Case Management
Two recent advances in managing diarrheal disease—(a) newly formulated ORS containing lower concentrations of glucose and salts and (b) zinc supplementation—used in combination with promotion of exclusive breastfeeding, general nutritional support, and selective and appropriate use of antibiotics, can further reduce the number of diarrheal deaths among children. Families and communities are key to achieving case management goals by making these recommendations routine practice in homes and health facilities.
New Oral Rehydration Solutions
For more than 25 years, UNICEF and WHO have recommended a single formulation of glucose-based ORS considered optimal for cholera, irrespective of cause or age group affected. This formulation has proven effective and without significant adverse effects (Ruxin 1994), but because watery stools persist and duration of diarrhea is not reduced, mothers' and health workers' acceptance of current ORSs has been suboptimal.
During the past 20 years, efforts to improve ORS to treat dehydration from all types of diarrhea and reduce stool output or duration have continued—for example, by reducing the sodium content in line with sodium losses for noncholera diarrhea. Compared with standard ORS, lower sodium and glucose ORS reduces stool output, vomiting, and the need for intravenous fluids (Hanh, Kim, and Garner 2001). If household use increases, new ORS can reduce childhood deaths from non-cholera diarrhea (Duggan and others 2004), and it appears to be as effective as standard ORS for children or adults with cholera. A WHO expert group now recommends that ORS containing 75 milliequivalents of sodium and 75 millimoles of glucose per liter (total osmolarity, 245 milliosmoles per liter) be used everywhere (WHO and UNICEF 2004).
Zinc Supplementation
A review of all relevant clinical trials indicates that zinc supplements given during an episode of acute diarrhea reduce both duration and severity and could prevent 300,000 deaths in children each year (Black 2003). WHO and UNICEF now recommend that all children with acute diarrhea be given zinc in some form for 10 to 14 days during and after diarrhea (10 milligrams per day for infants younger than 6 months and 20 milligrams per day for those older than 6 months) (WHO and UNICEF 2004).
Pilot studies in Brazil, Egypt, Ethiopia, India, Mali, Pakistan, and the Philippines that include zinc routinely in the management of acute diarrhea not only show an improvement over ORS alone but also suggest two important new effects: (a) use rates of ORS increase, and (b) use rates of antidiarrheals and antimicrobials decrease significantly (Baqui and others 2004). Large community-based studies are being implemented to corroborate these potentially important findings.
Management of Bloody Diarrhea
The primary treatment for shigellosis, the most common and severe cause of bloody diarrhea, is antimicrobials. The choice of effective, safe, and inexpensive oral drugs for use in developing countries has, however, become problematic because of the increasing prevalence of antimicrobial drug resistance (Salam 1998). Tetracycline, ampicillin, and the fixed-ratio combination of trimethoprim and sulfmethoxazole, once used as first-line treatment, are no longer reliably effective. When epidemic dysentery caused by multidrug-resistant S. dysenteriae type 1 appeared in Africa and Asia in the 1980s and 1990s, nalidixic acid was pressed into use (Salam and Bennish 1988). Nalidixic acid is a drug used primarily for urinary tract infections, but it is also effective against Shigella. Clinical responses were initially excellent, but with continued use, resistance to nalidixic acid has been increasing in many parts of the world (Dutta and others 2003).
A number of other drugs have been tested and shown effective, including ceftriaxone, azithromycin, pivmecillinam, and some new generation 5-fluoroquinolones, such as ciprofloxacin (Salam 1998). Because of its effectiveness, safety, ease of administration by the oral route, short course, and low cost (US$0.10 for a three-day course for a 15-kilogram child), ciprofloxacin is the current drug of choice for shigellosis (Zimbasa Dysentery Study Group 2002). However, ciprofloxacin-resistant strains are already appearing (Pazhani and others 2004), and it is only a matter of time before resistance becomes widespread, especially if the drug is readily available and indiscriminately used. Because of these concerns, development of a vaccine for Shigella is critical. The Diseases of the Most Impoverished initiative, supported by the Bill & Melinda Gates Foundation (Nossal 2003), which promotes vaccine development for Shigella, cholera, and typhoid, is a significant advance since the previous edition of this volume.
