The number of coronavirus patients has more than doubled in the past month, hitting 100,000 on Thursday (local time).
This is the highest level in eight months, according to the Department of Health and Human Services.
The all-time peak for admissions was on January 6 when there were reportedly 132,051 coronavirus-infected patients being treated in hospital.
Data from the Centres for Disease Control and Prevention suggests 500 people are being admitted to hospitals each hour on average.
The influx of sick people means the number of available hospital beds is drying up.
Medical experts are growing increasingly worried as cases climb.
“This can't be happening, should not be happening,” Dr Eric Topol, head of the Scripps Institute, tweeted.
Health officials in New Mexico have already been forced to establish a waiting list for intensive care unit beds for the first time ever.
They’re warning the state is about a week away from having to ration medical care as they grapple with staff shortages.
The spike comes just weeks after rising vaccination rates were reflected in lower hospitalisations, but this trend was short-lived as Delta cases rose rapidly in July.
US South a Covid hotspot
The US south is the epicentre of the latest outbreak but hospital admissions are surging across the nation as the Delta variant spreads among mostly unvaccinated populations.
Florida has the highest number of patients in hospital, followed by Texas and California, according to the US Department of Health and Human Services.
Florida’s daily death rate also cleared 200 for the first time earlier this week.
“Vaccines are working to prevent deaths in many other countries that have seen post-vaccine spike in cases, and most other states in the US as well. Florida is different,” Dr Vincent Rajkumar, a professor of medicine at the Mayo Clinic, recently explained on Twitter.
“What’s different in Florida is that, relative to the vaccination rate, the relaxation of distancing and masking was disproportionately high. Leaders expressed disdain for masks and mask mandates. The total number of people unvaccinated is high. And hospitals got overwhelmed.”
Rising cases among children
The difference with Delta is the record number of children requiring hospital treatment.
There are currently more than 2000 confirmed and suspected paediatric Covid-19 hospitalisations, which is 2.3 per cent of total patients.
Children make up about 2.3 per cent of the nation's Covid-19 hospitalisations.
About 32 per cent of them are in California, Florida and Texas.
It’s hoped the vaccine will be approved for children under 12 in the coming weeks.
Dr Anthony Fauci, the nation's top infectious disease expert, predicts Covid could be brought under control by early next year if vaccinations ramp up.
About 61 per cent of the US population has received one dose of the vaccine.
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