The Threat of Pandemic Influenza: Are We Ready?

Abstract

MOST INFECTIOUS DISEASE EXPERTS believe that the world stands on the verge of an influenza pandemic.1–3 Yet, despite the legacy of the 1918 “Spanish flu,” which was estimated to have killed at least 20 million people, and the additional deaths, social disruption, and economic losses that resulted from pandemics in 1957 and 1968, the general public and their elected representatives appear relatively unconcerned about the next “killer flu.” Considerably more attention has been focused on protecting the public from terrorist attacks than from the greater threat of pandemic influenza—an event conservatively expected to cause between 2 and 8 million deaths.2 Meanwhile, the danger mounts as the world’s capacity to produce vaccines shrinks and avian H5N1 influenza, which has infected many people and killed at least 44 to date, continues to circulate in Southeast Asia.4 With the H5N1 virus showing progressive genetic changes as it has adapted to new avian hosts in recent years and is now circulating at or near endemic levels in poultry in many parts of Asia, the pervasive threat of a pandemic outbreak in humans grows larger and more imminent. A summary was recently prepared for the Forum on Microbial Threats of the Institute of Medicine, entitled The Threat of Pandemic Influenza: Are We Ready?, based on discussions and presentations at a 2-day workshop convened in June 2004 by the Forum. It includes papers from leading experts that explore the history of influenza pandemics and its lessons along with the 2003–04 outbreak of highly pathogenic avian influenza in Asia and its implications for human health. It chronicles the emergence and toll of the H5N1 avian influenza strain and its appearance in mammals, including humans, and compares the costs of preparations with the costs of illness and death that could arise during an outbreak. It describes what steps the United States and other countries have taken thus far to prepare for a pandemic flu outbreak and discusses unmet needs, including the inability of hospitals to absorb the expected surge of critically ill patients and the gaps existing in many nations’ capacities to monitor and detect flu outbreaks among animals or people. The summary points to the need for international agreements regarding the sharing of influenza vaccine and antiviral stockpiles to ensure that the 88 percent of nations that cannot manufacture or stockpile these products have access to them. Several recurring themes emerged during the workshop. The assessments put forward by individual experts are included in the report. Echoing throughout the discussions of the question “Are we ready for a pandemic influenza?” was the answer: “no.” The unmet needs, gaps in knowledge, and opportunities not yet taken for improving preparedness that suggest such a conclusion are described here in brief.