The head of the World Health Organization said on Tuesday that the global mortality rate for Covid-19, the disease caused by the new coronavirus, was 3.4 percent, a figure that primarily reflects the outbreak in China, where the vast majority of cases have been detected.
Dr. Tedros Adhanom Ghebreyesus, the organization’s director general, said in a news conference in Geneva that Covid-19 was deadlier than the seasonal flu but did not transmit as easily. “Globally, about 3.4 percent of reported Covid-19 cases have died,” Dr. Tedros said. “By comparison, seasonal flu generally kills far fewer than 1 percent of those infected.”
The figure does not include all mild cases that do not require medical attention and is skewed by Wuhan, where the death rate is several times higher than elsewhere in China. Researchers expect the rate may be reduced as they discover a fuller picture of who has been infected.
The death rate could turn out to be below 1 percent, according to an editorial published by Dr. Anthony S. Fauci and Dr. H. Clifford Lane, of the National Institute of Allergy and Infectious Diseases, and Dr. Robert R. Redfield, director of the Centers for Disease Control and Prevention.
The W.H.O. estimate takes into account the growing number of infections being recorded outside China, mostly in Iran, Italy and South Korea.
Dr. Margaret Harris, a W.H.O. spokeswoman, said the figure was a “crudely calculated” snapshot of the disease’s death rate globally, and was expected to “change over time, and vary from place to place.”
“While many people globally have built up immunity to seasonal flu strains, Covid-19 is a new virus to which no one has immunity,” meaning more people can be infected and some will suffer severe illnesses, Dr. Tedros said. The coronavirus does not transmit as efficiently as the flu but “causes more severe disease,” he added.
When the outbreak was concentrated in Wuhan, the Chinese city where the new virus was first found, the W.H.O. said that the mortality rate of the disease had ranged from 0.7 percent outside of Wuhan to as high as 4 percent inside the city. The organization also said that the epidemic would affect different countries in different ways.
Data from the Chinese government shows that the mortality rate in that country is about 3.7 percent, with most deaths reported in the province of Hubei, which includes Wuhan.
Dr. Tedros added on Tuesday that it was still possible to contain the virus, but warned that “rising demand, hoarding and misuse” of medical supplies such as masks could compromise the world’s ability to fight the outbreak, and he recommended a 40 percent global increase in the production of such supplies.
