Source of multi-national outbreak of Salmonella unclear
The outbreak among junior ice hockey players at the Riga Cup was detected by municipal public health authorities in Finland.
However, due to budget cuts at the National Institute for Health and Welfare (THL), Salmonella isolates of foreign origin are no longer typed nor are cases monitored in real time and outbreaks of foreign origin can only be identified at a local level, according to a report in Eurosurveillance.
Comments were made in concluding remarks as part of a preliminary report on the investigation.
Researchers said cross-border outbreaks and those related to mass gatherings pose special problems and cooperation between national authorities and ECDC is needed.
Case count
As of 22 May, 42 teams reported 187 cases from six different countries (Estonia, Finland, Lithuania, Norway, Sweden and the UK).
The Eurosurveillance report said seven countries have reported 214 confirmed and suspected cases, among which 122 from Finland as of May 8.
The source has not been identified and no cases have been reported in the last two weeks.
Microbiological typing revealed S. Enteritidis Phage type 1 with a rare MLVA profile 3-10-6-4-1 as the causative agent, said the European Centre for Disease Control and Prevention (ECDC).
Around 5,000 players from Austria, Belarus, Czech Republic, Denmark, Estonia, Finland, Germany, Hungary, Latvia, Lithuania, Luxemburg, Norway, Poland, Russian Federation, Slovakia, Sweden, Switzerland, the UK and Ukraine participated from 27 March to 26 April.
Games were played in four arenas. A fifth site was added for the last Riga Cup weekend (24-26 April).
International reports
Through the Finnish Infectious Disease Registry, 75 salmonellosis cases from 16 teams were notified.
Dates of notification ranged between 1 April and 6 May and five boys have been hospitalised.
Based on the inquiry among 50 Finnish teams, 92 cases have been identified from 23 squads.
Sweden identified 15 cases via its notification system, as through the questionnaire, 57 cases from ten teams were identified.
Estonia reported five cases (one team affected), Lithuania four cases (two teams affected), Norway 14 cases (three affected teams) and the UK 15 cases (three teams affected).
No cases were identified from Latvian team members.
Teams with cases stayed at four different hotels in Latvia but all ate organised meals in the arenas.
On 16 and 27 April, the Latvian Public Health authority interviewed staff at the cafeteria where the tournament was and took environmental swabs and faecal samples that were found to be negative.
ECDC said it can be considered a point source outbreak with a common exposure.
“The Riga Cup tournament has ended but other tournaments are continuing in the same venue until the end of May,” it said.
“Despite the source(s) of infection still not identified, no new cases were reported in the past two weeks which could indicate that the measures implemented in the venues cafeterias in Riga might have been successful.
“ECDC encourages all Member States to report through EPIS-FWD any case possibly associated to an event occurring in the Riga until the end of May.”
Source: Eurosurveillance, Volume 20, Issue 20, 21 May 2015
“Multinational outbreak of Salmonella Enteritidis infection during an international youth ice hockey competition in Riga, Latvia, preliminary report, March and April 2015”
Authors: A K Pesola, T Pärn, S Huusko, J Perevoščikovs, J Ollgren, S Salmenlinna, T Lienemann, C Gossner, N Danielsson, R Rimhanen-Finne
