2 CASES OF INTRAOCULAR INFECTION WITH ALARIA-MESOCERCARIA (TREMATODA)

We encountered two cases of human intraocular infection with mesocerca riae of Alaria (Trematoda), involving unrelated Asian men who had unil ateral decreased vision. Both patients had pigmentary tracks in the re tina, areas of active or healed retinitis, or both, and other signs of diffuse unilateral subacute neuroretinitis. Similar, nonnematode worm s were seen in the patients' retinas and vitreous, respectively, sever al years after apparent infection. The worm in Case 1 was analyzed fro m projected fundus photographs and diagnosed as an Alaria mesocercaria on the basis of its shape, size (500 x 150 mu m), and movement; it wa s successfully killed with laser. The worm in Case 2 was removed surgi cally from the vitreous and identified as A. mesocercaria, 555 x 190 m u m most likely A. americana. The probable source of infection in the patients was ingestion, in local restaurants, of undercooked frogs' le gs containing A. mesocercaria. In addition to causing prolonged intrao cular infection, A. mesocercaria was found to be a cause of diffuse un ilateral subacute neuroretinitis, a condition previously attributed on ly to intraocular nematode larvae.