Rob Stein

The coronavirus keeps spreading around the United States. New hot spots are emerging and heating up by the day. The death toll keeps mounting. So how can the U.S. beat back the relentless onslaught of this deadly virus?

Public health experts agree on one powerful weapon that's gotten a lot of attention but apparently still needs a lot more: testing.

A new analysis that researchers at Harvard conducted for NPR finds that more states have begun to do enough testing to keep their outbreaks from getting worse, but most are still falling short.

The head of the federal Centers for Disease Control and Prevention said Friday that a new analysis shows the agency's delayed rollout of coronavirus testing did not hinder the nation's response to the pandemic.

The coronavirus didn't start spreading in the U.S. until late January or early February, the CDC analysis found, and it circulated at low levels for quite some time.

As a result, the availability of earlier widespread testing for the virus would not have been able to spot it, according to CDC Director Robert Redfield.

It's the question on everyone's minds: What will it take for us to come out of this period of extreme social distancing and return to some semblance of normal life?

It turns out that the Centers for Disease Control and Prevention has been working on a plan to allow the U.S. to safely begin to scale back those policies. CDC Director Robert Redfield spoke with NPR on Thursday, saying that the plan relies on not only ramped-up testing but "very aggressive" contact tracing of those who do test positive for the coronavirus, and a major scale-up of personnel to do the necessary work.

Updated at 8:25 p.m. ET

Federal health officials issued a blunt message Tuesday: Americans need to start preparing now for the possibility that more aggressive, disruptive measures might be needed to stop the spread of the new coronavirus in the U.S.

The strongly worded warning came in response to outbreaks of the virus outside China, including in Iran, Japan, South Korea and Italy, which officials say have raised the likelihood of outbreaks occurring stateside.

Chunlin Leonhard spends most of her time alone in her room at a hotel at the Travis Air Force Base in California, anxiously reading the latest news about the coronavirus outbreak in China.

"I'm doing about as well as can be hoped for under the circumstances," Leonhard, 55, a New Orleans law professor, says during an interview over Skype.

Chunlin Leonhard is grateful to be back in the United States, even though she's now living under the first federally mandated quarantine in 50 years. "The primary feeling is a sense of relief that I'm back in the States," she says. "I'm just tired and glad and grateful."

Updated at 6:15 a.m. ET

The scientist who stunned the world by claiming he created the first genetically modified babies defended his actions publicly for the first time on Wednesday, saying that editing the genes of the twin girls while they were embryos would protect them from contracting HIV.

He Jiankui of the Southern University of Science and Technology in Shenzhen, China, addressed hundreds of scientists gathered at an international gene- editing summit in Hong Kong that has been rocked by ethical questions swirling around his research.

A genetically modified poliovirus may help some patients fight a deadly form of brain cancer, researchers report.

The experimental treatment seems to have extended survival in a small group of patients with glioblastoma who faced a grim prognosis because standard treatments had failed, Duke University researchers say.

Federal health officials may be about to get greatly enhanced powers to quarantine people, as part of an ongoing effort to stop outbreaks of dangerous contagious diseases.

The new powers are outlined in a set of regulations the Centers for Disease Control and Prevention published late last month to update the agency's quarantine authority for the first time since the 1940s.

People who take certain popular medicines for heartburn, indigestion and acid reflux may want to proceed more cautiously, researchers reported Monday.

The drugs, known as proton-pump inhibitors (PPIs), appear to significantly elevate the chances of developing chronic kidney disease, according to a study involving more than 250,000 people.

One of the most intense debates in men's health has flared again: How often should men get screened for prostate cancer?

This debate has simmered since 2012, when the U.S. Preventive Services Task Force shocked many patients and doctors by recommending against routine prostate cancer screening.

After their third son was born, Tisha Scott and her husband decided they were done having kids. So Scott, 34, of Drakesville, Iowa, decided to get her tubes tied.

"As old married people, neither of us was really interested in using condoms for the rest of our life," Scott says. "So that was the decision that we made because we knew that our family was complete."

For the first time, the Food and Drug Administration has ordered a major tobacco company to stop selling several types of cigarettes.

The FDA on Tuesday ordered the R.J. Reynolds Tobacco Company to stop selling four products: Camel Bold Crush, Vantage Tech 13 and the regular and menthol versions of Pall Mall Deep Set Recessed Filter cigarettes.

The Food and Drug Administration approved the first drug designed to increase a woman's libido.

The controversial decision was hailed by some doctors and advocates as a long-sought victory for women's health, but was condemned by others as irresponsible and dangerous.

Could the microbes that inhabit our guts help explain that old idea of "gut feelings?" There's growing evidence that gut bacteria really might influence our minds.

"I'm always by profession a skeptic," says Dr. Emeran Mayer, a professor of medicine and psychiatry at the University of California, Los Angeles. "But I do believe that our gut microbes affect what goes on in our brains."

A few years ago, a doctor started prescribing Michael Israel painkillers for bad cramps in his gut. Israel had been struggling with Crohn's disease, a chronic digestive disorder, since he was a teenager.

"So he was prescribed, you know, Lortab, or Vicodin or whatever. You know, they would flip-flop it from one to another," says Avi Israel, Michael's father.

Then one day, Michael confessed that something was wrong.