My best guess is that water sources are so contaiminated at times that any virus would find a welcome home. If it proves that Mexico is considerably laced with this virus beyond any reporting to date, the 'source' has to be addressed and items to assist with clean water needs to be distributed.
None of this will be a reality until a more comprehensive study can be completed. It might work out that there is a small concentrated infection region, but, the current evidence does not point to that.
