People wear protective face masks as they walk down Whitehall in the Spring sunshine on Wednesday in central London. The Bank of England slashed its interest rate to a record low 0.25 percent on Wednesday as part of coordinated emergency action with the UK government to combat the economic fallout from the coronavirus outbreak. Photo:AFP

Animal tests made by Chinese researchers show the novel coronavirus can likely be transmitted via the ocular conjunctival route. Tears and other eye secretions that carry the virus can enter respiratory tissues internally through the nasolacrimal duct, or can pass to the digestive system after being swallowed, it was found.

Qin Chuan, director of the Institute of Laboratory Animal Sciences under the Chinese Academy of Medical Sciences, together with his team found that rhesus monkeys were effectively infected with SARS-CoV-2 via the ocular conjunctival route.

The team administered the novel coronavirus to two healthy rhesus monkeys via their conjunctiva, a tissue lining the inside of the eyelids, and to one monkey through its trachea to act as a control for the experiment.

After seven days of observation, sampling and anatomical analysis, it was found that all three monkeys were infected with the virus.

The test results showed that the ocular conjunctival infection route is different from the respiratory route, and that it is a relatively independent transmission route. 

While the coronavirus is passed on mainly through respiratory droplets and direct or close contact with confirmed infections, other potential transmission routes including ocular conjunctival transmission remain to be researched in depth.

In some clinical cases, tears and conjunctival secretion samples were linked with the coronavirus.

A previous study reported the case of a clinician who was infected with SARS-CoV-2 while treating patients under all safeguards except eye protection. 

Research on 1,099 novel coronavirus patients in 552 hospitals across 30 provinces of the Chinese mainland in January showed that nine patients (0.8 percent of the total) developed conjunctival hyperemia.

Qin's team said they hope to raise awareness, particularly among medical staff, of the possibility of coronavirus infection through the ocular conjunctival route. They are calling for the use of goggles and for people to wash their hands frequently.