Does Marler Clark, home to ace food safety attorney Bill Marler, have a European office? Maybe it should set one up?
It seems as if for most of the second half of 2007 Europe was experiencing a salmonella outbreak that the Europeans suspect was sourced from imported baby spinach.
172 cases in Sweden
15 cases in Denmark
22 cases in the United Kingdom
1 case in Finland
10 cases in Norway
2 cases in the Netherlands
1 case in the US who will be interviewed to see if the person traveled to Europe.
On 15 August 2007, Enter-net, the international surveillance network for the enteric infections Salmonella and VTEC O157, circulated a PFGE profile of S. Java outbreak strain in response to a cluster of cases first identified in Sweden on 10 August 2007. On 5 December 2007, the United Kingdom (UK) issued another urgent inquiry after an investigation of 20 cases of S. Java phage type 3b var 9; the majority of isolates were sensitive to all antimicrobial drugs at the levels used in the HPA Laboratory of Enteric Pathogens.
The rapid inquiry sent through the network requested Member States (MS) to check the occurrence of cases with a strain matching the PFGE pattern seen in the UK. As of 18 December, the results of this inquiry are the following:
- In Sweden, a total of 172 cases have been identified in a large outbreak between July and September 2007. The strain identified in this year demonstrated a PFGE pattern identical to the strains isolated from cases in the previous year (September-October, 2006). This PFGE profile has been designated SPTJXB.0001 in accordance with the Pulse-Net Europe  designations for PFGE profile types. An epidemiological investigation showed a strong association with imported baby spinach. Spinach samples were taken by the Swedish food authorities but Salmonella was not detected in any of the food samples. In the Swedish outbreak, more than 40% of the first 116 cases were hospitalized and no deaths have been reported. As a result of the Swedish investigation linking the outbreak with imported baby spinach, an alert was issued within the Rapid Alert System for Food and Feed (RASFF) on 24 August 2007 by the Swedish authorities. Five additional cases have become ill in November 2007.
- In Denmark, a total of 15 cases with SPTJXB.0001 were identified between August and November 2007; the PFGE pattern is pending for another four recent cases. In 2006, seven cases with SPTJXB.0001 were identified in September-October. Interviews of a subset of the 2007 cases have so far not confirmed baby spinach as the vehicle of infection nor led to alternative hypothesis.
- The UK is currently investigating 22 cases identified since 1 November 2007 (including three cases from Scotland and two believed to be from secondary spread). The PFGE pattern has shown to be indistinguishable from that of SPTJXB.0001. Twelve of the 17 primary cases in England have been interviewed to date to develop a hypothesis for disease transmission. It is notable that 11 of the 12 cases reported the consumption of salad vegetables purchased from a number of retailing and catering outlets. No single leaf type has been clearly identified. The frequencies of consumption of other foods were all markedly lower, and the investigation has ruled out fruit, fish, shellfish, dairy products, all meats, contact with animals and travel abroad. No new cases have been identified in December, but earlier cases occurring in August, September and October have been reported yet their exact numbers have not been established yet.
- In Finland, one case has been identified in August. Importantly, this case became ill after visiting Sweden. The strain isolated had the SPTJXB.0001 profile. No information is available on the food exposures of this case.
- In Norway, 10 cases with SPTJXB.0001 have been identified in August. Eight of these had also visited Sweden before becoming ill. No information on the food exposures of the ten cases is available.
- In the Netherlands, two cases with SPTJXB.0001 have been identified in October 2007. One of them had travel history to Bosnia-Herzegovina.
- In the United States, one case with an identical PFGE pattern to SPTJXB.0001 has been reported in August of 2007. This case will be interviewed to learn of any travel to Europe.
ECDC risk assessment
In an effort to respond to the ongoing outbreak and the increasing numbers of cases of acute gastroenteritis infected with S. Java strain with SPTJXB.0001 profile, the European Centre for Disease Prevention and Control (ECDC) produced a risk assessment for the European Commission with the following conclusions:
Cases have continued to occur since the summer of 2007 and microbiological evidence of the SPTJXB.0001 profile points towards a dispersed multinational outbreak with a continuous and sustained risk to human health in Europe. Of the over 300 cases of S. Java that have been reported in 2007, many are likely to be linked to this ongoing outbreak.
Based upon epidemiological evidence from Sweden, imported baby spinach appears to be the most likely vehicle, yet no microbiological confirmation of this has been obtained.
As there is a potential to have more cases linked to this outbreak in the future, efforts to confirm a food source through microbiological investigations should be encouraged via the collaboration between national public health and food safety authorities, especially in Sweden, the UK, and Denmark.
Summary and conclusion
In 2007, 354 S. Java cases have been reported to ECDC by 11 MS (Figure 1). 228 of these cases (as of December 18, 2007) have an indistinguishable PFGE pattern, designated SPTJXB.0001, and are therefore possibly linked to the multinational outbreak (Figure 2). Unfortunately microbiological investigations have failed to confirm the incriminated vehicle of the Swedish cases.
This case is an attempt by Pulsenet-Europe to resolve an international outbreak:
PulseNet Europe is the molecular surveillance network for food-borne infections in Europe. It is an internationally unique network that — in addition to public health laboratories — has institutions from the veterinary and food sector as equal participants.
The main aim in PulseNet Europe is to establish real-time linked surveillance database system to detect infection clusters and investigate outbreaks of Salmonella, verocytotoxigenic E. coli (VTEC) and Listeria monocytogenes.
The structure of the PulseNet Europe database is built in the BioNumerics server/client format and the on-line database server is at the Health Protection Agency, Colindale, England.
The good quality of PFGE profiles which will be uploaded to the central database and uniform naming are very important. Therefore, the six PulseNet Europe curators have been chosen. They will take care of the central database, perform the naming and confirmation of the PFGE profiles submitted by partners and perform central cluster detection of all pathogens at regular intervals and alerts PulseNet Europe partners of detected clusters throug communication system.
This web-based central PulseNet Europe database makes possible for partners to submit the generated and analysed PFGE data directly via the web. This will also enable the partners to have direct access to the database and compare their PFGE data to the data that are stored in the database. The direct access will ensure a uniform naming of PFGE-subtypes in all participating countries, provide portable data and make it easy for partners to check their own data when alerts of infections clusters are posted on the PulseNet Europe communication forum.
The direct access to comparable typing data for isolates from human infections as well as food and animals will significantly improve the surveillance and trace-back of food-borne infections at national, European and international level. Furthermore, international clusters of food-borne infections that have too few cases in each country to be detected by the National surveillance systems will be detected through central PulseNet Europe surveillance systems.
The data will be comparable internationally through PulseNet International (PulseNet Asia-Pacific region, PulseNet Canada, PulseNet Latin America and PulseNet USA) which gives the project a global aspect.
We’ve run several pieces analyzing the role of the US PulseNet system in the spinach crisis of last fall:
The Pundit also did several television interviews on the subject. Now PulseNet-Europe is dealing with similar issues to those PulseNet in the US has to deal with. Though, having only been established in 2004, the Europeans don’t have anywhere near the experience with the system that the US does.
Still, if you read through the report on Salmonella, you find all the same issues — except no plaintiff’s lawyers.
Attention Bill Marler — Stockholm is quite beautiful this time of year.
In any case, it will keep him far away from Salinas!