“The new swine influenza virus [H1N1], which appeared suddenly after years of warning about a potential pandemic of avian influenza, upset the WHO’s assumptions that most people have the same understanding of the word pandemic,” says the New York Times in a report that examines the difficultly health experts have had when attempting to agree upon what constitutes a pandemic.

“Generations of people have used the term to describe widespread epidemics of influenza, cholera and other diseases. But as the new H1N1 swine influenza virus spreads from continent to continent, it is clear that a useful definition is far more complicated and elusive than officials had thought,” the newspaper writes. “And what is at stake is far more than an exercise in semantics. A clear understanding of the term is central to the World Health Organization’s six-level staging system for declaring a pandemic, which in turn informs countries when to set their control efforts in motion.”

The article examines how “[j]ournals, textbooks and reference works use pandemic in discussing certain diseases, but rarely define the word” and the difficulty public health experts have when attempting to communicate risk assessment to the public. The piece also highlights several diseases that many health experts agree can be defined as pandemics, including AIDS, cholera and dengue.

The New York Times writes, “Dr. Keiji Fukuda, an influenza expert who is an assistant director-general at the WHO, said in an interview that ‘as difficult as things are right now,’ the problem of defining a pandemic and communicating risk ‘would be magnitudes worse and more confusing’ if the agency had not dealt with AIDS, SARS and avian influenza,” which “prompted new international health regulations and pandemic plans, and allowed critical scientific information to be disseminated quickly, he said” (Altman, New York Times, 6/9).