Health authorities in Utah are investigating a unique case of Zika found in a person who had been caring for a relative who had an unusually high level of the virus in his blood.
Exactly how the disease was transmitted is still a mystery, though the person has since recovered.
The elderly relative who died after contracting Zika abroad had amounts of the virus in his blood more than 100,000 times higher than other samples of infected people, according to the Centers for Disease Control and Prevention.
Though the tropical mosquito that mainly spreads Zika isn’t typically found in Utah, officials haven’t ruled out the possibility that the man brought a mosquito back with him from an area where he caught the virus, perhaps in a suitcase, according to the Centers for Disease Control and Prevention.
“The new case in Utah is a surprise, showing that we still have more to learn about Zika,” CDC medical epidemiologist Dr. Erin Staples said.
Authorities did not give further details about either patient, citing health privacy laws. The new case was discovered after a doctor noticed the caregiver’s Zika-like symptoms, which include rash, fever and pink eye, officials said.
He or she had cared for the older man both at home and in the hospital. That man died in late June and was the first death of a Zika-infected in the continental US His age and another health condition made his exact cause of death unclear. The caregiver did not travel to an affected area.
Health workers are testing other people who had contact with the first patient. Officials are trapping mosquitoes in Utah to test them, though the species that spread the disease don’t usually live in the state’s high altitude and cold winters.
The CDC did not immediately revise its advice to health care workers or caregivers after the new case emerged.
“Based on what we know so far about this case, there is no evidence that there is any risk of Zika virus transmission among the general public in Utah,” said Dr. Angela Dunn, deputy state epidemiologist at the Utah Department of Health.
Signs of Zika have been found in blood, urine, semen and saliva. There’s no evidence yet that the Zika infection in this case is an unusual mutation, but researchers are exploring that possibility through genomic analysis.