Hemolytic-uremic syndrome--an outbreak in Sacramento, California

Between July and November 1982, 14 cases of the hemolytic-uremic syndrome occurred in the Sacramento, California, metropolitan area; 9 of the 14 patients lived within a 7.5-mile radius in northeast Sacramento, 10 were female, 12 were white non-Hispanic and 13 were children with a mean age of 3.6 years. Of the 14 patients, 13 were admitted to hospital; 7 required peritoneal dialysis. The 14th child, a 3-month-old white female infant, was found dead in her crib and had renal histopathologic findings consistent with the hemolytic-uremic syndrome. Of the 13 nonfatal cases, 12 patients had diarrhea before being admitted to hospital. A case-control study involving 11 cases and 22 controls did not show any significant differences in exposure to a variety of possible risk factors including restaurants, specific foods and water supply. Stool specimens were negative for enteric bacterial pathogens by culture and for viruses by tissue culture assay, suckling mouse inoculation and immune electron microscopy; no serologic evidence was found for infection due to enteroviruses, respiratory viruses or arenaviruses. Two of four children tested, however, showed serologic evidence of infection by Vero-cytotoxin-producing Escherichia coli. These 14 cases represent one of the largest reported outbreaks of the hemolytic-uremic syndrome in the United States.