but now the UKMail says the Brazilian cases are spreading.
more here at CBSNews
According to the Pan American Health Organization, health officials have confirmed 371 yellow fever cases, including 241 deaths. Hundreds more cases are being investigated. This high number of cases is out of proportion to the number reported in a typical year, Anthony Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID) and colleague Catharine Paules, M.D., explain in a letter published this week in the New England Journal of Medicine.
Since the areas in Brazil currently affected by the outbreak are close to major urban centers, including Rio de Janeiro and Sao Paolo where millions of people live, infectious disease experts are concerned that the virus could spread into city populations there for the first time in decades. Yellow fever is spread from one person to the next by Aedes aegypti mosquitoes — the same species that transmits Zika virus.
the problem: These moquitoes are in the USA: the Yellow Fever epidemic of the 1790's killed 20 thousand people in Philadelphia.
and the world supply of vaccine was pretty well used up in the Angola epidemic...
the problem: The incubation period is 3-6 days and there is no "prodromal" time with low grade sypmtoms. When you get it, you get very sick quickly, and are infectious for a few days (spread via mosquitoes).
so if you have the virus, and you are traveling, you could indeed fly all over the globe before you knew you were sick.
Travelers need to be told to go to the ER if they get sick, during the week after they arrive, and tell the docs where you had been. They will isolate you from mosquitoes so it won't spread to anyone.
If the mosquitoes are under control (or if it is wintertime) the chances are it won't spread. And if mosquito control is being done, it shouldn't spread. China's cases did not cause en epidemic due to this.