Changes in the global environment, such as the rise in global temperature, the increase in urbanization, population density, air and water pollution, overuse of antibiotics, etc., have led to a continuing deterioration of the environment so that epidemic diseases that were successfully suppressed some time ago are now fighting back, and bacteria and viruses are more difficult to wipe out.
由於大環境變遷，如全球氣溫上升、都會化程度加深、人口密集、空氣與河川污染、抗生素濫用等等，造成環境持續惡化，使得早年被成功壓制的傳染病一一反撲，細菌、病毒等病原微生物很難被徹底撲滅。