The Zika virus might be able to pass from person to person through bodily fluids like tears or sweat, doctors reported.
Mosquitoes and sexual contact
A 38-year-old man in Salt Lake City appears to have contracted Zika while caring for an elderly man who died from complications related to Zika infection, according to a report in the New England Journal of Medicine.
The younger man came into direct contact with the older man's tears and sweat while taking care of him, and that appears to be the way he contracted Zika, doctors at the University of Utah School of Medicine wrote in the journal.
Up to now, Zika virus mainly has been transmitted through mosquito bites, although in rarer instances it has been passed on through sexual contact.
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The 73-year-old man had recently returned from a three-week trip to the southwest coast of Mexico, where he had been bitten by mosquitoes. Soon after returning to Utah, he reported Zika-like symptoms, including abdominal pain, sore throat, fever, red eyes and diarrhoea. He eventually was hospitalised due to dangerously low blood pressure, laboured breathing and an abnormally fast heart rate.
No active mosquito transmission
The man's condition declined while in the hospital, and he suffered respiratory and kidney failure. He died on day four of hospitalisation, after care was withdrawn, the doctors wrote.
Five days after the older man died, the younger man reported having developed red eyes, fever, muscle pain and a facial rash. His urine and blood tested positive for Zika.
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There has been no active mosquito transmission of Zika in Salt Lake City, the doctors reported, but the younger man had placed his hands on the older man while helping care for him.
The younger man had helped reposition the older man in his sick bed, and had wiped the man's eyes without using gloves, the doctors said.
Infections in Florida
The older man's death from Zika is rare. Up to now, only nine deaths directly caused by Zika infection have been confirmed in adults, the doctors noted in their letter.
Read: Zika may persist for months in newborns
"Whether contact with highly infectious bodily fluids from patients with severe [Zika] infection poses an increased risk of transmission is an important question that requires further research," the University of Utah doctors concluded.
Zika is the first mosquito-borne virus known to cause severe birth defects, most of them brain-related. The most common defect is microcephaly, in which a child is born with an abnormally small brain and skull. Thousands of babies have been born with Zika-linked microcephaly, most of them in Brazil, since an outbreak began in South America in April 2015.
Zika infections have been occurring in south Florida, with an estimated 40 to 50 cases in the Miami area, according to the federal Centres for Disease Control and Prevention. There have been no reports of locally transmitted cases of microcephaly in the state or anywhere else in the United States.
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