Trump fires chief US lawyer who defied him on migrant ban

Washington, Jun 9: When epidemiologists talked about "flattening the curve," they probably didn't mean it this way: the US hit its peak coronavirus caseload in April, but since that time the graph has been on a seemingly unending plateau.

That's unlike several other hard-hit countries which have successfully pushed down their numbers of new cases, including Spain and Italy, which now have bell-shaped curves.

Experts say the prolonged nature of the US epidemic is the result of the cumulative impact of regional outbreaks, as the virus that started out primarily on the coasts and in major cities moves inward.

Layered on top of that are the effects of lifting lockdowns in parts of the country that are experiencing rising cases, as well as a lapse in compliance with social distancing guidelines because of economic hardship, and in some cases a belief that the threat is overstated.

"The US is a large country both in geography and population, and the virus is at very different stages in different parts of the country," Tom Frieden, a former director of the Centers for Disease Control and Prevention told AFP.

The US saw more than 35,000 new cases for several days in April. While that figure has declined, it has still been exceeding 20,000 regularly in recent days.

By contrast, Italy was regularly hitting more than 5,000 cases per day in March but is currently experiencing figures in the low hundreds.

"We did not act quickly and robustly enough to stop the virus spreading initially, and data indicate that it travelled from initial hotspots along major transport routes into other urban and rural areas," added Frieden, now CEO of the non-profit Resolve to Save Lives.

To wit: the East Coast states of New York, New Jersey and Massachusetts accounted for about 50 percent of all cases until about a month or so ago -- but now the geographic footprint of the US epidemic has shifted to the Midwest and southeast, including Florida.

Another key problem, said Jennifer Nuzzo, an epidemiologist at Johns Hopkins, is that the United States is still not doing enough testing, contact tracing and isolation.

After coming late to the testing party -- for reasons ranging from technical issues to regulatory hurdles -- the US has now conducted more COVID-19 tests than any other country.

It even has one of the highest per capita rates per country of 62 per 1,000 people, according to the website ourworldindata.org -- better than Germany (52 per 1,000) and South Korea (20 per 1,000).

But according to Nuzzo, these numbers are misleading, because "the amount of testing that a country should do should be scaled to the size of its epidemic.

"The United States has the largest epidemic in the world so obviously we need to do a lot more testing than any other country."

For Johns Hopkins, the more important metric is the positivity rate -- that is, out of all tests conducted, how many came back positive for COVID-19.

As of June 7, the United States had an average daily positivity rate of 14 percent, well above the World Health Organization guideline of 5 percent over two weeks before social distancing guidelines should be relaxed.

By contrast, Germany, which has tested far fewer people in relation to its population, has a positivity rate of 5 percent.

Even if testing were scaled up, carrying out tests in of itself does very little good without the next steps -- finding out who was exposed and then asking them to isolate.

Here also, too many US states are lagging woefully behind.

Texas, which is experiencing a surge in cases after relaxing its lockdown, is a case in point. The state targeted hiring a modest 4,000 tracers by June, but according to local reports is still more than a thousand shy of even that goal.

Opt-in app based efforts have also been slow to get off the ground.

Then there is the fact that some people are growing tired of lockdowns, while others don't have the economic luxury of being able to stay home for prolonged periods.

The government sent some 160 million Americans a single stimulus check of up to $1,200 back in April but it's not clear whether more will be forthcoming.

Still others, particularly in so-called red states under Republican leadership, have chafed under restrictions and mask-wearing guidelines that they see as an affront to their personal freedom.

"The US is kind of on the extreme of the individual liberty side," Sten Vermund, dean of the Yale School of Public Health, told AFP.

Part of this has to do with mixed messaging from Republican leaders, including President Donald Trump, said Nuzzo.

"We have had at the highest political level an assertion that this is a situation that's been overblown, and that maybe certain protective behaviors are not necessary," she said.

More recently, tens of thousands of people across the country have taken to the streets to protest the killing on an unarmed black man by police, risking coronavirus infection to demonstrate against the public health threat of racialized state violence.

Washington, Apr 28: After nearly three weeks in an intensive care unit in Los Angeles, doctors treating 41-year-old Broadway actor Nick Cordero for COVID-19 were forced to amputate his right leg.

The flow of blood had been impeded by a blood clot: yet another dangerous complication of the disease that has been bubbling up in frontline reports from China, Europe and the United States.

To be sure, so-called "thrombotic events" occur for a variety of reasons among intensive care patients, but the rates among COVID-19 patients are far higher than would be otherwise expected.

"I have had 40-year-olds in my ICU who have clots in their fingers that look like they'll lose the finger, but there's no other reason to lose the finger than the virus," Shari Brosnahan, a critical care doctor at NYU Langone said.

One of these patients is suffering from a lack of blood flow to both feet and both hands, and she predicts an amputation may be necessary, or the blood vessels may get so damaged that an extremity could drop off by itself.

Blood clots aren't just dangerous for our limbs, but can make their way to the lungs, heart or brain, where they may cause lethal pulmonary embolisms, heart attacks, and strokes.

A recent paper from the Netherlands in the journal Thrombosis Research found that 31 percent of 184 patients suffered thrombotic complications, a figure that the researchers called "remarkably high" -- even if extreme consequences like amputation are rare.

Behnood Bikdeli, a doctor at New York-Presbyterian Hospital, assembled an international consortium of experts to study the issue. Their findings were published in the Journal of The American College of Cardiology.

The experts found the risks were so great that COVID-19 patients "may need to receive blood thinners, preventively, prophylactically," even before imaging tests are ordered, said Bikdeli.

What exactly is causing it? The reasons aren't fully understood, but he offered several possible explanations.

People with severe forms of COVID-19 often have underlying medical conditions like heart or lung disease -- which are themselves linked to higher rates of clotting.

Next, being in intensive care makes a person likelier to develop a clot because they are staying still for so long. That's why for example people are encouraged to stretch and move around on long haul flights.

It's also now clear the COVID-19 illness is associated with an abnormal immune reaction called "cytokine storm" -- and some research has indicated this too is linked to higher rates of clotting.

There could also be something about the virus itself that is causing coagulation, which has some precedent in other viral illnesses.

A paper in the journal The Lancet last week showed that the virus can infect the inner cell layer of organs and of blood vessels, called the endothelium. This, in theory, could interfere with the clotting process.

According to Brosnahan, while thinners like Heparin are effective in some patients, they don't work for all patients because the clots are at times too small.

"There are too many microclots," she said. "We're not sure exactly where they are."

Autopsies have in fact shown some people's lungs filled with hundreds of microclots.

The arrival of a new mystery however helps solve a slightly older one.

Cecilia Mirant-Borde, an intensive care doctor at a military veterans hospital in Manhattan, told AFP that lungs filled with microclots helped explain why ventilators work poorly for patients with low blood oxygen.

Earlier in the pandemic doctors were treating these patients according to protocols developed for acute respiratory distress syndrome, sometimes known as "wet lung."

But in some cases, "it's not because the lungs are occupied with water" -- rather, it's that the microclotting is blocking circulation and blood is leaving the lungs with less oxygen than it should.

It has just been a little under five months since the virus emerged in Wuhan, China, and researchers are learning more about its impact every day.

"While we react surprised, we shouldn't be as surprised as we were. Viruses tend to do weird things," said Brosnahan.

While the dizzying array of complications may seem daunting, "it's possible there'll be one or a couple of unifying mechanisms that describe how this damage happens," she said.

"It's possible it's all the same thing, and that there'll be the same solution."

Washington, Jul 1: The United States has approved four coronavirus vaccine candidates for clinical trials, Food and Drug Administration (FDA) head Stephen Hahn told reporters.

"Four vaccines have been approved for moving into clinical trials... and another six are in the pipeline for us to review," Hahn said during a press briefing on Tuesday.

The US Administration launched in May Operation Warp Speed, a joint project of Health and Defense Departments, which aims to deliver 300 million doses of a vaccine for COVID-19 by January 2021.

The country's top pandemics expert Anthony Fauci warned on Tuesday, however, that there is no certainty the United States will be able to develop a vaccine against COVID-19 that works and will be safe.

Data on vaccine effectiveness, he added, may be available in the winter or early next year.