A new hedrurid species (Nematoda) from galaxiid fishes in Patagonia (Argentina) and infection of amphipods as intermediate host.

During a parasite survey of galaxiid fishes (Galaxiidae) from Patagonian Andean lakes, a new species of nematode, Hedruris suttonae n. sp. was collected from the stomach of the native Galaxias maculatus (Jenyns) and G. platei (Steindachner). Specimens were examined by light and scanning electron microscopy, especially head morphology, female caudal prehensile structure, and distribution of spines. The new species is distinguished by body and tail size, morphology and size of spicules, the arrangement of caudal papillae in the male, the female caudal hook, and size of eggs. Hyalella patagonica (Ortmann), a Neotropical species of Amphipoda, is reported as its natural intermediate host. Data regarding prevalence and mean intensity in the intermediate and definitive hosts are included. The diet and habitat of the hosts, the percentage of gravid females, the high values of prevalence, and mean intensity in galaxiid fishes, as well as the wide distribution of H. suttonae , collectively indicate that, in these oligotrophic Andean lakes, G. maculatus and G. platei are true definitive hosts of this nematode.

[Gnathostoma (Spirurida: Gnathostomatidae) infection in the tigerfish Hoplias microlepis: prevalence, correlation with fish size, hosts, and public health implications]. / Infección por Gnathostoma (Spirurida: Gnathostomatidae) en Hoplias microlepis: prevalencia, correlación con la talla del pez, huéspedes e implicaciones para salud pública en Ecuador.

INTRODUCTION: Human gnathostomiasis has been reported in Ecuador since the early 1980s, when natural infections by Gnathostoma third larval stages were found in muscles of the second intermediary host, Hoplias microlepis (tigerfish). In Ecuador, this zoonotic disease is occasionally detected in humans, and its monitoring and eco-epidemiological assessment is of particular interest for its detection and control. OBJECTIVE: The most recent evidence is provided with respect to natural infections by Gnathostoma as it occurs in the tigerfish (Hoplias microlepis), including insights into its biological cycle. MATERIALS AND METHODS: A total of 74 fish were collected from two localities (rice fields-wetlands and local fish market) of Samborondón County (Guayas Province). Each was examined for the presence of Gnathostoma in muscle of Hoplias microlepis. The abundance intensity and prevalence of parasites was estimated. Statistical comparisons between the two sites and correlations of parasite load versus fish size were conducted. RESULTS: The infection prevalence by Gnathostoma was 69% (95% CI: 57-78%). The overall abundance intensity of parasites averaging the 2 sites was 1.7 larvae per fish. The proportion of infected fish was higher in rice fields (77%) when compared to those from the local fish market (62%). No statistically significant differences between the abundance intensity and prevalence were found between the sites (p>0.05). Parasite load and fish length were significantly correlated (Spearman p<0.05). CONCLUSIONS: Gnathostomiasis is a prevalent zoonosis in coastal Ecuador, and its etiologic agent is commonly found in the second intermediary host. Several Neotropical mammals are candidates as definitive reservoir hosts in the Gnathostoma biological cycle.

Gnathostomiasis: a review of a previously localized zoonosis now crossing numerous geographical boundaries.

Expansion in international travel and increases in immigration have resulted in an increased number of persons in Europe and other Western countries who have returned from foreign travel with parasitic infections rarely seen previously in the United States. Among the diseases caused by helminthic parasites is gnathostomiasis, a disease caused by Gnathostoma spp. Once confined primarily to Southeast Asia, it now is a public health concern in Mexico and other countries. This article reviews the causes and epidemiology of gnathostomiasis, the life cycle of the helminth, the clinical picture and diagnosis of gnathostomiasis, and the treatments for and means of avoiding the disease.

A case of gnathostomiasis in a European traveller returning from Mexico.

Hundreds of human cases of gnathostomiasis have recently been reported from Mexico, where the disease is becoming a public health problem. We report a case of gnathostomiasis in a French tourist returning from Mexico. Tourists travelling in endemic countries are at risk of gnathostomiasis and should be advised about the risks of eating raw fish as a suspected source of infection.