The University of Washington on Thursday (Aug 27) expanded the forecast of its widely cited model, projecting 317,697 deaths in the United States by Dec 1 due to the Covid-19 pandemic as cases climb in several states.
The new forecast, by the university's Institute for Health Metrics and Evaluation (IHME) reflects an increase of about 8,000 deaths from its previous forecast.
However, the report also suggests that if 95 per cent of Americans wore a mask, the death toll could be reduced by about 67,000 lives.
US confirmed cases are now over 5.8 millionthe highest total in the world. The US death toll is also the world's highest at over 180,000.
On a per capita basis, the United States ranks 12th in the world for the number of deaths, with 54 deaths per 100,000 people, and tenth in the world for cases, with 1,774 cases per 100,000 residents, according to a Reuters analysis.
The IHME's projections have been cited in the past by the White House and are watched closely by public health officials.
The IHME report comes as several US Midwest states reported record one-day increases in the number of new coronavirus cases on Thursday as nationwide deaths from the virus topped 180,000 and officials braced for the possibility of another surge with school openings.
Iowa, Minnesota, North Dakota and South Dakota all recorded on Thursday the biggest one-day increases in new infections since the pandemic started.
Nationally, metrics on new cases, deaths, hospitalisations and test positivity rates are all declining but there are emerging hotspots in the Midwest.
North Dakota, where cases rose 30 per cent the previous week, reported a record 333 new cases on Thursday.
Neighbouring South Dakota, where cases rose 50 per cent the previous week, reported a record 623 new infections.
Infections have been rising since an annual motorcycle rally in Sturgis, South Dakota drew more than 365,000 people from all over the country from Aug 7 to 16.
The South Dakota health department said 40 cases have been traced to the Sturgis rally. Iowa reported 1,288 new cases on Thursday after seeing infections rise nearly 7 per cent the previous week.
Minnesota reported 1,154 new cases and saw its new cases rise 4 per cent the previous week, according to a Reuters analysis. Cases are also rising in Illinois.
Minnesota's health department said 265 of the new cases were due to delayed test results from one lab and the backlog would affect future reports as well.
Health experts have warned there could be another surge in cases across the United States as schools reopen and colder weather forces more gatherings indoors.
This week, the US Centres for Disease Control and Prevention (CDC) said people exposed to Covid-19 but not symptomatic may not need to be tested.
That contradicted earlier guidance from the CDC, shocking doctors and politicians and prompting accusations that it may have been based not on sound science but on political pressure from the administration of President Donald Trump.
California, Connecticut, Florida, Texas, New Jersey and New York all plan continue to test asymptomatic people who have been exposed to Covid-19.
The governors of New York, New Jersey and Connecticut slammed the CDC's move as "reckless" and "not based on science,"and said they would not change testing guidelines in their states.
The CDC and Department of Health "have not shared their scientific rationale for this change in policy, which substitutes sound science-based public health guidance with the president's misinformation," they said in a joint statement.
"This type of robust testing by our states has been a key factor in our success so far to flatten the curve in the tristate area."
On Wednesday, the top US government infectious disease expert, Dr Anthony Fauci, told CNN he was having surgery during discussion of the change and expressed worry concerning the CDC's move.
The World Health Organization said, resources permitting, people exposed to the novel coronavirus should continue to get tested even if they do not show immediate symptoms of infection.