By Prof Laurent Renia Dr Lisa Ng, A*STAR’s Singapore Immunology Network (SigN)
No room for complacency amid new challenges of climate change and fast spread of pathogens
The world is paying close attention to Ebola - the deadly infectious disease that has resulted in more than 5,000 deaths in the West African region. Commentators say that the developing world's poorest countries will bear the brunt of such outbreaks, but more affluent nations such as Singapore should not be complacent.
Ten million of the 56 million deaths annually are caused by infectious diseases. The past three decades have been marked with a series of epidemics - malaria, dengue, Sars, influenza, MERS-CoV (Middle East Respiratory Syndrome Coronavirus) and, currently, Ebola. The spread of these, combined with the effects of climate change and greater human mobility across borders, indicates that the world's battle against infectious diseases is far from over.
While Singapore may be better equipped to manage such infectious diseases, factors such as climate change are throwing up tough challenges. Changes to weather and the environment are hastening the spread of infectious diseases across geographical boundaries.
Singapore's ongoing battle to contain dengue is a clear example. Global warming has greatly stimulated the breeding of mosquitoes in Singapore, increasing the rate of virus transmission in the densely populated country.
Globalisation and massive urbanisation also accelerate the spread of contagious diseases. Indeed, Singapore's status as a major transportation hub and an important stopover point between Australasia and Europe makes it particularly vulnerable to human pandemics. New diseases can be easily transported from one city to another - as seen in Singapore's Sars outbreak in 2003, as well as the avian influenza H5N1 and influenza H1N1 threats in 2004 to 2005 and 2009.
Complex trade and distribution systems can also spread even a non-contagious infectious disease beyond the reach of local public- health containment, as shown by the salmonella infection behind the Prima Deli food poisoning in 2007. Being situated within the tropics and simultaneously facing global warming also makes Singapore susceptible to tropical infectious diseases, particularly mosquito-borne threats. Singapore has been fighting dengue and chikungunya epidemics since 2008.
Another curve ball is the rise of anti-microbial resistance. The widespread misuse and overuse of antibiotics have caused bacteria to become increasingly resistant to antibiotics. This has driven up demand for stronger antibiotics and generated an additional burden for hospitals and the pharmaceutical industry.
Looking beyond front-line defence
The number of malaria cases in South-east Asia may have declined over the years, but a new, worrying sign has emerged. Malarial parasites that are resistant to Artemisinin, the last potent drug against the disease, have been identified. In the midst of these, there was also a reintroduction of malaria to Singapore in 2009.
To better the odds of winning the war against emerging and re-emerging diseases, Singapore's battle plan cannot depend solely on the front line. While public health systems must be prepared to manage outbreaks, the research community must also pull its weight.
The public health and scientific community must work hand in hand to gather new knowledge on novel pathogens, and enable the application of scientific and clinical information to develop effective mitigation strategies in both containment and treatment.
Singapore laid the foundation for such collaboration by building up capabilities in the area of biomedical sciences from the year 2000. In a short span of 10 years, it has developed an extensive R&D system that carries out disease-specific research.
With the ready expertise offered by A*STAR (Agency for Science, Technology and Research) institutes, local universities and health authorities, international companies and research institutes have anchored their infectious disease research here.
Novartis, for instance, collaborated with the Economic Development Board and A*Star to set up the Novartis Institute for Tropical Diseases in 2002. During the 2003 Sars outbreak, A*Star's Genome Institute of Singapore co-developed a Sars detection kit with Roche and tested the kit clinically in the Singapore General Hospital.
Such milestones are testament to the effective collaboration between the research and clinical community. A research institute called the Singapore Immunology Network was also set up by A*STAR in 2007 to conduct research on immunology and infectious diseases here and it has yielded new insights on tropical infectious diseases, such as a potential dengue vaccine against all four serotypes, and a diagnostic system with local firm Veredus Laboratories for detecting 26 different pathogens that cause 13 clinically important tropical diseases.
Fighting infectious diseases requires ground-breaking foundational research and clinical studies. Cutting-edge molecular techniques for analysing the molecular components of pathogens are crucial for faster detection of specific pathogens, to develop reliable diagnostic tests or devices against them. Deciphering the biochemistry and the interactions of the pathogens with their human hosts or in animal models must also accompany diagnosis to develop new drugs to control and treat the diseases.
There also needs to be careful follow-up of patients to understand how the body defends itself, so as to develop new vaccines, for example.
In this regard, Singapore is well placed to contribute towards the global fight against infectious diseases. Several clinicians and researchers have established long-term collaborative networks around the world to enable rapid sharing of information and reagents.
The Republic is also a hotbed of public-private partnerships. These have the potential to lead to drug discoveries by facilitating synergistic collaborations among academics, clinicians, patients, regulators and the industry.
An example is the partnership between A*STAR's Experimental Therapeutics Centre, D3 and bio-pharmaceutical company Cytos Biotechnology. The tie-up expedited the development of Singapore's first influenza vaccine against the H1N1 virus. The vaccine has achieved its planned goal of immunogenicity in healthy volunteers based on a completed Phase I clinical trial.
Although a strong foundation is already in place, Singapore must continue to invest and sharpen its capabilities in R&D. Training the next generation of local researchers in infectious diseases and translational research, as well as continuous support in foundational and clinical research, must remain key priorities.
Singapore is just one battlefront in the global pandemic war. With the right pieces in place, it can strengthen its domestic defences and make a significant contribution internationally to help fend off disease outbreaks.
About the author:
Laurent Renia is executive director of A*STAR's Singapore Immunology Network (SIgN), and Lisa Ng is its principal investigator.
This article first appeared in the Straits Times on November 28, 2014, with the headline “Singapore's war on infectious diseases”.