U.S. health officials say they believe that a man who recently died while infected with the Zika virus in the state of Utah passed the disease to a caregiver beforehand, raising questions about how the virus is spread.
Officials with the U.S. Centers for Disease Control and Prevention said Monday that the caregiver, a family contact, tested positive for the virus but appears to have recovered from the infection.
They are investigating how the disease could have spread between the two people. Officials say the type of mosquito that mainly spreads the virus in not found in the high-altitude area where they live. Also, officials say the two individuals did not have sexual contact - another way the virus is spread.
The man who died caught the virus while traveling abroad. He was the first person in the United States to die after becoming infected. Officials say the exact cause of death is not clear because the man was elderly and had an underlying heath condition.
Zika is spread primarily through mosquito bites. Experts are especially concerned about infected mosquitoes biting pregnant women. They say this could cause microcephaly, which is linked to brain defects from birth.