Epidemic Shiga-Bacillus Dysentery in Central America

Evolution of the Outbreak in El Salvador, 1969–70

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  • Center for Disease Control, Atlanta, Georgia 30333

In mid-1969 a regional outbreak of bacillary dysentery extended into El Salvador from neighboring Guatemala and Honduras. The etiologic agent was Shigella dysenteriae type 1; epidemic strains from El Salvador had antibiotic-resistance patterns identical to those of strains previously isolated in Guatemala. The areas first affected were the Departments of Ahuachapan, which is contiguous with Guatemala to the northwest, and Chalatenango, which borders Honduras to the north. Subsequently, cases of severe dysentery developed in all 14 departments of El Salvador with a general pattern of spread from north to south along main routes of commerce. The continued increase in cases late in 1969 and early in 1970 indicated that the epidemic would continue, since such contributing factors as overcrowding and poor sanitation remained unchanged. Infants seemed to be at greatest risk of severe illness and death. Similarly high attack rates in older children and adults suggest that the population was uniformly susceptible to this organism. Confusion about the etiology contributed to the high mortality rate: treatment at first was limited to antiamebic therapy and ineffective antimicrobial agents. The case-fatality ratio dropped wherever adequate antibiotic and fluid therapy were employed.

Author Notes

Present address: Department of Medicine, University of Washington Hospital, Seattle, Washington 98105.

Ministry of Public Health and Social Assistance, Republic of El Salvador.

Central Laboratory, Rosales Hospital, San Salvador, El Salvador.