A Philophthalmid Eyefluke from a Human in Japan

Philophthalmid eyeflukes are cosmopolitan parasites of birds and occasionally of mammals, including humans. A gravid adult of Philophthalmus sp. was found from the bulbar conjunctiva of a 64-yr-old woman in Japan, who was diagnosed with acute conjunctivitis. The parasite was morphologically most similar to Philophthalmus hegeneri, but distinctive in lacking an esophagus and in having clearly lobed testes. The DNA sequence analysis of genes for nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 supported the identification at generic level. The morphological and molecular analyses strongly suggest that the eyefluke from a human in Japan should be treated as an undescribed species of Philophthalmus. The occurrence of human philophthalmosis is very rare. As far as we know, a total of 11 human cases have been reported worldwide to date.