Such infections uncommon
A viral infection as severe as the one that hit Miss Tan Sumiao is uncommon, said two doctors The New Paper spoke to.
"In most cases, the body's immune system will be able to handle a viral infection," said Dr Madeleine Chew, founder and resident doctor at MW Medical.
But she notes that there are some viruses, such as the chicken pox virus, that can attack the brain.
Dr Clarence Yeo, who practises at Killiney Family & Wellness Clinic, agreed, but added: "Young children might be more susceptible to viral infections because their immune system might not be fully developed."
He said that Miss Tan's situation was unfortunate, but it is often difficult to tell when a viral infection can become severe.
"Blood tests may not be able to pick up all viruses so one should always be mindful of complications, especially if symptoms are persistent," he said.