Second case of zoonotic Onchocercainfection in a resident of Oita in Japan

A non-gravid female Onchocercawas found in histopathological sections of a biopsy specimen taken from a painful nodule in the wrist of a 57-year-old woman in Oita, in southern Japan. Six species of Onchocercahave been found in animals in Japan: two in wild bovids, one in equids, and three in domestic bovids of which one, Onchocercasp., is only known by the microfilaria and infective stage. Distinctive morphological features of the worm, including a three-layered thick cuticle with prominent annular ridges at wide intervals, high somatic muscles and narrow lateral chords, resembled those of O. gutturosa, one of the three bovine Onchocercaspecies transmitted in the Oita region. However Onchocercasp., which is also transmitted in this region, cannot be excluded.