Showing papers in "Journal of Helminthology in 1971"
TL;DR: By clarifying which taxonomic characters are of specific significance and by defining the intra specific limits of individual morphological variations, seventeen species of the genus Anisakis were shown to represent only three distinguishable forms, which were found to be satisfactory when discussed in geographical and ecological terms.
Abstract: By clarifying which taxonomic characters are of specific significance and by defining the intra specific limits of individual morphological variations, seventeen species of the genus Anisakis were shown to represent only three distinguishable forms, these being Anisakis simplex (Rudoiphi, 1809 det. Krabbe, 1878), A. typica (Diesing, 1860) and A. physeteris Baylis, 1923. The morphological characters in order of importance for identifying these species are the spicules, the postanal papillae, the form of the ventriculus, the position of the vulva and the form of the lips. These three species were also found to be satisfactory when discussed in geographical and ecological terms.The four remaining species in the genus, Anisakis dussumierii (van Beneden, 1870), A. alexandri Hsu and Hoeppli, 1933, A. insignis (Diesing, 1851) and A. schupakovi Mozgovoi, 1915 are retained as species inquirendae for lack of sufficient information concerning them.
149 citations
TL;DR: Identification of members of the family Schistosomatidae presents problems not only because of the imperfect state of their taxonomy, but also because no attempt has been made to collect and organise the available data.
Abstract: Identification of members of the family Schistosomatidae presents problems not only because of the imperfect state of their taxonomy, but also because no attempt has been made to collect and organise the available data. There are only two general keys on the schistosomes (Price, 1929 ; Yamaguti, 1958) both of which are incomplete. The result of this is that many authors, too numerous to mention, list genera which are no longer valid and erect new species without comparing them with species to which they are obviously closely related.
57 citations
TL;DR: Irrespective of the situation of the adult worms the microfilariae of O. gutturosa appear to have a directional mechanism and were always concentrated in the skin around the umbilicus.
Abstract: 1. O. gutturosa infections are of widespread occurrence in South-East England. 58% of 1583 cervical ligaments from milk cattle slaughtered in an abattoir at Reading, Berkshire, showed the presence of adult worms. A more detailed study of 50 cattle from a small abattoir near St. Albans in Hertfordshire showed 42 (84%) infected.2. The adult worms were found either in the connective tissue adjoining the nuchal ligament or between the spleen and rumen. There was no evidence of an increase in the parasite density with age of the cattle suggesting a strong immunity to superinfection.3. Irrespective of the situation of the adult worms the microfilariae of O. gutturosa appear to have a directional mechanism and were always concentrated in the skin around the umbilicus. This is an adaptation to transmission by Simulium ornatum which bites preferentially in the umbilical region.4. There were no marked pathological changes associated with the parasites and no evidence of clinical disease attributable to infection with O. gutturosa.
45 citations
TL;DR: In this paper, age-prevalence curves were derived from field collections of snails, using cercarial shedding as proof of infection by schistosomes, and the underlying assumptions of this form of analysis are discussed and in view of the independent verification of some of the calculated rates, the values are considered realistic.
Abstract: 1. With the aid of field growth curves, age-prevalence curves can be derived from field collections of snails, using cercarial shedding as proof of infection by schistosomes.2. Such curves were obtained from eight collections of field snails: one sample each of Bulinus (Physopsis) nasutus productus and Biomphalaria pfeifferi, intermediate hosts respectively of Schistosoma haematobium and S. mansoni in Tanzania, and six samples of Biomphalaria glabrata, intermediate host of S. mansoni on St. Lucia, West Indies.3. Catalytic curves were fitted to the data and in each case the two-stage curve gave the most satisfactory fit.4. This curve is the resultant of two opposing forces: one force being the rate of infection and the other the rate of loss of infection in a snail population.5. The rate of infection may be defined as the number of successful snail-miracidium contacts per 1,000 snails per week, while the rate of loss of infection is taken to represent the number of deaths per 1,000 infected snails per week.6. The underlying assumptions of this form of analysis are discussed and, in view of the independent verification of some of the calculated rates, the values are considered realistic.7. Besides providing quantitative data for inclusion in mathematical models of schistosome transmission, the technique offers an additional means of assessing the efficacy of certain methods of controlling transmission.
43 citations
TL;DR: Initial infection takes place mainly when periwinkles are spent after their first breeding season and though later damage to the gonad may prevent reproduction, the breeding potential of the periwinkle population at Scalby Rocks is unlikely to be affected seriously.
Abstract: 1. 5250 specimens of the common periwinkle, Littorina littorea (L.), from Scalby Rocks on the North Yorkshire coast were examined from October 1966 to November 1967 and data obtained on the size, sex and reproductive condition of the periwinkles and their infections with four species of Digenea, namely Cryptocotyle lingua (Creplin, 1825), Renicola roscovita (Stunkard, 1932), Himasthla leptosoma (Creplin, 1829) and Cercaria lebouri Stunkard, 1932.2. The normal breeding cycle of uninfected L. littorea and the breeding cycles found in periwinkles infected with larval Digenea are described and discussed. Initial infection takes place mainly when periwinkles are spent after their first breeding season and though later damage to the gonad may prevent reproduction, the breeding potential of the periwinkle population at Scalby Rocks is unlikely to be affected seriously. There was no evidence of sex reversal in uninfected or infected L. littorea and the normal sex ratio is 1:1. The phenomenon of gigantism as a result of digenean infection is discussed with respect to L. littorea.
39 citations
31 citations
TL;DR: It is concluded that the microfilaria of Brugia is a very much modified first stage nematode larva, adapted to life in the capillaries of the vertebrate host.
Abstract: (1) The structure of the microfilaria of Brugia ( B. patei and B. pahangi ) is redescribed and the development of B. patei is followed in the mosquito Aedes togoi for the first 4 days, up to the moult to the second larval stage. (2) The buccal cavity, the pharynx (or oesophagus), and the pharyngo-intestinal valve of the second stage larva are formed around the pharyngeal thread of the microfilaria. Part of this thread is moulted with the microfilarial cuticle at the moult to the second larval stage. (3) The intestine of the second stage larva is built up around the Innenkorper of the microfilaria from cells of the nuclear column. (4) The R cells (G 2—G 4 cells) of the microfilaria and the anal vesicle of the microfilaria continue into the second stage larva and eventually the rectum is formed between them. (5) The G cell (G 1 cell) does not form part of the gut of the second stage larva but becomes incorporated into the body wall with other cells from the nuclear column. (6) The subcuticular cells of the microfilaria continue as elongate spindle shaped cells in the cords of the second stage larva. (7) The significance of these results, which are at variance with earlier descriptions, are discussed and it is concluded that the microfilaria of Brugia is a very much modified first stage nematode larva, adapted to life in the capillaries of the vertebrate host. The microfilaria begins the metamorphosis to the structure of the second larval stage soon after entry into the insect vector.
30 citations
TL;DR: A comparison of the characteristics of two strains of S. haematobium in experimental infections in hamsters is made in this article, where the quantitative distribution of eggs in the tissues of the hamster is recorded.
Abstract: A comparison of the characteristics of two strains of S. haematobium in experimental infections in hamsters is made. A limited study of these strains is also made in Mastomys.Growth changes in male and female adult worms are compared, as are changes in the uterine egg counts.The quantitative distribution of eggs in the tissues of the hamster is recorded. The approximate mean daily egg output per female worm for each strain is calculated at specified time intervals, and for the entire period of observations.The recorded characteristics of the two strains of parasite are compared with those described for other strains of S. haematobium.It is considered that the hamster provides a useful model for such studies provided that standardised infection procedures are employed.It is considered that differences in host characteristics and susceptibility of individual animals account for the apparent variability recorded with regard to growth of parasites and egg depositions.
30 citations
29 citations
TL;DR: Five new species are described and nine known species and one new combination are reported from new hosts and new localities.
Abstract: Five new species are described and nine known species and one new combination are reported from new hosts and new localities. The new species are: Prosogonotrema pritchardae, Uroproctinella attenuata, Bivesiculoides scari, Stephanostomum attenuatum and S. adinterruptum. The known species are: Genolopa trifolifer Nicoll, 1915, Anaporrhutum albidum Brandes in Ofenheim, 1900, Hymenocotta mulli Manter, 1961, Pleorchis sciaenae Yamaguti, 1938, Mehratrema dollfusi Srivastava, 1939, Buckleytrema indica Gupta, 1956, Acanthocolpus tenuis Manter, 1963, A. liodorus Luhe, 1906, and A. luhei Srivastava, 1939. The new combination is Alloheterolebes indicus (Gupta, 1968).
22 citations
TL;DR: The structure and relative sizes of the larvae in the 3 kinds of hosts are compared and their growth was measured and some observations were made on their development during the prepatent period which was found to be 121 and 124 days.
Abstract: 1. Infective larvae of S. lupi were collected in Madras from scarabaeid beetles, (the usual intermediate host), from garden lizards and shrews. 2. The structure and relative sizes of the larvae in the 3 kinds of hosts are compared. 3. Infective larvae were given orally to 30 dogs which were autopsied at intervals and the developing worms were recovered. Their growth was measured and some observations were made on their development during the prepatent period which was found to be 121 and 124 days.
TL;DR: The varying susceptibility of local races of bulinid snails to different strains of Schistosoma haematobium has been recorded by many workers including Le Roux, 1954, Cridland, 1955, 1957; McCullough, 1957, 1962; Wright, 1962, 1963; Cowper, 1963, Pitchford, 1965 and Paperna, 1968 as mentioned in this paper.
Abstract: The varying susceptibility of local races of bulinid snails to different strains of Schistosoma haematobium has been recorded by many workers including Le Roux, 1954; Cridland, 1955, 1957; McCullough, 1957, 1962; Wright, 1962, 1963; Cowper, 1963; Pitchford, 1965 and Paperna, 1968. The respective species groups of snails referred to are those created by Mandahl-Barth (1958). As a result of his experiments Le Roux (1958) suggested that there are two separate species of parasite, the form transmitted in North Africa by the truncates group of snails being known as S. haematobium and that developing in Africa south of the Sahara in the africanus species group as S. capense (Harley, 1864), a view which has been supported by many workers.
TL;DR: S. maltheei females could mature and produce eggs in the absence of males in mice and hamsters but only nonviable eggs were produced during the 88 week observation period, evidence of their specific distinctness.
Abstract: S. maltheei females could mature and produce eggs in the absence of males in mice and hamsters but only nonviable eggs were produced during the 88 week observation period. S. mansoni, S. rodhaini and S. bovis females were studied under similar conditions for up to 30, 36 and 66 weeks, respectively, but in none of these species were any eggs produced by the female worms. The contrasting behaviour of S. mattheei and S. bovis is further evidence of their specific distinctness.
TL;DR: Blood containing microfilariae has been successfully transported from various laboratories to London and was used to infect mosquitoes with filarial parasites by means of a membrane feeding system.
Abstract: Blood containing microfilariae has been successfully transported from various laboratories to London. This blood was used to infect mosquitoes with filarial parasites by means of a membrane feeding system. Brugia malayi, Wuchereria bancrofti and Dirofilaria immitis have been successfully transported in this way.
TL;DR: The unequivocal demonstration of genetic heterogeneity of certain parasites of medical importance has resulted in a better understanding of their epidemiology and, in some cases, is leading to greater precision in attempts to control them.
Abstract: The epidemiology of parasitic infections may be profoundly influenced by infra-specific variations in infectivity for either intermediate or definitive hosts. Such variations will decide the basic ecology of the host-parasite relationship, and variations in virulence and pathogenicity therefore determine different patterns of disease. While some of the evidence of infra-specific variations has been derived from experimental studies, much of it has been recorded by those concerned with investigations of the epidemiology and transmission of parasitic infections and the practical aspects of their control. The unequivocal demonstration of genetic heterogeneity of certain parasites of medical importance has therefore resulted in a better understanding of their epidemiology and, in some cases, is leading to greater precision in attempts to control them.
TL;DR: The life cycle and biology of T. deminutus were studied and investigations were carried out on the site of infection in the host, the female to male ratio, the egg laying capacity of the female worms, the development of the eggs after leaving the host and preliminary observations on the effects of desiccation and low temperatures on the third stage larvae.
Abstract: The life cycle and biology of T. deminutus were studied and investigations were carried out on the site of infection in the host, the female to male ratio, the egg laying capacity of the female worms, the development of the eggs after leaving the host and preliminary observations on the effects of desiccation and low temperatures on the third stage larvae were made.
TL;DR: About 100 specimens of the fresh-water snail, Melanoides tuberculatus (Muller), collected on 30th March, 1962 from “Kukrail”, a tributory of river Gomati, were examined for larval infection and one specimen was found infected with a unique cercaria belonging to the genus Transversotrema.
Abstract: About 100 specimens of the fresh-water snail, Melanoides tuberculatus (Muller), collected on 30th March, 1962 from “Kukrail”, a tributory of river Gomati, were examined for larval infection. One specimen was found infected with a unique cercaria belonging to the genus Transversotrema. The writer subsequently attempted to collect this cercaria from the same place and 1750 specimens of the said host were examined in the following years (1962–67) without success. Further, a large number of specimens of fishes of the genera Channa Gronov; Colisa Cuv. and Val.; Xenentodon Regan and Nundus Cuv. and Val., common in the tributary were also examined for metacercarial infection of this cercaria but none were found.
TL;DR: Third stage infective juveniles of the genera Oesophagostomum and Ostertagia were found clinging to the abdomens of species of psychodid flies that breed in faeces, suggesting that these dipterans may be able to carry parasitic nematode larvae from farm to farm.
Abstract: Third stage infective juveniles of the genera Oesophagostomum and Ostertagia were found clinging to the abdomens of species of psychodid flies that breed in faeces. It is suggested that these dipterans may be able to carry parasitic nematode larvae from farm to farm.
TL;DR: Ichthybothrium and Ptychobothrium show some similarities but can be differentiated by the shape of the scolex and the position of the vitelline follicles.
Abstract: Ichthybothrium ichthybori gen. et sp. nov. (Pseudophyllidea : Ptychobothriidae) is described and figured from specimens collected from the intestine of the African freshwater fish Ichthyborus besse from the White Nile near Khartoum, Sudan. Ichthybothrium and Ptychobothrium show some similarities but can be differentiated by the shape of the scolex and the position of the vitelline follicles. Ptychobothrium cypseluri Rao, 1957 and Plicatobothrium cypseluri Cable and Michaelis, 1967 are congeneric and a new name Plicatobothrium raoi is proposed for the former.
TL;DR: 0·15% of Oesophagostomum larvae fed to laboratory rats became encapsulated in the intestinal mucosa and the juvenile nematodes were able to continue their development when the infected rat tissue was eaten by pigs.
Abstract: 0·15% of Oesophagostomum larvae fed to laboratory rats became encapsulated in the intestinal mucosa. The juvenile nematodes were able to continue their development when the infected rat tissue was eaten by pigs.
TL;DR: Twenty-three of 255 domesticated dogs surveyed in Lahore, West Pakistan, were blood positive for microfilariae, and A. dracunculoides adult worms from a dog in the Indian subcontinent may also have represented this species.
Abstract: Twenty-three (9%) of 255 domesticated dogs surveyed in Lahore, West Pakistan, were blood positive for microfilariae. Twenty-one (8·2%) had either pure or mixed infections with Acanthocheilonema dracunculoides . Dirofilaria repens microfilariae were present in 4 dogs and one had Dirofilaria immitis microfilariae. A single adult A. dracunculoides was found from the hind leg of an autopsied dog with A. dracunculoides microfilariae. Microfilariae had a diurnal periodicity in this animal. There is only one previous documented report of A. dracunculoides adult worms from a dog in the Indian subcontinent, but it is possible that microfilariae earlier described from India under other names may also have represented this species.
TL;DR: In this paper, the normal ultrastructure of the fundic gastric glands of cattle is described and compared with those from calves infected with T. axei. Loss and alterations in structure of zymogen and parietal cells are observed and are related to changes observed by light microscopy.
Abstract: The normal ultrastructure of the fundic gastric glands of cattle is described and compared with those from calves infected with T. axei. Loss and alterations in structure of zymogen and parietal cells are observed and are related to changes observed by light microscopy. The significance of these changes is discussed.