Shigellosis, 2008

During 2008, 311 culture-confirmed cases of Shigella infection (6.0 per 100,000 population) were reported (Figure 2). This represents a 32% increase from the 238 cases reported in 2007, and a 23% increase from the median number of cases reported annually from 1999 to 2007 (median, 254 cases; range, 68 to 904).

In 2007, S. sonnei accounted for 283 (91%) cases, S. flexneri for 21 (8%), S. boydii for 3(<1%), and 3 (<1%) had unknown serotype. Case-patients ranged in age from 3 months to 90 years (median, 7 years). Fifty-seven percent of case-patients were <10 years of age; children <5 years of age accounted for 37% of cases. Sixty-three (20%) case-patients were hospitalized. Seventy percent of case-patients resided in the metropolitan area, including 41% in Hennepin County and 12% in Ramsey County.

Ten outbreaks of shigellosis were identified in 2008; all were caused by S. sonnei. These outbreaks resulted in 54 culture-confirmed cases (representing 17% of reported Shigella cases). Seven person–to-person outbreaks occurred in child daycare facilities or elementary schools, and three community associated person-to-person outbreaks also occurred.

Every twentieth Shigella isolate received at MDH is tested for antimicrobial resistance. Fourteen isolates were tested in 2007; 93% were resistant to ampicillin and 7% were resistant to
trimethoprim-sulfamethoxazole. All isolates tested were susceptible to ceftriaxone.

figure 2

Updated Friday, November 19, 2010 at 03:16PM