Eurosurveillance - Volume 17, Issue 38, 20 September 2012

A cluster of time-linked cases and the identification of a clonal strain suggest the occurrence of an outbreak of listeriosis in Belgium in 2011, presumably due to the consumption of hard cheese made with pasteurised milk and produced by a Belgium manufacturer. The outbreak clone was identified as Listeria monocytogenes serovar 1/2a, sensitive to arsenic and cadmium and of multilocus sequence typing MLST-type 37. Food investigation of this outbreak was facilitated by the European Epidemic Intelligence Information System and data exchanged between French and Belgium listeriosis surveillance systems.

To assess the burden of influenza on the Finnish healthcare system, we analysed hospitalisations during 1996-2010 using the International Classification of Diseases codes potentially related to influenza and its complications from the national hospital discharge registry. To compare the influenza A(H1N1)pdm09 pandemic with previous influenza seasons in 1996-2009, we calculated hospitalisation rates by age- and diagnostic groups. We built a negative binomial regression model based on times series analysis to assess the impact of the pandemic. Influenza-associated hospitalisation rates were higher during the pandemic compared to pre-pandemic influenza seasons for 5-24 year-olds (incidence rate ratio (IRR): 1.52, 95% confidence interval (CI): 1.44-1.60) and 25-64 year-olds (IRR: 1.33, 95% CI: 1.29-1.36), but did not differ for persons aged ≥ 65 years (IRR: 0.98, 95% CI: 0.97-1.00). Hospitalisation rates exceeded the upper limit of the prediction line by 177% in 5-24 year-olds, 66% in 0-4 year-olds and 57% in 25-64 year-olds. During the influenza season of 2003/04, all age groups had higher-than-expected hospitalisation rates, whereas other seasonal peaks were only notable among persons aged ≥ 65 years. These age-specific differences in the hospital burden underscore the importance of the continuous surveillance of hospitalisations in order to evaluate immunisation priorities for seasonal influenza and pandemic preparedness including use of antiviral medication. .

Tuberculosis (TB) patients who do not complete treatment pose a potential public health risk. In West Yorkshire, local clinicians suspected that this risk was overestimated by the national Enhanced Tuberculosis Surveillance system. We audited patients who failed to complete treatment and were categorised as lost-to-follow-up (LTFU) between 2004 and 2008, using a combination of hand searching existing records and obtaining additional information from clinicians. In the study period 2,031 TB cases with reported outcome were notified in West Yorkshire, 23% (n=474) did not complete treatment, and 199 (42%) of those were categorised as LTFU 12 months after notification. Of these 199, 49% (n=98) remained LTFU after the audit, 51% (n=101) were re-classified to the following categories: 24% (n=47) transferred abroad, 16% (n=31) recommenced and completed treatment, 6% (n=13) transferred to another clinic in the United Kingdom (UK), and 5% (n=10) died. These patients therefore no-longer posed a public health risk. Further training for clinicians to improve accuracy of outcome reporting has been initiated. Nationally, the collection of treatment outcome data needs to be strengthened and extending the follow-up for treatment outcome monitoring should be considered.