By Julie Steenhuysen

CHICAGO (Reuters) - The Centers for Disease Control and Prevention has confirmed that a Utah resident's death last month is the first Zika-related death in the continental United States, the CDC said in an emailed statement.

Health officials in the Salt Lake County health department in Utah reported the death on Friday of an elderly resident who had been infected with the Zika virus while traveling to an area with active transmission of the virus.

The exact cause of death is not known, the health department said in a press release.

The resident had an undisclosed health condition and had tested positive for the Zika virus. County health officials said it may not be possible to determine how the Zika infection contributed to the person's death.

The resident was not identified.

The Zika virus typically causes mild illness with symptoms lasting for several days to a week after being bitten by an infected mosquito. Many people infected with Zika have no symptoms.

In April, the CDC reported the first U.S. death from Zika occurring in a patient infected with the virus in Puerto Rico. The man, who was in his 70s, died from severe thrombocytopenia, a bleeding disorder caused by abnormally low blood platelets, which are needed for blood clotting.

Zika is spread primarily through the bite of an infected mosquito, however, the virus can also be spread through sexual transmission.

There is currently no vaccine or treatment for Zika.

Health officials are most concerned about Zika infections in pregnant women because the virus has been shown to cause microcephaly and other severe fetal brain defects. The connection between Zika and microcephaly first came to light last fall in Brazil, which has now confirmed more than 1,600 cases of microcephaly that it considers to be related to Zika infections in the mothers.

The World Health Organization has said there is strong scientific consensus that Zika can also cause Guillain-Barre, a rare neurological syndrome that causes temporary paralysis in adults.

(Reporting by Julie Steenhuysen; Editing by Leslie Adler and Bernard Orr)