The patient was diagnosed with Zika following care for a family member, an older man, who was infected with Zika from his travels abroad. The man also had other health issues, and later died in June of this year. It is unknown whether the Zika infection worsened his symptoms and contributed to the man’s death, or if the two events were coincidental. Nevertheless, he is the first case of Zika-related death in the continental US.
The Zika virus is known to be transmitted via bites from mosquitos of the Aedes genus. Once infected, humans can transmit the virus to their fetuses. In addition, men infected with the virus can transmit the infection in their semen during sex. And most recently, a case in New York proved that the transmission can go the other way too: from women to men during sex.
What’s perplexing about the Utah case is that the patient is confirmed to not have traveled abroad to high-risk areas, or had sexual contact with either the deceased patient or another person who was infected with Zika. Furthermore, mosquitos of the Aedes genus have not been found in Utah. So how did the infection happen?
Though there’s been no conclusive evidence that Zika can kill, CDC officials revealed the deceased Utah man had a significantly high amount of virus in his blood – as much as 100,000 times more than general Zika infections. Could this have a role in transmitting the virus to the care giver? That’s where the officials are hedging their bets first. “The investigation is focused on determining how the eighth case became infected after having contact with the deceased patient who had a uniquely high amount of virus in the blood,” the Utah health department.
“This raises some interesting questions,” said Dr. William Schaffner, an infectious disease specialist in Tennessee. “Was there a needle stick or injury? Or if not, possible contact with other bodily fluid like urine or saliva?”
Another avenue for investigation is whether there are unknown populations of Aedes mosquitos in Utah. Or perhaps other strains of mosquitos are able to transmit the Zika virus too. But so far, trapping efforts have ruled against this possibility. “We have found no evidence that mosquitoes here in Utah are transmitting the Zika virus,” said Dr. Angela Dunn, the deputy state epidemiologist at the Utah Department of Health.
Meanwhile, other health authorities are reiterating calm amidst this baffling Zika case. “We don’t have any evidence that suggests Zika can be passed from one person to another by sneezing or coughing or kissing or sharing utensils,” said Dr. Thomas R. Frieden, the director of 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,” said Dr. Erin Staples, the CDC’s medical epidemiologist in Utah. “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.”
Additional sources: TIME, NY Times