What is the Zika virus?

Dr. Nicholas Kaloudis

Concerns are growing over the mosquito-borne illness known as Zika virus, which has been spreading through Central and South America and is believed to be linked to a surge in serious birth defects in Brazil.

The U.S. Centers for Disease Control and Prevention has issued a travel advisory urging pregnant women to consider postponing travel to more than two dozen countries and territories, mostly in Latin America and the Caribbean, where Zika virus is present. Because of the possible link to birth defects, pregnant women who must travel to affected areas should talk to their doctor or other health care provider first and strictly follow steps to avoid mosquito bites during the trip, the CDC said.

The virus reached Mexico in November and Puerto Rico in December, and the CDC has confirmed more than 30 cases of Zika in the US. in travelers who recently returned from trips to Latin America.

What is Zika virus?

Zika virus is an illness transmitted to people through bites from mosquitoes of the Aedes species — the same mosquitoes that spread dengue and chikungunya viruses. It not communicable from person to person but can be transmitted when a mosquito bites someone who’s infected and then bites someone else.

The virus was first discovered in Uganda in 1947 and named after the forest in which it was found.

Officials say the current Zika outbreak in Brazil began last May. Authorities there estimate that since then, between 440,000 and 1.3 million people have caught it. Zika has spread to other countries in Latin America and the Caribbean, including Colombia, Venezuela, Honduras and Mexico. Puerto Rico reported its first case of locally transmitted Zika virus in December.

What are the symptoms?

According to the CDC, the most common symptoms of Zika virus are fever, rash, joint pain, and conjunctivitis. Other symptoms can include muscle pain, headache, pain behind the eyes, and vomiting.

Symptoms are usually mild, lasting from a few days to a week. Many people infected with the virus experience no symptoms at all. In rare cases, symptoms can become severe and require hospitalization.

A number of Zika patients in Brazil have also gone on to develop a rare autoimmune condition called Guillain-Barre syndrome which can cause at least temporary paralysis. Health officials are investigating the possible connection.

Is there a vaccine or cure?

There is no vaccine to prevent Zika virus. The U.S. National Institutes of Health is ramping up efforts to develop one, but the process will take time.

There is no specific treatment for Zika except to try to ease the symptoms.

What do we know about its possible link to birth defects?

Health officials in Brazil say they’ve found strong evidence that Zika has been linked to a sudden rise in the number of babies being born with abnormally small heads, a condition called microcephaly, which often results in mental retardation.

Brazil’s government reports more than 4,000 babies have been born with microcephaly since the Zika outbreak began there, up from fewer than 150 in 2014.

While more research is needed to confirm true cause and effect, and experts acknowledge other factors may be at play, researchers say the evidence to support the link is strong. In response, authorities in Brazil, El Salvador and some other affected areas have told women to put off pregnancy if they can.

I’m traveling to an affected region. Should I be concerned?

Currently, the CDC recommends that all travelers to areas where Zika is spreading — mostly in South America, Central America, the Caribbean — take steps to protect themselves from mosquitoes.

“Out of an abundance of caution,” the CDC said it’s advising pregnant women in any trimester to avoid travel to areas where Zika is spreading, if possible, or to take extra precautions to avoid mosquito bites if they must be there. Women trying to become pregnant or who are thinking about becoming pregnant should consult with their health care provider before traveling to these areas and take care to protect themselves from mosquito bites.

The countries named in the CDC travel alert are:

• In Latin America: Bolivia, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Suriname and Venezuela.
• In the Caribbean: Barbados, Curacao, the Dominican Republic, Guadeloupe, Haiti, Martinique, St. Martin, Puerto Rico, the U.S. Virgin Islands.
• Cape Verde, off the coast of western Africa.
• Samoa and American Samoa in the South Pacific.

What can I do to protect myself?

The CDC recommends the following steps to avoid mosquito bites:

• Cover exposed skin by wearing long-sleeved shirts and long pants.
• Use an insect repellent approved by the Environmental Protection Agency as directed.
• Higher percentages of active ingredients provide longer protection. Use products with the following active ingredients: DEET, Picaridin, oil of lemon eucalyptus (OLE), IR3535.
• Use permethrin-treated clothing and gear, such as boots, pants, socks, and tents. You can buy pre-treated clothing and gear or treat them yourself.
• Stay and sleep in screened-in or air-conditioned rooms.
• Use a bed net if the area where you are sleeping is exposed to the outdoors.

Will Zika virus become a problem in the U.S.?

Though no locally acquired cases have been reported in the U.S., Zika has been reported in American travelers who recently visited affected locations. Experts believe it is inevitable that we will see more cases in the US.

The mosquitoes are here. They’re certainly not as abundant in the winter months as they are in the spring, but there are probably a fair number of people here who have visited the Caribbean or Latin America who are already infected with Zika virus. Our mosquitoes are going to bite those individuals, pick up the virus, and transmit it to another person.

We’re seeing rapid spread of the virus and we need to act now. The first thing is to undertake a program of active surveillance throughout the Western Hemisphere, not only where it is right now, but in places it could soon rise, including the Caribbean, and the Gulf Coast of the U.S. Then if we start seeing transmission in these areas, we should  provide appropriate advisories, and education materials to women of reproductive age, who are pregnant or are planning on getting pregnant.