Puerto Rico is the US Frontline in the War on Zika

The New York Times reports that Zika virus has begun to spread across Puerto Rico, now the United States' front line in the epidemic.

Zika is asymptomatic for the great majority of people. However, for pregnant women, it is a disaster because it can cause an infant to be born with a small head and brain (in medial terms, "microcephaly"). Zika virus has also occasionally caused paralysis in adults.

(It should be noted that linkages of Zika to microcephaly and paralysis are intuitive and based on observation, as no rigorous scientific studies on the virus to confirm them has been conducted. There simply hasn't been time).

The outbreak is expected to be worse in Puerto Rico than anywhere in the US Mainland. The island is warm, wet, poor, and tropical. It's countryside contains abandoned tires, cars, houses that ordinarily breed mosquitoes. Many buildings lack screens, let alone HVAC. Puerto Ricans have little choice but to open the windows and let in the air, bugs and all.

Puerto Rico's economic crisis has laid off numerous civil servants, just when their services are needed to combat the bugs.

The Times reports that the chemical most frequently used to control adult mosquitoes has lost its effectiveness against them, at a time when regulators have yet to approve a different insecticide

A quarter of the island's 3.5 million people will probably get the Zika virus within a year, according to the Centers for Disease Control and Prevention. Bearing in mind that 80% of infected people are without symptoms, eventually 80 percent or more may be infected.

"I'm very concerned," Dr. Thomas R. Frieden, the C.D.C. director, said in an interview after a recent three-day visit to Puerto Rico. "There could be thousands of infections of pregnant women this year."

Like other major Caribbean islands, Puerto Rico is a popular vacation destination. Thousands of tourists disembark daily from planes and ships.

Finally, it has recently become apparent that the disease can be transmitted sexually. The Times reports that the price of condoms in Puerto Rico has been controlled by the government, along with screening.

Health officials have begun intensive efforts to stop the virus in Puerto Rico.