Why people don’t die or get serious flu or infection when they travel to different continent? Won’t our immune system get exposed to altogether different kinds of bacteria and viruses?

Question

There had been many incidents in history when people from other continents brought outbreak of diseases along with them (for eg, diseases brought by the Spaniards to the Incas), why such things doesn’t happen today, atleast not on a large scale?

Also I’m not from science background, so sorry if the question was dumb.

In: Biology

Answer 1

There have been a few examples of this, and it was contact with people unknown for many centuries. That doesn’t happen any more. Sometimes new diseases spring up, like SARS or MRSA, but we have scientific medicine now that detects them and contains their spread.

The flu kills 650K people every year, even with the flu vaccines we have developed. This is more than malaria (585K). The top of the contagious disease pyramid kills a lot of folks, things like yellow fever (30K) of even Ebola (4K) are way down the list. Exotic, new diseases are just very unlikely.