The migration of Zika into North America is proving to be a headache for all involved in health care, because while the symptoms of Zika are relatively mild in most patients, there are serious complications for infected women who are pregnant.

The Centers for Disease Control and Prevention confirmed what many already believed: the Zika virus causes microcephaly and other “severe fetal abnormalities,” according to a Washington Post report. The full CDC report was published in the New England Journal of Medicine. The virus was also linked to an autoimmune disorder similar to multiple sclerosis called acute disseminated encephalomyelitis, which causes swelling of the brain and spinal cord, affecting the coating around nerve fibers, according to a paper reported on by USA Today

The following are facts and guidelines from the Centers for Disease Control and Prevention and the World Health Organization:

1. One in five infected develop symptoms, which include acute onset of fever with maculopapular rash, arthralgia or conjunctivitis.

2. There isn’t a vaccine or medicine for Zika, but patients should get rest, drink fluids, take acetaminophen or paracetamol, but avoid aspirin and other nonsteroidal anti-inflammatory drugs.

3. Cases of Guillain-Barre syndrome have been reported in patients thought to have Zika and the CDC has concluded Zika is a cause of microcephaly and other severe fetal brain defects in newborns.

4. The CDC suggests that exposed individuals wait at least eight weeks before attempting conception if they don't live in an area of active Zika transmission.

5. There were 358 travel-associated cases reported in the continental U.S. as of this writing — 31 of which were in pregnant women and seven were sexually transmitted cases.