SAN JUAN — The Zika epidemic that has spread from Brazil to the rest of Latin America is raging in Puerto Rico — and the island’s response is in chaos.
The war against the Aedes aegypti mosquito carrying the virus is failing. 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.
There are only about 5,500 confirmed infections on the island, including the cases of 672 pregnant women. But experts at the Centers for Disease Control and Prevention say they believe that is a radical undercount.
In Puerto Rico, officials believe thousands of residents — including up to 50 pregnant women — are infected each day.
Most never get tested. Tests on donated blood, the most reliable barometer of the epidemic’s spread, show that almost 2 percent of the donors were infected in the last 10 days.
“That’s a stunning number and reflects an explosion of cases,” said Dr. Tom Frieden, director of the CDC.
The proportion of pregnant women testing positive for the virus has risen sevenfold since January, the agency said Friday. Officials warned that hundreds of infants could be born with microcephaly in the coming year.
But a wave of microcephaly like Brazil’s may yet be averted. The pregnancy rate is falling so precipitously that this year, for the first time in history, Puerto Rico will have fewer births than deaths.
Obstetricians are urging their infected pregnant patients to have regular ultrasounds and to consider abortion if brain damage turns up.
And damage is turning up.
At the University of Puerto Rico Hospital, the curves of the graph on Dr. Alberto De la Vega’s computer screen trace a horror story.
They are the head circumferences of dozens of fetuses whose mothers have been infected with the Zika virus — and almost 75 percent are below the mean; normally, only half should be.
Only one was microcephalic, with the extreme shrinkage and brain damage that is the worst consequence of the infection, and that curve abruptly ends: The mother chose abortion.
“What worries me is not 100 kids with microcephaly,” said De la Vega, chief of ultrasound diagnosis. “What worries me is a lot of kids affected in some way we cannot determine yet.
“We may be facing a generation with learning and behavioral disabilities,” he said.