"The current scenario of a YF outbreak in Angola, where there is a large Chinese workforce, most of whom are unvaccinated, coupled with high volumes of air travel to an environment conducive to transmission in Asia, is unprecedented in history," warns lead author Sean Wasserman, MBChB, of the University of Cape Town, Cape Town, South Africa. "These conditions raise the alarming possibility of a YF epidemic, with a case fatality of up to 50%, in a region with a susceptible population of two billion people and where there is extremely limited infrastructure to respond effectively." The growing number of imported cases in China shows how critical it is to recognize this risk now in order to take adequate preemptive action so that a global catastrophe can be averted.
Now, I'm old enough to remember when you had to carry a yellow booklet with proof that you had been vaccinated for smallpox and (for visiting or returning from certain countries) yellow fever.
So the question is: why didn't these Chinese workers get vaccinated before going there, and why hasn't China arranged for them to get the vaccine. (update: The Chinese gov't is now arranging their workers in Angola to get the vaccine).
and again, the problem is that the mosquito eradificaation programs were weakened, partly by environmentalists who shun DDT and pesticides.
And from what I see outside my window, probably because of open sewers or lack of drainage, lack of cleaning up garbage, etc because either there is no money designated for such projects, or else the local politicians are diverting the money to their pockets.