iStock/Thinkstock(WASHINGTON) — More information on a mysterious case of Zika virus in Utah has come to light, health officials said Tuesday.

Researchers from the U.S. Centers of Disease Control and Prevention (CDC) examined the case of a Utah man who contracted a Zika infection, although he was not exposed through a mosquito or sexual transmission. Their findings were published today in the CDC’s Morbidity and Mortality Weekly Report.

The man had been caring for an elderly family member, who contracted the virus while abroad in June. The original elderly patient was extremely ill and developed septic shock, according to the CDC. Further testing found his levels of virus were “approximately 100,000 times higher than the average level reported in persons infected with Zika virus.”

The elderly patient died on June 25 and, less than a week later, the family member started to exhibit symptoms of the virus even though he had not traveled to an area with Zika transmission. After a thorough investigation, health officials remained unclear about how the virus spread.

The Zika virus is known to spread through mosquito bites, sexual transmission and blood transfusions. But none of those circumstances were documented in this case.

“Patient A was known to have had close contact (i.e. kissing and hugging) with the index patient while the index patient’s viral load was found to be very high,” researchers from the CDC said in the report. “Although it is not certain that these types of close contact were the source of transmission, family contacts should be aware that blood and body fluids of severely ill patients might be infectious.”

Now, CDC health officials are investigating if bodily fluids in some patients with extremely high levels of virus could also transmit the virus in a mway that has not been previously documented.

Copyright © 2016, ABC Radio. All rights reserved.