Confirmed Autochthonous Case of Human Alveolar Echinococcosis, Italy, 2023

Abstract

In September 2023, a patient in Italy who had never traveled abroad was referred for testing for suspected hepatic cystic echinococcosis. Lesions were incompatible with cystic echinococcosis; instead, autochthonous alveolar echinococcosis was confirmed. Alveolar echinococcosis can be fatal, and awareness must be raised of the infection's expanding distribution.

Keywords: Echinococcus multilocularis; Italy; alveolar echinococcosis; autochthonous; parasites.

Figure

Diagnostic tests for patient in Italy with confirmed autochthonous case of human alveolar echinococcosis, 2023; white arrows indicate lesions. A–D) Contrast-enhanced computed tomography arterial phase. E–H) T2-weighted magnetic resonance imaging. I–L) Ultrasonography and contrast-enhanced ultrasonography. M–P) ¹⁸F-FDG-PET scan delayed acquisition (4 hours). Q–T) Em2 immunohistochemistry indicating small particles of Echinococcus multilocularis (spems) stained in red in patient’s sample (original magnification ×2.5 [Q] and ×20 [R]); positive alveolar echinococcosis sample control (original magnification ×20 [S]); Em2 negative control (cystic echinococcosis case, negative laminated layer; original magnification ×20) (T).