This week the World Health Organization (WHO) declared the H1N1 “swine” flu pandemic over, renewing calls that the organization should change the criteria for its six-level pandemic scale or risk increased ambivalence toward public health threats.
The highest level of the WHO’s scale—which H1N1 reached in June of last year— simply indicates “human-to-human spread of the virus in two or more countries” in one of the WHO’s six global regions, and “in at least one other country in another WHO region.”
While relatively contagious, H1N1’s virulence—its ability to cause severe illness and death—paled next to the 1918 Spanish flu and even seasonal flu in the U.S. The 1918 outbreak is estimated to have killed between 50 and 100 million people, while as many as 56,000 people die from seasonal flu in the United States each year, according to the U.S. Centers for Disease Control and Prevention. H1N1 has killed roughly 18,500 people worldwide, according to the WHO.
As the outbreak leveled off late last year experts began to question the WHO’s classification criteria more fervently, while in March former U.S. public health official Dr. Henry I. Miller, writing in Forbes magazine, noted that even seasonal flu meets the WHO’s definition of a pandemic.