SAN JUAN, P.R. — The Zika epidemic that has spread from Brazil to the rest of Latin America is now raging in Puerto Rico — and the island’s response is in chaos.

The war against the Aedes aegypti mosquito carrying the virus is sputtering out in failure. Infections are skyrocketing: Many residents fail to protect themselves against bites because they believe the threat is exaggerated.

Federal and local health officials are feuding, and the governor’s special adviser on Zika has quit in disgust.

There are only about 5,500 confirmed infections on the island, including of 672 pregnant women. But experts at the Centers for Disease Control and Prevention say they believe that is a radical undercount.