Showing papers in "Journal of Helminthology in 1980"
TL;DR: Natural infection of mice deprived of their T-cells by pre-adult thymectomy and administration of antithymocyte serum resulted in superinfection and widespread metastasis of aberrant cysticercoids that were greatly enlarged and without scolices, causing death after about five months.
Abstract: Observations on the course of Hymenolepis nana infection in immunosuppressed mice are presented. Treatment of the host with hydrocortisone acetate caused superinfection of the bowel with worms and the development of normal cysticercoids in the mesenteric lymph node and liver. Natural infection of mice deprived of their T-cells by pre-adult thymectomy and administration of antithymocyte serum resulted in superinfection and widespread metastasis of aberrant cysticercoids that were greatly enlarged and without scolices, causing death after about five months. The significance of these findings and their possible relevance to human infection with H. nana are discussed.
30 citations
TL;DR: Direct comparison of Praziquantel with potassium antimony tartrate indicated that treatment with the former drug allowed retention of a greater level of acquired resistance than the antimonial in the immediate post-treatment period.
Abstract: Effective treatment of mice with six to eight week-old patent S. mansoni infections with any one of five schistosomicidal agents (Oxamniquine, Praziquantel, potassium antimony tartrate, Niridazole and Hycanthone) resulted in a reduction in the degree of resistance to homologous challenge in the treated animals when compared with the level of resistance to reinfection observed in untreated mice with intact primary infections. Mice challenged five to six weeks after treatment with Praziquantel, Niridazole or Hycanthone demonstrated a lower level of resistance than mice challenged within 10 days of the termination of the chemotherapeutic schedules. Direct comparison of Praziquantel with potassium antimony tartrate indicated that treatment with the former drug allowed retention of a greater level of acquired resistance than the antimonial in the immediate post-treatment period. Resistance to reinfection in Hycanthone-treated mice was not restored by intravenous injection of S. mansoni eggs before challenge.
26 citations
TL;DR: The results indicate that existing infections of 4 or 8 months duration increase the susceptibility to subsequent homologous infections.
Abstract: The effect of existing Brugia pahangi infections on the establishment of a subsequent population was studied using jirds which had pre-challenge infections of 4 and 8 months duration. Necropsies were performed 28 days post-challenge inoculation in order to separate challenge and initial worm populations. The results indicate that existing infections of 4 or 8 months duration increase the susceptibility to subsequent homologous infections. The location of challenge population worms in tissue sites examined did not differ significantly between previously infected and uninfected groups. Previous infections did not affect the early growth of challenge population worms as indicated by their length.
24 citations
TL;DR: A substantial reduction in parasitic faecal egg counts and subsequently mean egg production per worm was observed in all 3 groups of animals receiving spleen cells, serum, or both, from infected donors when compared to their respective control groups.
Abstract: Three groups of golden Syrian hamsters received intraperitoneally either, (1) 1 x 10(7) spleen cells, (2) 0.5 ml. serum or, (3) 1 x 10(7) spleen cells plus 0.5 ml. serum, from donors infected 6 weeks previously with 25 Opisthorchis viverrini metacercariae, one day before and at the same time as challenge with 25 metacercariae. Three groups of control animals received the same quantities of spleen cells, serum or an admixture of both from normal non-infected donors in the same manner followed by challenge with 25 metacercariae. Animals were killed six weeks after challenge, livers and extrahepatic biliary systems carefully removed, and liver worm burdens estimated. Additionally, parasitic egg counts were performed on pooled faeces samples collected one hour prior to death. Animals receiving spleen cells, serum, or an admixture of both, from normal non-infected donors had mean worm burdens of 11.44, 12.00 and 12.66, respectively. Animals receiving spleen cells, serum, or both, from infected donors had mean worm burdens of 9.88, 7.77 and 12.00, respectively. There were no significant differences in mean worm burdens between control and experimental groups. However, a substantial reduction in parasitic faecal egg counts and subsequently mean egg production per worm was observed in all 3 groups of animals receiving spleen cells, serum, or both, from infected donors when compared to their respective control groups. These findings are discussed in relation to adoptive transfer studies performed with other helminths and their possible relevance to naturally acquired immunity is commented on.
24 citations
TL;DR: The suggestion is made that the ascaridoids of sirenians originated from forms in fluviatile lower vertebrates.
Abstract: The two ascaridoids of sirenians, Heterocheilus tunicatus Diesing, 1839, and Paradujardinia halicoris (Owen, 1833), are redescribed. A basic affinity between the two species is indicated in the bilateral structure of the excretory system, the globular ventriculus, long intestinal caecum, and the form of the male tail. The subfamily Heterocheilinae is redefined so as to contain these two genera. It is proposed that the subfamily comprises a natural suprageneric group within the Ascarididae sensu Hartwich, 1974 containing, in addition to Heterocheilus and Paradujardinia, the following genera occurring in freshwater, estuarine and coastal vertebrates: Multicaecum Baylis, 1923; Dujardinascaris Baylis, 1947; Gedoelstascaris Sprent, 1978; Ortleppascaris Sprent, 1978; Brevimulticaecum Mozgovoy sensu Sprent, 1979; Krefftascaris Sprent, 1980. The suggestion is made that the ascaridoids of sirenians originated from forms in fluviatile lower vertebrates.
22 citations
TL;DR: In this paper, the possibility of human infection by certain helminth parasites of domestic animals (e.g., dogs and cats) has been investigated, which may lead to serious problems of public health.
Abstract: Owing to the close association and proximity of man with his domestic animals (in particular the dog and cat), there exist the possibilities of human infection by certain helminth parasites of these animals which may, in some circumstances, lead to serious problems of public health, e.g. encephalitis and granulomatous lesions of the eye caused by toxocariasis (Ashton, 1960; Woodruff et al., 1964).
21 citations
20 citations
TL;DR: A survey was carried out in the abattoirs in Kano (Sudan zone), Kaduna and Zaria (Northern Guinea zone) and Jos (Bauchi plateau zone) to assess the actual prevalence of bovine and porcine cysticercosis, and of hydatid cyst infections in slaughtered food animals as discussed by the authors.
Abstract: A survey was carried out in the abattoirs in Kano (Sudan zone), Kaduna and Zaria (Northern Guinea zone) and Jos (Bauchi plateau zone) to assess the actual prevalence of bovine and porcine cysticercosis, and of hydatid cyst infections in slaughtered food animals.Hydatid cysts were detected in all species of animals slaughtered at the abattoir in the Sudan zone where the prevalence was: camels (55.5%), cattle (14.70%), sheep (11.4%), goats (26.4%). In the Northern Guinea zone, the prevalence was: camels (50%), cattle (0%), pigs (0%), sheep (0.21%) and goats (0.79%). In the Bauchi plateau zone, sheep were found to harbour hydatid cysts, with a prevalence of 1.4%. In the various animal species, hydatid cysts were detected in the lungs, liver and spleen. Fertility rates of the hydatid cysts from various hosts were as follows: camels 94.5%, cattle 7.4%, goats 81.3%, and sheep 59.7%.Cysticercus bovis was detected in slaughtered cattle from the three zones surveyed. Northern Guinea zone had the highest prevalence (4%), followed by Bauchi plateau zone (2.1%) and Sudan (1.9%). C. bovis was detected in the tongue, masseter muscle, heart, diaphragm and the quarters of infected cattle.C. cellulosae was detected in 18.4% and 1.76% of slaughtered pigs examined in Northern Guinea and Bauchi plateau zones respectively. The cysts were found in the tongue, masseter muscle, heart, diaphragm, thigh and fore-limbs. No pigs were available for examination in the Sudan zone.The data obtained in this survey are believed to be a better indication of the rate of infection in the various animal species than data obtained from previous abattoir records.
20 citations
TL;DR: It was found that a higher percentage of the initial inoculum had become established in the younger lambs but that there were no differences between the intestinal distributions of the population in either age group.
Abstract: Two age groups of parasite-free lambs, 4 months and 8 months, were infected with 50 000 infective larvae (L3) of T. vitrinus. A further group of 8 month old lambs were infected with 250 000 L3 T. vitrinus. The lambs were slaughtered at intervals after infection, and the size and linear distribution of their intestinal worm burdens examined and compared statistically. After the 50 000 L3 infections, it was found that a higher percentage of the initial inoculum had become established in the younger lambs but that there were no differences between the intestinal distributions of the population in either age group. After infection with 250 000 L3, the percentage of the larvae retained changed with time. Up to sixteen days post infection, 38% of the larvae administered were retained; thereafter the percentage fell to 22%. The linear distribution of the population in this size of infection showed that a significantly greater percentage was present between 4.8 and 7.2 metres distal to the pylorus when compared with that after infection with 50 000 L3.
18 citations
TL;DR: The prevalence of human taeniasis by age and sex in the 3 ecological zones indicates that males were more often infected, while age factor, Taenia infection was more common up to the age of 40.
Abstract: A retrospective analysis of hospital records in 3 ecological zones of Nigeria was carried out to ascertain the prevalence of human taeniasis, cysticercosis and hydatidosis. The prevalence of Taenia infection in Sudan, Bauchi Plateau and Northern Guinea zones was 0.9%, 0.6% and 0.6%, respectively. The prevalence of human taeniasis by age and sex in the 3 ecological zones indicates that males were more often infected. Because males by habit eat more "suya" (half-grilled beef) than females, they are more likely to be exposed to Taenia saginata cysts. As for age factor, Taenia infection was more common up to the age of 40. Human hydatidosis was recorded only once in the Sudan zone and was not recorded at all in the Northern Guinea and Bauchi zones. Human cysticercosis was not documented in any of the three ecological zones covered by the survey. It is suspected that the low prevalence or the non-documentation of some of these diseases is due to poor diagnostic facilities and inefficient disease-recording system.
17 citations
TL;DR: It is concluded that the ascaridoid nematodes reported from terrestrial and freshwater chelonians are most closely related to species in other genera in terrestrial reptiles, whereas the latter is closest to Gedoelstascaris spp.
Abstract: Ascaridoid nematodes reported from terrestrial and freshwater chelonians are described under two monotypic genera, Angusticaecum and a new genus Krefftascaris respectively. The former genus contains A. holopterum (Rudolphi, 1819) Baylis, 1920 [synonym A. brevispiculum Chapin, 1924], reported in the natural state from testudinid and emydid tortoises in Europe, U.S.S.R., Iran, Brazil and North Africa. The latter genus contains a new species, K. parmenteri, reported from chelid freshwater turtles in Eastern Australia. It is concluded that the former is most closely related to species in other genera in terrestrial reptiles, whereas the latter is closest to Gedoelstascaris spp. in crocodilians. Host-parasite relationships over evolutionary time between ascaridoids and chelonians are discussed.
TL;DR: Adult worms of the rural strain of Wuchereria bancrofti in Peninsular Malaysia obtained from a successful experimental transmission in an immunosuppressed Macaca fascicularis are described for the first time.
Abstract: Adult worms of the rural strain of Wuchereria bancrofti in Peninsular Malaysia obtained from a successful experimental transmission in an immunosuppressed Macaca fascicularis are described for the first time. Although the worms, especially females, were slightly smaller, they were similar in morphology to those of the periodic and non-periodic W. bancrofti previously described.
TL;DR: It was concluded that a host immune response was not involved in irradiation of infective larvae of Nematospiroides dubius and the survival of irradiated N. dubius in vivo was related to the extent of the damage caused at the time of irradiation and was not dependent on additional host parameters.
Abstract: The infective larvae of Nematospiroides dubius were exposed to various levels (0-30 krad) of gamma irradiation by means of a Cobalt 60 source. Groups of mice were infected with these larvae and autopsied 5 weeks later for worm counts. It was found that male worms were more susceptible to irradiation than female worms. In both instances, however, the survival curve on a semi logarithmic plot was characterised by a shoulder at low doses and an exponential component at the higher levels of exposure. No male worms were recovered from mice infected with larvae given more than 12 krad but some female worms were capable of surviving 20 krad. The fecundity of female worms was reduced by 61% at 4 krad and totally ablated at 8 krad. Further experiments demonstrated that the survival of irradiated N. dubius in vivo was related to the extent of the damage caused at the time of irradiation and was not dependent on additional host parameters. Thus neither the number of irradiated worms inoculated nor the sex of the host radically altered the sex ratio or proportion of the worms lost as a result of irradiating the larvae. Furthermore, treatment with cortisone or sublethal irradiation of the host did not increase the proportion of surviving worms. It was, therefore, concluded that a host immune response was not involved.
TL;DR: For the first 66 hours after the subcutaneous injection of rabbits with the infective larvae of Strongyloides papillosus, larvae spread gradually from the injection site to other parts of the body musculature, but by 90 hours, the appearance of larvae in the lungs, trachea and oesophagus suggests that migration is taking place within the circulation.
Abstract: For the first 66 hours after the subcutaneous injection of rabbits with the infective larvae of Strongyloides papillosus, larvae spread gradually from the injection site to other parts of the body musculature. Their number and distribution suggests that they do so by the direct penetration of the tissues as the majority remain close to the site of injection. By 90 hours, however, the appearance of larvae in the lungs, trachea and oesophagus suggests that migration is taking place within the circulation. Although some 90% of the total worms recovered were already established in the intestine by 8 days post-infection, significant numbers of larvae continued to be present in the muscles at 14 and 21 days. Even by 35 days the muscles of 1 of 2 rabbits still contained 43 larvae. This prolonged presence of Strongyloides papillosus in the muscle of rabbits uniformly at the early fourth stage may be analogous to the arrested development of other nematodes. While there is evidence to suggest that immunity is a major factor in the aetiology of arrested development in Strongyloides ransomi, it is an unimportant factor in the case of Strongyloides papillosus in rabbits.
TL;DR: There is a strong possibility of a high rate of faecal contamination of the environments under consideration with Echinococcus eggs, which places the human population at a high risk.
Abstract: Echinococcus granulosus (Batsch, 1786; Rudolphi, 1801) infections in stray dogs were recorded in the Sudan and Northern Guinea zones at a prevalence rate of 6.2% and 1.2% respectively. The parasite was not recorded in any stray dog obtained from the Bauchi Plateau zone, although fewer dogs were examined from this zone. The high prevalence of echinococcosis in dogs reported in the Sudan zone bears a true epidemiological relationship with the high prevalence of cystic hydatidosis recorded for slaughtered livestock within the same locality. There is therefore a strong possibility of a high rate of faecal contamination of the environments under consideration with Echinococcus eggs, which places the human population at a high risk.
TL;DR: In this paper, a series of 3, 5-dibromosalicylanilides, possessing a molecular framework similar to that of niclosamide, was tested for taenicidal activity.
Abstract: Many compounds have been claimed to possess powerful taenicidal activity but only a few are able to remove the tapeworms complete with scolices; accordingly better drugs are still needed. A series of 3, 5-dibromosalicylanilides, possessing a molecular framework similar to that of niclosamide (Gonnert and Schraufstatter, 1960) was tested for taenicidal activity; the most potent anticestode compound was found to be 3, 5-dibromo-2' -chlorosalicylanilide-4' -isothiocyanate (CDRI Compound 77–6). The present communication compares the efficacy of Compound 77–6 with niclosamide, N-(2' -chloro-4-nitrophenyl)-5-chlorosalicylamid (Bayer, power with 75% active ingredient) and praziquantel, 2-cyclohexylcarbonyl-1–3, 4, 6, 7, 11 b-hexahydro-2H-Pyrazino [2–1-a], isoquinoline-4-one (Droncit, E. Merck & Bayer, powder, 100% pure) (Seubert et al., 1977) in rats and mice.
TL;DR: Three cestode species, namelyTaenia taeniaeformis Batsch, 1786, Taenia pisiformis and Mesocestoides litteratus and one nematodes species, Toxocara cati Schrank, 1788, were found in wild cats collected in Grampian region, Scotland.
Abstract: Three cestode species, namely Taenia taeniaeformis Batsch, 1786, Taenia pisiformis (Bloch, 1780) and Mesocestoides litteratus (Batsch, 1786) and one nematode species, Toxocara cati Schrank, 1788, were found in wild cats collected in Grampian region, Scotland. Of the 41 cats examined, 25 were Felis silvestris, 12 were feral Felis catus and four were hybrids of F. silvestris and F. catus.
TL;DR: The present observations show that the indirect fluorescent antibody technique and Cyanogen bromide-activated sepharose coated with soluble antigens prepared from microfilariae and adult worms can be usefully applied for detention of filarial infections.
Abstract: The indirect fluorescent antibody technique has been applied to detect antibody levels in jirds (Meriones unguiculatus) infected with Brugia malayi Sonicated antigens were prepared from microfilariae and adult worms Sonicated microfilariae were found to be satisfactory for this purpose Cyanogen bromide-activated sepharose coated with soluble antigens prepared from microfilariae and adult worms was also used to detect antibodies to Brugia infections The present observations show that these techniques can be usefully applied for detention of filarial infections Antibody titres in infected jirds generally ranged from 1:16-1:256 and were not affected by treatment with diethylcarbamazine
TL;DR: Results showed that eosinophil numbers rose significantly from day 28 to 170 and a maximum was observed on day 80 (41%) in rabbits of the fourth generation, while total globulins increased with decrease in albumin.
Abstract: Necator americanus, originally isolated from man, developed completely in infant rabbits (RSG-1). This infection was serially passed in infant rabbits up to the 6th generation without using any immunosuppressant. Two day old infant rabbits demonstrated a high degree of susceptibility to N. americanus. Studies revealed the retention of worms in the intestine for more than 150 days during which egg production was high. In this experimental model the leukocyte, antibody and serum protein responses due to N. americanus infection were monitored. Results showed that eosinophil numbers rose significantly from day 28 to 170. A maximum was observed on day 80 (41%) in rabbits of the fourth generation. Antibodies to N. americanus were detectable in infected rabbits by counterimmunoelectrophoresis using third stage larval antigen (Rabbit strain). Generally, total globulins increased with decrease in albumin. Serum protein increase was associated with alpha-2, beta and gamma globulin components.
TL;DR: Quantitative examinations for the distribution and density of microfilariae were carried out on male Guatemalan onchocerciasis patients by taking 6 or 13 skin biopsies each from 74 subjects; it was found that microfiliariae were distributed most frequently on the iliac crest and secondarily in the scapular region; higher detection rates and greatermicrofilarial densities were seen in these areas.
Abstract: Quantitative examinations for the distribution and density of microfilariae were carried out on male Guatemalan onchocerciasis patients by taking 6 or 13 skin biopsies each from 74 subjects. We found that microfilariae were distributed most frequently on the iliac crest and secondarily in the scapular region; higher detection rates and greater microfilarial densities were seen in these areas. From these results we recommend the taking of biopsies from both of these anatomical regions so as to avoid false negative cases. The infected patients were classified into 3 groups (light, moderate and heavy infections) on the basis of the numbers of negative skin snips out of the 13 biopsies taken. In heavy infections, a higher densities of microfilariae were detected in the head and neck regions, as compared with the densities in the lower extremities (calf). The high concentration of microfilariae in these regions is of importance in relation to the development of eye lesions and/or transmission. Of patients who had microfilariae in the anterior segment of the eye some had negative skin biopsies frm the outer canthus, retroauricular region and neck.
TL;DR: The presence of precipitin antibody and soluble circulating antigen was demonstrated in sera of individuals with clinical filariasis by counterimmunoelectrophoresis, suggesting that 5.7% of cases diagnosed as bancroftian filARIasis by parasitological examination can be increased to 62.8% by serological means.
Abstract: The presence of precipitin antibody and soluble circulating antigen was demonstrated in sera of individuals with clinical filariasis by counterimmunoelectrophoresis. Antigens derived from Litomosoides carinii and antisera raised in rabbits to the adult worm antigens were used for the detection of antibody and antigen in human sera. Of 35 subjects, 2 had microfilariae in the peripheral blood, 9 soluble circulating antigen, 19 antibody in sera, and 6 had both antigen and antibody. It suggests that 5.7% of cases diagnosed as bancroftian filariasis by parasitological examination can be increased to 62.8% by serological means.
TL;DR: Dauerlarvae of Pelodera strongyloides recovered from two species of lemmings trapped at Eskimo Point and cultured on agar medium with E. coli survived freezing temperatures, short periods of desiccation and prolonged periods without food.
Abstract: Dauerlarvae of Pelodera strongyloides, recovered from two species of lemmings, Dicrostonyx groenlandicus (Traill) and Lemmus trimucronatus (Richardson) trapped at Eskimo Point, N.W.T, were cultured on agar medium with E. coli. Development from egg to adult stage was followed. Eggs hatched between 22 and 26 hours at 22 degrees C. The first moult occurred 24 to 28 hours after the eggs hatched, the second at 40 to 48 hours, the third at 60 to 64 hours and the fourth at 84 to 88 hours at 22 degrees C. Adults lived approximately 5 to 6 days and females oviposited for 2 to 3 days during this time. All stages were measured and described. The effect of temperature on development was examined. Dauerlarvae survived freezing temperatures, short periods of desiccation and prolonged periods without food.
TL;DR: Regular monthly examination of lungs of donkeys revealed that in Morocco Dictyocaulus arnfieldi infection is present throughout the year with an annual incidence of 47.8% and although this relation was significant, cases with high worm burden and no larvae in faeces were observed.
Abstract: Regular monthly examination of lungs of donkeys, with a total of 423 in a year, revealed that in Morocco Dictyocaulus arnfieldi infection is present throughout the year with an annual incidence of 47.8% (range 30 to 62.2%). The monthly mean number of worms per animal varied from 19.4 to 69.6 (annual average 39.5) with a maximum of 1000 worms in a donkey. October, February and June are the months when peaks of infections were observed. The ratio of worms in lungs to larvae per g in faeces (L.P.G.) ratio varied from 1:0.57 to 1:1.33 (average 1:0.97) and although this relation was significant, cases with high worm burden and no larvae in faeces were observed.