Pitfalls and difficulties in histological diagnosis of human dirofilariasis due to Dirofilaria (Nochtiella) repens

The authors have conducted a histologic study of over 90 cases of Dirofilaria infection in man due to Dirofilaria repens, the most extensive study of its kind in the would. On the basis of their findings, they illustrate the diagnostic difficulties that may arise when regreessive phenomena I ender the parasite´s morphologic characteristics largely or completely unrecognizable. These phenomena are due to the death of the filaria inside the inflammatory nodule weeks ol months prior to surgical removal, and to the consequent invasion of inflammatory cells. They start at the nenatode´s natural orifices (mouth, vulva, anus, cloaca) and gradually spread throughout ifs body. In cases of difficult diagnosis, therefore, it is recommended that rite nodule be sectioned at different points comprising caudal, cephalic and middle body aspects, so as to reveal the Jew morphologic features that ale still recognizable and which may afford a correct diagnosis. The authors present examples of histologic sections in color plates in which the nematode was in an excellent state of preservation and others illustrating the full range of regressive phenomena, from slight to total disintegration of the bodily structure

La dirofilariose humaine en Italie

Dans le Laboratoire de Parasitologie de la Faculté de Médecine Vétérinaire de l’Université de Bologna les auteurs ont observé, depuis 1971, 30 cas de dirofilariose humaine (sur 101 signalés en Italie) identifiés dans la presque totalité comme étant dus à Dirofilaria repens (Railliet et Henry, 1911) nématode parasite du chien relativement fréquent en Italie. De ces 30 cas, 23 étaient à localisation sous-cutanée, 4 sous-muqueux et 3 pulmonaires. La parasitose a été presque toujours méconnue cliniquement, étant interprétée comme une néoplasie bénigne ou maligne ou comme un corps étranger. Le parasite a pu être reconnu grâce à l’examen des coupes histologiques. Dans 3 cas on a pu énucléer du nodule l’helminthe entier. Les auteurs ont l’impression que la parasitose est beaucoup plus fréquente chez l’homme en Italie que ce qu’il apparaît dans la littérature scientifique : certains cas, pouvant guérir spontanément et d’autres n’étant pas diagnostiqués

Parassiti di Cerastoderma glaucum (Poiret,1879) (Bivalvia: Cardiidae) della laguna di S.ta Gilla, Sardegna meridionale

Sono stati esaminati parassitologicamente, dall’Aprile 2002 al Dicembre 2004, 146 esemplari di Cerastoderma glaucum della laguna di S.ta Gilla (Sardegna). L’83,6% è risultato infetto da oocisti di Nematopsis sp., il 20,5% da ipnospore di Perkinsus sp., il 12,3% da un Nematode non identificato, il 6,2% da metacercarie di Gymnophallus choledochus, lo 0,7% dal turbellare Paravortex cardii. Nel 2004 si è registrato un aumento della prevalenza di Nematopsis sp. e la quasi totale scomparsa delle altre infezioni parassitarie. La prevalenza delle infezioni di Nematopsis sp., Perkinsus sp. e Gymnophallus choledochus è correlata positivamente alle dimensioni del bivalve.From April 2002 to December 2004, 146 specimens of Cerastoderma glaucum, from St. Gilla lagoon, were parasitologically examined: 122 (83.6%) proved infected by Nematopsis sp. oocysts, 30 (20.5%) by Perkinsus sp. hypnospores, 19 (12.3%) by an unidentified Nematode, 9 (6.2%) by metacercariae of the Digenea Gymnophallus choledochus, 1 (0.7%) by the Turbellarian Paravortex cardii. An increase in Nematopsis sp. infection was registered in 2004, while in the same year the disappearance of nearly all other parasitic infections was observed. Prevalence of Nematopsis sp., Perkinsus sp. and Gymnophallus choledochus has a positive relationship with bivalve size