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
- Researchers have found the
presence of the Zika virus infection in tears in animal studies conducted
- This finding could have several
implications in humans.
- Further studies in humans could
help to understand the significance of these findings in humans.
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
during pregnancy spurred research to discover more about
‘The finding of the Zika virus in tears can have several clinical implications.’
The exact way of how the Zika virus reaches
the eye is not currently known. Some patients affected with Zika suffer from
, 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.
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 accidently 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.