Pacific Broad Tapeworm Adenocephalus pacificus as a Causative Agent of Globally Reemerging Diphyllobothriosis.

The Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum) is the causative agent of the third most common fish-borne cestodosis among humans. Although most of the nearly 1,000 cases among humans have been reported in South America (Peru, Chile, and Ecuador), cases recently imported to Europe demonstrate the potential for spread of this tapeworm throughout the world as a result of global trade of fresh or chilled marine fish and travel or migration of humans. We provide a comprehensive survey of human cases of infection with this zoonotic parasite, summarize the history of this re-emerging disease, and identify marine fish species that may serve as a source of human infection when eaten raw or undercooked.

Diphyllobothrium sp. en Canis familiares de la región del subtrópico argentino (Puerto Iguazú, Misiones) / Diphyllobothrium sp. in Canis familiaris from the subtropical area of Argentina (Puerto Iguazú, Misiones)

En este trabajo se informa el hallazgo de huevos de Diphyllobothrium sp. en ejemplares de Canis familiaris (perro doméstico) de Puerto Iguazú, una ciudad subtropical de la provincia de Misiones, Argentina. Durante 2013, en el marco de un relevamiento de la fauna parasitológica de los perros de Puerto Iguazú, se detectaron dos casos positivos en la búsqueda de huevos de Diphyllobothrium sp. La materia fecal de los perros fue recolectada en frascos con formol al 10% y procesada mediante las técnicas de sedimentación de Telemann y de flotación de Sheather. Dado que Misiones no forma parte de la zona endémica de difilobotriasis y considerando, además, su ubicación fronteriza, este hallazgo reviste gran importancia para la salud pública. Se señala la necesidad de actualizar el estado de conocimiento sobre el ciclo de vida de estos parásitos identificando el rango de hospederos intermediarios y definitivos, su potencial zoonótico y la situación epidemiológica en áreas no endémicas

This paper reports the first finding of Diphyllobothrium sp. eggs in Canis familiaris (domestic dog) from Puerto Iguazú, a subtropical city of Misiones province, Argentina. In 2013, two positive cases of Diphyllobothrium sp. eggs were detected during an annual parasitological survey of dogs. Dog feces were collected in vials containing 10% formalin and processed using Telemann's sedimentation and Sheather's flotation techniques. The two cases were detected in rural areas of the municipality. Since Misiones is not a part of the endemic area of diphyllobothriasis and given the fact that it is located in the three-border area of Argentina, Brazil and Paraguay, we consider this finding of great importance to public health. We stress the need for updating the current knowledge about the life cycle of these parasites considering the range of intermediate and definitive hosts, their zoonotic potential, and the epidemiological situation in non-endemic areas

Diphyllobothriasis, Brazil.

Cases of human diphyllobothriasis have been reported worldwide. Only 1 case in Brazil was diagnosed by our institution from January 1998 to December 2003. By comparison, 18 cases were diagnosed from March 2004 to January 2005. All patients who became infected ate raw fish in sushi or sashimi.

Diphyllobothriasis: update on human cases, foci, patterns and sources of human infections and future considerations.

Diphylobothriasis is a well documented disease of humans. On a world scale new infections are reported regularly, especially from Russia and parts of Japan. Globally, new species have been discovered and the etiology of the disease may be changing. Human infections appear to be in decline but it is not clear if the sources of infection are also in decline or if public health awareness has improved. In North America there has been a decline in human cases while in South America an increase in reports from fish, especially salmonids suggests high levels in these fish species. The history of human infections of Diphyllobothrium latum is primarily associated with the consumption of the northern circumpolar distributed pike and percids and is often considered a parasite of humans only. Indeed some researchers believe that D. latum was introduced to North America by northern European immigrants. The more benign human infections of D. dendriticum appears to be primarily associated with salmonids and coregonid fishes and fish eating birds. Although the early cases of diphyllobothriasis in the 1930s in North America came from fish originating in Lake Winnipeg, Manitoba, there was general belief that it was declining in fish populations and therefore of little significance to humans in the area. However, high levels of a plerocercoid in the flesh of walleyes and pike led to rejection of commercially harvested walleye and pike in Manitoba and northern Ontario, Canada, and a financial loss to Aboriginal fishers. D. latum is widely distributed in fishes of Manitoba and is infective to humans where it is not pathogenic and has a life span up to 4.5 years. The distribution and potential infection routes has not changed in a century and is still well established in natural hosts in the boreal regions of North America. Evidence is building for an old pre-European presence in North America, involving the Beringian land bridge and later involvement of susceptible hosts (northern European immigrants).

Diphyllobothrium dendriticum and Diphyllobothrium latum in fishes from southern Argentina: association, abundance, distribution, pathological effects, and risk of human infection.

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.