INFECTIOUS-DISEASES - NEW AND ANCIENT THREATS TO WORLD HEALTH

Infectious and parasitic diseases (IPDs) are leading cause of death an d disability in low-income countries, and are re-emerging as a serious health problem in developed countries. The recent rise in IPDs runs c ounter to the long-term decline made possible by advances in medicine- especially antibiotics and immunization-wide-scale improvements in san itation and other living conditions, and growing public awareness of h ealth and nutritional practices. After the eradication of smallpox in 1977, many health experts were optimistic that humans would soon conqu er IPDs, which have caused untold suffering and death throughout histo ry. But the HIV/AIDS epidemic opened the eyes of both health workers a nd the general public to the fact that IPDs had been on the resurgence for the past quarter-century. Since 1973, scientists have identified more than 28 new disease-causing microbes. Outbreaks of Ebola, dengue hemorrhagic fever, cholera, bubonic plague, and other serious diseases have been reported in many low-income countries, and multidrug-resist ant organisms have surfaced throughout the world. This Population Bull etin examines the phenomenon of ''new'' and re-emerging IPDs from an i nternational perspective. The authors discuss the factors that have in fluenced the re-emergence of these diseases, including urbanization, m igration and travel, and agricultural practices that have increased ex posure to diseases once confined to other animals and small geographic areas. They also review the changes in medical practice and treatment that have helped breed bacterial strains resistant to standard drug t reatment. These diseases have led to some of this century's most rapid and dramatic demographic changes. HIV/AIDS, for example, has slowed s ub-Saharan Africa's population growth and may halve the average life e xpectancy in some African countries. The authors explore strategies fo r slowing the rise of IPDs. These include efforts to stem poverty, imp rove immunization programs, and conduct educational campaigns.