Avian influenza pandemic threat and health systems response.

Avian influenza is a panzootic and recurring human epidemic with pandemic potential. Pandemic requirements for a viral pathogen are: a novel virus must emerge against which the general population has little or no immunity; the new virus must be able to replicate in humans and cause serious illness; and the new virus must be efficiently transmitted from person to person. At present, only the first two conditions have been met. Nonetheless, influenza pandemics are considered inevitable. Expected worldwide human mortality from a moderate pandemic scenario is 45 million people or more than 75% of the current annual global death burden. Although mathematical models have predicted that an emerging pandemic could be contained at its source, this conclusion remains controversial among public health experts. The Terrestrial Animal Health Code and International Health Regulations are enforceable legal instruments integral to pandemic preparedness. Donor support in financial, material and technical assistance remains critical to disease control efforts - particularly in developing countries where avian influenza predominately occurs at present. Personal protective equipment kits, decontamination kits and specimen collection kits in lightweight, portable packages are becoming standardized. Air transport border control measures purporting to delay importation and spread of human avian influenza are scientifically controversial. National pandemic plans prioritize beneficiary access to antiviral drugs and vaccines for some countries. Other medical commodities including ventilators, hospital beds and intensive care units remain less well prioritized in national plans. These resources will play virtually no role in care of the overwhelming majority of patients worldwide in a pandemic. Prehospital care, triage and acute care all require additional professional standardization for the high patient volumes anticipated in a pandemic.