Chasing pathogens: tracking the paths of deadly coronaviruses
Kwok Yung Yuen is one of Hong Kong’s most eminent scientists, familiar to many inside and outside his field of expertise for his pioneering work combating high-profile infectious diseases such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS).
Trained as both a physician and a surgeon, Yuen has worked as a clinical microbiologist at the Department of Microbiology at the University of Hong Kong (HKU) since 1988 and is now the Henry Fok Professor in Infectious Diseases and Director of the State Key Laboratory of Emerging Infectious Diseases.
He recalls that the Apollo 11 moon landing in 1969 inspired his original interest in science. Yuen was fascinated by the project and joined his school’s astronomy club, his heart set on becoming an astronaut.
“It was only when I realised that all astronauts were American or Russian white men who did not wear glasses, that I looked for an alternative career path,” says Yuen who subsequently set his goal to becoming a vet.
“Doctors were limited to humans, but vets could treat a wide number of animals and that appealed to me,” says Yuen, who reared and studied all types of creatures at home, from mice to cockroaches, much to his mother’s dismay.
Unfortunately, there were no veterinary colleges in Hong Kong and his family could not afford for him to study overseas. Instead, his grandfather, who was a Traditional Chinese Medicine practitioner, suggested the young Yuen should set his sights on medical school.
A shift to medicine
Having been accepted at the University of Hong Kong’s Li Ka Shing Faculty of Medicine in 1976, Yuen read an article in the student magazine reporting how the university’s professor of microbiology, C T Huang had investigated the unexplained deaths of 25 captive dolphins at the recently opened Ocean Park. When Huang described meliodosis, a rare condition thought only to be found in humans, his findings were treated with extreme scepticism until confirmed by the prestigious Pasteur Institute in Paris.
“I was very intrigued by what Professor Huang had done. He was very much a pioneer in detecting novel pathogens in animals,” says Yuen and this inspiration proved to define his future career path.
“Today we are still looking for new bugs and 75% of all new emerging infectious diseases in humans cross over from animals,” he says.
Yuen made a major breakthrough during the 1997 Avian flu outbreak when he studied the H5N1 highly pathogenic influenza strain which resulted in the death of six out of the eighteen diagnosed with the condition. Yuen published the first clinical and laboratory diagnostic paper on Influenza A H5N1 in The Lancet, which has been cited hundreds of times since 1998, and in a review paper on this subject in the New England Journal of Medicine in 2005.
His profile was raised still further during his work to combat the SARS epidemic in 2003, which had a devastating impact in Hong Kong, causing an estimated US$40 billion in economic damage and resulting in 774 deaths across 37 countries.
Working closely alongside clinical colleagues treating infected patients at Queen Mary Hospital and under severe pressure, Yuen and his team traced the precursor SARS coronavirus to caged civets sold in live animal markets in Shenzhen.
It was subsequently discovered that wild civets did not have the microbe unique to SARS, implying that the caged civets must have been infected by a third party species.
In 2004/5 they eventually traced the precursor virus to horseshoe bats prevalent in southern China. It had taken two years of intensive research but the riddle of SARS was solved, meaning that proper and effective diagnostic, treatment, and preventive measures could be put in place.
In 2006 a Croucher Senior Medical Research Fellowship meant that Yuen could take a break his teaching and clinical duties for one year and concentrate exclusively on further research into these recently discovered bat coronaviruses.
“The SARS discovery may not have been a direct result of the Croucher award but it gave me the opportunity to follow up on the bat coronaviruses,” he says and the research also led to the discovery of HKU 4 and HKU 5, which were found to have some similar characteristics to MERS.
His department has identified over 45 new infectious diseases and are currently investigating the mechanisms behind why the MERS coronavirus has a much higher mortality rate (30%) compared to SARS (10%) and why up to 60% of MERS patients may suffer kidney failure compared to 6% for SARS.
Despite his impressive scientific achievements, Yuen has little interest in fame or the potential trappings of such an elevated international academic status.
“In my 30 year career as an academic, I have never had an office with a window,” he jokes and insists it is only the pursuit of novel microbes in emerging infectious diseases and understanding them better that provides him with professional satisfaction.
Trained both as a clinician and a surgeon, Professor Yuen Kwok Yung has worked as a clinical microbiologist at the Department of Microbiology at the University of Hong Kong (HKU) since 1988 and is now the Henry Fok Professor in Infectious Diseases and Director of the State Key Laboratory of Emerging Infectious Diseases. Yuen is ranked one of the Thompson Reuter highly cited researchers in the world, as measured by the Essential Science Indicator (ISI web) and has over 700 publications with more than 20,000 citations. He is Fellow of the Royal Colleges of Physicians, Surgeons and Pathologists in the United Kingdom and his numerous awards include being nominated as a Time Magazine Asian hero of 2003 and the silver Bauhinia Star from the HKSAR government in 2004. Yuen is often called on to advise government and the public on preventative measures for infectious diseases, most recently regarding the Zika virus. He was awarded a Senior Medical Research Fellowship by the Croucher Foundation in 2006.
To view Yuen’s personal Croucher profile, please click here.