U.S. probes "unique" Zika case apparently not linked to travel, sex

U.S. health authorities confirmed on Monday a new case of Zika in Utah and have launched an investigation to determine how the person became infected.

The new case is a "family contact" who helped care for the elderly Utah resident who become the first person in the continental U.S. to die after being infected with Zika in late June, according to the U.S. Centers for Disease Control and Prevention (CDC).

However, the new patient has not recently traveled to an area with Zika and has not had sex with someone who is infected with Zika or who has traveled to an area with Zika, the Utah Department of Health said.

In addition, there is no evidence at this time that mosquitoes that commonly spread Zika virus are in Utah.

"The new case in Utah is a surprise, showing that we still have more to learn about Zika," Erin Staples, CDC's Medical Epidemiologist who was on the ground in Utah to assist in the investigation, said in a statement.

"Fortunately, the patient recovered quickly, and from what we have seen with more than 1,300 travel-associated cases of Zika in the continental United States and Hawaii, non-sexual spread from one person to another does not appear to be common."

The investigation is focused on determining how the new case became infected after having contact with the deceased patient who had a "uniquely high amount" of virus -- more than 100,000 times higher than seen in other samples of infected people -- in the blood.

The investigation includes additional interviews with and laboratory testing of family members and health care workers who may have had contact with the deceased patient and trapping mosquitoes and assessing the risk of local spread by mosquitoes, the CDC said.

"Our knowledge of this virus continues to evolve and our investigation is expected to help us better understand how this individual became infected," Angela Dunn, deputy state epidemiologist at the Utah Department of Health, said in a statement.

As of July 13, 1,306 cases of Zika have been reported in the continental United States and Hawaii, and none of these have been the result of local spread by mosquitoes, according to the CDC.

These cases include 14 believed to be the result of sexual transmission and one that was the result of a laboratory exposure, it said.

Zika is spread mostly by the bite of an infected Aedes species mosquito and it can also be spread sexually.

The illness is usually mild with symptoms lasting up to a week, and many people do not have symptoms or will have only mild symptoms.

However, Zika infection during pregnancy can cause a serious birth defect called microcephaly and other severe brain defects. Enditem