Prevailing effectiveness of the 2009 influenza A(H1N1)pdm09 vaccine during the 2010/11 season in Sweden.

Sixty per cent of the Swedish population received the monovalent AS03-adjuvanted pandemic influenza vaccine in the autumn of 2009. We assessed the age-specific effectiveness of this pandemic vaccine against hospitalisation with laboratory-confirmed influenza A(H1N1)pdm09 during the season 2010/11, in the age group from six months to 64 years in Sweden. The screening method was applied to available surveillance data. Our results suggest a prevailing effectiveness of 72% (95% confidence interval (CI): 63­80%) with the highest effectiveness among children, six months to nine years-old (92%, 95%CI: 80­97%). However, there were limitations in data quality and study design due to the lack of systematic recording of administered vaccinations, which underline the importance of preparing for an evaluation when planning for large public health actions. Despite these limitations, we believe the results reflect true, high prevailing vaccine effectiveness. Indeed, there were fewer deaths caused by influenza and the impact of influenza on intensive care units was less severe during the 2010/11 season in Sweden than in countries with lower pandemic vaccination coverage. The association between the pandemic vaccine and narcolepsy has increased the importance of assessing the risks and benefits of the vaccination; studies on the effectiveness and the duration of protection are needed for this.

Bacterial arthritis in a Swedish health district.

The aim of this retrospective investigation was to study the occurrence, characteristics and outcome of culture-positive bacterial arthritis in a Swedish county hospital for the period 1994-97. Using registers of diagnosis, 15 adult patients with infectious arthritis in native joints were identified. Staphylococcus aureus was, as expected, the most common microbial agent. Six cases were caused by direct inoculation. The risk for bacterial arthritis caused by intra-articular steroid injection was estimated at 1/12,000. Joint damage was seen in 6 cases. Two patients died during the infection. White blood cell count in synovial fluid was performed in 5 cases, with median value 1.9 x 10(9)/l and, since it was not a good predictor of infection in this study, the value of this method for this indication is questioned.

Campylobacter pylori in Swedish patients referred for gastroscopy.

Campylobacter pylori was isolated more often from patient with peptic ulcers and in an age-related manner in a material of 395 consecutive patients referred for gastroscopy. Direct microscopy was done with Gram and Acridine Orange stain and found too insensitive for practical use. All patients were investigated serologically with an enzyme immunoassay which showed excellent correlation with positive cultures for C. pylori. The findings were discussed, and the enzyme immunoassay, with a negative predictive value of 0.99, was found to be a valuable tool for primary screening of patients suspected of being carriers of C. pylori.