Zika rates could grow in US this summer

May 04, 2016

So far, all of the Zika virus cases identified in the U.S. have been related to travel, but that’s likely to change soon. As warmer months approach, we expect to see the mosquito-borne virus spread locally in regions such as the Gulf Coast, home to Texas, Louisiana, Mississippi, Alabama and Florida.

We will not see locally-acquired cases of Zika in the Pacific Northwest, since the mosquito that carries the virus is not found here. The exception to this might be sexual transmission from a partner who has been infected while traveling.

Advice on screening

Since the virus continues to spread through the Americas and its presence could grow in parts of the U.S., we are advising travel screening for all pregnant women. If a provider believes a pregnant woman may have been exposed to the virus, the care giver will recommend appropriate testing and follow-up. We also will track at-risk pregnant women planning to deliver their babies at Swedish so we can follow up as new information about Zika becomes available.

As a reminder, only 4 out of 5 people who contract Zika have symptoms, which include fever, rash, joint pain and conjunctivitis.

The main concern about Zika is its potential effect on the developing fetus. When the virus infects a pregnant woman, it can be transmitted from mother to fetus and cause birth defects. The most severe of these is microcephaly, a birth defect associated with a small head and incomplete brain development. But Zika likely causes a spectrum of abnormalities.

Still many unknowns about Zika

We still don’t know the mother-to-fetus transmission rate, or what time in pregnancy transmission is most likely to occur.

There is no treatment for Zika, and no vaccine to prevent infection. Women who are currently (or planning to become) pregnant and their partners should avoid travel to affected areas. If travel is unavoidable, it is essential to protect against mosquito bites.

Preventing sexual transmission

As we now know, Zika can be sexually transmitted. This means that a pregnant woman whose partner has traveled to an affected area should avoid intercourse or use condoms for the remainder of the pregnancy. For couples who are planning pregnancy, women who have traveled to a Zika-affected area should wait eight weeks, regardless of whether they have symptoms. Men with travel exposure and no symptoms should wait eight weeks, and those with symptoms should wait six months.

Testing for Zika is limited and not available commercially. In the first week after exposure, a blood test (PCR) for the virus can be done. From two to 12 weeks after exposure, an IgM antibody blood test is available.

CDC a good source of information

The accuracy and detection rates for these tests are not perfect, and results may not be available for several weeks. This may change with time as more testing becomes available. In many cases of known or potential exposure to Zika in pregnancy, the best monitoring will be over time with ultrasound.

The Centers for Disease Control and Prevention frequently updates its website with Zika news and is an excellent source for the latest information.

If you are pregnant and have concerns about Zika, call 206-386-2229 to schedule an appointment with your provider. If you are planning to become pregnant, we also can answer your questions and help you find a doctor or midwife.