Focus Area: Diarrheal Diseases

Photo: USAID/L. Chomiak

Statement of the Problem

Diarrhea was the leading cause of childhood morbidity and mortality in developing countries, (but has now dropped to the second most common cause) resulting in an estimated 3 billion episodes and 1.5 to 2 million deaths annually. The effective use of good case management, including oral rehydration therapy (ORT), in the last two decades has dramatically reduced the case fatality rate for diarrhea and the overall diarrhea-related mortality by about three million per year. Nevertheless, many infants continue to die as a result of dehydration secondary to diarrhea because of the lack of use or delayed use of ORT or as a complication of severe untreated dehydration, persistent diarrhea or bloody dysentery. A majority of diarrheal mortality occurs in developing countries and the highest rates of diarrhea occur among infants with malnutrition. Malnourished children are particularly prone to diarrhea. In developing countries infants suffer about three to six episodes of diarrhea per year. Infants often do not receive appropriate diet during diarrheal episodes, which results in loss of nutrients and exacerbation of the malnutrition, and this results in increased susceptibility to both diarrhea and other infections. Therefore, appropriate treatment of diarrhea is important for the immediate illness and also for the long-term well-being of the infant. Approximately, 7.5-23% of the diarrheal episodes result in persistent diarrhea (more than two weeks duration). These infants also need specialized treatment in addition to rehydration therapy. In many setting up to 50% diarrhea-associated deaths occur in children with malnutrition associated persistent diarrhea.

Both acute and persistent diarrhea can be caused by a variety of viral, bacterial and parasitic pathogens. The leading causes of diarrhea among children in developing countries are rotavirus, enterotoxigenic E. coli, shigella and cholera in certain areas. Antimicrobial resistance (AMR) against shigella is becoming an increasing problem. Cholera is now endemic in many countries and is an important cause of diarrhea in children as well as adults in certain regions.

In addition to causing diarrheal symptoms, enteric pathogens can also cause sepsis (e.g. typhoid fever), gastritis (e.g. H. pylori), and autoimmune diseases (e.g. C. jejuni, salmonella, shigella, all of which may cause serious illness. Typhoid is one of the most common causes of serious systemic infection in developing countries. H. pylori is linked to peptic ulcer and gastric cancer, and may also be linked to increased susceptibility to other enteric pathogens by lowering gastric acidity. C. jejuni is linked to Guillain-Barre syndrome which is becoming increasingly recognized with the decline in polio cases. Diarrhea is also a complicating factor in the management of patients with HIV-AIDS.

HaRP Approach

The Health Research Program (HaRP) seeks to improve diagnosis and assessment and increase prevention, and treatment by:

• Advancing the understanding of causes and risk factors of diarrheal diseases
• Developing new revised guidelines for management of diarrhea
• Evaluating new and alternate drug treatments and rehydration therapies
• Contributing to the prevention of diarrhea and through evaluation of new vaccines.

Related Links

• Diarrhea Treatment Guidelines - Not Yet Field Tested [PDF, 282KB]
  Guidance on how to implement the new WHO/UNICEF recommendations for the use of ORS and zinc supplementation in the clinical management of diarrhea. The guidelines presented in this document are generic; that is, they will be most effective when modified to support the particular strategy being used to introduce the new recommendations in each country.
  • Spanish Version [PDF, 322KB]
• Diarrhea Guidelines for New Diarrhea Treatment Protocols for Community-Based Healthcare Workers - Not Yet Field Tested [PDF, 116KB]
  A generic guide to help community-based healthcare workers improve diarrhea management. The new tools described in this guide will help to prepare community-based healthcare workers to better help mothers treat a child with diarrhea. In addition this guide will help them to know when to refer children with more severe diarrhea and dehydration.
• Report to Congress: Health-Related Research and Development Activities at USAID - September 2009 [PDF, 447KB] (requires Adobe Reader)
  With this report, USAID provides an update on it's five-year health research strategy outlined in the 2006 Health Related Research Report to Congress. Significant progress has been made in many areas, influencing policies and programming on the ground in real time. Also access the 2008 Report to Congress [PDF, 1MB], 2006 Report to Congress [PDF, 881KB], and the 2005 Report to Congress [PDF, 2.8MB], which highlights the contribution of USAID Health Research investments to global health programs through 2005.