Alice McWalter, a resident of The Sequoias retirement community, developed hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, which health officials call "rare consequences of E. coli 0157 infection.''
Meanwhile, one of two other residents who were hospitalized with E. coli complications has been released from Stanford University Medical Center, the San Mateo County Health Services Agency announced today.
Of 13 residents who tested positive for the bacteria, 11 were hospitalized, health officials now say.
Health officials today added another person to the list of those residents and employees of The Sequoias being monitored for possible infection, bringing the current total to 46.
Investigators are still looking for the source of the outbreak.
They have ruled out ground beef and sprouts as possible sources. Soil from the communal garden, which was fertilized with manure, tested negative for the presence of E. coli.
According to the Centers for Disease Control and Prevention, symptoms of E. coli include fever, abdominal cramps, nausea, vomiting, and watery or bloody diarrhea.
Young children and the elderly are most likely to suffer severe symptoms including kidney failure and, in rare cases, death.
The CDC says most people get E. coli from contaminated food, such as undercooked ground beef, and recover without antibiotics or other specific treatment in five to 10 days.