Global epidemiology of hemoglobin disorders.

Thalassemias and the hemoglobinopathies such as Hemoglobins S, C and E, are now a global problem. They have spread through migration from their native areas in the Mediterranean, Africa and Asia and are now endemic throughout Europe, the Americas and Australia. Comprehensive control programs in recent years have succeeded in limiting the numbers of new births and prolonging life in affected individuals. Such programs have been successful in a minority of countries and have little global impact. Over 300,000 infants with major syndromes are born every year and the majority die undiagnosed, untreated or under-treated. Countries may be divided into three general categories according to the services available: A. Endemic Mediterranean countries. In these long-established prevention programs have succeeded in achieving 80%-100% prevention. Specialized clinics able to provide optimum treatment. B. Areas of the developed, industrialized world where prevalence is increasing because of migration. These countries have the means to provide adequate control but have problems in reaching immigrant groups with different cultural background. C. Countries of the developing world where the provision of services is hampered by economic difficulties, other health priorities due to high infant mortality from infectious diseases, and religious/cultural constraints.