Case Stud A.- Oral Dehydration Therapy for Diarrheal Diseases

In the living conditions prevalent in the less developed world, characterized by a lack of potable water, sanitation, and refrigeration, the bacteria and other pathogens that cause diarrheal diseases are easily transmitted to young children by contaminated water, hands, and food. As a result, infants in less developed countries suffer on the average six to eight separate episodes of diarrheal disease per child. The two major consequences of infant diarrhea are dehydration and malnutrition. Diarrhea causes a loss of body water and salts (electrolytes), which, if sufficiently copious and not adequately replaced, may result in dehydration. Approximately 1 of every 150 to 200 episodes of infant diarrhea results in severe, lifethreatening dehydration. In the last decade, diarrheal dehydration was one of the major causes of infant mortality in virtually all less developed countries, All episodes of infant diarrhea have nutritional consequences, in part because ill infants eat less and in part because the pathogens that cause diarrhea often diminish the ability of the small intestine to absorb nutrients. Repeated diarrheal infections within a short period of time can lead to clinically overt malnutrition. Irrespective of the specific infectious agent causing diarrhea, the treatment of diarrheal dehydration is the same and involves the replacement of body water and electrolytes (salts in solution). In the 1950s and 1960s, this treatment was accomplished by intravenous rehydration—i.e., infusion of sterile water and electrolytes into the vein of an infant. Although intravenous therapy is very effective, it was poorly suited to use in the less developed world where it was most needed. The drawbacks of intravenous dehydration include its expense; the need for sterility of the fluids, tubing, and needles; the requirement for relatively sophisticated health workers to administer the infusion; and the difficulties of distribution and supply of all the materials. In recent years, thanks to important contributions by a number of laboratory scientists, clinicians, epidemiologists, and health delivery experts, a simple, efficacious, technologically appropriate alternative to intravenous dehydration has become available—namely, oral dehydration therapy (ORT) using sugar/electrolyte solutions. An application of ORT other than for treating dehydration involves its use early in the course of infant diarrhea to prevent dehydration. The ingredients used in oral dehydration solutions are widely available, easily transported, and need not be sterile. Furthermore, sophisticated health workers are not required to administer ORT. The efficacy of an oral glucose/electrolyte solution to promote sodium and water absorption was demonstrated in clinical intestinal balance studies by U.S. investigators in the Philippines in the early 1960s. By the end of that decade, clinical studies by U.S. physicians and their Bangladeshi and Indian collaborators had established that ORT could diminish by 80 percent the intravenous fluid requirements of adults with severe cholera. Similar studies were carried out in children with cholera and adults and older children with severe diarrhea not due to cholera. Since 1977, investigators have carried out a number of clinical studies perfecting the use of ORT in noncholera infant diarrhea in many less developed areas of the world. These studies have examined modifications in oral dehydration formulas including the sugar, base, sodium, and potassium content; they have resulted in practical regimens for health workers to follow in orally dehydrating infants; they have demonstrated the efficacy of oral dehydration, irrespective of the etiology of the diarrhea; and they have defined the limitations of ORT. Several methods have been devised for the preparation of simple sugar/salt solutions that are safe and can be prepared in the home. These simple solutions are just as effective as more complex balanced glucose/ electrolyte solutions in stimulating sodium and water absorption by the intestine, though infants treated with such solutions have inadequate potassium replacement and can become potassium depleted, a state with adverse clinical consequences. ORT has been perfected in recent years to the point where it represents one of the most powerful weapons in the armamentarium against disease in the less developed world. Increasingly, less developed countries are undertaking national diarrheal disease control programs in which ORT constitutes the keystone.