Zika Virus: High Alert for Pregnant Women

 

Under the C.D.C's testing algorithm, pregnant women who have been to affected regions - whether they have symptoms or not, and whether they have negative or positive blood tests - should eventually have an ultrasound scan to see if their fetuses are developing microcephaly or calcification of the skull.

Unfortunately, an ultrasound usually cannot detect microcephaly before the end of the second trimester.

Some women also should have amniocentesis to test the fluid around the fetus for Zika virus. But amniocentesis involves piercing the amniotic sac with a long needle through the abdomen; it is slightly risky for the fetus and is not recommended before 15 weeks gestation.

Several companies are working on rapid tests for Zika infection. The C.D.C. also usually distributes test kits and training materials to state health departments during outbreaks, which should increase testing capacity.

Half of pregnancies are unintended. If you want to visit a country where Zika transmission has been reported, Dr. Laura E. Riley, a specialist who works with high-risk pregnancies and infectious disease at Massachusetts General Hospital, advises strict use of birth control to ensure you don't get pregnant.

Women who become unexpectedly pregnant while traveling or shortly afterward will face blood tests, monthly ultrasounds and a great deal of anxiety.

"Why would you ever sign yourself up for that?" said Dr. Riley. "There's enough in life to worry about. I wouldn't add that to my list."

With rare exceptions, the virus does not appear to linger in the body, and people who recover from the infection are immune.

"Our understanding, thus far, is that the risk is very, very low if you were in that place prior to conception," said Dr. Laura E. Riley of Massachusetts General Hospital.

"I wouldn't be worried about if you conceived after you got back to the U.S."

The most dangerous time is thought to be during the first trimester - when some women do not realize they are pregnant. Experts do not know how the virus enters the placenta and damages the growing brain of the fetus.

Closely related viruses, including yellow fever, dengue and West Nile, do not normally do so. Viruses from other families, including rubella (German measles) and cytomegalovirus, sometimes do.

Federal health officials say that newborns should be tested for infection with the Zika virus if their mothers have visited or lived in any country experiencing an outbreak and if the mothers' own tests are positive or inconclusive.

The reason, officials said in interviews, is that infection with the virus could be linked to defects in vision and hearing, among other abnormalities, even if the child does not suffer microcephaly. The other defects may require further assessments and testing.

The new guidance applies only to infants of mothers who reported symptoms of Zika virus infection - a rash, joint pain, red eyes or fever - while living abroad in an affected country or within two weeks of travel to such a destination.

The C.D.C. does not recommend a particular antiviral medication for people infected with the Zika virus. The symptoms are mild - when they appear at all - and usually require only rest, nourishment and other supportive care.

There is no vaccine against the Zika virus. Efforts to make one have just begun, and creating and testing a vaccine normally takes years and costs hundreds of millions of dollars.

Because it is impossible to completely prevent mosquito bites, the C.D.C. has advised pregnant women to avoid going to regions where Zika is being transmitted, and has advised women thinking of becoming pregnant to consult doctors before going.

Travelers to these countries are advised to avoid or minimize mosquito bites by staying in screened or air-conditioned rooms or sleeping under mosquito nets, wearing insect repellent at all times and wearing long pants, long sleeves, shoes and hats.

Microcephaly is rare, and it has many other causes, including infection of the fetus with rubella (German measles), cytomegalovirus or toxoplasmosis; poisoning of the fetus by alcohol, mercury or radiation; or severe maternal malnutrition and diabetes. It is also caused by several gene mutations, including Down syndrome.

Until recently, health officials paid little attention to Zika virus. It circulated in the same regions as dengue and chikungunya, and compared to those two painful infections - nicknamed "break-bone fever" and "bending-up fever" - Zika was usually mild.

The virus is thought to have reached Asia from Africa at least 50 years ago. While it may have caused spikes in microcephaly as it first spread, there was no testing to pin down which of many possible causes was to blame.

In 2007, a Southeast Asian strain of the Zika virus began leap-frogging the South Pacific, sparking rapid outbreaks on islands where no one had immunity to it. Because island populations are small, rare side effects did not occur often enough to be noticed. But in 2013, during an outbreak in French Polynesia, which has 270,000 residents, doctors confirmed 42 cases of Guillain-Barre syndrome, which can cause paralysis. That was about eight times the normal number and the first hint that Zika virus can attack the nervous system, which includes the brain.

Zika was first confirmed in Brazil - a country of 200 million - last May, and it spread like wildfire. The first alarms about microcephaly were raised only in October, when doctors in the northeastern state of Pernambuco reported a surge in babies born with it. Pernambuco has nine million people and 129,000 annual births. In a typical year, nine are microcephalic infants.

By November 2015, when Brazil declared a health emergency, Pernambuco had had 646 such births.

French Polynesia is the only area outside of Brazil to be affected by a Zika outbreak in which public health officials have identified an increase in the number of fetuses and babies with unusually small heads. There is "very high suspicion" of a link between the Zika virus and microcephaly in French Polynesia, said Dr. Didier Musso, an infectious disease specialist at the archipelago's Institut Louis Malarde - though he said additional research was still needed.

Last November French Polynesian officials re-investigated an outbreak of Zika that lasted from October 2013 to April 2014. They reported finding an unusual increase - from around one case annually to 17 cases in 2014-15 - of unborn babies developing "central nervous system malformations," a classification that includes microcephaly.

There were no investigations at the time to determine whether the mothers were infected with Zika virus during pregnancy. Four of the mothers were tested later and the results indicated they may have been infected with the virus. Additional research is underway, Dr. Musso said.

We do not know the risk to an infant if a woman is infected with Zika virus while she is pregnant. Zika virus usually remains in the blood of an infected person for only a few days to a week. The virus will not cause infections in an infant that is conceived after the virus is cleared from the blood. There is currently no evidence that Zika virus infection poses a risk of birth defects in future pregnancies. A women contemplating pregnancy, who has recently traveled to an area with local Zika transmission, should consult her healthcare provider after returning.

Women Fitness advice's pregnant women to follow all precautions from getting infected from zika virus, as it has no cure.