[Detection of echinococcal infection in rodents and shrews caught in Asahikawa and Kushiro districts]

During the May-October period of 1983, rodents and shrews were caught in Asahikawa and Kushiro districts and examined for the presence of echinococcal infection. 603 individuals representing 8 species and 110 individuals of 9 species were collected in Asahikawa and Kushiro districts, respectively. Among these animals, a vole, Clethrionomys rutilus mikado caught in Akkeshi in Kusiro district was infected with larval Echinococcus multilocularis, but no evidence of echinococcal infection was found in the animals caught in Asahikawa.

Prevalence of toxocariasis and echinococcosis among dogs in the Niger Delta

A sample of 60 dogs in the Port Harcourt area of the Niger Delta was examined for intestinal parasites. The high prevalence rates of Toxocara canis (56.6%) and Echinococcus granulosus (85.0%) in the area are discussed in relation to public health. Other parasites found in dogs include Toxascaris leonina (3.3%), Uncinaria stenocephala (70.0%), Dipylidium caninum (88.3%), Trichuris vulpis (56.7%), Ancylostoma caninum (65.0%) and Taenia hydatigenia (43.3%).

Cost-effectiveness analysis of echinococcosis-hydatidosis eradication project in Sardinia

In this study we attempt to evaluate the convenience of a campaign to eradicate the echinococcosis in Sardinia vs a 'do-nothing' or do-very-little policy adopted at this time. The main conditions which have to be met in setting up the eradication programme are identified as follows: (a) precise knowledge of the real diffusion of the parasitosis in man and animals; (b) eradication project control (action research); (c) health education; (d) reduction of stray canine population; (e) anthelmintics distribution and permanent health control to registered dogs. In Italy, echinococcosis-hydatidosis is present in many regions but in none has reached the diffusion rate present in Sardinia where over 200 patients per year are surgically treated, with a prevalence rate of 13.32 per 100,000 inhabitants. The disease does not spare any social or age group. The economic aspects of hydatidosis involve losses due both to human and to livestock resources, evaluated in monetary or non-monetary terms, according to circumstances. As a method to evaluate the human life has been assumed the years gained related to the Potential Years of Life Lost (PYLL). Several Net Present Values (NPV) have been calculated under alternative discount rates inclusive of the Internal Rate of Return (IRR).

[Parasitoses of food origin in Tunisia]

About diet parasitosis, the author distincts three origins of contamination: telluric, proteinic, and both. The telluric parasitosis are the most frequent, intestinal (by helminths or protozoairs) as visceral (hydatidosis). The frequence of these parasitosis is subjected to changes in the different areas, in intensity, but also in the nature of identified parasite. Toxoplasmosis, transmitted by the two mods occurs in Tunisia. The population average percentage protection is however no sufficient to prevent the risk of contamination during pregnancy.

Studies on the sero-epidemiology of endemic diseases in Libya. I. Echinococcosis in Libya

In Libya traditional animal husbandry and the practice of domestic slaughter of food animals contribute to the maintenance of the Echinococcus cycle. The cost of echinococcosis is high and may significantly affect the national economy. This study, employing the ELISA test, has indicated an approximately 10% infection rate in children and young adults from the environs of Benghazi, no difference being apparent between rural and urban dwellers. The prevalence of the infection should be determined in both animals and man and possible disease inter-relationships investigated. Surveys are required in all alleged endemic areas and in sheep and camel breeding areas. It is also necessary to determine the importance of foxes, hyaenas and jackals in transmission among other animals. A clinical trial is recommended to assess the value of mebendazole against Echinococcus cysts.

An active intermediate host role for man in the life cycle of Echinococcus granulosus in Turkana, Kenya

Hydatid material removed at operation from 97 Turkana was compared for fertility and viability with hydatid material removed from camels, cattle, sheep, and goats. The results showed that the human material was extremely fertile and viable, as was material from the camels, goats, and sheep. Cattle cysts were invariably sterile, and the protoscoleces, when present, were comparatively less viable. The high incidence and fertility of hydatid cysts in the Turkana, together with the lack of burial customs thus allowing dogs to have ready access to infected human corpses, means that the Turkana are potential biological participants in the cyclic transmission of Echinococcus granulosus in this region. This is a unique situation, for elsewhere in the world man is regarded as an accidental host who plays no role in the parasite's life cycle.

Hydatid disease in the Turkana District of Kenya. III. The significance of wild animals in the transmission of Echinococcus granulosus, with particular reference to Turkana and Masailand in Kenya

The results are given of a study on the role of wildlife in the transmission of Echinococcus granulosus in the Turkana and Narok Districts of Kenya. A total of 76 wild carnivores belonging to three separate species was examined from Turkana District. Echinococcus adults were found in 11 of 38 silver-backed jackals (Canis mesomelas) and in six of 22 golden jackals (Canis aureus). This is the first record of golden jackals being infected with this parasite in Kenya. None of 16 spotted hyaenas (Crocuta crocuta) harboured the parasite. Morphological features of the parasites obtained from the jackals were compared with material obtained from dogs in the same area. No morphological differences were recorded when this material was compared with data reported by others, hence the Turkana material belonged to the single species E. granulosus. Three silver-backed jackals and three puppies (Canis familiaris) were successfully infected with protoscolices obtained from a hydatid cyst surgically removed from a Turkana patient. Three spotted hyaenas fed the same material failed to become infected. None of 152 wild herbivores of five species examined in Turkana harboured hydatid cysts. The natural jackal infections in this District are thought to be incidental and dependent on the continuance of the domestic cycle. The role of the Turkana themselves in the perpetuation of the cycle is discussed. Twenty-six wild herbivores of six species were examined for hydatid cysts, in Narok District; hydatids were found in three wildebeest (Connochaetes taurinus) and a single topi (Damaliscus korrigum). The discovery of fertile cysts in wildebeest and the reported infections in lions (Panthera leo), Cape hunting dogs (Lycaon pictus) and silver-backed jackals, support previous evidence of the existence of a wildlife cycle in the Masailand and Serengeti regions of East Africa. The relationship of this cycle to the domestic cycle operating in the same area is unclear and requires further investigation.

The susceptibility of the European red fox (Vulpes vulpes) to infection with Echinococcus granulosus of Australian sheep origin

A detailed comparative study was made of the development of Echinococcus granulosus of Australia sheep origin in European red foxes (Vulpes vulpes) and dogs. No significant differences in growth, segmentation or maturation of the parasite between dogs or foxes was found, although worm burdens were slightly lower in foxes than in dogs. It is concluded that although the role of foxes in the epidemiology of hydatidosis in Australia may not be significant, foxes should nevertheless be regarded as potential definitive hosts of the Australian strains of E. granulosus.

Hydatidosis and cysticercosis: the dynamics of transmission

The infective pattern of taeniids in their intermediate hosts is determined by the complex interaction of parasite- and host-related factors. Many of these have been examined in this review, but particular emphasis has been placed on environmental factors that affect the free-living egg. While number, infectivity and distribution of eggs are among the important factors determining the infective pattern, the dynamics of this aspect of transmission have been previously neglected. The biotic potential of the large taeniid tapeworms is enormous. Eggs deposited on pasture are subjected to the microclimatic effects of the environment. They seem to tolerate a relatively wide temperature range. Heat down to -30 degrees C. However, they are rapidly killed by low humidity at all temperatures. Under more favourable conditions, they have finite life spans largely determined by the environmental temperature. At deposition, the egg population seems to be at various stages of maturity. Immature eggs appear to be able to mature under suitable environmental conditions and to become infective. They then age, and their infectivity to the intermediate host declines. At the population level, the changes in infectivity with time are determined by the relative stages of maturity within the egg population and the temperatures that it experiences. Under certain circumstances the infectivity of a given population may increase temporarily. The movements and defaecation habits of the definitive host determine the primary site of egg deposition. However, evidence is accumulating that considerable dispersion occurs almost immediately afterwards. Eggs have been shown to disperse up to 80 m within 10 days and there are indications that small numbers travel much further. Intermediate hosts, such as cattle and sheep, generally avoid grazing areas contaminated with faeces. Thus, dispersal enhances the chance of the eggs being ingested. The combination of high biotic potential and long-range dispersal means that individual infected definitive hosts can be responsible for infecting intermediate hosts over a very wide area. Although various possible agents have been suggested, the mechanisms responsible for disseminating eggs are still uncertain.(ABSTRACT TRUNCATED AT 400 WORDS)

[Our experience with rare primary localizations of hydatidosis. Analysis of etiopathogenetic aspects]

The authors relate their experience on seventeen cases of unusual localizations of Echinococcus cyst operated in the last fifteen years. They present a critical analysis of the different pathogenetic theories trying to explain the peripheral localization of the larva. It is made examination of the factors which would consent the passing through of the hepatic and pulmonary filter, the mechanisms that could avoid such filters and the hypothesis referring to the possibility of direct setting up. They dwell quickly on the peculiar pathogenetic aspects of the various observed localizations.

Possible factors influencing distribution and prevalence of Echinococcus granulosus in Utah

A descriptive epidemiologic study was designed to test an impression that infections of Echinococcus granulosus in dogs, sheep, and human beings were concentrated in central Utah, and to determine when and how the parasite was introduced into the state, which factors were involved in the distribution of the cestode, and which factors increased either a person's risk of infection of the number of people at risk. Data were secured by review of available records, interviews, questionnaires, and field observations. It was found that 37 of 39 infections in human beings, and seven of eight counties with endemic hydatid disease in dogs and sheep, are located in central Utah. Possible factors responsible for the increasing number of people at risk were use of local people as herders, the existence of community herds, and specific dog management practices. Determinants such as trailing sheep between seasonal pastures, association of sheepmen from several counties on winter range, and sheep marketing practices undoubtedly influence distribution of infections in dogs and sheep.

Disseminated pelvic Echinococcosis simulating ovarian carcinomatosis: case report and review of pelvic hydatid disease

Pelvic pathology due to the parasite Echinococcus is infrequent in industrialized nations. It, however, may involve multiple organs and can mimic virtually any disease process. The parasitology, epidemiology, diagnosis, and treatment of hydatid disease is reviewed with particular emphasis on pelvic hydatid disease.