• Total Cases: 147

• Shigella Species Type:

– 101 (68.7%) sonnei

– 5 (3.4%) flexneri

– 41 (27.9%) species not yet available.

• Severity of Disease:

– 67 (45.6%) of the cases have been hospitalized due to shigella.

– 1 (0.7%) death has been attributed to shigella.

An outbreak of Shigellosis has been impacting the Spokane community since October 23rd, 2023. The first case of shigellosis was diagnosed in a person experiencing homelessness. Spokane Regional Health District (SRHD) initiated an investigation and response from this initial case, providing education and guidance to the community. On November 20th,

2023, SRHD declared an outbreak among people experiencing homelessness. Early patterns indicated a broad distribution of cases across shelters and among campers, pointing to a community-wide transmission without a single identifiable source. Since then, the outbreak has escalated, affecting the broader Spokane community.

As of October 2023 147, cases have been identified in Spokane County. As a reference, annual case counts of shigellosis in Spokane county for the last 5 years have ranged from 3 to 23 cases.

Shigellosis, a bacterial infection caused by Shigella, is a significant public health concern. In the United States, it leads to approximately 450,000 cases annually with an estimated direct medical cost of $93 million. Shigella is highly contagious, spreading through the fecal-oral route, often via contaminated hands, surfaces, food, water, or during sexual contact.

Control is challenging because of the low infectious dose necessary for transmission. The four species of Shigella are S. flexneri, S. boydii, and S. dysenteriae. S. sonnei. S. sonnei is the most prevalent in the U.S., and is the primary species associated with Spokane’s current outbreak. Symptoms include diarrhea (often bloody), fever, stomach pain, and the urge to pass stool even when the bowels are empty, typically starting 1-2 days post-exposure and lasting one week. Cases may be infectious for several weeks after diarrhea ends.

Shigella affects all age groups and spreads easily in places like day care and educational settings, among travelers to regions with poor sanitation, in men who have sex with men, among people experiencing homelessness, and in people with weakened immune systems.

A growing concern with Shigella is antimicrobial resistance, rendering first-line antibiotics ineffective and necessitating antimicrobial resistance testing. The risk of resistance emphasizes the importance of prudent antibiotic use and highlights the challenges in managing and treating Shigella infections.