Students infected by Schistosoma shed light on cause of Katayama syndrome

1. The results of this case study suggested that male Schistosoma mansoni larvae can cause Katayama syndrome amongst individuals exposed.

2. The authors were able to diagnose Katayama syndrome as early as 5 weeks after students’ exposure to the parasite.

Evidence Rating Level: 2 (Good)

Study Rundown: Katayama syndrome is a self-limiting disease that is known to occur several weeks after infection with shistosome larvae. The purpose of this case report was to further study the cause of Katayama syndrome. The authors observed that this inflammatory syndrome could occur in the absence of parasite eggs, which indicates that newly expressed antigens on the developing worms may actually be the cause of the illness. The limitations of this study related to participant numbers. Greater numbers of case participants will be necessary to shed further light on the syndrome and would be beneficial to assess any long-term sequellae associated with this infection.

Click to read the study in Annals of Internal Medicine

Relevant Reading: Early Neuroschistosomiasis Complicating Katayama Syndrome

In-Depth [case report]: The authors of this study conducted a case report, where two human participants were infected with male cercariae of Schistosoma mansoni. Male parasitic worms were selected for this experiment so that no eggs could be produced in the hosts. Both patients developed typical symptoms of Katayama syndrome, including fever, myalgia and headaches, after exposure to the larvae in the absence of eggs. This finding suggested that newly expressed antigens on the developing worms may be responsible for triggering Katayama syndrome. Additionally, both patients were observed to develop seroconversion and eosinophilia following the improvement of severe symptoms.

Image: PD

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