Want a Zika Test? It’s Not Easy

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MIAMI — After returning from a honeymoon in the Dominican Republic, Jamie Palmeroni-Lavis asked to be tested for the Zika virus. Ms. Palmeroni-Lavis, 28, a publicist in Rochester, N.Y., wants to get pregnant, but not before she knows her body is Zika-free.

But she and other would-be parents are quickly learning that getting a Zika test isn’t easy.

As worries about the spread of Zika virus in the United States continue to mount, public health department labs in Florida and New York City are running at or close to capacity, while private commercial labs have won emergency approval to run Zika tests and ramped up their testing capacity.

But that doesn’t mean that just anybody can get a Zika test. Even people like Ms. Palmeroni-Lavis, who have compelling reasons to be tested for a virus known to cause devastating brain defects in the fetus, can’t walk into a local health department and get tested on-demand.

That’s because the Centers for Disease Control and Prevention has issued strict guidelines about who can be tested, giving priority to pregnant women with possible exposure to Zika and people with Zika-like symptoms. Already public health officials in Florida say they face a backlog of tests for pregnant women, some of whom may be waiting to make decisions about whether to have abortions if they test positive.

But the C.D.C.’s testing policy largely ignores a sizable subgroup of women and men also at risk — those who are trying to conceive but fear they have been exposed to Zika. The C.D.C. recommends women contemplating pregnancy avoid travel to areas where Zika transmission is occurring and, if they have traveled, says they should wait at least eight weeks or more before trying to conceive. But it does not recommend testing.

Guidance for men is inconsistent. Although the virus can persist in sperm for months after exposure, the C.D.C. recommends that men who may have been exposed to the virus have protected sex for at least eight weeks after potential exposure unless they have symptoms. The World Health Organization just changed its recommendation to six months of protected sex for men and women. Neither group recommends testing.

The restrictions are aimed at preventing an onslaught of requests for Zika tests that could clog the system and prevent public health officials from identifying new cases quickly. They also shape medical practice and influence insurance coverage, making doctors reluctant to order tests and insurers unwilling to cover the costs — between $229 and $800 on the private market — if patients don’t fit the C.D.C.’s testing criteria.

In the case of Ms. Palmeroni-Lavis and her husband, both her obstetrician and primary care doctors declined to refer her for testing because she didn’t meet the criteria.

“If I have to wait a year, I will, because you want a healthy baby,” said Ms. Palmeroni-Lavis, who booked her trip to the Dominican Republic almost a year ago, long before Zika had emerged as a threat. She and her husband already have a 2½-year-old son and want to conceive now so the children are close in age. “If I could conceive sooner rather than later, that would be good for our family,” she said.

Public health experts say the restrictions are necessary to ensure that people most at risk have access to Zika testing.

“We aren’t interested in stimulating the testing of simply anxious people,” Dr. William Schaffner, an infectious disease specialist who is head of preventive medicine at Vanderbilt University Medical Center. “We want health care providers to provide the appropriate counseling and to be selective in the use of this test, as they are in the use of any other test.”

Laboratories and public health agencies say they are inundated with requests for tests, but declined to provide specifics. Julie Kliegl, president of Viracor-IBT Laboratories, a commercial lab in Lee’s Summit, Mo., said demand for Zika testing doubled between July and August.

Clarissa Bradstock, chief executive of Any Lab Test Now, a franchise company with headquarters in Alpharetta, Ga., said its central call center has been getting dozens of calls a day from people asking about Zika testing. The lab briefly offered on-demand Zika testing, in defiance of C.D.C. guidelines, but last week stopped the practice after one of the company’s testing partners raised concerns.

“We’re just trying to respond to customers’ demands,” she said. “We don’t want to add to the hype, but we’re getting many people who want to conceive or are concerned about themselves or their partners being infected.”

One problem with private testing, say health officials, is that most commercial labs can’t offer all the tests needed to determine conclusively if a person has been exposed to Zika.

Testing for Zika is surprisingly complex, and may require three tests to be sure of a result. One test is called a Polymerase Chain Reaction or P.C.R., designed to detect the active virus in blood and urine. The test is similar to those used for more common viruses like West Nile and influenza.

But the P.C.R. test is reliable only if it’s used within a week or two of exposure to the virus. Since most people don’t have symptoms for Zika, many can’t pinpoint the date of exposure. While a positive P.C.R. test shows definitively that a person has Zika, a negative test does not mean a person is Zika free.

If a P.C.R. test is negative, the next step is to test the blood sample for Zika antibodies. Antibody tests are not widely available and can also produce equivocal results.

A negative antibody test means a person wasn’t exposed to Zika. But a positive test result on the antibody test requires a third test to be sure the detected antibodies aren’t other viruses, dengue or Chikungunya, both of which cause flulike symptoms and are present in Latin and South American countries.

The third test, the Plaque Reduction Neutralization Test or P.R.N.T., determines conclusively if a person was exposed to Zika. Currently the test is performed only by the C.D.C. and a limited number of local health department labs.

For men, the story is even more complicated. Men infected with Zika may carry it in their semen for up to six months, but there is no approved test for screening semen.

“Unfortunately, telling someone ‘you do not have Zika and never had Zika’ can be challenging. There are limitations to the best available tests,” said Dr. Jay K. Varma, deputy commissioner for disease control at New York City’s Department of Health and Mental Hygiene. “There are situations in which we have to tell people, ‘We don’t know for sure whether or not you’ve been infected. We can’t conclusively say you were infected, and we can’t conclusively say you weren’t infected.’ That’s the limitation of the technology.”

For Elizabeth Agraz-Sanchez, 33, of Los Angeles, the lack of reliable testing for women who want to conceive has been disappointing. Ms. Agraz-Sanchez had her dream wedding last May on a beach in Puerto Rico, an active zone of mosquito-borne Zika transmission, and didn’t realize the impact it would have on her path to pregnancy.

A cancer survivor, she consulted a fertility specialist after returning home to Los Angeles to talk about getting pregnant. “My doctor just said ‘No, you can’t. No, you have to wait,’” Ms. Agraz-Sanchez said. “It was kind of heartbreaking.”

Some medical groups are pushing back against the C.D.C. guidelines. On Thursday, the American Society of Reproductive Medicine, a membership organization that represents fertility experts, recommended that men and women who may have been exposed to Zika should consider being tested and attempt pregnancy only if tests are negative.

But Kristin Bendikson, assistant professor of obstetrics and gynecology at the Keck School of Medicine at the University of Southern California, said that for now, patients should comply with federal testing guidelines.

“Until we know more about these tests and know that people who test negative are absolutely negative and are at absolutely no risk, I won’t do something different from what the Centers for Disease Control recommends,” Dr. Bendikson said. “Everyone is proceeding with an abundance of caution.”