Shigellosis OutbreakKanawha CountyFall 2010 Rachel Holloway, CDC Public Health Associate Brandon Merritt, Regional Epidemiologist
Objectives • To describe an outbreak of Shigella sonnei in Kanawha County in Fall 2010 • To explain the epidemiologic procedures used during the shigellosis outbreak • To describe recommendations made by KCHD as a result of this outbreak
Shigellosis • CDC clinical definition: • An illness of variable severity characterized by diarrhea, fever, nausea, cramps, and tenesmus. • Caused by the shigella bacterium: • Shigella dysenteriae • Shigella flexneri • Shigella boydii • Shigella sonnei
Shigellosis • Mode of transmission: • Person to person via fecal-oral route • Food handlers • Incubation Period:1-3 days • Infectious Period: up to several weeks • Duration of illness: 5-7 days • Medical treatment: • Self-limiting • Antibiotics
Shigellosis in Kanawha Co. • Between 1999-2008, Kanawha County had an endemic rate of <1 case per 100,000 population.
And so it begins… • August 30, 2010: • Four confirmed S. sonnei at CAMC • 1 from elementary School “A” • 3 from elementary School “B” • Outbreak investigation opened • Reported to DIDE • Case definition established • Line list developed • Phone questionnaire created • Health Alert Network Advisory issued county wide
Case Definition • Confirmed case: • Laboratory confirmed s. sonnei stool specimen • Probable case: • Onset after August 28, 2010 with three or more episodes of diarrhea in a 24 hour period and an epi-link to a confirmed case
School Return Guidelines • Children with culture confirmed shigellosis who had begun antibiotic treatment were allowed to return to school after the diarrhea and fever was resolved for 24 hours; • Children with culture confirmed shigellosis and who were not given antibiotics were required to have a negative stool sample prior to returning to school; • Children who were showing symptoms of shigellosis, but were not culture confirmed, could only return to school 24 hours after diarrhea and fever had resolved.
Other Steps • On-site visit to School B • Provided staff education • Environmental cleaning procedures • Recommended limiting bathroom use • Health advisory to school nurses • Requested absence lists from prior weeks • Health advisory to daycares • Press release to local media • CAMC Emergency Room physician education
Shigella Sonnei PFGE Patterns With band markings: J16X01.wv021 J16X01.wv021 J16X01.wv014 J16X01.wv014 Without band markings:
School B Floorplan 1 of 19 2 of 17 0 of 24 4 of 20 4 of 21 6 of 23 3 of 23 1 of 25 2 of 21 9 of 22 Speech Therapist 4 of 19 6 of 19 7 of 22 Clinic Bathroom
Other Results • Ill household contacts • 61% mentioned at least one ill contact • City X • 81% of cases located in one city • School B (49%) and School C (21%) located within 1 mile of each other
Recommendations • Schools and daycares should notify their local health department (LHD) immediately upon recognizing increased clusters of illness or higher than normal absenteeism; • Schools and daycares should implement additional hand-washing tutorials for students and staff especially after return to school from extended breaks and during flu season; • School administration should provide staff with sanitizing products, such as wipes and hand-sanitizer, to encourage frequent cleaning throughout the day; • Schools should always restrict clinic bathrooms to sick children only; • Physicians, clinics, and hospitals should stay up to date on all community health advisories and inform their LHD of any reportable illness as instructed.
Thank you! 108 LEE STREET EASTCHARLESTON, WV 25301304-344-KCHD(5243)