An audit in the Czech Republic has found a significantly lower Salmonella detection rate in food company tests compared with official sampling of laying hens and broilers. Test results from authorities for 2018 show their detection rate was 15 times higher for laying hens than the companies’ results.

DG Sante, the European Commission’s unit for food safety and health, found overall the Salmonella National Control Programmes (SNCP) are in line with EU requirements, are well implemented by food businesses and under adequate official supervision.

Samples were positive 3.48 percent of the time (3 of 86 tests) versus 0.22 percent (1 of 453) found in food businesses’ sampling. Authorities said increased prevalence in official samples was due to higher detection sensitivity and additional fecal samples taken.

Results for broiler flocks last year show a Salmonella positive detection rate five times higher in official samples of 8.1 percent (4 of 36 tests) versus 1.6 percent (75 of 4,667)  from food company samples. Authorities have been aware of this difference for several years but cannot identify a reason.

“The lower rate of Salmonella detection in food business operator sampling lowers its effectiveness and therefore may also be one of the reasons that outbreaks still occur even when other measures of the SNCP are implemented,” according to the audit report.

Czech authorities said to find out the cause of the lower rate of Salmonella detection in food company sampling and to correct deficiencies, official checks on selected holdings will be carried out repeatedly in 2020. This will include verification of sampling methods, packaging and transport of sample.

A similar finding was made during an audit to Poland last year where detection of Salmonella was 100 times lower in testing by food businesses versus official tests.

High Salmonella rates
The audit in Czech Republic in June this year included visits to a broiler holding positive for Salmonella in 2017 and 2018, two laying hen holdings – one positive in 2016 and the other suspected in 2018 and one breeding holding suspected for Salmonella in 2018.

During January 2017 to mid-May 2019, in the Rapid Alert System for Food and Feed, there was one notification linked to table eggs and egg products of Czech origin due to Salmonella enteritidis, seven in poultry meat products of Czech origin due to Salmonella enteritidis, infantis and typhimurium and a notification related to detection of Salmonella montevideo in feed materials used for poultry.

According to the 2017 EFSA Zoonosis report, the proportion of domestic Salmonella cases at 97.68 percent is one of the highest in the EU and amongst all EU countries the highest notification rate of infections was also reported by Czech Republic. However, there has been a decreasing trend since 2013.

In several foodborne outbreaks, authorities identified eggs as the source of infection. In some instances, the holding of origin of the eggs was identified. Trace back from some Salmonella outbreaks allowed detection of additional infected holdings and flocks not previously identified.

In 2018, 706 samples of complete feeding stuffs for farmed animals were taken; all were negative. Salmonella positive laying hen flocks are slaughtered and meat is used only for heat treated products.

Some EU targets met; others missed
The SNCPs have achieved low Salmonella prevalence, in compliance with EU targets, for breeding and laying hen holdings. Prevalence in broilers and fattening turkeys was, in the last two years, above EU targets with an increasing trend in broilers. Authorities are trying to understand the cause of the increasing trend in broilers and fine-tune actions to tackle this problem.

The EU target for Salmonella prevalence in laying hen flocks of a prevalence less than 2 percent was reached in 2012 and has not been exceeded since.

For official samples the data since 2016 shows not all holdings with more than 1,000 birds were sampled and tested for Salmonella. According to SVA analysis, in 2017 only 56 of 71 eligible holdings were officially sampled.

Since 2016, confirmatory sampling was done in 15 of 21 laying flocks that had food business operator samples with results positive for Salmonella. Only two confirmatory samples returned positive for relevant Salmonella serotypes. If the food firms’ positive results had been included instead of discarded after confirmatory sampling returned negative for 13 of 15 flocks, the prevalence would have gone above the 2 percent target.

Salmonella prevalence of broiler flocks in 2017 was 1.28 percent and in 2018 it was 1.7 percent for targeted serotypes which is above the EU target of below 1 percent.

There has been no holding in the Czech Republic since 2014 with breeding turkeys. The EU target for Salmonella in fattening turkey flocks of 1 percent was not reached in 2018 as the prevalence of targeted serotypes was 1.2 percent. However, this was down from 1.9 percent in 2016 and 2017.

A total of 259 inspections were carried out on poultry holdings in 2018 with nine non-compliances. These most frequently related to bio-security, handling of animal byproducts, and the methodology of animal health control and ordered vaccination including the SNCP.

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