Friday, December 15, 2017
Health

As the Aedes aegypti mosquito spreads globally, so does the risk of epidemics

Of all the mosquito species that populate the planet, few have proved themselves more resilient or more deadly to humans than the Aedes aegypti. The epidemics fueled by this tiny mosquito stretch across hundreds of years and include millions of victims.

Yellow fever, dengue fever, chikungunya. And now Zika, which has spread to more than 50 countries and can cause an array of severe birth defects.

"One of the most efficient killers in the world," Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told the Washington Post this year in discussing A. aegypti.

These days, travel, global commerce and a warming planet only seem to be helping the mosquito to again flourish after widespread eradication efforts in the first half of the 20th century. That could mean more outbreaks of more diseases in more places.

Writing Thursday in the journal Science, Yale University's Jeffrey R. Powell, a professor of ecology and evolutionary biology, detailed how this species now breeds year-round in locations where it once didn't exist.

"These expansions are putting at risk large human populations that never experienced aegypti-borne viruses and therefore have no immune defenses against them," he wrote. "This greatly increases the likelihood of severe epidemics."

Powell noted that researchers have documented two subspecies of A. aegypti — the human-loving "Aaf" and the "Aaf" form traditionally found in forests — interbreeding in certain parts of the world from Argentina to Africa.

"The consequences of increasing hybridization between the two subspecies remain unclear," he continued, although warning that it could lead to increased genetic variation and still more spread of disease.

Part of what has made A. aegypti such a formidable foe and such an efficient disease transmitter is its ability to adapt. It has evolved to thrive in the densely populated places, particularly urban environments littered with old tires, trash and other open containers. It can breed in spots as tiny as a bottle cap. Its larvae don't necessarily need water to survive, and eggs can lie dormant for a year or more — only to hatch once submerged in water. The sticky eggs glue themselves to containers as common and varied as the insides of old tires and the edges of birdbaths.

"It's one of those pests, like cockroaches, that has evolved over the last 15,000 years to exploit changes in human behavior and habitation," Ronald Rosenberg, acting director for the Division of Vector-Borne Diseases at the Centers for Disease Control and Prevention, said at a conference this year.

In an interview last week, Powell called for far stronger mosquito-control campaigns in the United States and other countries.

"Rather than treating each disease after there's an outbreak, why not spend more money trying to control the mosquito?" he said.

Aside from yellow fever, no vaccine exists for other aegypti-borne diseases such as dengue, chikungunya and Zika — although scientists have been racing to develop a Zika vaccine. Powell said scientists have linked the species to "hundreds" of other viruses, mostly circulating among primates in Africa, that could one day cause the next global outbreak.

"We know they are there," he said. "We know it's going to happen again."

Comments
Pigs can be therapy animals too. So can horses and rats and cats and llamas and … (w/video)

Pigs can be therapy animals too. So can horses and rats and cats and llamas and … (w/video)

Shrieks of laughter echoed off the walls of the hospital as Thunder the mini pig flopped onto his side and the children huddled around him, scratching his pink, hairy belly. He and his wet-nosed partner, Bolt, drew patients in wheelchairs and bandage...
Updated: 10 hours ago
Obamacare enrollment ends today, but some can get an extension

Obamacare enrollment ends today, but some can get an extension

Today is the day that open enrollment for the Affordable Care Act will close for most people. But those affected by the slew of hurricanes that pummelled Florida, Texas, Puerto Rico and other states earlier this year can take advantage of a two-week ...
Published: 12/15/17
City Council sinks deal to alter ownership of Bayfront Health St. Petersburg

City Council sinks deal to alter ownership of Bayfront Health St. Petersburg

ST. PETERSBURG — After months of tense negotiations and weeks of political impasse, the City Council on Thursday derailed a proposal that would have changed the ownership structure of the city’s largest hospital, Bayfront Health St. Petersburg.The 5-...
Published: 12/14/17
Florida hospitals call for more funding in effort to address looming doctor shortage

Florida hospitals call for more funding in effort to address looming doctor shortage

The number of doctors practicing in Florida has not kept up with the state’s surging population growth, and more money is needed to recruit and keep them here, hospital leaders said Wednesday.The shortage is particularly acute in four speciality area...
Published: 12/13/17
An overlooked epidemic: Older Americans taking too many unneeded drugs

An overlooked epidemic: Older Americans taking too many unneeded drugs

Consider it America’s other prescription drug epidemic.For decades, experts have warned that older Americans are taking too many unnecessary drugs, often prescribed by multiple doctors, for dubious or unknown reasons. Researchers estimate that 25 per...
Published: 12/13/17
How is Florida’s health? Not so great, report says

How is Florida’s health? Not so great, report says

Florida slightly improved its national standing this year, rising from 36th to 32nd overall in the annual America’s Health Rankings report. But the takeaway for the nation’s third-largest state is that it has a long way to go in many important health...
Published: 12/12/17
Driven by demand, Planned Parenthood opens second clinic in Tampa

Driven by demand, Planned Parenthood opens second clinic in Tampa

The floor-to-ceiling glass windows are heavily tinted and the inside is hidden behind rows of curtains. Security cameras monitor every corner, and only patients with an appointment and valid identification can pass through the intentionally cramped e...
Published: 12/12/17
Video: Jimmy Kimmel holds his baby son, post-heart surgery, in emotional health-care monologue

Video: Jimmy Kimmel holds his baby son, post-heart surgery, in emotional health-care monologue

Jimmy Kimmel was absent from his ABC late-night show last week while his 8-month-old son, Billy, recovered from his second heart surgery. Ever since Billy was born with a heart defect and required immediate surgery, Kimmel has become an outspoken adv...
Published: 12/12/17
Record numbers are signing up for Obamacare in Florida as enrollment period draws to a close

Record numbers are signing up for Obamacare in Florida as enrollment period draws to a close

With just four days left to enroll for health insurance on the federal exchange, advocates for the Affordable Care Act say Florida is headed for a record-breaking year. In week five of the six-week open enrollment period, about 823,180 people signed ...
Published: 12/12/17
A boy shares the pain of being bullied - inspiring thousands to show him love (w/video)

A boy shares the pain of being bullied - inspiring thousands to show him love (w/video)

While fighting back tears, young Keaton Jones couldn’t stop asking one question: Why?"Just out of curiosity, why do they bully? What’s the point of it?" he asks his mother while in the passenger seat of a parked car. "Why do you find joy in taking in...
Published: 12/10/17
Updated: 12/11/17