NH Department of Health and Human Services Division of Public Health Services Salmonella Oranienburg Infections associated with Fruit Salad Served in Healthcare Settings—Northeastern United States, June-July 2006 Beth Daly, MPH Communicable Disease Epidemiologist Communicable Disease Surveillance Section

NH Department of Health and Human Services Division of Public Health Services Salmonellosis US: >30,000 infections reported each year NH: 2 nd most common bacterial foodborne illness with cases each year >2500 different serotypes Poultry and cattle serve as reservoirs Source of outbreaks include meat, produce, ill food service workers, etc. Primarily diarrheal illness Illness lasts 2-5 days Incubation period 6-72 hours

NH Department of Health and Human Services Division of Public Health Services Salmonella Oranienburg 13th most common serotype of Salmonella reported to CDC –495 cases reported in 2004 (1.4%) 9 outbreaks reported to CDC since 1996 Outbreaks associated with meats and produce –Ground beef, chicken, pizza, mango

NH Department of Health and Human Services Division of Public Health Services Salmonella Surveillance Mandated reporting of salmonellosis in NH Reports received from HCP, ICP, laboratories For each case reported there are an estimated 38 cases that go unreported

NH Department of Health and Human Services Division of Public Health Services

NH Department of Health and Human Services Division of Public Health Services Pulsed Field Gel Electrophoresis Isolated bacteria from each case used DNA from the bacteria is restricted by an enzyme and undergoes electophoresis to produce a pattern or DNA fingerprint Patterns compared to determine if isolated organisms are different, similar, or indistinguishable Two-enzyme approach used

NH Department of Health and Human Services Division of Public Health Services PFGE Analysis

NH Department of Health and Human Services Division of Public Health Services Use of PFGE in Surveillance NH PHL performs PFGE on all isolates of: – Campylobacter –Salmonella –Shigella –Listeria –E. coli O157:H7 These patterns are entered into a national and state database to look for “matches” This allows for recognize of local and multi- state outbreaks

NH Department of Health and Human Services Division of Public Health Services Nosocomial Salmonellosis Uncommon in developed countries Healthcare facilities (HCF) don’t test for salmonellosis in patients hospitalized >72 hours with diarrhea –C. diff the most common cause of hospital acquired diarrhea Since 1960, 56 outbreaks have been described –Most often associated with food, feed, visitors, staff –9 occurred in the US, most recent in 2002 and 1996

NH Department of Health and Human Services Division of Public Health Services NH Outbreak July 19 th : NH DHHS investigated a salmonellosis outbreak at a local hospital Initially 5 cases identified –2 patients, 2 HCP, 1 cafeteria patron 3 of 5 cases determined to be S. Oranienburg Concerns about medical devices, ill HCP, or ill FSW Challenging disease control approach

NH Department of Health and Human Services Division of Public Health Services Immediate Infection Control Active surveillance and exclusion among staff in affected units –Shift change sign-in Mandatory in-service training to staff Alert hospital-wide Inspection of hospital kitchen Routine salmonellosis testing for patients with diarrhea

NH Department of Health and Human Services Division of Public Health Services Multistate Outbreak Recognition July 19 th: NH DHHS and MHD investigated outbreak of S. Oranienburg at local hospital July 21 st: MA DPH reported S. Oranienburg cases at local LTCF NH cases and other northeastern states report cases with the same PFGE pattern as MA cases Xbal pattern uncommon and seen only 14 times prior to this cluster BlnI pattern not seen before

NH Department of Health and Human Services Division of Public Health Services Frequency of BlnI Patterns in S. Oranienburg with the Xbal JJXX Pattern,

NH Department of Health and Human Services Division of Public Health Services Methods- Case Finding Case Definition: culture-confirmed cases of S. Oranienburg with –Illness onset after June 1 st –Xbal pattern JJXX and Blnl pattern JJA if available PulseNet queried weekly Announcements on listserves: foodborne outbreaks, promed mail, SHEA, APIC, EIN Active case finding in affected facilities

NH Department of Health and Human Services Division of Public Health Services Methods- Hypothesis Generation Routine surveillance questionnaires reviewed Extended questionnaires administered to small subset of cases –300 exposures including 234 food items Facilities with cases surveyed to determine brand and distributor information for fruit salad served in the facility 26 unaffected facilities in NH surveyed for comparison

NH Department of Health and Human Services Division of Public Health Services Methods- Case Control Study Case control study conducted between August 15 th and September 6 th Cases were eligible if –Onset between June 15 th and July 31 st –Experienced diarrhea –Two enzyme match –Could be interviewed Control selection was based on type of case and eligible if –No diarrhea since June 1 st –Must be on a solid diet

NH Department of Health and Human Services Division of Public Health Services Control Selection Patients exposed in HCF –7 day period before onset calculated –Dates of hospitalization during these 7 days –List of patients hospitalized on same days created –List randomized and selected until 3 controls found Healthcare Employees –7 day period before onset calculated –Dates case worked during these 7 days –List of coworkers on same days created –List randomized and selected until 3 controls found Community Cases –List of neighbors generated using reverse phone –Closest neighbors called until 3 controls found

NH Department of Health and Human Services Division of Public Health Services Results- Geographic Distribution 42 cases in 10 states and Canada: MA (12) NH (10) NY (4) PA (3) VT (3) Canada (2) KY (2) MD (2) ME (2) CT (1) NJ (1)

NH Department of Health and Human Services Division of Public Health Services Results- Case Details Age: 8 months to 96 years (median=59) 31% over age 70 Sex: 28 females (67%) Healthcare Relationship: –21 hospitalized patients or LTCF residents –9 healthcare employees –1 case who ate in hospital cafeteria Illness onset dates ranged from June 15 th to July 25 th

NH Department of Health and Human Services Division of Public Health Services Culture Confirmed Cases of Salmonella Oranienburg by Date of Onset (n=22)

NH Department of Health and Human Services Division of Public Health Services Results- Hypothesis Generation Interviews showed a high proportion of cases consumed fruit salad in healthcare facilities –23 of 33 cases (70%) consumed fruit salad –19 of 23 consumed Brand X fruit in a HCF 10 (91%) of 11 facilities with cases served Brand X fruit salad from Ontario, Canada –Cantaloupe and honeydew melon 3 (15%) of 20 control facilities served Brand X (OR=57, p-value=0.0005)

NH Department of Health and Human Services Division of Public Health Services Results- Case Control Study Illness significantly associated with fruit salad consumption –Any Fruit Salad= OR: 8.9, 95% CI: –Fruit Salad in a HCF= OR: 6.0, 95% CI: Many fruit salad components also significant Significant correlations between many individual components Multivariate analysis not feasible Specific component not statistically implicated

NH Department of Health and Human Services Division of Public Health Services Results- Matched Univariate Food ItemCases (n=21) Controls (n=33) Matched OR 95% CI N%N% Any Fruit Salad14/2070%4/3013% Fruit Salad in a Healthcare Facility 12/2060%4/3013% Cantaloupe in Fruit Salad12/2060%2/307% Honeydew in Fruit Salad11/2055%1/303% Watermelon in Fruit Salad9/1947%2/307% Pineapple in Fruit Salad8/1942%1/294% Red Grapes in Fruit Salad7/2035%0/300%9.8* *Uses a 0.5 continuity correction

NH Department of Health and Human Services Division of Public Health Services Traceback and Product Investigation Several recent outbreaks of Salmonella associated with cantaloupe and honeydew –> 25 since 1984, 16 since 1998 –1998 outbreak of S. Oranienburg in Ontario Canada associated with cantaloupe FDA and CFIA conducted traceback and traceforward investigations on August 24 th Brand X Canadian facility inspected Cantaloupe and honeydew from California Unable to traceback to farm due to large number of supplying brokers

NH Department of Health and Human Services Division of Public Health Services Challenges Affected population –Other significant medical issues –Age –Mental status Distinguishing between primary and secondary cases Infection control Identification of the source within the fruit salad components

NH Department of Health and Human Services Division of Public Health Services Conclusions Interventions on farm may prevent produce- associated outbreaks Nosocomial salmonellosis rare in US –Recognition is difficult due to stool testing practices in hospitals –May be difficult to distinguish between primary and secondary cases –Foodborne outbreaks in healthcare settings can cause significant illness, costs, fear

NH Department of Health and Human Services Division of Public Health Services Acknowledgements Hospital ICP NH Disease Control and Laboratory Staff Collaborating States: MA, NY, PA, VT, KY, MD, ME, CT, NJ CDC: Dr. Christine Olson, MD, MPH, EISO Dr. Michael Lynch, MD, MPH