Spleen enlargement is a common finding in acute Puumala hantavirus infection and it does not associate with thrombocytopenia.

The pathogenesis of thrombocytopenia in Puumala hantavirus (PUUV) infection is probably multifactorial. We aimed to evaluate the possible spleen enlargement during acute PUUV infection, and to determine its association with thrombocytopenia and disease severity. Magnetic resonance imaging (MRI) of the spleen was performed in 20 patients with acute PUUV infection. MRI was repeated 5-8 months later. The change in spleen length was compared with markers describing the severity of the disease. In all patients, the spleen length was increased in the acute phase compared with the control phase (median 129 mm vs 111 mm, p < 0.001). The change correlated with maximum C-reactive protein value (r = 0.513, p = 0.021) and inversely with maximum leukocyte count (r = -0.471, p = 0.036), but not with maximum serum creatinine level or minimum platelet count. Enlarged spleen, evaluated by MRI, was shown to be a common finding during acute PUUV infection. However, it does not associate with thrombocytopenia and acute kidney injury.

The severity of Puumala hantavirus induced nephropathia epidemica can be better evaluated using plasma interleukin-6 than C-reactive protein determinations.

BACKGROUND: Nephropathia epidemica (NE) is a Scandinavian type of hemorrhagic fever with renal syndrome caused by Puumala hantavirus. The clinical course of the disease varies greatly in severity. The aim of the present study was to evaluate whether plasma C-reactive protein (CRP) and interleukin (IL)-6 levels associate with the severity of NE. METHODS: A prospectively collected cohort of 118 consecutive hospital-treated patients with acute serologically confirmed NE was examined. Plasma IL-6, CRP, and creatinine, as well as blood cell count and daily urinary protein excretion were measured on three consecutive days after admission. Plasma IL-6 and CRP levels higher than the median were considered high. RESULTS: We found that high IL-6 associated with most variables reflecting the severity of the disease. When compared to patients with low IL-6, patients with high IL-6 had higher maximum blood leukocyte count (11.9 vs 9.0 x 10(9)/l, P = 0.001) and urinary protein excretion (2.51 vs 1.68 g/day, P = 0.017), as well as a lower minimum blood platelet count (55 vs 80 x 10(9)/l, P < 0.001), hematocrit (0.34 vs 0.38, P = 0.001), and urinary output (1040 vs 2180 ml/day, P < 0.001). They also stayed longer in hospital than patients with low IL-6 (8 vs 6 days, P < 0.001). In contrast, high CRP did not associate with severe disease. CONCLUSIONS: High plasma IL-6 concentrations associate with a clinically severe acute Puumala hantavirus infection, whereas high plasma CRP as such does not reflect the severity of the disease.

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.