, MD, incident manager of CDC’s Zika response efforts, said in the release. “As we learn more about the limitations of antibody testing, we continue to update our guidance to ensure that health care professionals have the latest information for counseling patients who are infected with Zika during pregnancy.” – by Stephanie Viguers
Disclosure: Walke reports no relevant financial disclosures.