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The present study offers the first description of proventriculitis associated with the presence of gravid female nematodes of the genus Tetrameres (Nematoda: Tetrameridae) in 3 juvenile Magellanic penguins ( Spheniscus magellanicus ) found dead on the coast of Brazil. This study broadens knowledge on parasites associated with these hosts and the real impact of this association.

We report a rare parasitic nematode infection in a 26-year-old healthy African American man. Gongylonema nematode infections in humans are unique in their ability to localize in the submucosa of the oral cavity and oropharynx. Humans are incidental hosts for the Gongylonema nematode, which is more commonly found in rudimentary animals, birds, and rodents. Approximately 50 cases of human Gongylonema infections have been reported worldwide, including 11 documented cases in the United States.(1) The pathogenesis, characteristic clinic findings, and identification features will be discussed.

Gongylonema ingluvicola and Spirocerca lupi are spirurid nematodes that require arthropod intermediate hosts in order to complete their life cycle. Beetles of the family Scarabaeidae are reported to serve as intermediate hosts for both these parasites. In this study selected species of beetles of the family Scarabaeidae as well as other groups of arthropods were screened for susceptibility to infection with S. lupi and G. ingluvicola. Arthropods were exposed to infective eggs of both parasites for a determined period of time and dissected/digested to determine the presence or absence of pre-infective and infective larvae. All the five species of dung beetles exposed to infection with S. lupi, namely, Pachylomerus femoralis, Scarabaeus rugosus, Gymnopleurus humanus, Kheper nigroaeneus and Anachalcos convexus were susceptible and, of the two species exposed to G. ingluvicola, only Gy. humanus was susceptible. Spirocerca lupi eggs developed in millipede species, Daratoagonus cristulatus, and remained as encysted larvae, while in Orthoporoides kyrhocephalus no development was observed. Spirocerca lupi larvae were not detected in the cricket species Gryllus assimilis, or the cockroach species Periplaneta americana, and, similarly, G. ingluvicola larvae were not detected in the millipede species O. kyrhocephalus. The difference in the susceptibility of the arthropods to the two parasite species may depend on their feeding biology.

This report describes the morphologic and histologic features of a case of esophageal Gongylonema pulchrum infection and esophageal squamous cell carcinoma in a 17-yr-old, female vari (Lemur macaco variegates). The lemur had lived in a German zoo and had a clinical history of dyspnea, vomiting, and anorexia. At necropsy, a whitish, soft, nodular, centrally necrotic mass was found in the caudal third of the esophagus. In addition, numerous intraepithelial nematodes (G. pulchrum) were observed in the entire esophagus. Results suggest a relation between infection with G. pulchrum and development of an esophageal squamous cell carcinoma.

An experimental infection model for the heteroecious spiruid nematode Tetrameres americana (Cram 1927) was developed. The cockroach Blattella germanica (L.) and the locust Locusta migratoria (L.) were found to serve as intermediate hosts for the parasite. T. americana larvae developed to full maturity in these intermediate hosts and were infective to young Lohman Brown chickens after 32 days in the cockroach and 28 days in the locust. The maximum length of the larvae was reached in the insects at 28-30 degrees C after 10-15 days, at which time the larvae measured up to 2.2 mm. The parasite did not develop in the cockroach Periplaneta americana (L.), the woodlouse Oniscus asellus (L.), or the pupal stage of the giant mealworm Zophobas morio (Fabricius). Trials in which chickens were infected directly without an intermediate host failed. Infection of 24 chickens with a dosage of 100 larvae was followed by weekly post-mortems until day 48 post-infection (p.i.) and used to describe the development of T. americana. The average establishment rate (%) and the average worm burden varied from 16.5 to 30.8. The total numbers of parasites recovered ranged from 9 to 40. During mating, in the first 2 weeks p.i. females and males were equally abundant, whereas from day 20 p.i. twice as many females were recovered. From day 13 p.i. the females average length fluctuated between 2.6 and 3.7 mm, whereas they reached their maximum width of 2.4 mm on day 48 p.i. Males reached their full length after 27 days p.i. and measured up to 6.7 mm.

In November 1993, unusual mortality occurred among endangered Laysan ducks on Laysan Island, one of the remote refugia of the Northwestern Hawaiian Islands National Wildlife Refuge (USA). Ten live ducks were emaciated, and blood samples documented anemia, heterophilia, and eosinophilia. Pathology in 13 duck carcasses revealed emaciation, marked thickening of the proventricular wall, abundant mucus, and nodules in the gastrointestinal tract. Histology revealed granulomata associated with nematodes in the proventriculus, small intestines, and body walls of nine of 10 ducks examined on histology. We suspect that low rainfall and low food abundance that year contributed to enhanced pathogenicity of parasite infection, either through increased exposure or decreased host resistance. Because the Laysan duck is found only on Laysan island and is critically endangered, translocation of this species to other islands is being considered. Given that we have not seen pathology associated with Echinuria spp. in native waterfowl on other Hawaiian Islands and given the parasite's potential to cause significant lesions in Laysan ducks, it will be important to prevent the translocation of Echinuria spp.

A case of infection with Gongylonema is described in a 41-year-old woman living in New York City. The patient sought medical attention with the complaint of a sensation of 1-year duration of something moving in her mouth. On two occasions she removed worms from her mouth, once from her lip, once from the gum. One of the specimens submitted for examination was an adult female Gongylonema. It is not possible to say whether the infection was acquired in New York City, or elsewhere, since the patient traveled frequently to Mississippi to visit relatives. As cases of delusional parasitosis continue to increase, clinicians and laboratorians alike need to be alert to the possibility that foreign objects removed from the mouth, or elsewhere, may indeed represent unusual parasitic infections, and that these objects should be examined before being discarded.

The histopathology induced by Camallanus oxycephalus and Spinitectus carolini in the intestine of green sunfish Lepomis cyanellus was examined. At what is assumed to be more recent attachment sites, penetration of C. oxycephalus was restricted to the mucosal layer, causing complete destruction of the columnar epithelium. At what appeared to be older attachment sites, the parasite penetrated deep into the intestinal wall, even to the circular muscle layer. At these sites of attachment, there were flask-shaped ulcers in the mucosal and submucosal layers. Surrounding the ulcers, there was granulomatous tissue, with extensive fibrosis at the surface; the fibrosis probably reduced the loss of body fluids and blood cells from the intestinal wall. The number of goblet cells in the posterior end of the intestine increased significantly, from 92.6 cells/mm in uninfected fish to 168.4 cells/mm in fish infected with more than 5 C. oxycephalus. Adult S. carolini also causes severe damage to the intestinal wall of green sunfish. Parasite penetration was not limited to the mucosal layer. Mature worms were observed invading both the muscular and serosal layers. Penetration by the parasite was usually associated with the local loss of columnar epithelium and infiltration by lymphocytes and granulocytic leukocytes. Fibrosis in the mucosal layer was commonly observed. There was goblet cell hyperplasia in the anterior portion of the intestine, with numbers of goblet cells increasing from 64.4 cells/mm in uninfected fish to 95.0 cells/mm in heavily infected fish.

Studies were conducted on the pathogenicity and the route of migration to the central nervous system by the immature larval stage of G.spinigerum in experimental animals. Five mice and one rat showed signs of nervous tissue damage and CNS involvement. The significant findings were massive haemorrhagic areas and blood clot around large lower nerve trunk and spinal cord invasion by the worm. The possible roles of the immature larval stages of G.spinigerum in human was discussed.

The authors report the first case observed in Cameroon of an intraocular localization of the nematode Gnastostoma spinigerum. The course of about 3 months presented three phases. The first one consisted of pains in the right hypochondrium, with scapulalgia during three weeks, probably correlated with the crossing of the digestive wall and intraocular migrations. The second phase consisted of ambulatory oedema in the face and neck during three weeks. The last phase consisted of a localization of the parasite in the right eye anterior chamber. After three weeks' observations the surgical extraction of a living gnastostoma larva was carried out. The biological signs were an increase of the sedimentation rate, hyperleucocytosis with marked eosinophilia during the first two phases of the disease. These symptoms became normal after the ocular localization. From the functional point of view the result was better than foreseen.