Coronavirus death toll in US likely worse than numbers say Experts say the more than 10,000 deaths is an undercount, full picture unknown.

The nation's death toll from the novel coronavirus surpassed 10,000 in the last 24 hours, but even that figure belied a grim truth: the real number of deaths is higher, but no one knows how much.

"There is no doubt the official death toll is an undercount,” New York City Councilman Mark Levine, the health committee chairman, told ABC News.

The U.S. Centers for Disease Control and Prevention (CDC) is well aware that the figures – which keep going up – do not tell the full story.

“The current data on presumptive and lab-confirmed cases and deaths are underestimates,” CDC spokesman Scott Pauley said Monday. “Right now, we believe that the number of deaths we have reported paints an informative picture of the scope of epidemic.”

In New York City, the current epicenter of the U.S. coronavirus outbreak, the number of dead stood at 2,738 as of Monday evening, according to city statistics. And getting a full picture of the disease remains as important as it is elusive in these first weeks of the American COVID-19 crisis.

Experts say the only way to get a full understanding of the viral enemy is to know how many it has killed and from there, who succumbed, if they were old or young, if they were in perfect health or likely suffering from some underlying condition that made them vulnerable. How fast did they die? And did they die of the virus directly or of something like heart failure caused by their bodies fighting off coronavirus?

As to that last question, Pauley said, "It’s likely that COVID-19 related deaths may not be included on a death certificate or COVID-19 might be a factor related to an individual’s death but not the main cause."

That type of information is more than just cold statistics, experts say.

Deployed by public health agencies, that data could help cities across the country and throughout the world properly prepare for the surge in hospitalizations and deaths that could occur as the disease strikes elsewhere. As it turns out, doctors and scientists believe, it was an underestimation of potential COVID-19 fatalities in New York City that has wrought serious consequences.

Dr. Robert Glatter, assistant professor of emergency medicine and an attending emergency physician at Lenox Hill Hospital in Manhattan, explained the crisis hit before key record-keeping protocols could be established.

"There is still no formal uniform platform for reporting coronavirus-related deaths in the US,” Glatter said. “Along with a lack of test kits or even rapid antigen identification kits, the reality is that many states have been unable to categorize deaths as COVID vs. non-COVID.”

The issue goes back to January, when the average American seemed unbothered by the coronavirus. Glatter said that even in February most hospital systems and medical examiners did not yet have access to COVID-19 testing.

"We did the best we could with what we had,” said one emergency department doctor in Philadelphia, speaking on condition of anonymity. “We didn’t have much and that’s a fact. I’m confident we saw patients who died of COVID before we could test. We suspected it, but couldn't confirm it so the death certificates never contained COVID as the cause.”

The doctor said it is also possible that, before public health officials detected community spread within the US, many people who died of the coronavirus disease were diagnosed simply with influenza-like illnesses or pneumonia.

Now, with the public and private hospital networks in New York City overwhelmed to the point of drowning, there are no resources or time to test samples from the dead or resolve statistical problems, officials acknowledged. At the moment, hospitals in New York City are only testing for novel coronavirus among hospitalized patients.

With limited resources reserved for the severely ill, many are dying before getting tested or while test results are pending, city officials said, and there simply is no opportunity to conduct post-mortem testing – something routinely done in normal times.

According to Levine, the number of deaths at home in New York City has grown 10-fold since the end of last week, even as hospitalizations for trauma and other emergencies have dropped to nearly nothing.

"Normally we have 20 to 25 deaths at home and now we are at 200 to 215,” Levine said, explaining that coronavirus would likely be the only way to explain such a spike.

Mayor Bill de Blasio said Tuesday he assumed the “vast majority” of the recent at-home deaths are coronavirus-related.

“It’s understandable in a crisis that being able to make a confirmation is harder to do with all the resources stretched so thin,” de Blasio said during his daily news conference.

The mayor said the priority now should be on saving lives.

“We do want to know the truth about what happened in every death at home but I think we can say at this point it’s right to assume the vast majority of those deaths are coronavirus related," he added. "That makes it even more sober how many people we are losing, how many families are suffering. how real this crisis is.”

Medical examiners offices across the country are now pitching in amid the crisis, shifting resources away from typical forensic pathology work to help with identifying the cause of death for the growing numbers of people dying at home – because that work is so important.

“We are helping because we have experience in death and know about management and storage of dead bodies, but these cases are not the usual cases that come to us,” said Sally Aiken, chief medical examiner in Spokane, Wash., and president of the National Association of Medical Examiners.

In her own community, Aiken said anyone who has died at home and is suspected of having COVID-19 would be tested after death with a nasal swab, but she admitted that could change if testing were to become more limited.

"If there are enough deaths, there is a point it will overwhelm the jurisdiction, no matter the size and everyone will have to make practical decisions that are not pretty to think about,” Aiken said. “We have to understand that at some point we may not be able to test everyone or look at every body.”

That is what has happened in New York City, the nation’s largest city and the site of the worst outbreak of coronavirus in North America.

"There is no swabbing of deceased individuals anymore and unless the medical examiner has knowledge of a confirmed coronavirus test, then they aren’t being marked down as having coronavirus,” said Levine, whose committee has oversight for the Office of the Chief Medical Examiner.

The CDC last month issued guidance on postmortem specimen collection of suspected COVID-19 deceased patients to ensure consistency across state response, but Aiken said she doubts there would be a “uniform response to the death of COVID-19” because of the lack of a “uniform system” across medical examiner offices – something that could also lead to coronavirus deaths being omitted from the stats.

And, she said, the many patients with underlying conditions who are dying before they can even get to a hospital are also likely to be counted inaccurately.

"You have a lot of [emergency medical services] workers who are pronouncing people dead from things like cardiac issues,” Levine said. “Are those coronavirus victims? Probably are, but they are not being categorized as such in death."

To try and get a more accurate picture of the crisis, the CDC last week issued updated guidance for certifying deaths due to COVID-19 – protocols similar to those in place for pneumonia and influenza. According to the new directions, if a patient has died from pneumonia, for example, but was also tested positive for COVID-19, someone is required to specify whether COVID-19 played a role in the death and whether it was actually the underlying, primary cause of death.

"Ideally, testing for COVID-19 should be conducted but it is acceptable to report COVID-19 on a death certificate without this confirmation if the circumstances are coming within a reasonable degree of certainty,” according to the new CDC protocols, though coronavirus still cannot be listed as the primary cause of death without a confirmed lab diagnosis.

Cécile Viboud, a staff scientist at the National Institutes of Health (NIH) who specializes in the mortality associated with infectious diseases, said it will likely take years to know the actual death toll of the contagion that has nearly paralyzed much of the nation.

In previous research on the 2009 H1N1 pandemic, Viboud said she concluded that only 15% of the deaths attributed to the disease were identified in laboratory testing.

When it comes to COVID-19, she said it's hard to predict how far off the U.S. will be. Experts said there are other factors that make the grim accounting even more challenging. For one thing, the vast majority of those who die from COVID-19 are older or have other ailments, making it harder to pinpoint the precise cause of death. Plus, experts will have to wait years before they can accurately quantify the number of people who may have died indirectly from the pandemic.

“Everything we're doing to flatten the curve has major societal and financial impacts that can increase death rates,” explained Samuel Scarpino, who leads Northeastern University's Emergent Epidemics Lab. For instance, he said, there can be “indirect mortalities because a hospital, for example, doesn’t have a ventilator available for a non-COVID-19 patient.”

Undercounting the death toll impedes policy makers’ ability to understand severity of the disease, effectively allocate resources, or make decisions regarding school and business closures, experts and public health officials agree.

The emotional toll is no less important. Funeral homes are overwhelmed by the number of deceased bodies and funeral directors have said they are worried for the safety and health of their own employees asked to bury and handle bodies who may have been infected with COVID-19.

Family and friends are also left to wonder whether have been exposed to the virus and are contributing to its spread, without realizing it.

What to know about Coronavirus:

How it started and how to protect yourself: Coronavirus explained

What to do if you have symptoms: Coronavirus symptoms

Tracking the spread in the U.S. and worldwide: Coronavirus map

Editor's note: This story has been updated.