Over the past 35 years, dozens of new and frightening diseases have been identified, among them hepatitis C virus, Ebola and other hemorrhagic viruses, Legionnaires' disease, Nipahencephalitis, H5N1 influenza, SARS, the new arenavirus Lujo, which causes hemorrhagic fever in its victim s, and, most pervasively, the hum an immunodeficiency virus (HIV/AIDS). The emergence of H5N1 avian flu in 1996, coupled with the recent declaration of an H1N1 influenza pandemic, demonstrate the urgent need for countries to have pandemic preparedness plans in place. For nations that are unprepared, a pandemic could result in devastating social, economic, and health consequences, including a high number of fatalities. Nowhere is this more so the case than in countries with underdeveloped health care systems.