[(THE CURRENT SITUATION OF DIPHYLLOBOTHRIASIS: EPIDEMIOLOGY AND EPIDEMIOLOGICAL SURVEILLANCE)].

The paper analyzes the etiology of diphyllobothriasis pathogens and their distribution in the world. It estimates the infection rate of the population with tapeworms, the value of different fish species and procedures for their cooking as factors for transmission of Diphyllobothrium to the population and the risk for infection with tapeworms through infected foods. Epidemiological surveillance measures in different (synanthropic and natural) foci of diphyllobothriasis and with various types of pathogens are considered.

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

[Cytomorphological and biochemical characteristics of the whitefish, Baikal omul Coregonus migratorius, infected by plerocercoids of Diphyllobothrium dendriticum (Cestoda: Pseudophyllidae)].

The cytomorphological and biochemical composition of the blood has been studied for the deep-dwelling (bottom) morphotype of the Baikal omul infected by plerocercoids of Diphyllobothrium dendriticum, during the fish spawning migration. A decrease in hemoglobin synthesis and an increase in the proliferative activity of erythroid cells have been registered. The changes in the leukocyte population composition, immunoglobulin, and total protein concentrations evidenced a disorder of blood cell proliferation and differentiation and suppression of the immune response in the infected fish. The changes in the humoral and cell factors of homeostasis in Coregonus migratorius infected by D. dendriticum during the spawning period remain within the limits of the adaptive possibilities of the species.

[Localization of prostaglandin E2, γ-aminobutyric acid, and other potential immunomodulators in the plerocercoid Diphyllobothrium dendriticum (Cestoda)].

For the first time, the potential immunomodulators prostaglandin E2 and γ-aminobutyric acid (GABA) have been revealed in the plerocercoid Diphyllobothrium dendriticum, which is a parasite in the tissues and abdominal cavity of the Baikal omul Coregonus migratorius. The localization of immunomodulators in parasite tissues was compared with the location of typical markers of the nervous system (serotonin (5-HT) and FMRF-amide) and a marker of microtubules (α-tubulin). Prostaglandin E2 was revealed in the cells that are immunoreactive to α-tubulin and are situated in the cortical parenchyma outside the central nervous system (CNS). It is supposed that prostaglandin E2 is produced by the frontal glands and is carried out onto the tegument surface through specialized ducts. Immunoreaction to GABA was revealed in the central and peripheral nervous systems. GABA-ergic neurosomes, the neurites of which form a net on the surface of muscle layers and in the subtegument, were revealed in the cerebral ganglion and main nerve cords. The morphological characteristics for the identification of serotoninergic neurons in the CNS were described.

[The environmental conditions and predictors of formation of the bases for a combination of Diphyllobothrium dendriticum and Triaenophorus nodulosus foci in the flood-river ecosystem of the Angara River].

Investigations were conducted in the context of the landscape-biocenological concept. The formation of water-storage basins in the valley of the Angara River was shown to give rise to the transformation of the morphological structure and hydrological regimen of a landscape, which determined a change in some environmental conditions and factors of a combination of foci and the emergence of others. The morphological structure and hydrological regimen of a landscape, the species composition of ecosystems, the populations of hosts, and their biocenotic relations were transformed due to the direct anthropogenic impact on the landscape. There was an emergence of populations of pathogens, parasitic systems of foci, their functional and spatial structures and a formation of invasion foci as the ecosystems of water-storage basins were transformed. There changes were responsible for the formation of an anthropurgic focus of D. dendriticum and a two-host population-combined natural-anthropurgic focus of diphyllobothriasis - Triaenophorus infection. The susceptibility of hosts, the polyhostality of pathogens, and the mechanisms of their transmission are environmental factors that predetermine the formation of epizootic bases for a combination of foci and, being evolutionally formed and relatively strictly determined, have not undergone cardinal changes in the anthropologically transformed landscape.

[Morpho-functional changes of cloacal bursa of the herring gull in experimental infection with gull tapeworm].

Using the methods of light microscopy, the quantitative changes in the cells of the cloacal bursa of herring gull (Larus argentatus mongolicus) chicks were studied during experimental infection with gull-tapeworm Diphyllobothrium dendriticum. The area of the follicles within the bursa and the number of eosinophils in the infected chicks were found to increase. In the follicles the number of blast cells and large lymphocytes was elevated. The reduction of small lymphocytes and plasma cells numbers in the infected gulls may be due to a slower cell cycle or cell migration into the inflammatory focus. Overall, the changes in the bursa indicate the suppression of the B-link of the host immune system in tapeworm invasion.

A case of Diphyllobothrium latum infection with a brief review of diphyllobothriasis in the Republic of Korea.

A case of Diphyllobothrium latum infection in a 49-year old man is described, and diphyllobothriasis latum in the Republic of Korea is briefly reviewed. An incomplete strobila of a tapeworm, 95 cm in length, without scolex and neck, was spontaneously discharged in the feces of a patient. On the basis of morphologic characteristics of the worm and eggs, the worm was identified as D. latum. The patient was successfully treated with a single dose (15 mg/kg) of praziquantel. The most probable source of infection was salmon flesh according to the past history of the patient. The first case of D. latum infection was documented in 1971, and this is the 43rd recorded case in the Republic of Korea. The 43 cases were briefly reviewed. The patientso main complaints were gastrointestinal troubles, such as mild abdominal pain, indigestion, and diarrhea, and discharge of tapeworm segments in the feces. The suspected infection sources included raw or improperly cooked flesh of fresh or brackish water fish, including the perch, mullet, salmon, and trout.

Selected pathological, immunohistochemical and ultrastructural changes associated with an infection by Diphyllobothrium dendriticum (Nitzsch, 1824) (Cestoda) plerocercoids in Coregonus lavaretus (L.) (Coregonidae).

The pathological changes induced by an infection of Diphyllobothrium dendriticum (Nitzsch, 1824) plerocercoids in powan, Coregonus lavaretus (L.), from Loch Lomond, Scotland, were assessed using immunohistochemical and ultrastructural techniques. In a sample of 26 powan, the occurrence of encysted plerocercoids of D. dendriticum on the outer surface of the stomach was 38.5% (n = 10) with the number of cysts ranging from 4 to 15 and measuring 4.2 +/- 1.0 mm x 3.4 +/- 0.9 mm (mean +/- SD). Histological examination of intestinal samples also revealed plerocercoids (2-21) encapsulated within a proliferation of mesenteric fibrous tissues of the gastric wall and, occasionally, by the gut lamina propria-submucosa and lamina muscularis. In section, cysts were tri-layered and were formed from a series of concentric whorls of fibroblast and collagen fibre-based connective elements. The extent of necrosis within each muscle layer and the serosa of the stomach differed, notably within the latter that was marked by a chronic inflammatory reaction and fibrosis. Within the cyst and around it, a large number of degranulating mast cell/eosinophilic granule cells were seen, in addition to melano-macrophage centres. Immunohistochemical staining of sections of infected stomach revealed a high density of elements, in close proximity to plerocercoids, staining positive for serotonin, bombesin, substance P and galanin. Uninfected material did not present the same levels of activity. Sections through both infected and uninfected tissue were also tested for elements containing vasoactive intestinal peptide, met-enkephalin, calcitonin gene-related peptide, neuropeptide Y and nitric oxide synthase, but these were absent.

Diphyllobothrium latum: a case of an incidental finding.

Colorectal cancer screening can be performed by fecal occult blood testing, sigmoidoscopy, double contrast barium enema or colonoscopy. Colonoscopy has the significant advantage that polyps can be removed during the same procedure. Occasionally, colonoscopy can also reveal unexpected findings, including parasitic infections, even in asymptomatic patients. Tapeworms or cestodes are hermaphroditic parasites, which can live for considerable periods of time in the human gastrointestinal tract. Fish tapeworm (Diphyllobothrium species) are endemic in various parts of the world, the commonest species being Diphyllobothrium latum. Humans are the main definitive host for D. Latum and the majority of individuals harbouring the parasite are asymptomatic, while 40% of infected individuals may have low vitamin B12 levels. We describe a case of D. latum infection found on routine colonoscopic screening for colorectal cancer in an asymptomatic patient, which was successfully treated with praziquantel. The infection likely arose following raw fish (sushi) consumption.

Frecuencia de infección por diphyllobothrium sp cestoda diphyllobothriidae en carnívoros silvestres de Argentina / Diphyllobothrium sp cestoda diphyllobothriidae infection frequency in Argentina wild carnivores

With the aims to determine the infection frequency by tapeworms of Diphyllobothrium genus 30 samples from captive wild carnivores were analyzed. A 30 percent of the animal analyzed was positive to the infection. Whereas the family Procionidae has a high percentage of positivity (60 percent). Canidae have lower infection ratio (20-25 percent). The accuracy for the diagnosis of Diphylobothrium was made by the morphology of scolex, proglottids and eggs. This is the first report of the parasite presence in Argentine wild carnivores

Infección por helmintos parásitos en salmón coho, oncorhynchus kisutch, durante su retorno al río Simpson, Chile / Infection by parasitic helmiths in coho sallmon, oncorhynchus kisutch, during their return to Simpson river, Chile

Between may and july 1994, 17 adult returning salmons, oncorhynchus kisutch, were collected in the River Simpson, Chile. All fishes showed infection by plerocercoids of diphyllobothrium sp. in different locations: stomach, spleen, liver, mesenteries and gonads. Infection with larval cestodes of an unidentified species of phillobothriidae was determined in the intestine of seven (41,2 percent) salmons and its prevalences of infection showed significant differences between female and male salmons. The 94,4 percent of total plerocercoids of diphyllobothrium were isolated from the stomach wall. Prevalence and mean intensity of infection by diphyllobothrium sp. did not show significant differences between fishes of different sex

Helminthic food-borne infections.

The importance of food-borne helminthic infections is not well recognized and has not received the same attention as food-borne bacterial infections. Poverty, overpopulation, and cultural practices contribute to conditions that maintain food-borne helminthic infections. The development of better means of transportation and the ease of reaching otherwise inaccessible markets have increased significantly our risk of coming in contact with food containing infectious organisms. The education of industry, public health workers, governmental organizations, and consumers is the most effective means to prevent food-borne helminthic infections and safeguard the world's food supply. Prevention and intervention measures focused at the production level to disrupt the parasite's life cycle are critical for maintaining a safe food supply.

Difilobotriasis humana por diphyllobothrium pacificum: un nuevo caso en Antofagasta, norte de Chile / Diphyllobothrium pacificum human infection: report of one case

We report a 26 years old asymptomatic female that expelled spontaneously a 39 proglottid strobila. The taxonomic study of proglottids and eggs found in the stool examination concluded that the patient was infected by Diphyllobothrium pacificum. This infection was probably acquired by the ingestion of raw fish (Sciaena deliciosa) with lemon in a traditional plate called "cebiche". She was treated with a single dose of praziquantel in a dose of 10 mg/kg body weight. After 24 h of treatment there were no scolices on feces. The patient did not have anemia. All eight family members studied, did no have the infection. A follow up stool examination three months later remained negative

[An experimental study of the susceptibility of the snakehead Ophiocephalus argus to infestation by larvae of the tapeworm Diphyllobothrium latum]. / Eksperimental'noe izuchenie zarazhaemosti zmeegolova Ophiocephalus argus lichinkami lentetsa shirokogo Diphyllobothrium latum.

Experiments were made to infect young Ophiocephalus argus, the fish of prey delivered from eastern Asia in the Amu-Dar'ya River basin, outside the area of the broad tapeworm Diphyllobothrium latum. The dalags were infected mainly by ingesting the local copepods Arctodiaptomus salinus, the experimentally invaded larvae of the broad tapeworm. The latter larvae were obtained from the development of eggs of the helminth isolated from strobilae from the patients treated in Perm Province. D. latum plerocercoids lived in the dalags nearly 3 weeks, then they died and lysed. Thus, the dalag cannot be a supplementary host of D. latum.

Infecciones por taenia sp y otros cestodos intestinales en pacientes de consultorios y hospitales públicos del sector norte de Santiago de Chile: 1985-1994 / Taenia sp and other intestinal cestode infections in individuals from public outpatient clinics and hospitals from the north sector of Santiago, Chile: 1985-1994

During 1985-1994 period, 70,642 parasitological stool examinations were perfomed. The exam was made to each patient which presenting gastrointestinal symptoms or nutritional problems, specially in children. 59,960 out of the 70,642 examinations corresponded to 1 month -15 years old chidren, 4,280 to 16-30 years old individuals and 6,402 to up to 30 years old adults. The infection rates (x 100,000) were: taenia sp, 86; hymenolepis nana, 1,165; diphyllobotrium sp, 4 and hymenolepis diminuta, 1. In this period, 11 cases of infection by taenia saginata were detected, and none taenia solium infection. Although infections rates by intestinal cestodes were higher in males than females, in the taenia sp. infection the difference was not statistical significative. Médico-veterinary control of animals slaughtered in abbatoirs and the improvement of sanitary conditions in the last two decades have contributed to the control of most of human intestinal cestodiases