Woman infected with Zika in Pittsburgh lab accident

A female lab researcher in the University of Pittsburgh area has been infected with the Zika virus from an accidental needle stick, in what federal health officials believe may be the U.S.'s first case of the disease contracted through a laboratory.

The needle stick occurred May 23, according to a university statement. The woman developed symptoms of Zika June 1, including a fever. Symptoms of Zika can include fever, rash, joint pain, headache and pink eye. The university learned that the blood test was positive for Zika virus June 8.

The woman's fever disappeared June 6, and she returned to work the same day, according to the University of Pittsburgh.

Zika primarily spreads through the bite of infected Aedes aegypti or Aedes albopictus mosquitoes. The woman has agreed to wear long sleeves, pants and insect repellent for three weeks to prevent mosquitoes from biting her, according to the university.

The woman doesn't pose a health risk to her coworkers, because the virus doesn't spread from person to person through casual contact, like a cold. Although men can transmit the virus through sex, it's not known if women can transmit the virus through sex.

In order for the woman to spread the virus, an Aedes mosquito would have to bite her, incubate the virus for several days, then bite someone else, said Amesh Adalja, a senior associate the Center for Health Security at the University of Pittsburgh Medical Center who has no personal knowledge of the woman's case. A mosquito who bites an infected person is not immediately contagious.

Most people face no serious risk from Zika infections. Only 20% of patients develop any symptoms, which are usually mild, according to the Centers for Disease Control and Prevention. In rare cases, Zika can cause Guillain-Barre syndrome, a type of paralysis that occurs when the body's immune system attacks the nerves. Zika also can cause devastating birth defects in fetuses.

The woman's case appears to be the first time that a U.S. lab worker has been infected with Zika during the current outbreak, according to the CDC.

More than 600 Americans in the continental U.S. have been infected with Zika, including 195 cases in pregnant women. All of those cases were related to travel to an outbreak area or sex with an infected traveler. More than 1,100 people have been diagnosed with Zika in Puerto Rico, including 146 pregnant women, where the disease is spreading among local mosquitoes, according to the CDC.