A Rare Case Report of a Human Dirofilaria repens Infection

In June 2024, a 41 year-old woman presented to the infectious diseases outpatient clinic with a left inguinal mass progressing in size. The patient had previously been on vacation in Greece. When a tumor was initially suspected, the mass was surgically removed. Staining with Grocott methenamine silver and Alzian blue were inconspicuous, but histopathologic examination revealed a clear histiocytic demarcation, followed by a confirmation of the suspected diagnosis of dirofilariasis caused by <i>Dirofilaria repens</i> by PCR. Even though still a rare event in Austria, the number of human <i>D. repens</i> cases has been continuously increasing in recent years. This is partly due to the increased spread of the parasite due to climate change and globalization.