Yellow fever is caused by the yellow fever virus and is spread by the bite of an infected female mosquito. The mosquitoes feeds during the daytime. Chikungunya is caused by the chikungunya virus. The virus is spread by the female mosquito. It might be possible they could become established in the future. But mosquito control and avoiding mosquito bites will control the endemic spread of the infection. Also vaccinations of the travelers and immigrants will also avoid the spreading of the disease. Solution Yellow fever is caused by the yellow fever virus and is spread by the bite of an infected female mosquito. The mosquitoes feeds during the daytime. Chikungunya is caused by the chikungunya virus. The virus is spread by the female mosquito. It might be possible they could become established in the future. But mosquito control and avoiding mosquito bites will control the endemic spread of the infection. Also vaccinations of the travelers and immigrants will also avoid the spreading of the disease..