A new way to catch Zika.

The Washington Post puzzles over a case of Zika in Utah that points to a new way for the virus to transmit itself:

Until now, scientists have said that Zika is spread primarily through the bite of an infected mosquito. It can also be spread through sex as well as blood transfusions, and a pregnant woman can pass the virus to her fetus.

But information released Tuesday by federal and state health officials suggest that contact with bodily fluids, such as tears, discharge from infected eyes, saliva, vomit, urine or stool, could have been how a Utah man became infected after caring for his elderly father. The father died in June after contracting Zika from travel abroad. The father’s blood had a level of infectious virus 100,000 times as high as the average level reported in people infected with Zika, according to a report released Tuesday by the Centers for Disease Control and Prevention.

Most people who get Zika infections don’t show symptoms or have mild illnesses. But in some cases when patients are very sick, “they often have a lot of diarrhea” and the virus could have spread through that exposure, [deputy state epidemiologist Angela] Dunn said. The son reported hugging and kissing his father and helped hospital personnel in holding him while he was being cleaned, the report said.

Although it’s perplexing that no one else developed an infection, officials say it’s hard for a retrospective investigation to fully capture all aspects of the son’s exposure.

“We don’t know if there may have been some unrecognized contact with mucous membranes, or whether it was just bad luck that he came in contact with infected fluid,” [CDC officer Alexander] Kallen said.