[Finny]

Where do the mosquitoes get it?

I don't know, but post #49 has info that's helpful.

I know it isn't contagious because I had it once, and it's nasty; had a temperature of over 104 at one point. I lost about 10 pounds in a little more than a week. I got it in Pago Pago, American Samoa, 1975. Just to be sure, I did an internet search to see if the doc who treated me and told me it wasn't contagious was correct. He was.

[Smokin' Joe]

I guess my question was more of one if mosquito infections occur in offspring of mothers who have bitten people or animals which were infected.

If so, the presence of infected people could spread the disease to mosquito populations which spread the disease to more people and so on. In something like that, the presence of non indigenous people who are infected (not subjected to health screening at the border due to illegal entry, for instance) could well cause the spread of the disease to mosquito populations which previously did not have the pathogen.

Parts of the area I live in are notorious for mosquitoes, and therein lies my interest.