- The Washington Times - Sunday, August 21, 2016

Despite a mosquito hot spot that popped up last week in Miami Beach, Florida, Zika remains overwhelmingly a travel-related disease, challenging the public’s understanding of the infection and policymakers’ attempts to manage the outbreak.

Two Miami-area neighborhoods are reporting mosquito-borne cases, with a total of 36 infections as of Friday. That’s still less than 2 percent of the more than 2,000 cases throughout the continental U.S. The rest of them were contracted outside the country or by sexual contact with an infected person.

“The sheer volume of travel to Zika-laden areas from the U.S. is such that travel-associated cases will dominate local acquisition,” said Amesh Adalja, a senior associate at the University of Pittsburgh Center for Health Security. “Only specific parts of the continental U.S. are at risk for local mosquito-borne transmission of Zika as well.”

Scientists long feared an outbreak in states along the Gulf of Mexico, where the Aedes aegypti mosquito was expected to transmit Zika.

But with summer nearing an end, just two neighborhoods — the artsy Wynwood district of Miami and a 20-block stretch of Miami Beach, both in southeast Florida — are reporting mosquitoes carrying the disease.

What dominates instead are travel-related cases, from people who became infected outside the continental U.S. and brought the virus into the country. Indeed, New York, where no mosquito bite transmission has been reported, has a nation-leading 579 cases.

As Zika fears grew this spring, officials focused on mosquitoes that might pick up the disease in infected travelers and spread the virus. President Obama asked for $1.9 billion to combat the disease, including testing of Zika vaccines and bolstering mosquito eradication.

Color-coded maps of the potential reach of the Aedes aegypti and a secondary carrier, the Aedes albopictus, or Asian tiger mosquito, warned about the risk of Zika transmission deep into the Northeast, South and Southwest.

“While we absolutely hope we don’t see widespread local transmission in the continental U.S., we need the states to be ready for that,” Dr. Anne Schuchat of the federal Centers for Disease Control and Prevention said at a White House briefing in April, standing in front of that mosquito map.

Michael S. Kaufman, an associate professor of entomology at Michigan State University, said that map was probably too broad.

A more nuanced map released by NASA, which cross-referenced the presence of mosquitoes with the amount of returning travelers from Zika-affected areas, also seemed to overstate the risk in New York, which isn’t home to the aegypti mosquitoes that are primary carriers of the virus.

Indeed, the CDC has said the continental U.S. is unlikely to see the type of rampant transmission that has hammered Brazil and other parts of Latin America because of widespread use of window screens and air conditioning, and the relative U.S. population density.

“However, it is likely that we will see additional pockets of local transmission in restricted geographic areas,” CDC spokesman Benjamin Haynes said. “We are working hard to learn more about Zika, and while we cannot rule out the possibility of a larger outbreak in an urban area, everything we have seen so far suggests that this would be unlikely.”

‘The big threat’

Mosquito-borne Zika transmission remains limited to Florida, where Gov. Rick Scott, a Republican, has to deal with the risk to public health and the economic consequences.

Five new cases were found in Miami Beach, where two residents and a trio of travelers from New York, Texas and Taiwan were infected in a 20-block stretch of the popular tourist hub.

Yet even the state Department of Health is reporting far more travel-related cases in its daily updates. A dozen more travel cases were reported Wednesday, compared with three that were locally acquired, and 18 more travel cases were reported Thursday versus two locally.

Despite the lopsided case counts, analysts said officials continue to focus on the mosquito population instead of human carriers because it poses a less-manageable risk. Scores of pregnant women are returning to the U.S. with infections from overseas.

“The big threat was, and remains, an epidemic spreading among the scores of millions of Americans who live in states with lots of Aedes aegypti mosquitoes,” said Hank Greely, a law professor and director of the Center for Law and the Biosciences at Stanford University. “To me, it makes sense to work hard to avoid the somewhat less likely but more devastating scenario of widespread domestic spread, but we certainly can’t ignore the people who contracted it overseas.”

For now, New York City is well-positioned to provide care for babies who develop birth defects because their mothers return with Zika, said Christopher Miller, a spokesman for the city’s health department.

“The Health Department is confident that its [early intervention program] can handle an increase in the number of children with microcephaly,” he said, adding that officials will monitor the program’s service delivery system to ensure it has enough capacity.

The city accounts for more than three-quarters of travel-related Zika cases in the Empire State because its boroughs hold a vast, diverse immigrant population with ties to hard-hit countries.

No calls for quarantine

New York City also dealt with the last global health scare — Ebola — when a 33-year-old doctor reported symptoms and tested positive after volunteering in West Africa.

New York Gov. Andrew Cuomo, a Democrat, initially called for a mandatory quarantine of health care workers who returned to the cosmopolitan hub after treating patients in West Africa, but softened his approach and said they could wait out the incubation period of the virus at home.

Other governors and congressional Republicans wanted more stringent measures, and some called for a travel ban, but no such calls have been made for Zika.

The disease is hard to detect in most people, and it doesn’t spread from close personal contact — even if it can be transmitted sexually — so screening protocols are impractical. Plus, health professionals have discouraged travel bans because it makes global response more cumbersome.

“Zika is different in that 80 percent of people of people infected with Zika virus do not experience symptoms and many don’t get ill,” Mr. Haynes said. “Our travel guidelines are specifically designed to protect pregnant women and women planning to become pregnant by encouraging them not to travel to areas where local transmission is occurring.”

Florida’s outbreak has infected a traveler who fell ill and tested positive for Zika after returning to Texas — a state that has braced for but not reported mosquito-borne transmission so far.

Texas has reported more than 100 travel-related cases, however, and said this month that an infant died from Zika-related causes after her mother contracted the disease in Latin America and then traveled to Harris County.

Chris Van Deusen, a spokesman for the Texas Department of State Health Services, said doctors and hospitals are on high alert for patients who present symptoms and travel histories that are consistent with the virus.

Two years ago, a Dallas-area hospital turned away a Liberian man who presented a mild fever. When his health worsened, he was admitted with an Ebola diagnosis before he died. Officials later pointed to missteps in recording his migration from West Africa, where the deadly virus was spreading.

“I think we all learned it’s important to ask those questions,” Mr. Van Deusen said. “The world is becoming smaller, and people are traveling all over the place.”

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