Extensive spread of Campylobacter infection in Sweden

Transcription

1 EURL Campylobacter workshop , Nantes, France Extensive spread of Campylobacter infection in Sweden Rikard Dryselius, National Food Agency Sweden

2 Reported cases Campylobacteriosis i Sweden ( ) total number of cases domestic infections jan feb mar apr may jun jul aug sep oct nov dec Month - 77,4 reported cases per inhabitants - Approximately 40 % domestically acquired infections - Number of positive poultry flocks peaks in August and is at its lowest in winter/spring

3 Reported cases Domestic cases of Campylobacteriosis apr2014-mar2015 apr2015-mar2016 jan feb mar apr may jun jul aug sep oct nov dec Month A 43 % increase in domestic cases and a 58 % increase in

4 Information about the winter peaks and An additional 2900 cases of campylobacteriosis reported - One dominant clone behind each of the two winter peaks - Same clone identified at a number of breeders connected to one single large slaughterhouse - Dirty transport cages likely reason behind the winter peaks - New washing system installed in summer 2016

5 Reported cases 1400 Development from summer Alert from NVI about increase in Campypositive flocks Alert from PHA about high incidence of Campylobacteriosis Info from large producer about faulty connected cage wash Increased interest from media. County medical officers upset 0 apr may jun jul aug sep oct nov dec jan feb mar Press releases from central authoroties about increase in Campylobacteriosis Collection of isolates from chicken farms, retail and the clinic

6 Examination at the retail level To examine the prevalence and levels of Campylobacter in poultry meat from the retail and better understand the high increase in cases of Campylobacteriosis Four cathegories examined: - Meat from producer with cage wash problems - Other conventional domestically farmed chicken - Ecological domestically farmed chicken - Chicken meat from abroad

7 Chicken meat from retail BPW (400 ml/kg chicken) Microaerophilic enrichment in 100 ml Bolton broth Shakning 3x30 s 10 ml wash solution corresponding to 25 g sample for qualitative analysis 10 µl sample Methodology Dilution series for quantitative analysis Microaerophilic growth on mccda Trensfer to non-selective bloodagar Microaerophilic growth on mccda followed by colony count Microaerophilic growth followed by: 1. Confirmation with microscopy, oxidase test and microaerophilic growth at 25 C 2. Species identification with catalase, hippurate, indoxylacetate and MALDI-TOF 3. Typing with whole genome sequencings NMKL No. 119, 3. Ed, Thermotolerant Campylobacter. Detection, semi-quantitive and quantitive determination in foods and drinking water

8 Number of samples Campylobacter prevalence in Producer with dirty cages March and May 2017 Other conventional Ecological Farmed abroad Totalt Number/(%) positive # 38/(69,1)* 14/(23,3)* 18/(38,3) 16/(42,1) 86/(43,0) Confidense interval 56,0-79,7 14,4-35,4 25,8-52,6 27,9-57,8 36,3-49,9 # Detected in 25 g chicken meat * Statistically significant over- or underrepresentation (p<0,01, Fisher s exact test)

9 Proportion (%) Occurrence of Campylobacter in the separate cathegories Dirty cage prod. (n=55 Positive in 25 g Positive in 2,8 g >10 CFU/g Other conv. (n=60) Ecological (n=47) Cathegory Farmed abroad (n=38) Total (n=200) Five samples exceeding 100 CFU/g, highest amount detected 513 CFU/g

10 Number Typing of isolates STs for 40 isolates from meat samples with production dates 9-31 mars 2017 Slaughter house ST607 ST52 ST47 ST45 ST19 ST1003 ST6808 ST4875 ST2178 ST354 ST50 ST21 ST586 ST918 ST829 ST6427 ST?

11 Comparison to clinical isolates Chicken isolates 9-31 mars (n=40) ST19 ST21 ST45 ST47 ST50 ST52 ST354 ST586 ST607 ST829 ST918 ST1003 ST2178 ST4875 ST6427 ST6808 ST? Clinical isolates mars (n=83) ST19 ST45 ST257 ST464 ST918 ST2100 ST2325 ST6461 ST6532 Sequence types in common ST19 ST45 ST918 Near identical sequence ST918

12 Clinical isolates and isolates from chicken meat with shared STs ST918 Other clinical STs 81.9 % of the clinical isolates were identical to ST918 isolated from chicken ST19 ST45

13 Reported cases Discovery of faulty cage wash Development in 2017 Lack of effect from interventions Extended time between flocks (promised) Publication of clinical results Communication of first retail results to industry and the public Publication of clinical and retail results combined New collection of isolates from breeding farms, retail and the clinic Pasteurisation of cage containers jan feb mar apr may jun jul aug Month In summary: 6300 extra cases between August 2016 and July > extra cases in total Outbreak declared over?

14 What happened? different farms Slaughterhouse Approximately 50 % of the fresh chicken produced in Sweden Dirty transport cages and split slaughter has enabled and enhanced spread Short time between flocks has maintained spread

15 Thanks to National Veterinary Institute, Hanna Skarin Public Health Agency, Cia Jernberg