In Brazil&#x27;s case, as least, it&#x27;s simpler than that.<p>Mosquito eradication used to be done at the federal level, with military like organization. It kept things in control.<p>A few years ago it has been re-assigned to municipalities. Not only are local authorities less equipped to handle it, but mosquitoes do not conform to city boundaries. If one city is doing a good job but it&#x27;s neighbor isn&#x27;t you&#x27;re screwed.<p>There&#x27;s probably lots to be done through technical advances, but most of this could be avoided using common sense.