When SARS broke out of China’s Guangdong province in 2003 and went on to sweep the globe, we saw how quickly and unpredictably, lethal infectious diseases can debilitate cities and societies that otherwise appear unconnected. According to Dr. Kamran Kahn, infectious disease specialist at Toronto’s St. Michael’s Hospital, infectious diseases are emerging faster than ever and new microbes are appearing nearly every year, just as many old diseases like measles, diphtheria, and polio are returning.
Speaking to THIA’s 16th Annual Conference in Nashville, Tennessee in April, 2014, Dr. Khan noted that as the world becomes increasingly interconnected and globalized, the risk of exposure intensifies. “Of the more than seven billion people alive today, more than half live in urban areas, often in crowded environments…where diseases can spread,” he said. These are also areas where airports are located, “where travellers can get on a plane and take a disease with them to another part of the globe.” He said that more than 2.5 billion travellers board commercial flights “every single year,” thereby providing a network of arteries that allow diseases to spread quickly and leave long-lasting consequences.
Dr. Kahn told the conference that in the last few decades, three quarters of infectious diseases have been caused by bacteria, viruses, parasites and fungi, carried by animals and insects: HIV, SARS (Severe Acute Respiratory Syndrome), avian influenza, MERS (Middle East Respiratory Syndrome-thought by some to have originated with camels). “These are microbes that have been found in animals and we seem to be increasingly encountering them because of livestock consumption…(and our) huge demand for animal consumption products.”
Climate change is also an important variable in the transmission of infectious diseases as many insect species are starting to survive in areas that were previously hostile to them. “We’re disrupting wildlife eco systems and coming into contact with microbes we’ve never seen before in humans and they can start to… adapt themselves to the human population.”
Despite the increasing threat these transmissions represent, Dr. Kahn emphasized that science and technology, particularly the internet, have provided some “amazing opportunities” to track the emergence and flow of infectious diseases, to gather information about them, and to be able to anticipate where and when they might emerge.
The widespread use of mobile phones also creates an interesting opportunity to gather information from travellers: about where they have been, where they are going and what they have seen, heard and experienced, said Dr. Kahn. “What’s really exciting about this is that we could have a situation in the not-too-distant future where every single city or geography in the world has some understanding of how vulnerable it might be to a particular type of infectious disease.”
These same technologies, said Dr. Kahn, could be tailored to travellers and help them make the smartest decisions possible to keep them safe and healthy during the course of their travels. With the world demanding a “crystal ball” to help predict where and when the next disease may strike, “what we got was the internet.”