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In controlled clinical trials, which were first performed with use of the sulfonamides, antimicrobial agents have been shown to shorten the duration of symptoms and lessen the excretion of pathogens during episodes of shigellosis. Not all antimicrobial agents that are active in vitro against Shigella are effective in vivo, and efficacy of an agent can only be assessed by properly conducted clinical trials. Resistance to both ampicillin and trimethoprim-sulfamethoxazole, the drugs of choice for the treatment of shigellosis, is now common among Shigella dysenteriae type I isolates in Africa and Asia and is increasing among isolates of other Shigella species, including Shigella sonnei in the United States. Nalidixic acid, the newer quinolones, and amnidocillin pivoxil are additional agents that have been found to be effective in controlled clinical trials. There is a need, however, for more data on the safety of the quinolones before they can be routinely administered to children. Newer agents that deserve evaluation include the orally administered to children. Newer agents that deserve evaluation include the orally administered second- and third-generation cephalosporins, which are highly active in vitro against most strains of Shigella.

Almost all fatal cases of shigellosis occur in developing countries, and data on mortality are generally compiled from three sources: investigations of epidemics caused by Shigella dysenteriae type 1, surveillance of endemic diarrheal disease, and reports from hospitals. Attack rates during epidemics of dysentery due to infection with S. dysenteriae type 1 have ranged from 1% to 33%, and case-fatality rates have ranged from 1% to 7%. In Matlab, a rural district in Bangladesh, most diarrhea-related deaths and approximately 25% of all deaths among children 1 through 4 years of age are attributable to dysentery. In 1984, an epidemic of dysentery was associated with a 42% increase in the death rate in that age group. At the Dhaka Treatment Centre of the International Centre for Diarrhoeal Disease Research, Bangladesh, the fatality rate for 970 inpatients with shigellosis was 11% in 1988, with most deaths occurring among malnourished children who were infected with Shigella flexneri. Control of mortality from shigellosis will require prevention of epidemic S. dysenteriae type 1 disease and endemic S. flexneri infections in children who live in countries with a high prevalence of malnutrition.

A rural area of Bangladesh with a population of 191,000 had 643 health care providers, of whom 324 (50%) practiced allopathic (Western) medicine, 152 (24%) were spiritualists, 109 (17%) were herbalists, and 58 (9%) were homeopaths. Two hundred eight (64%) of the allopaths had no formal training, and only 18 (6%) were graduates of medical school. In a community-based study of 480 children with bloody diarrhea and 480 children with nonbloody diarrhea, allopathic treatment was the most common care provided. Furazolidone and metronidazole were the two most commonly prescribed drugs, given to 26% and 23% of children, respectively, who were seen by a practitioner. Only 25% of children had received oral rehydration therapy. We conclude that in this region of Bangladesh care of acute diarrhea is provided mostly by private medical practitioners who have little or no training; that such care currently is largely irrational; and that the provision of rational care will require the development of simple algorithms that these practitioners can implement for treatment of this disease.

Complications that can lead to death during shigellosis include intestinal as well as systemic manifestations. The former include intestinal perforation, toxic megacolon, and dehydration, and the latter include sepsis, hyponatremia, hypoglycemia, seizures and encephalopathy, hemolyticuremic syndrome, pneumonia, and malnutrition. Data on the frequency of these complications come primarily from hospital-based studies, in which sepsis-either with Shigella or with other Enterobacteriaceae-and hypoglycemia are the most common causes of death. Management of these two complications requires broad-spectrum empiric antibiotic treatment of all severely ill, malnourished patients with shigellosis as well as frequent feedings to prevent hypoglycemia. Unfortunately, in developing countries, access to parenteral broad-spectrum antimicrobial agents is often limited, and frequent feedings are often precluded by the severe anorexia that is characteristic of shigellosis. Realistic approaches to the reduction of mortality from shigellosis must continue to focus on prevention and early antimicrobial therapy rather than on treatment of established complications.