Zika isn't a worry as far as getting sick goes. They say you hardly even know you're sick when you have it. It's only dangerous to pregnant women whose unborn kidlets could be born with microcephalus. The worry is once it's in the mosquito population, if you're sick and get bitten, that mosquito can then spread the disease to anybody else it bites. The more people get it the more it can spread and then every pregnant woman will have to stay indoors for their whole pregnancy to be safe. An ugly scenario. But they're not even sure we have mosquitoes here that can carry it.
On the mascara brush, it really IS a great idea! I always use waterproof mascara otherwise it sweats right off me instantly. Just clean the brush with makeup remover first, then wash with dish detergent.