All can cause a variety of flu-like symptoms that range in severity and can last from a few days to more than a week. As with Zika, few people infected with dengue or West Nile will show any symptoms.
How is Zika virus treated?
There’s no treatment, but Adalja says most people with symptoms do well with over-the-counter medications for aches and pains. The disease usually runs its course within a week or so.
What is the connection between Zika, microcephaly, and pregnancy?
Zika has been tied to cases of microcephaly in babies born to infected pregnant women. Microcephaly stunts a baby’s head growth, causing devastating, sometimes-fatal brain damage, and it can result in miscarriage or stillbirth. A cause-and-effect link with the Zika virus hasn’t been definitely established, though.
Child with microcephaly
The virus has caused panic in Brazil since it first appeared there in May. More than 4,000 babies in Brazil have reportedly been born with microcephaly. Brazil and several other nations have advised women to postpone pregnancy.
Although there are many causes of microcephaly in babies, including infections during pregnancy, genetic problems, and exposure to toxic substances during pregnancy, Frieden said that the link between the two appears to be getting stronger the more that researchers learn. In addition, research has suggested that infection during the earliest stages of pregnancy, when a baby’s organs are still forming, seems to be linked to the worst outcomes.
The CDC said in January that it tested samples provided by Brazilian health authorities from two pregnancies that ended in miscarriage and two infants with microcephaly who died shortly after birth. In the two full-term infants, the Zika virus was present in the brain. In all four cases, genetic testing showed the virus was the same as the Zika strain circulating in Brazil. All four mothers reported having a fever and a rash consistent with Zika virus during their pregnancies, the CDC says.
As of Feb. 26, the CDC has confirmed nine Zika infections in pregnant women who had traveled to other countries and returned to the U.S. Two resulted in healthy births. Two resulted in miscarriages, and one baby was born with microcephaly. Two pregnancies are proceeding without known complications, and two women ended their pregnancies, the agency says. In one case, the pregnancy was ended after an ultrasound showed signs of severe brain damage in the fetus at 20 weeks. Details of the other termination were not reported.
The CDC also advises that men who have lived or traveled in areas with Zika infections and have a pregnant sex partner either use condoms or abstain from sex during the pregnancy.
In January, the World Health Organization declared birth defects linked to the Zika virus an international public health emergency.
That declaration will speed up research into the suspected connection between the virus and cases of microcephaly in babies of infected pregnant women.