Health In Focus
  • Researchers have found the presence of the Zika virus infection in tears in animal studies conducted in mice.
  • This finding could have several implications in humans.
  • Further studies in humans could help to understand the significance of these findings in humans.

Researchers at the Washington University School of Medicine in St. Louis have found evidence of Zika virus in the tears of mice that were artificially infected with the virus in the laboratory. The study is published in Cell Reports.

The recent outbreak of the Zika viral fever in South and Central America has resulted in several aspects emerging for the first time since the discovery of the virus in 1947. The serious consequences of the viral infection resulting in microcephaly (small head) and brain damage in babies born to mothers who were affected by the viral infection during pregnancy spurred research to discover more about the virus.
Zika Virus in Tears: Possible Clinical Implications

The exact way of how the Zika virus reaches the eye is not currently known. Some patients affected with Zika suffer from conjunctivitis, commonly referred to as red eye or sore eye. Deeper eye tissues may also rarely be affected, resulting in a condition called uveitis. Uveitis can result in permanent blindness. Children with Zika infection have been afflicted with inflammation of the optic nerve, the nerve that carries messages from the eye to the brain, damage to the retina or the inner light-sensitive layer of the eye and even blindness.

Researchers have found that genetic material of the virus can be detected in the tears of mice infected with the virus. For the experiment, the researchers introduced the virus under the skin of mice, just as it is inoculated under the human skin by the Aedes mosquito. After seven days, genetic material from the virus was detected in the tears of the mice.

The researchers suggest that there are several clinical implications of their findings.
  • Though the viral material isolated from the tears is non-infective in nature, the possibility of transmission of the virus through tears of patients should not be completely ruled out and should be further explored.
  • The duration that the viral material remains in the eye could give an indication of how long the patient may be infective. The researchers found the genetic material in the tears of the infected mice even 28 days following the infection.
  • If the virus persists in the cornea, it can be transferred accidentally from a cornea donor to a recipient during transplantation. Therefore, it may be necessary to test the cornea for the Zika virus before transplantation.
  • It may be possible to test a person whether he/she is positive for Zika through a test conducted on the tears. Obtaining a tear sample is much easier than obtaining a blood sample, especially in places with poor resources.
  • The study has also implications for drug research. Medications for Zika can be tested on the eyes of animals to test for their effectiveness against the virus.
Further studies in humans will help to understand whether the study findings are relevant in humans as well.

Source: Medindia

Most Popular on Medindia