Fourteen newborn babies at KK Women's and Children's Hospital's (KKH) neonatal intensive care unit (Nicu) contracted conjunctivitis between mid-October and Dec 1.
Associate Professor Ng Kee Chong, chairman of the hospital's Division of Medicine, said that all the babies were in the Nicu for serious medical conditions.
He told The Straits Times that 12 hospital employees working in the Nicu were also diagnosed with the condition. "Upon diagnosis, these staff were treated and put on medical leave," he said.
Conjunctivitis is a common eye problem often referred to as "red eye". It can be painful with swelling of the eyelids and eye discharge.
The first baby diagnosed with this eye condition likely contracted the viral infection from its mother, the hospital said. Two to three weeks later, another two newborns had the same eye disease.
Prof Ng said: "Isolation measures were immediately instituted for these babies upon diagnosis.
"Additional precautionary measures were undertaken by KKH, which included enhanced barrier protection for better efficacy against this type of virus, implementing donning of additional personal protective equipment and universal surgical masking in the neonatal unit."
Nevertheless, another 11 babies were later diagnosed with the same conjunctivitis caused by Adenovirus type 8.
Prof Ng said these babies, who had been warded in the neonatal unit for serious conditions, had been exposed to the virus before they were isolated in Nicu.
He said the disease is generally self-limiting and treatment is to relieve the symptoms. Antibiotic eye drops are given to prevent secondary bacterial infection.
KKH has been diverting neonates needing specialist care to other hospitals. But Prof Ng said the hospital had not closed its Nicu for this or any other reason.
He said: "It had stopped accepting non-urgent new external referrals because it was full."
The Nicu at KKH is the largest such facility in Singapore and it takes in referrals from other hospitals for complex cases.
Prof Ng said: "The cases of viral conjunctivitis were not the reason that the Nicu was not taking new external referrals."
Whenever its Nicu is full, Prof Ng said the hospital "may arrange for non-KKH cases to be re-directed to other hospitals". The Straits Times understands that some neonates were diverted to the National University Hospital.