The good news came at around 11.30pm on Thursday. Ms Leianne Tan was told she had tested negative for Zika.

The freelance actress was finally free to leave the chilly room where she had spent 11 hours waiting.

It was a spartan space, with a heavy metal shutter at the door, watched over by a security guard.

"All of us had to stay in that room - once we stepped in, we couldn't step out," recalled Ms Tan.

The 26-year-old had arrived at Tan Tock Seng Hospital at around noon that day, worried that she might have Zika as she lives in Bedok - close to a new cluster of cases - and had symptoms associated with the virus such as fever, rashes and aches.

Within 15 minutes of telling staff at the Accident and Emergency ward of her symptoms, she was whisked away to have her blood and urine samples collected for testing, and sent to the quarantine room.

But that swift start was followed by a tedious wait on plastic chairs. Those waiting for their test results - about 20 of them, estimated Ms Tan - had a lone television set and their smartphones for entertainment. They had to use a portable toilet, of the sort used at outdoor events.

Nonetheless, they were taken care of, said Ms Tan. Neatly sliced oranges were provided as snacks, with porridge for lunch and dinner.

Medical personnel took Ms Tan's temperature and blood pressure every two to three hours, and gave medicine to some of her fellow test cases who had serious fever. There was even a cabinet for charging mobile phones.

But the long wait of up to 12 hours could put people off from getting tested, said Ms Tan.

And for some, the conditions might be particularly hard to bear: "For pregnant ladies especially, it's not conducive for them at all."

One heavily pregnant woman had been waiting patiently, but her husband later turned up and argued with the staff. She was eventually allowed to leave, said Ms Tan.