A new study at the University of Washington, St. Louis, which was published in the journal “Cell”, has detected that the Zika virus is present in tears for five days. The experiment, conducted with mice, gives important information about a possible new source of contagion alert and taking precautions when dealing with infected patients.
This finding explains why a number of patients with Zika virus have developed an eye disease called uveitis, which can cause, if not controlled, loss of vision. It also demonstrates that it remains a disease to be discovered. “Our study suggests that the eye could be a reservoir for the Zika virus,” said Dr. Michael Diamond, Washington University of St. Louis. “Now, we must consider that people with zika have infectious virus in their eyes and you have to check the survival time in the eye.”
For the study, it was infected a group of mice under the skin, similar to how the disease is spread to humans by mosquito bites form. A week later, it was found that the virus was dormant. When 28 days after the tears of mice were studied there was no virus but zika genetic material was detected. The researchers said this may pose a potential new source of contagion, but must be tested in humans to see if the virus behaves the same as in the experiment.
“We are planning human studies to determine whether the infectious virus persists in the cornea or other parts of the eye, as it may cause the obligation to perform corneal transplants,” said Rajendra Apte, principal author of the study. Other blood borne viruses, such as herpes simplex have been accidentally transmitted through corneal transplants.
Although the infection is mainly caused by mosquito bite, the zika persist in body sites where the immune system is less active, including semen, vaginal fluid, saliva and now possibly tears. This could help explain why the zika has spread so quickly, surpassing what might be expected if the virus only by mosquitoes, is transmitted Diamond said.
“Sexual transmission probably is not playing a role, but it could be some other responsible body fluid such as saliva or urine or tears,” he said.