As Congress debates emergency Zika funding for the third time this year, new findings from a mysterious Utah case suggest that the virus may spread through contact with bodily fluids, a worrisome new possible route of transmission.
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.
Health officials are recommending that family contacts and close friends caring for Zika patients who are very sick avoid contact with the patient's bodily fluids and use good hand hygiene, said Angela Dunn, deputy state epidemiologist in Utah. Health care workers are urged to continue to apply standard precautions while caring for all patients, including those who might have Zika virus disease. Such measures include wearing gloves, masks and other personal protective equipment.
People may often be lulled into a false sense of security about the way Zika spreads, thinking it may just be through mosquitoes or sex.
Although local, state and federal officials cannot say definitively how the son became sick, the Utah case suggests that the way the virus was transmitted "doesn't appear to be one of the modes we've seen before," said Alexander Kallen, a CDC medical officer.
"It does raise the possibility that there was potential exposure to the blood and bodily fluids of the index patient, and that could have led to transmission of the second case," Kallen said.
Earlier this summer, the Food and Drug Administration asked blood centers in two Florida counties to immediately stop collection because of possible local transmission of the Zika virus. The CDC has since issued travel advisories warning pregnant women from heading to Miami Beach and an area north of downtown Miami known as Wynwood where the virus is being spread locally by mosquitoes.
As part of the investigation in Utah, health officials interviewed and tested 18 other family members, and none were positive for the virus. They also identified medical workers who cared for the elderly man and surveyed 238 households living within a 200-meter radius of the two homes in which the father lived before becoming hospitalized. Eighty-six medical workers and the community residents who agreed to provide blood or urine specimens were tested. No one else has tested positive. Nor have officials found any evidence of either mosquito species that transmit the virus, Dunn said.