Characterisation of inflammatory response, coagulation, and radiological findings in Katayama fever: a report of three cases at the Medical University of Vienna, Austria

BACKGROUND Katayama fever is an acute clinical condition characterised by high fever, dry cough and general malaise occurring during early Schistosoma spp. infection. It is predominantly reported in travellers from non-endemic regions. Whereas the immunological response to Schistosoma infection is well characterised, alterations in inflammatory markers and coagulation in response to acute infection are poorly understood. METHODS Here we report the clinical, laboratory and radiological characteristics of three returning travellers with Katayama fever. Inflammatory markers and coagulation status were assessed repeatedly during follow-up to characterise the host response to infection. Radiographic findings were correlated with clinical and laboratory markers. RESULTS Clinical symptoms were suggestive of a significant inflammatory response in all patients including high fever (>39°C), cough, and general malaise. Classical inflammatory markers including blood sedimentation rate, C-reactive protein, and serum amyloid A were only moderately elevated. Marked eosinophilia (33-42% of white blood cells) was observed and persisted despite anti-inflammatory and anthelminthic treatment for up to 32 weeks. Analysis of blood coagulation markers indicated increased coagulability reflected by elevated D-dimer values (0.57-1.17 μg/ml) and high thrombin generating potentials (peak thrombin activity: 311-384 nM). One patient showed particularly high levels of microparticle-associated tissue factor activity at initial presentation (1.64 pg/ml). Multiple pulmonary and hepatic opacities demonstrated by computed tomography (CT) scanning were associated with raised inflammatory markers in one patient. CONCLUSIONS The characterisation of the inflammatory response, blood coagulation parameters and radiological findings in three patients adds to our current understanding of Katayama fever and serves as a starting point for further systematic investigations of the pathophysiology of this acute helminthic infection.