When, not if

An panel of communicable disease experts convened by the World Health Organization (WHO) to consider the growing threat posed by avian flu H5N1 released its findings yesterday, and they should serve as a call to action for the pharmaceutical and health care industries. The panel suggested that an H5N1 pandemic could easily be as deadly as the worst flu virus yet: the pandemic flu of 1918 that killed 50 million people worldwide — half of them young, healthy adults.

Michael T. Osterholm, director of the Center for Infectious Disease Research at the University of Minnesota, described a likely scenario in the May 5 issue of The New England Journal of Medicine. "We would be facing a 1918-like scenario.... We would have no surge capacity for health care, food supplies, and many other products and services.... We have no detailed plans for staffing the temporary hospitals that would have to be set up in high-school gymnasiums and community centers — and that might need to remain in operation for one to two years.... We have no way of urgently increasing production of critical items such as antiviral drugs, masks for respiratory protection, or antibiotics for the treatment of secondary bacterial infections. ... Nor do we have detailed plans for handling the massive number of dead bodies that would soon exceed our ability to cope with them."

The WHO lists six stages from the detection of a new influenza virus in animals to a global human flu pandemic. Currently the H5N1 bird flu is at stage 4: small, highly localized clusters of human infections. At this stage, the virus cannot spread easily from person to person. New evidence suggests — but does not yet prove — that H5N1 may be moving to stage 5, meaning that the virus is becoming increasingly better at person-to-person spread. When stage 6 is reached, there will be rapid human-to-human flu spread and pandemic flu.

It's only a matter of time, according to virologist Klaus Stöhr, project leader for the WHO Global Influenza Program. "We are in a situation where we simply have to deal with uncertainties on when this will happen — not whether this will happen or not," Stöhr said yesterday in a news conference. "We believe a pandemic will happen, but we don't know when and also [we don't know] the severity of the event."

"In the last 18 months, we have seen an incremental increase in our concern," Stöhr said. "We do not know if a pandemic can occur next week or next year." Only one thing is sure: H5N1 is coming.