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Showing papers in "Journal of Helminthology in 1994"


Journal ArticleDOI
TL;DR: An experiment was carried out to investigate the anthelmintic activity of papaya latex against natural infection of Ascaris suum in pigs, and some of the pigs receiving the highest dose of the latex showed mild diarrhoea on the day following treatment.
Abstract: An experiment was carried out to investigate the anthelmintic activity of papaya latex (Carica papaya) against natural infection of Ascaris suum in pigs. Sixteen naturally infected pigs were, on the basis of faecal egg counts and body weight, allocated into four groups, each of four pigs. Three groups (groups B, C, and D) were given papaya latex per os at dose levels of 2, 4, and 8 g of papaya latex per kg body weight, respectively. The fourth group (group A) served as a non-treated control. Results of post mortem counts on day 7 post treatment revealed worm count reductions of 39.5, 80.1 and 100% in groups B, C, and D, respectively. Some of the pigs receiving the highest dose of the latex showed mild diarrhoea on the day following treatment. Otherwise, no clinical or pathological changes were observed in the treated animals. The possible future use of this traditional herbal medicine for livestock and humans is discussed.

104 citations


Journal ArticleDOI
TL;DR: The relationship between the length of mature T. canis female worms and the proportion of body length occupied by the uterus was highly significant and the distribution of parasite burdens in both dogs and cats was overdispersed.
Abstract: A survey was undertaken to study the epidemiology of Toxocara spp. in 350 dogs and 181 cats. A prevalence of 82.6% was recorded for Toxocara canis and 42% for T. cati. The distribution of parasite burdens in both dogs and cats was overdispersed. The highest parasite prevalence rates and burdens were found in hosts of 12 to 24 weeks of age. No Toxocara parasites were found in cats between 0 to 4 weeks old. There was no significant difference in parasite prevalence between male and female dogs or between male and female cats. The relationships between host age and sex with parasite prevalence, burden and length are discussed. Female T. canis worms with mature ova and those with immature ova differed significantly with regard to their length. The relationship between the length of mature T. canis female worms and the proportion of body length occupied by the uterus was highly significant.

80 citations


Journal ArticleDOI
TL;DR: An attempt was made to control Ostertagia ostertagi by feeding the nematode-trapping fungus Duddingtonia flagrans to grazing calves, but due to weight loss at the end of the grazing season, the control group showed a significantly lower average weight increase.
Abstract: An attempt was made to control Ostertagia ostertagi by feeding the nematode-trapping fungus Duddingtonia flagrans (DSM 6703) to grazing calves. One group of calves (group E) was fed the fungal material in the first two months of the grazing season while another group was a non-treated control group (group C). Group E showed significantly lower faecal egg count in August and September. On four occasions in July and September, the herbage larval counts were significantly lower on the plot with the fungal-treated group than those recorded on the control plot. The average abomasal larval and adult worm counts were significantly reduced in August in group E and the average total worm count in the abomasum of group E was reduced by 87% in August compared to the non-treated group C. In October, the difference in average abomasal worm counts between group E and C was insignificant. Due to weight loss at the end of the grazing season, the control group showed a significantly lower average weight increase.

65 citations


Journal ArticleDOI
TL;DR: The findings in this study suggest that the sample's moisture content contributes to the long term survival of infective Toxocara ova in the environment.
Abstract: A total of nine playground sites in Dublin city and county were surveyed from which 228 samples were removed. Of these samples, 15% were positive for Toxocara canis ova and a mean egg density of 1.4 ova/100 g was calculated. Two types of playground sites were identified and that the level of toxocaral contamination was found to be greater in 'neighbourhood playgrounds' than in 'adventure playgrounds'. There was no significant difference in the number of positive samples taken from sites both inside and outside these playgrounds. No evidence of Toxocara cati ova was found. Only one sample was positive for Toxascaris leonina ova. Over 50% of the T. canis ova identified were infective. The findings in this study suggest that the sample's moisture content contributes to the long term survival of infective Toxocara ova in the environment. A recovery rate of 69.8% was achieved with a modified version of the flotation method.

62 citations


Journal ArticleDOI
TL;DR: These nematodes were present at high temperatures and neither the monsoon rain nor the drought had any effect on their prevalence, however, no parasitized insects were found although insect species were encountered which are potentially natural hosts.
Abstract: Entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) were isolated from Sri Lankan soils using the Galleria baiting technique. Samples collected from different agro-ecological regions and different habitat types revealed that the presence of nematodes was restricted to sandy coastal soils. Two heterorhabditid and three steinernematid RFLP types were discovered within 5–100 m of the sea. Members of both families were equally prevalent. However, no parasitized insects were found although insect species were encountered which are potentially natural hosts. These nematodes were present at high temperatures (some above 30°C) and neither the monsoon rain nor the drought had any effect on their prevalence.

56 citations


Journal ArticleDOI
TL;DR: The migratory route of Toxocara canis in the mouse includes two phases: a hepato-pulmonary phase and a myotropic-neurotropic phase, which shows a reduction when the experiment was prolonged for one year.
Abstract: The migratory route of Toxocara canis in the mouse includes two phases: a hepato-pulmonary phase and a myotropic-neurotropic phase. A study was made of the migratory behaviour of larvae one year post-inoculation (p.i.) comparing the results to those obtained at the end of an initial experiment (day 63 p.i.). The larval distribution per organ was already definitive at 9 weeks p.i. The total parasitic load showed a reduction when the experiment was prolonged for one year.

39 citations


Journal ArticleDOI
TL;DR: Angiostrongylus vasorum infection was detected for the first time in eight foxes captured in the south of the State of Minas Gerais, Brazil and two crossbred dogs were successfully infected orally with larvae from the foxes' faeces.
Abstract: Angiostrongylus vasorum infection was detected for the first time in eight foxes (Dusicyon vetulus) captured in the south of the State of Minas Gerais, Brazil. Two crossbred dogs were successfully infected orally with larvae from the foxes' faeces.

39 citations


Journal ArticleDOI
TL;DR: In epidemiological surveys for urinary schistosomiasis caused by Schistosoma haematobium in communities around Agulu Lake, Anambra State, Nigeria, between 1990 and 1992, the infection was found to be endemic in the area, especially in three towns: Nri, Agulu, and Adazi Nnukwu.
Abstract: In epidemiological surveys for urinary schistosomiasis caused by Schistosoma haematobium in communities around Agulu Lake, Anambra State, Nigeria, between 1990 and 1992, the infection was found to be endemic in the area, especially in three towns: Nri, Agulu, and Adazi Nnukwu The prevalence rates varied between these communities and with the year Inter-town prevalence rates ranged from 596% to 5400% Intravillage prevalence rates ranged between 550% to 9643% Prevalence rates were highest in villages very close to Agulu lake There was no significant difference in prevalence between the schools Host age, but not sex, was found to play a significant role in prevalence and intensity of infection There was also a strong correlation between visible haematuria and egg count per 10 ml urine, but eggs could be isolated in urine samples of different shades of coloration Analysis of incidence of infection in these communities shows that Schistosoma haematobium incidence is high in Nri (5517%) and low at Adazi Nnukwu (526%) Both Bulinus globosus and B truncatus were found in the lake and both shed mammalian bifid schistosome cercariae

38 citations


Journal ArticleDOI
TL;DR: The viability rate of hydatid cysts was investigated in animals slaughtered in the abattoir of Thessaloniki, Macedonia, Greece and all fertile cysts contained viable protoscoleces.
Abstract: The viability rate of hydatid cysts was investigated in animals slaughtered in the abattoir of Thessaloniki, Macedonia, Greece. Two hundred sheep (100% infection rate), 106 cattle (56.6% infected), 203 pigs (9.3%) and 52 goats (15.4%) were examined. All fertile cysts contained viable protoscoleces. In sheep there was a mean of 1.1 (29.8% of total cysts) fertile cysts per animal containing 297.3 (81.3%) viable protoscoleces. The percentage of viable protoscoleces in the lungs was 82.3% and in the liver 71.2%. In cattle there was a mean of 0.1 (6.6% of total) fertile cysts per animal containing 46.4 (72.2%) viable protoscoleces. The percentage of viable protoscoleces in the lungs was 69.5 and in the liver 87. In swine there was a mean of 0.02 (9.5% of total) fertile cysts per animal containing 32.0 (76.8%) viable protoscoleces. The percentage of viable protoscoleces in the lungs was 97.1 and in the liver 68.9. In goats there was a mean of 0.1 (12.5% of total) fertile cysts per animal containing 12 (54.6%) viable protoscoleces. The percentage of viable protoscoleces in the lungs was 54.4% but no fertile cysts were found in the liver.

35 citations


Journal ArticleDOI
TL;DR: The trapping capability of Arthrobotrys oligospora and A. conoides against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial and the trapping capability shown was higher than 90% for both kinds of nematode.
Abstract: The trapping capability of Arthrobotrys oligospora and A. conoides (Hyphomycetales) against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial. Arthrobotrys oligospora showed a 35.87% and 25.71% trapping effectiveness against H. contortus infective larvae at 18 and 25°C, respectively; whereas the trapping capability of A. conoides was 92.17% and 90.40% at the same temperatures, respectively. Microscopic examination demonstrated that A. conoides spontaneously developed a large quantity of three-dimensional loops before the nematodes were added. Neither of the two species studied developed three-dimensional adhesive loops at 30°C, consequently no trapped nematode was observed. In a second trial, the trapping capability of A. conoides against H. contortus (L3) and second stage larvae (J2) of Nacobbus aberrans (Pratylenchidae), was evaluated at 25°C. The trapping capability shown by A. conoides was higher than 90% for both kinds of nematode. The possible use of A. conoides to control ovine haemonchosis is discussed.

32 citations


Journal ArticleDOI
TL;DR: Japanese worms (31, of which six were established as uniparental laboratory strains), which reproduce by parthenogenesis, exhibited three different isozyme patterns, indicating that triploidy has arisen more than once in Japanese flukes.
Abstract: Twelve enzymes (encoded by 14 loci) in liver flukes of Fasciola species originating from Japan (parthenogenetic triploids), Korea (parthenogenetic diploids), the United States of America (USA) and Australia (all sexual diploids) were analysed using starch gel electrophoresis. Variation in electrophoretic patterns between samples was detected at five enzyme loci (Ak, Got, Gpi, 6-Pgd and Pgm-2). Japanese worms (31, of which six were established as uniparental laboratory strains), which reproduce by parthenogenesis, exhibited three different isozyme patterns. This indicates that triploidy has arisen more than once in Japanese flukes. Japanese Fasciola sp. can be separated into three types on morphological grounds. For the six laboratory strains of Japanese worms, the parental morphological type was known. Each of the three isozyme patterns observed was restricted to one morphological type. Most alleles detected in the Japanese triploids were also found in diploid worms from the other countries: the only alleles not represented elsewhere were four at the Got locus and two at the Pgm locus. Flukes from a laboratory strain derived from a single Korean diploid worm resembled the Japanese worms in genotype more closely than did American (seven uniparental laboratory strains) or Australian (30 worms) specimens. Worms from the last two countries were closely related.

Journal ArticleDOI
TL;DR: The population dynamics of Labratrema minimus (Stossich, 1887) metacercariae were studied in its second intermediate fish host Atherina boyeri during the cercarial shedding period and it was deduced that the infection pattern observed over the May-September period was a dynamic process controlled by availability of infective cerbariae.
Abstract: The population dynamics of Labratrema minimus (Stossich, 1887) metacercariae (Trematoda, Bucephalidae) were studied in its second intermediate fish host Atherina boyeri from Salses-Leucate lagoon (Northwest Mediterranean Sea, South of France), during the cercarial shedding period. The infection parameters (prevalence and mean abundance of infection) showed the high susceptibility of silversides (juveniles and adults) to infection. The observed variation in the mean abundance of infection with respect to time and host size was explained by (i) the susceptibility of A. boyeri to multiple successive infections (increase in abundance of infection with host length and raising of parasite burden until August) and (ii) the loss, probably by more rapid death, of heavily infected silversides from each host size group (decrease in abundance of infection in September within each host size group, stability of the parasite burden within the older class of hosts over the whole period, premature decrease in the condition factor in August). Finally, it was deduced that the infection pattern observed over the May-September period was a dynamic process controlled by: availability of infective cercariae, influx of newborn silversides free of metacercariae until September, high susceptibility of juvenile and adult A. boyeri to infection, metacercarial loss and probably by parasite-induced host mortality.

Journal ArticleDOI
TL;DR: Blood samples from 50 dogs with episodic weakness and 50 clinically normal dogs, all belonging to hunting breeds, were examined for microfilariae using the modified Knott's method, with no significant difference.
Abstract: Blood samples from 50 dogs with episodic weakness and 50 clinically normal dogs, all belonging to hunting breeds, were examined for microfilariae using the modified Knott's method. The prevalence of microfilaraemia in dogs belonging to the episodic weakness group was 10% for Dirofilaria immitis, 30% for Dirofilaria repens and 8% for Acanthocheilonema reconditum. In the clinically normal group, the figures were 14% for Dirofilaria repens and 4% for Acanthocheilonema reconditum. The overall percentage of dogs with microfilaremia in the episodic weakness group was 44 and that of the clinically normal group 16, with a statistically significant difference (P < 0.01). The prevalence of microfilaremia due to the nonpathogenic filarial species (Dirofilaria repens, Acanthocheilonema reconditum) was 34% and 16% for the episodic weakness group and the clinically normal dogs, respectively, with no significant difference.

Journal ArticleDOI
TL;DR: Fasciola hepatica miracidia were experimentally introduced into five sites colonized by Lymnaea palustris causing the prevalence to drop as compared with the initial values and to subsequently increase in 1991-1992.
Abstract: Fasciola hepatica miracidia were experimentally introduced into five sites colonized by Lymnaea palustris over a period of 4 or 6 years. In the first four ponds, a progressive increase in the prevalence of the spring-generation juvenile snails was observed (from 0.4 to 18.1%), with a corresponding increase in the shell height of infected snails (from 3.6 to 7.8 mm). In the fifth habitat, the pond dried in 1990 causing the prevalence to drop as compared with the initial values and to subsequently increase in 1991–1992.

Journal ArticleDOI
TL;DR: A total of 358 cattle was examined for schistosome infection in Zambian slaughterhouses and worms collected from 104 infected individuals showed one of two distinct heterozygote patterns, identical to that of a laboratory-produced F1 S. mattheei x S. leiperi hybrid.
Abstract: A total of 358 cattle was examined for schistosome infection in Zambian slaughterhouses. A total of 542 worms collected from 104 infected individuals was examined for glucose-6-phosphate dehydrogenase and phosphoglucomutase using isoelectric focusing. The overall prevalence of infection was 51%. Ninety three percent of the infected animals had less than 100 worm pairs in the mesenteric veins. Schistosoma mattheei was the predominant species (75%); S. leiperi (12%) and S. margrebowiei (2%) were also identified. The remaining 11% of the worms showed one of two distinct heterozygote patterns. Pattern A is identical to that of a laboratory-produced Fl S. mattheei × S. haematobium hybrid, but could also represent a S. mattheei × S. leiperi hybrid. Further studies are required to elucidate the origins of pattern B.

Journal ArticleDOI
TL;DR: It appears from this study, on chromosomal and electrophoretic evidence, that generative (haploid) parthenogenesis occurs in S. mansoni females paired with S. intercalatum males.
Abstract: Experimental studies of mating behaviour of Schistosoma intercalatum and Schistosoma mansoni in mixed infections in mice showed that in simultaneous infections, without the possibility of choice of mate, heterologous pairing occurs readily. The paired females reach sexual maturity, are inseminated and lay parthenogenetic eggs. Miracidia originating from the S. mansoni male × S. intercalatum female are non infective to either Biomphalaria glabrata or Bulinus forskalii , whereas those from the reverse cross show a very low infectivity to only B. glabrata . The resulting haploid male cercariae also show a very low infectivity to mice (1.1%) and consequently only a very small number of adult worms develop. It appears from this study, on chromosomal and electrophoretic evidence, that generative (haploid) parthenogenesis occurs in S. mansoni females paired with S. intercalatum males.

Journal ArticleDOI
TL;DR: It was found that out of 16 restriction enzymes, PstI, HaeIII and RsaI revealed consistently different cleavage patterns between the two types of Paragonimus westermani originating from Japan.
Abstract: Restriction endonuclease analysis of mitochondrial DNA was carried out in order to differentiate diploid and triploid types of Paragonimus westermani originating from Japan. It was found that out of 16 restriction enzymes. PstI, HaeIII and RsaI revealed consistently different cleavage patterns between the two types.

Journal ArticleDOI
TL;DR: Levels of intestinal nematode infections were assessed six months after a two year trial of ivermectin for efficacy against onchocerciasis had ended and it was concluded that there was no significant protection from infection with this species among the iverMectin relative to the placebo-treated subjects.
Abstract: Levels of intestinal nematode infections were assessed six months after a two year trial of ivermectin for efficacy against onchocerciasis had ended. In the trial the inhabitants of six villages in Sierra Leone were offered treatment with ivermectin or placebo at six monthly intervals for four rounds in total. Quantitative faecal egg counts were carried out on stool samples provided by 202 subjects, all of whom had received all four rounds of treatment, in two of the villages (Dodo and Mogibisi). These data were analysed by a novel procedure in which a 3-way ANOVA with negative binomial errors enabled village and host gender influences on the outcome of treatment to be identified. Necator americanus was the most common species showing an overall prevalence of 90% but a higher intensity in Mogibisi relative to Dodo, particularly among male subjects. Neither prevalence nor intensity of infection were altered in ivermectin-treated compared with placebo-treated subjects. Trichuris trichiura was the least common species with a prevalence of 15%. It was concluded that there was no significant protection from infection with this species among the ivermectin relative to the placebo-treated subjects. Ascaris lumbricoides, with an overall prevalence of 39%, was more common among female (50%) compared with male (27%) villagers. Prevalence was not significantly affected by ivermectin but the intensity of infection declined by 91.3% in Dodo whilst in Mogibisi intensity was only reduced by 14.6%. The results indicate that the long-term benefits of treatment of necatoriasis and trichuriasis with ivermectin are likely to be minimal whilst those of ascariasis will depend on the individual characteristics of local communities and may differ quite markedly within a limited geographical area. Possible explanations for the discrepancy in efficacy between villages are considered.

Journal ArticleDOI
TL;DR: The present study determined the susceptibility of domestic animals to an isolate of Taenia solium from Hainan Province, People's Republic of China to be susceptible to T. solium.
Abstract: The present study was designed to determine the susceptibility of domestic animals to an isolate of Taenia solium from Hainan Province, People's Republic of China. A total of 162 cysticerci were recovered from two pigs and 21 from two dogs after experimental inoculation. Cats, goats and a calf were not susceptible to T. solium . Cysticerci were recovered mainly from muscles of the pigs and all were alive. The remainder were in the liver and only one was alive. In the dog, all cysticerci were recovered from the muscles and all were alive.

Journal ArticleDOI
TL;DR: The cytological study of males and females of Trichuris muris revealed the diploid number of chromosomes to be 2n = 6, and the sex determining mechanism was XX female/XY male.
Abstract: The cytological study of males and females of Trichuris muris (Schrank, 1788) revealed the diploid number of chromosomes to be 2n = 6. The sex determining mechanism was XX female/XY male. All the chromosomes were subtelocentric. Sex chromosomes formed the smallest pair, but X and Y were difficult to distinguish morphologically. Chromosome changes during gametogenesis in both sexes followed a classical pattern except in the male prophase and metaphase I. Four male autosomes formed two bivalents, each with one proximal chiasma with strict localization, while sex chromosomes X and Y formed two univalents. Female chromosomes formed three rod bivalents of normal type, which possessed three, two and two chiasmata.

Journal ArticleDOI
TL;DR: There was a progressive increase of prevalence to the second decade of life, although 96.6% of cases with skin microfilariae had only a light infection, hence onchocercomata prevalence may be used as a yardstick for predicting skin microFilariae prevalence.
Abstract: The prevalence of onchocercosis was determined in three Local Government Areas (Ezeagu, Oji-River and Uzo-Uwani) in Enugu State, Eastern Nigeria between March 1989 and June 1990. Enugu State was shown to be mesoendemic for onchocercosis. A total of 7472 (26.9%) persons out of 27,831 examined were positive for skin microfilariae. There was no significant difference in infection rates between males (27.6%) and females (26.2%). Of the 118 villages surveyed only five had no inhabitant with skin microfilariae. There was a progressive increase of prevalence to the second decade of life, although 96.6% of cases with skin microfilariae had only a light infection. Onchocercomata prevalence was recorded as 27.3% which tallies with the prevalence of skin microfilariae at 26.9% hence onchocercomata prevalence may be used as a yardstick for predicting skin microfilariae prevalence.

Journal ArticleDOI
TL;DR: It is demonstrated that only infected nymphal ticks can support the complete development of the filarial worm in the brown dog tick.
Abstract: This paper reports the development of the canid filarial worm, Dipetalonema dracunculoides, in the brown dog tick, Rhipicephalus sanguineus by determining whether development is similar within larval, nymphal and adult stages of infected ticks. This study demonstrates that only infected nymphal ticks can support the complete development of the filarial worm. Infected larval ticks are not suitable intermediate hosts, nor are infected adults. Development depends on some stage-specific property of the vector, and the maturation to the infective stage is stimulated during the course of the nymphal-adult moult.

Journal ArticleDOI
TL;DR: It was concluded that the hamster host provided a model of trichinellosis that, in many respects was closer than mice and rats to the pattern of infection seen in economically and clinically important host species.
Abstract: The duration of primary infections with T. spiralis was dose-dependent with greater proportional loss of worms from heavily infected hamsters and longer persistence of worms in syngeneic DSN hamsters carrying initially low intensity infections. Intestinal worms were lost more rapidly from challenged immunized animals with over 80% loss of established worms by day 6 post infection, but survival of residual worms for a further 2 weeks. Hamsters carrying initially more than 140 intestinal worms began to lose weight during the second week indicating severe pathology at this stage of infection. Mucosal mast cell numbers increased from 50 cells/20 villus crypt units in uninfected animals to a peak in excess of 150 during week 4 pi, although intestinal mastocytosis persisted long after the loss of the majority of adult worms. Serum antibody responses to muscle stage larval antigen were detected in week 3 and increased subsequently. Both mastocytosis and antibody responses were more intense on secondary exposure to infection. Hamsters vaccinated with muscle stage larval antigen showed only a moderately accelerated loss of the intestinal phase but the fecundity of worms was severely suppressed. Overall it was concluded that the hamster host provided a model of trichinellosis that, in many respects was closer than mice and rats to the pattern of infection seen in economically and clinically important host species.

Journal ArticleDOI
TL;DR: The highest percentages of snails harbouring immature sporocysts were detected in March and June-July, while the highest percentages with sporocyst containing mature cercariae were observed in spring and at the end of summer-autumn, and cercarial shedding in the latter.
Abstract: To study the distribution of Lymnaea truncatula in the Porma river basin (Leon, NW Spain) and its helminth fauna, malacological samplings were carried out at 66 points in the basin and the presence of these molluscs was detected in 31. To trace the dynamics of this mollusc population and the prevalence and intensity of its infection by trematodes, malacological samplings were made at fortnightly intervals over two years at five locations, situated in the upper and middle regions of the river Porma basin. To confirm the identity of the larval stages found in the molluscs, second intermediate and/or definitive hosts, depending on the trematode species, were experimentally infected to complete the life cycles. Two different species of Plagiorchiidae and one of Notocotylidae were identified. The infection prevalence of Plagiorchis elegans for the 6291 specimens of L. truncatula examined was 2.8% and infection was observed in snails collected in 7 of the 31 sample localities. This parasite was found in all months of the year, with the highest prevalence observed in July and October. When the corrected frequency values were considered, a slightly positive relationship was observed between the infection prevalence and the latter months. The highest percentages of snails harbouring immature sporocysts were detected in March and June–July, while the highest percentages with sporocysts containing mature cercariae were observed in spring and at the end of summer–autumn, and cercarial shedding in the latter. Of the 6291 L. truncatula examined 0.3% were infected by sporocysts of Opisthioglyphe ranae. The infection was detected in only one locality, in four months of the year, with the highest prevalence in May. Notocotylus neyrai was found in 2.6% of the 6291 mollusc specimens checked and was collected from 12 of the 31 localities. The highest prevalence was observed in October, April and July and the corrected frequency values reveal a positive relationship between the infection prevalence and those three months. The highest percentage of molluscs harbouring rediae of N. neyrai with germinal mass was found in April and September–October. On the other hand, rediae with mature cercariae were present in almost every month, but we only observed cercarial shedding in October and March. The L. truncatula infection prevalence by P. elegans, O. ranae and N. neyrai increased with the size of the molluscs. Double infection was only observed in four snails: one harboured O. ranae and N. neyrai and three F. hepatica and P. elegans.

Journal ArticleDOI
TL;DR: DNA from species and races of plant parasitic nematodes and a human parasitic Nematode were subjected to polymerase chain reaction amplification using one arbitrary primer to results in relatively simple DNA profiles that include polymorphic markers known as random amplified polymorphic DNA (RAPDs).
Abstract: DNA from species and races of plant parasitic nematodes (Meloidogyne, Globodera and Heterodera) and a human parasitic nematode (Trichinella) were subjected to polymerase chain reaction amplification using one arbitrary primer (M-10). This technique results in relatively simple DNA profiles that include polymorphic markers known as random amplified polymorphic DNA (RAPDs). The RAPD profiles of the plant nematode species of Meloidogyne made possible the identification of M. incognita and M. hapla, but no differences were found between the patterns of M. javanica, M. arenaria and M. graminicola. Moreover, the four races of M. incognita were indistinguishable by this primer. In contrast, when races of the plant nematode Globodera rostochiensis (Ro1 and Ro2/3) were studied under the same RAPDs conditions, a race specific profile allows these two most devastating races to be differentiated. When DNAs of eight Trichinella isolates were subjected to RAPD studies, four different patterns were identified, corresponding to the four Trichinella clusters previously defined by isozyme polymorphism.

Journal ArticleDOI
TL;DR: Adult Lymnaea truncatula were subjected to 10 days of experimental desiccation and then remained in water for 1 or 8 days before each was exposed to a single miracidium and the redial burden clearly decreased in stressed snails.
Abstract: Adult Lymnaea truncatula were subjected to 10 days of experimental desiccation and then remained in water for 1 or 8 days before each was exposed to a single miracidium. The infection rate was lower in these snails than in infected controls that were not exposed to stress (52-54% vs 73%). The redial burden clearly decreased in stressed snails (18-25 rediae per snail) than in controls (43 rediae). This numerical decrease concerned essentially: i) live independent rediae of the first generation and the first cohort of the second generation, and ii) dependent rediae of subsequent generations. Mature rediae were more numerous in the first cohort of the second generation than in the other generations. Desiccation before exposure limited the size of the redial burden but placement in water for 8 days just after the stress attenuated the effects of this factor.

Journal ArticleDOI
TL;DR: The relationship between different climatic factors (temperature, relative humidity and rainfall) and the pattern of lungworm larval excretion was studied in sheep under a continuous grazing pattern in North-west Spain, where the climate is intermediate between sub-humid Mediterranean with an Atlantic tendency and European Atlantic.
Abstract: The relationship between different climatic factors (temperature, relative humidity and rainfall) and the pattern of lungworm larval excretion was studied in sheep under a continuous grazing pattern in North-west Spain, where the climate is intermediate between sub-humid Mediterranean with an Atlantic tendency and European Atlantic. Over a period of one year, 44 animals were sampled once a month at random from a flock of 80 Galician breed sheep, all over 4 years old. Faeces were taken directly from the rectum and the number of first stage larvae per gram of faeces was determined for each animal, and the species of Protostrongylidae (Nematoda) identified. Larval excretion was irregular during the study. The prevalence and intensity of infection were greater in the colder months (40.9%; x = 12.3 +/- 40.4) and less in the warmer months (21.9%; mean = 0.7 +/- 2.7). The species of Protostrongylidae identified and prevalences (%) were Neostrongylus linearis (71.5), Muellerius capillaris (18.8) and Cystocaulus ocreatus (9.7). Between November and March, with low temperatures, the prevalence and intensity of parasitism with N. linearis and M. capillaris were greater than in the months with high temperatures (May to September). Multiple linear regression analysis showed statistical correlation between temperature, relative humidity and rainfall considered together and the number of N. linearis larvae per gram of faeces. Linear regression showed a correlation between the temperature and the percentage of sheep that passed M. capillaris. In general, the prevalence and intensity of infection of the sheep with N. linearis, M. capillaris and C. ocreatus larvae decrease when the temperature increases and increase when the relative humidity and rainfall increases.

Journal ArticleDOI
TL;DR: The pattern in EPG presumably reflected the effect of faecal production on the total eggs excreted in each 3 h period, and the observed cycle in total eggs probably describes the pattern of egg production by the worm, although other factors, such as the host's intestinal rhythms, may contribute to this cycle.
Abstract: The rhythmicity of egg production by Heligmosomoides polygyrus (Nematoda) in wild caught wood mice (Apodemus sylvaticus) was studied. Faecal production followed a 24 h cycle, with peaks at 0400 h and troughs at 1300-1900 h. The patterns in eggs per gram of faeces (EPG) and total eggs were similar to each other, though the former was more accentuated. Both of these followed a 24 h cycle, with peaks coinciding with troughs in faecal production and vice versa. Faecal weight was inversely correlated with EPG, but was not significantly correlated with total eggs. The pattern in EPG presumably reflected the effect of faecal production on the total eggs excreted in each 3 h period. The observed cycle in total eggs probably describes the pattern of egg production by the worm, although other factors, such as the host's intestinal rhythms, may contribute to this cycle.

Journal ArticleDOI
TL;DR: Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.
Abstract: In a survey carried out in 1991-1992 in the town of Yirka in Northern Israel, 49 dogs were examined for Echinococcus granulosus infection and abattoir data, based on organs condemned for the presence of parasites, was collected. The presence of E. granulosus by arecoline test was demonstrated in 7 (14.2%) of the dogs examined, but not parasites were found in the intestines of five stray dogs shot in the area. A survey of sheep slaughtered in the local abattoir during a one-month period revealed Echinococcus cysts in 10% of the 255 animals examined. No Echinococcus parasites were detected in 21 dogs examined 3 months after the initiation of praziquantel treatment. Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.

Journal ArticleDOI
TL;DR: The first record of the co-occurrence of two species of Sanguinicola (S. inermis and S. volgensis) in a British inland water is reported and the importance of blood flukes and the role of anthropochore movement of fish hosts in dissemination of S.Inermis are discussed.
Abstract: The distribution and host range of Sanguinicola armata, S. inermis and S. volgensis in British freshwater fish are described. S. inermis has been recorded in carp Cyprinus carpio, crucian carp Carassius carassius and tench Tinca tinca in southern, central and eastern England and in koi carp imported from Japan. S. armata has been detected in pike Esox lucius and tench and S. volgensis has been found in chub leuciscus cephalus, dace Leuciscus leuciscus, perch Perca fluviatilis, roach Rutilus rutilus and pike in southern and eastern England. The first record of the co-occurrence of two species of Sanguinicola (S. inermis and S. volgensis) in a British inland water is reported. The importance of blood flukes and the role of anthropochore movement of fish hosts in dissemination of S. inermis are discussed.