A breakout star in battle against virus outbreaks

SINGAPORE - The year is only halfway through, yet Associate Professor Leo Yee Sin has already had plenty to deal with.

First, there was the Middle East Respiratory Syndrome, then the H7N9 bird flu, and now, what is shaping up to be Singapore's worst dengue outbreak.

Prof Leo, as head of the Communicable Disease Centre (CDC), has to worry about these public health threats.

But the infectious disease specialist has taken it all in her stride, after more than a decade of experience in managing outbreaks after first being thrown into the deep end when the Nipah virus hit in 1999.

The pig virus is what Prof Leo credits with giving her a "significant and tremendous amount of insight" into how to react to emerging infections.

"It was very fresh and challenging as my training did not prepare me for outbreaks, and it built up the foundation for me to respond to Sars (severe acute respiratory syndrome)," said Prof Leo, who is 53.

The scale of the Nipah outbreak was small, with 11 cases detected and a single death. But when pig handlers had to be screened for encephalitis, a brain inflammation caused by the Nipah virus, the CDC's clinics became crammed with patients. Health-care workers, equipped with just a mask and a plastic apron, were inadequately protected.

In hindsight, if the virus had been capable of human-to-human transmission, there would have been "big trouble", she admitted. But the lessons learnt would prove invaluable when Sars hit Singapore in 2003, and H1N1 broke out in 2009.

Besides her role in containing outbreaks, Prof Leo is also widely recognised for her research. She is currently leading a $25 million dengue study which aims to increase understanding of the disease so that it can be better controlled.

She also remains a strong advocate for HIV patients, having spent the first 10 years of her working life focused on the disease. In 1992, she was a clinical fellow in Los Angeles, where 50 per cent of her workload involved HIV cases. When she returned to Singapore a year later, the number of local sufferers was also rising.

Many of them were "young and talented", but lacked societal and, in some cases, family support. They were what she called a "neglected group".

"They are basically a faceless group of people with a lot of social, financial and medical issues, with no place to turn to," she said. "I could not allow myself to neglect them too."

To make treatment more accessible, highlight the issues faced by HIV patients and engage the community, she set up an HIV programme in 1995 and an HIV patient care centre two years later.

Prof Leo also had to confront the discrimination faced by those with the disease. Her decision to choose HIV medicine as a sub-speciality was seen as odd. On occasion, she felt ostracised and stereotyped by those in her extended social circles.

"There are some who think that anyone who takes up HIV medicine must be abnormal or homosexual," she said.

But Prof Leo's immediate family has been nothing but supportive. Her husband, who is in his 50s, is a biotechnologist who runs his own company. They have three children, aged 15, 18 and 22.

Infectious diseases were never Prof Leo's first choice of study.

Immunology was what intrigued her as a young medical student, but there were no training positions open in that field.

Then, she had an opportunity to meet American infectious disease physician David Allen, who came to Singapore in 1989 at the Health Ministry's request to help establish this field of study.

After attending several of his lectures, Prof Leo became convinced that the subject was close enough to immunology, and would interest her.

She became one of the first infectious disease doctors here trained by Dr Allen, and committed herself to public service for the long haul.

The speciality was then seen as an "institution-based practice", with the bulk of patients coming in through hospitals. Although things have changed with her colleagues successfully branching into the private sector, she has stayed on to play a pivotal role in meeting the country's health-care needs.

The various awards she has won in her long career prove that. These include the Public Service Star for her contribution to fighting Sars in 2003 and, more recently, an award by the National Healthcare Group for her achievements.

To Prof Leo, these awards are an honour. The workload may be increasing, but each outbreak the country experiences results in better preparedness, and helps quench her thirst for knowledge. "Even though it has proven to be very challenging, looking back, I have never regretted the decision to enter this field."

melpang@sph.com.sg

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