Lassa fever has reached the US for the first time in a decade, in a case that has surprised health officials . Lassa fever has reached the US for the first time in a decade, in a case that has surprised health officials .
Lassa fever has reached the US for the first time in a decade, in a case that has surprised health officials . Lassa fever has reached the US for the first time in a decade, in a case that has surprised health officials .