From early March to the end of July, 76,088 Americans between the ages of 25 and 44 lost their lives.

In July alone, the tally rose above 16,500 deaths, amounting to what could well be the deadliest month in US history for young adults.

With the COVID-19 pandemic more than likely responsible for the increase, the statistic is a bleak reminder that age isn't a reliable way to distinguish just who is at risk in our community.

A research letter published in the Journal of the American Medical Association has estimated the level of mortality we should expect for that same month to be just over 13,000, giving us just over 3,400 deaths that – statistically speaking – we never expected.

It's a pattern that has since continued through the seasons. Informed by trends throughout recent years, we would expect around 150,000 adults in this age group to pass away this year.

Sadly, as we approach the end of December, that number will almost certainly climb beyond 170,000.

It's hard to accurately measure 'deadliest months' alongisde a range of variables and a growing population, but for perspective, during WWII, US casualties averaged around 6,600 a month.

They're extraordinary figures. Then again, these are extraordinary times. As the COVID-19 death count in America continues to soar, the coronavirus is a convenient place to turn for an explanation.

Based on the CDC's own count, nearly 2,000 people aged between 25 and 34 have so far died from COVID-19. The measure is more than double among those in their late 30s and early 40s, adding up to a total of 7,070 lives lost.

Marrying up the official count with excess figures can only account for just a little over a third of all excess casualties.

That's a lot, but it still suggests around 62 percent of superfluous deaths in 2020 can't be officially attributed to the fever, pneumonia, and eventual organ failure brought on by COVID-19.

Putting reported numbers aside, the true cost of the pandemic lurks just out of sight like an iceberg below the surface.

It's difficult to estimate at this stage how the pandemic has indirectly affected our healthcare in other ways, from the way we seek medical care for non-COVID conditions to how we eat, socialise, and exercise.

More importantly, the official tallies could represent just a fraction of all community cases.

How many of those result in a death we can attribute directly (or even indirectly) to COVID-19 is impossible to say, but the researchers don't feel it's a stretch to make an association.

"Although the remaining excess deaths are unexplained, inadequate testing in this otherwise healthy demographic likely contributed," they suggest in their report.

Unfortunately authoritative data takes time to collect and analyse, and with 2020 still rolling on, there's no convenient source of statistics for easy crunching as of yet. The best we can do is look back on previous years and take a guess at what the breakdown of numbers in 2020 should look like.

At the top of the list of usual mortalities for adults in this age group is a jumble of causes labelled 'unintentional injury'.

This includes things like falls and motor vehicle accidents, yet a growing contributor to this category are accidental drug overdoses, especially opioids.

The researchers behind this study looked at the contributions opioid overdoses have made to the total number of deaths in the 25 to 44 demographic in previous years to get a sense of perspective on the size of each category.

They found a total of 10,347 unintentional opioid deaths recorded between March and July of 2018.

Compared with the 11,899 excess deaths in this period in 2020 for the same age group, we start to get a sense of the scale of damage this year's events have wrought on a section of the community who are barely half way through their lives.

And this is just one demographic. In total, excess deaths will count in the hundreds of thousands of people by the end of the year, all a consequence of a single virus.

We'll be unravelling the exact nature of these excess deaths for years to come, hopefully learning lessons along the way.

That doesn't mean we need to wait. There are lessons we can be learning right now.

This research was published in the JAMA.