Saturday, June 18, 2016

CDC Director Addresses the 'Unprecedented' Risks of Zika

According to the head of the Centers for Disease Control and Prevention, the Zika virus poses a "most urgent situation" – but is the United States adequately prepared to respond to the public health crisis?

DIRE CIRCUMSTANCES: Centers for Disease Control and Prevention Director Tom Frieden said much more funding is necessary to safeguard U.S. citizens against Zika. "It really is impeding our ability to protect American women from this virus," he said at a June 9 presentation in Atlanta. (Photo Credit: James Swift)
By: James Swift

ATLANTA  The ritzy Capital City Club, the venue for a June 9 presentation by Centers for Disease Control and Prevention Director Dr. Tom Frieden, seems hundreds of miles removed from its downtown surroundings. Flanked by towering hotels, the colonial-style building – which has served as a hobnobbing spot for many of Atlanta’s wealthiest impact players since the late 1800s – feels like it was airlifted out of the rural Georgia countryside and plucked down in the middle of John Portman Boulevard, a bustling, grey-hued strip of modernity with sidewalks jammed with speed-walking businessmen, water jug swigging homeless women and a seemingly never-ending stream of deliverymen.
The muggy, sweltering climate in Atlanta – where summertime temperatures routinely eclipse 90 degrees Fahrenheit – is comparable to the conditions of Brazil, a nation 3,000 miles to its south. The similar environments make both the American southeast and South America’s largest country fertile grounds for the aedes aegypti mosquito – and with it, a litany of highly infectious diseases like dengue and yellow fever.
The breed’s reputation as the “cockroach of mosquitoes,” Frieden said, is well-deserved.
“It lives indoors, it loves urban environments, it’s hard to kill,” he said. “This mosquito also likes to bite multiple people at one blood meal … it’s very difficult to control it.”
While the breed has been a known carrier of the Zika for decades, only recently have researchers been aware of the devastating effects of the virus on developing fetuses.
Frieden recalled speaking with a colleague, who described the ongoing Zika epidemic in Brazil as the “most urgent situation” they’ve experienced in three decades studying birth defects.
“I’ve seen in our laboratories the actual virus invading the brain cells of the fetus, and it’s horrible,” he remarked. “What’s happening here is the brain is being severely damaged in its development … the baby’s skull is collapsed around it [and] there have been calcifications of the brain.”
While no locally acquired vector borne cases of the virus have been reported thus far in the continental United States, more than 750 travel associated cases – including nearly a dozen cases of sexually transmitted Zika  have been documented.
Frieden said the extent to which Zika impacts the U.S. hinges on many factors – none more important than the number of pregnant women who are exposed to the virus.  
“We have 372 up to today that we know about in the United States, including territories, and that where our hearts go out to,” he said, “and that’s what we need to work on to keep that number as low as possible.”

Things known and unknown

Frieden said researchers are unsure if the developmental malformations are a relatively new mutation of the Zika virus – which was first discovered in Uganda in 1947 – or simply a side effect that has always existed, but never documented, due to substandard monitoring in Africa.
Another possibility, he added, was that the virus was so commonly spread in most affected areas that children were infected before they reached child-bearing ages and researchers never had the opportunity to chart its impact on fetuses. 
While certain Zika effects like microcephaly are horrifically apparent, Frieden said there is a strong chance other long-term, neurological complications could also stem from the virus. However, he notes that little longitudinal research outlining the developmental impacts of the virus exists, and since rarer neurological disorders are already more common in places likely to be ravaged by Zika, determining a direct cause-and-effect may prove challenging.
One such side effect may be Guillain-Barré syndrome – a form of rapid-onset muscle weakness that often leads to paralysis of the peripheral nervous system. “It appears to occur about once every 5,000 to 10,000 Zika infections, based on the data we’ve seen so far,” Frieden said. “It tends to affect older people more than younger people and it can be quite severe.”

Although current diagnostic tools indicate Zika is detectable in bodily fluids for up to two weeks, the CDC does not know how long individuals infected with Zika are able to transmit the virus. Conclusive results would take months of study, Frieden said, perhaps even a year.

“This is a devastating birth defect for some children, but we don’t know the whole range of it,” he said. “Some may be very mildly affected. Some other things, we may not know for years and years, or even decades.”

A perfect storm in Puerto Rico

Frieden said the CDC fully anticipates more spread throughout the U.S. this summer. The chances of one-off transmissions are especially high in the continental southeast – a swath sweeping westward from Texas to the Gulf states to Florida – where the mosquito known for carrying Zika is common.

“We do understand that will cause understandable concern, so we’re doing everything we can to support a global governance of mosquito control programs to track, monitor and test so we can identify that,” Frieden said.
His greatest concern, however, is in Puerto Rico and other territories in the Caribbean, where the crowded urban agglomerations and lacking public infrastructure greatly amplifies Zika risks. More than 1,400 infections in the region have already been chronicled, virtually all of which are locally acquired cases.
“They have a fiscal crisis, and they are going to need a debt restructuring,” he said. “They have a health care crisis, the Medicaid program has severe, severe problems. These all intersect in incredibly challenging ways.”

The situation may be worse than the CDC imagined. On June 17, the organization announced that blood donation tests conducted earlier that month reveal that as many as 1 percent of all Puerto Ricans - at least 35,000 people - may currently be infected with the virus. "In the coming months, it is possible that thousands of pregnant women in Puerto Rico will catch Zika," Frieden said in a press briefing. "This could lead to dozens or hundreds of infants being born with microcephaly in the coming year."

Solutions, safeguards and shortcomings
Diagnostically, Frieden said the CDC is well-equipped for Zika. Food and Drug Administration-approved diagnosis kits are already in 100 labs across the U.S. and similar tools have been shipped to nearly 100 other countries.
The CDC is also nearing breakthroughs in antibody and confirmatory tests. “They’ve already created a chimeric virus that merges, basically, Zika with another virus, so that it will go faster in the lab and we can get the results of the patients three or four days faster,” Frieden said.
When it comes to preventing the spread of Zika at the source, he said many promising tools are on the horizon. “To get rid of the mosquito, you kill them inside, you kill them outside, you kill them as adults, you kill them as larvae,” he said. “There are some new ways to do that with ultra-low volume spread of insecticide. And it really is a low volume – it’s less than an ounce per acre.”
One of the most encouraging safeguards is a rather simple and inexpensive device called a Gravid Aedes Trap, which Frieden described as the mosquito equivalent of a “roach motel.” The bucket-like containers thin out the mosquito population by luring in females with an attractant concealing a lethal insecticide.
Although low-tech, Frieden said the results speak for themselves. In a series of randomized cluster-prevention trials, communities with the traps installed posted Zika infection rates half those of communities without them.
The bigger problem, however, is a lack of new “scalable” chemical interventions. “We’re running out of insecticide [and] we haven’t had a new class in a long time,” Frieden said. “These are mosquitoes that don’t fly more than 150 meters in a lifetime, so if you’re trying to replace a population, you have to release virtually every block and you may have to do that repeatedly as outside mosquitoes come back in.”
Despite these advances, Frieden said a “cure” for Zika is still years away.
Vaccines do tend to take longer than you like,” he said. “We believe that natural immunity to Zika is long-lasting and potentially lifelong [but] how quickly it can get documented to be safe and effective and made available, we’ll see.”

Echoes of the past

Frieden said it is hard to not think about previous public health crises when devising strategies for combating Zika domestically and abroad.
“H1N1, I think people still don’t understand what happened,” he said. “There is a sense that we cried wolf and said the sky was falling when it wasn’t so bad. Actually, 1,500 Americans died from H1N1 … way more than an average flu season.”
Another crucial lesson, he said, can be culled from the 2014 Ebola crisis. While the response wasn’t as efficient and quick enough for his liking, Frieden nonetheless acknowledges the outcomes could have been far worse.
“I think one of the least understood things about Ebola was that we were within days of it getting completely out of control,” he said. “This happened July 24 in Lagos. An outpatient had been diagnosed from Liberia, a cluster had started, the doctors and nurses who cared for him were getting sick and there was nowhere to care for them. The contacts were not being traced, no facility had been found to care for those individuals who were going to get sick and the initial response was ineffective.”
Had CDC staff and international workers not intervened then, Frieden said the results would have been disastrous. “In all likelihood, Ebola would have spread all over Lagos, all over Nigeria, all over Africa and might well still be spreading in Africa,” he said. “And it would just be killing people from Ebola, it would shut up their systems. That’s what we saw in West Africa – patients won’t come and health care workers are scared. It could have set back a decade or more of progress in HIV, TB, malaria and other areas.”
The Ebola scourge is far from a resolved issue, Frieden said. Another cluster flared up in Guinea last March; equally unnerving, he said researchers recently found a man who appears to have passed on Ebola through sexual intercourse 15 months after it was first detected in his RNA - six months longer than CDC specialists believed the virus was transmittable via semen.

The Funding Problem

One of the biggest barriers to fighting Zika, Frieden said, is gridlock on Capitol Hill. Although President Obama has requested almost $2 billion to combat Zika, congress has yet to hash out a final fiscal apportionment. A U.S. Senate plan would approve about $1 billion in funding while a U.S. House proposal would authorize just $622 million
To finance Zika response efforts up to this point, the CDC has had to borrow emergency preparedness funds from states and pull money from West African Ebola monitoring programs.
“There are specific political dynamics in one of the chambers of congress that makes it very difficult for them to get a bill through,” Frieden said. “I know there are people of goodwill in both houses of congress, in both parties, who understand it’s an emergency and want to make it happen. Congress did the right thing with Ebola and I am hopeful they will do the right thing with Zika.”
In the interim, the CDC’s efforts to combat Zika have been bolstered by private sector contributions from companies such as Bayer AG and SC Johnson. Although the CDC Foundation has amassed tens of millions of dollars in Zika research funding, Frieden said their coffers remain dangerously light.
“It really is impeding our ability to protect American women from this virus,” he said.

An Olympic-Sized Catastrophe?

With Brazil in the grips of one of the largest public health crises of the 21st century, the nation hosting the Summer Olympics sounds like nothing short of a recipe for international disaster.
However, Frieden says he sees no reason to cancel, move or postpone the world’s premiere international sporting event.
“Our advice on travel, regardless of what you’re going for – a wedding, for business or the Olympics – if you’re pregnant, you shouldn’t go,” he said. “Now, if you are pregnant and you choose to go, then you really have to be as careful as possible to avoid mosquitoes, and that’s going to be very difficult.”
The CDC is working closely with the U.S. Olympic Committee and Brazilian authorities to monitor the situation this summer. The protocol for travelers to the games in Rio is no different than those anywhere else; if you have symptoms, get tested, and if the results are positive, wait at least six months before engaging in unprotected sexual activity.
With more than 40 million air trips taking off from the U.S. to Zika-impacted nations each year, there is little that can be done to eliminate infection risks for travelers – Summer Olympiads or not.
“It’s already all over the world,” he said. “The number of people going to the Olympics account for less than 0.25 percent of all travel to Zika-affected areas. So even if the Olympics didn’t exist, 99.75 percent-plus of that risk would continue.” 

Uncommon Journalism, 2016.

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