(Updates with cases topping 1 million)
By Lisa Shumaker
April 28 (Reuters) - U.S. cases of the novel coronavirus topped 1 million on Tuesday, having doubled in 18 days, and making up one-third of all infections in the world, according to a Reuters tally.
More than 56,500 Americans have died of the highly contagious respiratory illness COVID-19 caused by the virus, an average of about 2,000 a day this month, according to the tally.
The actual number of cases is thought to be higher, with state public health officials cautioning that shortages of trained workers and materials have limited testing capacity.
About 30% of the cases have occurred in New York state, the epicenter of the U.S. outbreak, followed by New Jersey, Massachusetts, California and Pennsylvania.
The outbreak could take more than 74,000 U.S. lives by Aug. 4, compared with an April 22 forecast of over 67,600, according to the University of Washington's predictive model https://covid19.healthdata.org/united-states-of-america, often cited by White House officials.
Globally, coronavirus cases top 3 million since the outbreak began in China late last year. The United States, with the world's third-largest population, has five times as many cases as the next hardest-hit countries of Italy, Spain and France.
Of the top 20 most severely affected countries, the United States ranks fifth based on cases per capita, according to a Reuters tally. The United States has about 30 cases per 10,000 people. Spain ranks first at over 48 cases per 10,000 people, followed by Belgium, Switzerland and Italy.
U.S. coronavirus deaths, the highest in the world, now exceed the total number of Americans killed in the 1950-53 Korean War - 36,516. Coronavirus deaths total just below the 58,220 Americans killed during the Vietnam War that ended in 1975.
The coronavirus has killed more people in the United States than the seasonal flu in recent years, except for the 2017-2018 season, according to the U.S. Centers for Disease Control and Prevention (CDC) https://www.cdc.gov/flu/about/burden/past-seasons.html.
Flu deaths range from a low of 12,000 in the 2011-2012 season to a high of 61,000 during 2017-2018.
Coronavirus deaths in the United States fall far short of the Spanish flu, which began in 1918 and killed 675,000 Americans, according to the CDC.
Unprecedented stay-at-home orders to try to curb the spread of the virus have hammered the economy, with the number of Americans seeking unemployment benefits over the last five weeks soaring to 26.5 million.
About a dozen states are beginning to relax the stay-at-home restrictions despite the warning of health experts that premature actions could cause a surge in new cases.
A Reuters/Ipsos survey this month found that a bipartisan majority of Americans want to go on sheltering in place to protect themselves from the coronavirus, despite the impact on the economy.
(Writing by Lisa Shumaker; Editing by Howard Goller)
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