An Active Intermediate Host Role for Man in the Life Cycle of Echinococcus Granulosus in Turkana, Kenya

ABSTRACTThe present study investigated the suitability and importance of buffaloes, camels, sheep, goats and pigs in maintaining the life-cycle of Echinococcus granulosus in Aligarh, India. A total of 565 (36%) of 1556 buffaloes, 20 (2%) of 1208 goats, 5 (1%) of 559 pigs, 6 (6%) of 109 sheep and two of three camels were found to harbour hydatid cysts. The frequency distribution of the hydatid cysts in each intermediate host species was over-dispersed and in buffaloes cyst fertility increased with increasing cyst size. Of 2171, 95 and four buffalo, goat, and camel cysts examined 327 (15%), two (2%) and three cysts respectively were fertile. No pig or sheep cysts were found to contain protoscoleces. The unfenced buffalo abattoir and the large number of dogs allowed access to the abattoir coupled to the number of buffaloes slaughtered in comparison to the other potential hosts, indicates that the buffalo is the most significant host for maintaining the life-cycle of the parasite in this area of India. Applicable control measures for the region are suggested.

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Management of Hydatid Cyst of the Spleen. A Case Report

Journal of Clinical Case Reports and Studies ◽

10.31579/2690-8808/001 ◽

2020 ◽

Vol 1 (1) ◽

pp. 01-03

Author(s):

Yakoubi Becherki

Keyword(s):

Case Report ◽

Life Cycle ◽

Hydatid Cyst ◽

Intermediate Host ◽

Echinococcus Granulosus ◽

Hydatid Disease ◽

Definitive Host ◽

The Body ◽

Human Beings ◽

Larval Form

Echinococcosis (hydatid disease) primarily affects the liver; however, secondary involvement due to hematogenous dissemination may be seen in almost any anatomic location. Isolated hydatid disease of the spleen is rare (1, 2). It is caused by the larval form of the tapeworm Echinococcus granulosus, E. multilocularis, E. vogeli, or E. oligarthrus. E. granulosus is the most common organism involved, with dogsEchinoccocus granulosus; splenic hydatid; Laparotomy as the definitive host and sheep as an intermediate host. Human beings exposed to certain stages of the life cycle of the organism are also an intermediate host. Human hydatid disease can involve the liver (55%–70%), lung (18%–35%), spleen, kidney, peritoneal cavity, skin and muscles (<2%) and rarely the remaining parts of the body.

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Epidemiology of hydatid disease in Sardinia: a study of fertility of cysts in sheep

Journal of Helminthology ◽

10.1017/s0022149x00012189 ◽

1990 ◽

Vol 64 (3) ◽

pp. 212-216 ◽

Cited By ~ 13

Author(s):

G. Bortoletti ◽

F. Gabriele ◽

V. Seu ◽

C. Palmas

Keyword(s):

Life Cycle ◽

Intermediate Host ◽

Echinococcus Granulosus ◽

Infected Sheep ◽

Hydatid Cysts ◽

Intermediate Hosts ◽

Economic Significance ◽

Important Intermediate ◽

Ready Access ◽

Epidemiological Significance

ABSTRACTHydatidosis, caused by Echinococcus granulosus, is a cyclozoonotic disease of economic significance in Sardinia. The life-cycle involves stray and sheep dogs as definitive hosts and sheep, pigs, goats and cattle as intermediate hosts. The most important intermediate host is sheep, due to home slaughtering with ready access of the viscera to dogs. This survey was undertaken in 1987 to ascertain the epidemiological significance of sheep in maintaining the life-cycle. A total of 700 (91·3%) of 767 sheep harboured hydatid cysts. The frequency distribution of the number of hydatid cysts was over-dispersed. Of 497 infected sheep, 7·6% had fertile cysts, 75·7% sterile cysts and 16·7% fertile + sterile cysts.

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The Output of First Stage Larvae by Cats Infested with Aelurostrongylus abstrusus

Journal of Helminthology ◽

10.1017/s0022149x00017892 ◽

1968 ◽

Vol 42 (3-4) ◽

pp. 295-298 ◽

Cited By ~ 15

Author(s):

J. M. Hamilton ◽

A. W. McCaw

Keyword(s):

Life Cycle ◽

Great Britain ◽

Intermediate Host ◽

World Wide ◽

Wide Distribution ◽

Clinical Disease ◽

Complex Life Cycle ◽

Patent Period ◽

Aelurostrongylus Abstrusus

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

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Observations on the Morphology and Life Cycle ofNeodiplostomum intermedium(Trematoda: Diplostomatidae)

Parasitology ◽

10.1017/s0031182000068566 ◽

1961 ◽

Vol 51 (1-2) ◽

pp. 133-172 ◽

Cited By ~ 27

Author(s):

J. C. Pearson

Keyword(s):

Life Cycle ◽

Special Reference ◽

Intermediate Host ◽

Technical Assistance ◽

Snail Host ◽

Tree Frog ◽

Mother Sporocyst ◽

Egg Transformation ◽

Hydromys Chrysogaster ◽

Paratenic Hosts

1.Neodiplostomum intermediumPearson is recorded from four new hosts; as an adult from the water rat,Hydromys chrysogasterGeoffroy, and as a metacercaria (diplostomulum), from tadpole and adult of an undescribed tree frog,Hylasp., tadpole of (Hyla latopalmata(Günther)Mixophyes fasciolatusGünther and frog of an unidentified leptodactylid.2. The life cycle ofNeodiplostomum intermediumwas followed experimentally; the hosts were:Pettancylus assimilis(Petterd), a fresh-water limpet, as first intermediate host; tadpole ofHyla pearsoniCopland as second intermediate host;Hyla caerulea(Shaw) a tree frog, andHemisphaerodon gerrardiPeters, the pinktongued skink, as paratenic hosts; andRattus assimilis(Gould) and laboratory rats as definitive hosts.3. Descriptions are given of the morphology of the miracidium, mother sporocyst, daughter sporocyst, cercaria, and diplostomulum, with special reference to the structure of the miracidium and of the cercarial tail.4. Observations are given on the embryology of the miracidium, hatching of the egg, transformation of the miracidium into the mother sporocyst with special reference to the germinal cells, the route and manner of escape of cercariae from the snail host, the development of the diplostomulum with special reference to the reserve excretory system, and the movements of diplostomula during metamorphosis of the tadpole host.5. The haploid chromosome number is ten, as determined from squashes of testes. One paratype and a series of experimental adults have been compared with and found different fromNeodiplostomum(Fibricola)sarcophilusn.comb. The orthography and formal proposing of the names of the species ofFibricolatransferred toNeodiplostomumby Pearson (1959b) are corrected.The writer wishes to thank Dr M. J. Mackerras, Queensland Institute for Medical Research, for generously supplying water rats; Professor J. F. A. Sprent, University of Queensland Veterinary School, for his criticism of the manuscript; Mr K. Webber and his sons for their assistance in catching rats and for permission to collect snails, frogs and tadpoles from their streams; and Mr R. J. Ballantyne for technical assistance. This study was supported by a grant from the Rural Credits Fund of the Commonwealth Bank of Australia.

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Life cycle studies on two Digenea, Paradistomum geckonum (Dicrocoeliidae) and Mesocoelium sociale (Mesocoeliidae), in geckonid lizards from Indonesia

Canadian Journal of Zoology ◽

10.1139/z87-376 ◽

1987 ◽

Vol 65 (10) ◽

pp. 2491-2497 ◽

Cited By ~ 4

Author(s):

Murray J. Kennedy ◽

L. M. Killick ◽

M. Beverley-Burton

Keyword(s):

Life Cycle ◽

Intermediate Host ◽

Intermediate Hosts ◽

Larval Stages ◽

Hemidactylus Frenatus ◽

Pulmonate Gastropod ◽

First Intermediate Host

Life cycle studies of Paradistomum geckonum (Dicrocoeliidae) were attempted experimentally. The pulmonate gastropod Lamellaxis gracilis served as the first intermediate host; geckonid lizards (Cosymbotus platyurus, Gehyra mutilata, and Hemidactylus frenatus) served as definitive hosts. The life cycle of Mesocoelium sociale (Mesocoeliidae) was studied in naturally infected first intermediate hosts (L. gracilis, Huttonella bicolor) and experimentally in geckonid definitive hosts (C. platyurus, G. mutilata, and H. frenatus). Some naturally infected L. gracilis were infected concurrently with larval stages of both digeneans. Second intermediate hosts, presumed to be arthropods, were experimentally unnecessary. Metacercariae of P. geckonum were not found. Cercariae of M. sociale formed encysted metacercariae in the same individual snails.

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On the Life Cycle of Spirocerca lupi: Preinfective Stages in the Intermediate Host

Journal of Helminthology ◽

10.1017/s0022149x00022203 ◽

1972 ◽

Vol 46 (2) ◽

pp. 125-137 ◽

Cited By ~ 8

Author(s):

R. C. Chhabra ◽

Kunwar Suresh Singh

Keyword(s):

Life Cycle ◽

Intermediate Host ◽

Spirocerca Lupi ◽

Second Stage ◽

Stage 1 ◽

First Time

The development of the preinfective stages of S. lupi has been described and illustrated and the details of morphology given for the first time.The sex of the first stage juveniles can be distinguished by locating the position of the genital primordium. On an average, the first stage juveniles measure 0·39 mm. in length and 0·036 mm. in breadth, early second stage 0·78 and 0·044 mm. and the advanced second stage 1·40 mm. and 0·63 mm. respectively. The second stage juveniles obtained from beetles were not infective to dogs.

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Experimental life cycle of Lagochilascaris minor Leiper, 1909

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651992000400003 ◽

1992 ◽

Vol 34 (4) ◽

pp. 277-287 ◽

Cited By ~ 34

Author(s):

Dulcinéa Maria Barbosa Campos ◽

Lindomar G. Freire Filha ◽

Miguel Alípio Vieira ◽

Julieta Machado Paçô ◽

Moacir A. Maia

Keyword(s):

Life Cycle ◽

Intermediate Host ◽

Subcutaneous Tissue ◽

Cervical Region ◽

Parasite Development ◽

Mature Stage ◽

Post Inoculation ◽

Skeletal Musculature ◽

Third Stage

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivorae (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymphonodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivorae gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth.

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The life cycle of Paraquimperia tenerrima: a parasite of the European eel Anguilla anguilla

Journal of Helminthology ◽

10.1079/joh2004270 ◽

2005 ◽

Vol 79 (2) ◽

pp. 169-176 ◽

Cited By ~ 4

Author(s):

J.A. Shears ◽

C.R. Kennedy

Keyword(s):

Life Cycle ◽

Intermediate Host ◽

Anguilla Anguilla ◽

European Eel ◽

Temperature Dependent ◽

Free Living ◽

Freshwater Invertebrate ◽

Third Stage ◽

History Of ◽

Whole Life Cycle

AbstractPrevious studies on the life history of the nematode eel specialist Paraquimperia tenerrima (Nematoda: Quimperiidae) have failed to determine whether an intermediate host is required in the life cycle. In the laboratory, eggs failed to hatch below 10°C, hatching occurring only at temperatures between 11 and 30°C. Survival of the free-living second stage larvae (L2) was also temperature dependent, with maximal survival between 10 and 20°C. Total survival of the free-living stages (eggs and L2) is unlikely to exceed a month at normal summer water temperatures, confirming that parasite could not survive the 6 month gap between shedding of eggs in spring and infection of eels in early winter outside of a host. Eels could not be infected directly with L2, nor could a range of common freshwater invertebrate species. Third stage larvae (L3) resembling P. tenerrima were found frequently and abundantly in the swimbladder of minnows Phoxinus phoxinus from several localities throughout the year and were able to survive in this host in the laboratory for at least 6 months. Third stage larvae identical to these larvae were recovered from minnows experimentally fed L2 of P. tenerrima, and eels infected experimentally with naturally and experimentally infected minnows were found to harbour fourth stage larvae (L4) and juvenile P. tenerrima in their intestines. Finally, the whole life cycle from eggs to adult was completed in the laboratory, confirming that minnows are an obligate intermediate host for P. tenerrima.

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Studies on the life-cycle ofHimasthla militaris(Trematoda: Echinostomatidae): influence of temperature and salinity on the life-span of the miracidium and the infection of the first intermediate host,Hydrobia ventrosa

Parasitology ◽

10.1017/s0031182000051726 ◽

1982 ◽

Vol 84 (1) ◽

pp. 131-135 ◽

Cited By ~ 3

Author(s):

R. Vanoverschelde

Keyword(s):

Life Cycle ◽

Life Span ◽

Intermediate Host ◽

Half Life ◽

Snail Host ◽

Influence Of Temperature ◽

First Intermediate Host

SUMMARYThe influence of temperature and salinity on miracidial longevity and miracidial infectivity of the digenean,Himasthla militaris, has been examined. At 14, 25 and 30 °C the half-life of the miracidia was 1200, 630 and 420 min respectively, and infection of the first intermediate host,Hydrobia ventrosa, only occurred at 25 and 30 °C, for both temperatures 52% became infected. In the range 2·1 to 34‰ (2·1, 4·2, 8·5, 17 and 34‰) the miracidia had a minimal and maximal half-life of 60 and 630 min in water with a salinity of 2·1 and 17‰ respectively, while the infection of the snail host was possible only in water with a salinity of 8·5 and 17‰.

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