Outcome of reactive arthritis after an extensive Finnish waterborne gastroenteritis outbreak: a 1-year prospective follow-up study.

The purpose of the study was to assess the 1-year outcome of definitive reactive arthritis (ReA) after a waterborne outbreak. A cohort of 21 patients (15 females and 6 males, median age 54 years) with ReA related to an extensive waterborne outbreak in Finland was clinically followed-up by rheumatologists with visits at baseline, at 1 month and 3, 6 and 12 months. Although the outcome was in general favourable, 1/3 of the patients had chronic course; 7 (33 %) of the 21 patients needed disease-modifying anti-rheumatic drugs (DMARDs) and even 8 (38 %) of them used glucocorticoids at 12 months. Four (19 %) were using non-steroidal anti-inflammatory drugs and nine (43 %) other analgesics. Many patients had articular pain and impaired physical function still at 12 months, even though inflammatory parameters and the number of swollen joints were low. Only one patient (5 %) was human leucocyte antigen-B27-positive. She had the most severe ReA and also additional infectious arthritis caused by Salmonella serotype enteritidis leading to osteonecrosis of her hip joint with subsequent need for arthroplasty. ReA as observed in our study was overall fairly mild, but in many individuals, postinfectious arthralgia and DMARD use continued at least up to 1 year.

Influenza vaccination of dialysis patients: cross-reactivity of induced haemagglutination-inhibiting antibodies to H3N2 subtype antigenic variants is comparable with the response of naturally infected young healthy adults.

BACKGROUND: Annual influenza vaccination is recommended for patients with chronic renal failure, although vaccination responses in haemodialysis (HD) patients may be suboptimal. Typically, the seroreactivity has been analysed against the vaccine virus or the corresponding year's epidemic virus. No studies analysing cross-reactivity against subsequent years' viruses have been presented. METHODS: Twenty-three chronic HD patients and 26 cardiac patients were, in autumn 1995, vaccinated with a trivalent influenza vaccine. The cross-reacting haemagglutination-inhibiting antibodies to five consecutive years' (the last season 1999-2000) drift variants of H3N2 subtype influenza A virus were measured and compared with those of vaccinated cardiac patients and with those of 26 healthy military conscripts who suffered a serologically confirmed influenza A infection in the season 1995-1996. RESULTS: The influenza vaccination in HD patients resulted in comparable cross-reacting antibodies to the antibodies induced both by vaccination in cardiac patients and by natural infection in military conscripts. After a steady decline, the cross-reactivity to the latest epidemic virus improved in all the groups. This may be due to two reverted amino acid changes in the HA1 domain of the virus haemagglutinin. CONCLUSIONS: Influenza vaccination in HD patients is as effective as the vaccination of cardiac patients with normal kidney function. The cross-reactivity of vaccination-induced antibodies is even as good as that of antibodies induced by natural infection of young healthy males. Additionally, vaccination seems to prime the individual beneficially against subsequent years' influenza viruses.