Infectious diseases have been plaguing human populations throughout the course of history. Despite scientific advances that benefit healthcare, the three main factors of population growth, globalization, and widespread poverty mean such diseases will, unfortunately, become an even bigger problem in the coming decades.
As Earth's population increases, it becomes easier for infectious diseases to spread. As much of the planet becomes densely populated, close contact among people creates an ideal environment for disease outbreaks and epidemics. What is more, as human populations encroach on animal habitats, germs harbored in these animals can more easily infect people.
People are also increasingly mobile, and more travel will make it harder to track and halt disease outbreaks. Disease-spreading organisms such as insects are often transported along with people, making it likely that infections once limited to local populations will become problematic globally. To make matters worse, doctors will struggle to diagnose diseases previously unseen in their areas.
The developing world will be particularly vulnerable. With limited access to healthcare and medicine, populations in developing nations could be decimated by the spread of a lethal infection. Moreover, as urban slums grow larger, unhygienic conditions and lack of access to clean water will make it easier for infections to occur.
Population growth, globalization, and poverty are rampant in the world today. Given the current situation, it is hard to imagine a scenario in which infectious diseases do not pose an increasingly significant challenge in the coming decades.