Shigella

Shigella is a genus of Enterobacteriaceae genetically nested within Escherichia, technically a subgenus of Escherichia, found naturally only in humans and gorillas as enteric bacteria, and is a leading cause of bacterial diarrhea, responsible for 80–165 million cases of diarrheal illness and 74,000 to 600,000 deaths annually worldwide. The U.S. sees ~450,000 cases and 38–70 deaths annually.