system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why does it seem like many lethal viruses start in developing countries but not 1st world countries?

For example bird flu and coronavirus both originated in China, Ebola in Africa. It seems as though the viruses that have the highest mortality rate begin in developing countries. Is this just purely because 1st world countries have better vaccinations and healthcare or does living in a third world country lead to being exposed to more unsanitary living conditions and exposure to carrier animals.
gpt
A lot of it is the number of people living in close proximity to domesticated animals. These viruses tend to be ones that have just mutated in a way that results in it being transmissible to people and sometimes contagious between people too.