Diphyllobothrium dendriticum and Diphyllobothrium latum in Fishes from Southern Argentina: Association, Abundance, Distribution, Pathological Effects, and Risk of Human Infection

Abstract

Diphyllobothrium dendriticum and Diphyllobothrium latum are reported for the first time from Argentina. The following species from Lake Moreno (southern Argentina) were studied to determine whether plerocercoids were present: 11 brook trout (Salvelinus fontinalis), 32 perca (Percichthys sp.), 21 pejerrey (Patagonina hatcheri), and 114 rainbow trout (Oncorhynchus mykiss). Brook trout harbored both species (27.3% prevalence of D. dendriticum and 9.0% of D. latum); perca harbored only D. latum (18.7% prevalence); pejerrey were not infected and rainbow trout also harbored both species, with significant association. Diphyllobothrium latum was less abundant (1.4 plerocercoids/fish, 28.0% prevalence) than D. dendriticum (7.2 plerocercoids/fish, 57.8% prevalence) implying a lower health risk for humans. For both parasites, rainbow trout seem to be more important than the other host species studied. There is no evidence that either of the species is more harmful to the host. The lack of significant weight variation of the liver as related to intensity of infection strongly suggests that competition for energy is not an important aspect of the host pathology.

Infections by Helminth Parasites in "Puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes)

“…Revenga (1993) reports two parasites with zoonotic importance: Diphyllobothrium dendriticum and D. latum in fish from Lake Moreno, which is connected with Nahuel Huapi Lake. He suggests that salmonids can act as paratenic hosts for both species and states the importance of studying the role of G. maculatus populations in the life cycle of D. dendriticum and D. latum.…”

“…The "puyen" Galaxias maculatus (Galaxiidae, Salmoniformes) is a small autochthonous fish (total asymptotic growth length = 97 mm in Ezquerra pond, near Lake Nahuel Huapi), (Cervellini et al 1993) that inhabits southern South America and Oceania (Quaggiotto & Valverde 1993) and may be predated by salmonids whereby transmission of parasites may occurr (Revenga 1993). Studies in New Zealand (McDowall 1968) and Australia (Pollard 1971) agree that most of each population dies during its first year, immediately after spawning, but a small proportion might reach three years of age.…”

Difilobotriasis humana en la Patagonia, Argentina

“…La trucha arco iris, especie muy apreciada por los pescadores deportivos, parecería cumplir el rol principal en la transmisión del parásito al hombre 24,28,30 . Sin embargo, los datos de prevalencia e intensidad en éste y otros salmónidos, no quedarían reflejados en la prevalencia de esta parasitosis en la población humana.…”

“…En 1957, los mismos autores 32 señalaron la presencia de dos especies de Diphyllobothrium en trucha arco iris (Oncorhynchus mykiss), trucha de arroyo (Salvelinus fontinalis) y salmón del Atlántico (Salmo salar). Estudios recientes en la región andinopatagónica reportan dos especies del parásito, D.latum (Linnaeus, 1758) y D.dendriticum (Nitzsch, l824), que coexisten o pueden vivir separadamente tanto en peces autócto-nos como introducidos en numerosos lagos y ríos andinopatagónicos 21,24,25,30 . Si bien existían registros de infecciones humanas en Argentina, estos corresponden a inmigrantes provenientes de otros países 17 .…”

Diphyllobothrium latum: relato de caso no Brasil

“…Em peixes dos lagos da região sul da Argentina foi observada prevalência de 28% de Diphyllobothrium latum e de 57,8% de D. dendriticum 11 .…”