The present study attempted to induce an acquired immunity against the dog hookworm, Ancylostoma caninum. The experiments were carried out to demonstrate and confirm whether an acquired resistance could be developed by the repeated lowgrade infections with the infective larvae of A. caninum in the abnormal host of mouse. In order to determined the distribution of hookworm larvae in the lungs and liver of mice after inoculation of infective larvae, 54 mice were inoculated with 1,000 larvae and sacrificed in batches daily up to 9 days after infection. It was found that in all cases the average total number of larvae recovered from the lungs and liver increased at 48 hours after infection, then began to decrease and reached 0 to 1 at the 9th day after inoculation. One hundred fifteen mice were immunized 2 or 4 times at 7 day intervals with 50 infective larvae, followed by challenging infection with 1,000 infective larvae and killed in batches at 48 hours after challenge. The interval between challenge and last immunization were from one to four weeks for each group. Sixty mice as the controls were given only challenging infection without previous immunization infection. Induced resistance was evaluated by the rate of recovery or the average total number of the larvae recovered from the lungs and liver in the challenged mice, compared with the controls. It was noted that the rates of recovery in the controls were twice or nearly higher than those in the previously infected mice in all instances and these remained low for the first 7 day intervals between the last immunizing infection and challenge, then gradually increased. From the above observations it is highly suggested that an acquired resistance can be produced by repeated previous infections with the larvae of A. caninum, even in low grade, in the abnormal host of mouse, and evaluated by the rate of recovery of the larvae after challenge.
parasitology-helminth-nematode-Ancylostoma caninum ; immunology ; recovery rate

No significant difference was noted in canine hookworm infection due to hormone influence between the control group and the gonadectomized rats which were sacrificed 17 days after gonadectomy and 7 days after the infection. However in the rats which were infected 20 days after oophorectomy a significant difference was thought to be present in this group(176 +- 12.9 larvae/rat) compared with the control group (138 +- 21.2 larvae/rat). On the other hand, in the castrated group the number of larvae (138 +- 37.1 larvae/rat) was less than that in the control group (208 +- 43.4 larvae/rat). In the estrogen-injected male and female groups, there were no difference compared to the control, but the testosterone-injected groups of males and females showed more susceptibility to infection by A. caninum than in the control group. The Capillaria hepatica infection to the castracted host showed no significant difference between the gonadectomized and the control group. (oophorectomy; 214 +- 28.0), castration; 250 +- 36.5 and control; 191 +- 58.2 and 270 +- 30.1 adults/rat). Concerning the influence of the host's sex hormone on egg production of canine hookworm, there was a significantly decreased egg production in castrated dogs(6,578 +- 664.0 egg per gram) compared to the control dogs(9,711 +- 1,322.3 egg per gram). The same results were observed in vitro test. In the host, the susceptibility to hookworm infection was reduced in castrated rats, while oophorectomy group had a little or no effect. In the favorable or unfavorable hosts, testosterone gave the tendency of increasing susceptibility of the host to infection, while estrogen did a little or no effect.
parasitology-helminth-nematoda ; hookworm ; estrogen ; testosterone ; rat ; dog Ancylostoma caninum ; Capillaria hepatica ; gonadectomy ; estrogen ; testosterone

The eggs and rhabditoid larvae of canine hookworm were irradiated with ultraviolet rays for one hour at a distance of 10, 20, 30, and 40 cm. The infective stage larvae of the same parasites were irradiated for l, 3, 5 and 14 hours from the same distances. The infective larvae were also exposed under direct sunlight for l, 2, 3 and 4 hours. Parasites: Ancylostoma caninum was used. Eggs were collected in vitro from female adult worms. The worms were kept at 37 C in petri-dish filled with Kreb's Ringer solution. There was an average of two cell stages, and they were used as early as possible before the morula stage. Rhabditoid larvae were obtained by culture of the above eggs for twenty-four hours in 25 C incubator. The larvae reached the infective stage in seven days culture at the same condition. Irradiation of Ultraviolet Ray: Kingston ultraviolet light (100 volt, 10 watt, 50 cycles, 0.230 ampere) was used. The potential U.V.R. power was 1.8 watts. The distances between the material and the light were 10, 20, 30 and 40 cm at a temperature of 25 C in each case. The samples were smeared on the tile in order to keep them in saturated moisture. Fully wetted ten ply gauze was laid underneath the tile. The tile was surrounded by 2x5 cm rectangular piece of glass in order to prevent the spread of the larvae to the outside. All of the samples received irradiation for one hour and were cultured for a period of seven days. The hatching of the egg and the development of the larvae were observed. For the purpose of the study, the infectivity and pathogenicity of the irradiated samples, were inoculated into mice orally. The lungs, livers and carcass were examined three days after the infection. A routine pathological examination of the organs was also carried out. In order to study the eggs productivity, the larvae were given to the proper host, dog. The eggs in the feces were examined from three to 6 weeks after infection, both quantitatively and qualitatively. As a supplementary experiment, the infective larvae of canine hookworm were exposed four hours under direct sunlight (September 25), and the infectivity and pathogenicity of the host were examined. Hatching, development and infectivity of irradiated eggs: Hatchability of the irradiated group for one hour according to the distance from the light to the sample were 48.0 percent at 10 cm, 60.3 percent at 20 cm, 85.2 percent at 30 cm and 88. 2 percent at 40 cm respectively. None of them developed to the infective stage. They remained rhabitoid for several days and were destroyed. None was found alive in the host. 93.0 percent of the control group hatched and developed to the infective stage. Development and infectivity of irradiated rhabditoid larvae: None of the irradiated group reached the infective stage. Under irradiation they coiled and died soon after straightening out again. Only the group irradiated at the distance of 40cm survived for six days. They finally granulated. There was no manifestion of irradiated larvae alive in the host tissue. Life span, infectivity, pathogenicity and egg-productivity of the irradiated infectve stage larvae: All were destroyed in the group of fourteen hours irradiation at 40 cm distance. Thirteen precent survived in the five hours irradiation group at the same distance. The survivability of larvae was reduced by the period of irradiation and at the shortest distance. The infectivity to mice was only 0.8 percent at 30 cm, and 8.2 percent at 40 cm in the three hour irradiation group. The recovery of the infected larvae from the host tissues was reduced as the irradiation period was increased and the distance shortened. The pathogenicity was paralleled with the vitality of the irradiated larvae. From the groups of one hour irradiation and ten cm distance, three hour irradiation and ten to thirty cm distance, the egg-productivity was all negative. But as the irradiation period decreased and the distance lengthened the egg-productivity tended closer to normal. The infective stage larvae which were exposed to direct sunlight were destroyed within three hours, but survived 81 percent in the one hour exposure group and 20 percent in the two hour exposure group. The summary of the results is as follows: The hatching of eggs was reduced to half for one hour irradiation at the ten cm distance. Even hatched larvae did not develop to infective stage. Infectivity was inhibited by the irradiation to at the ten cm distance for one hour. About ten percent of the irradiated infective stage larvae were recovered from the infected animal among the group of 40 cm distance for one hour. The egg-productivity became lower in the group of one hour irradiation at 40 cm distance. The pathogenicity of the irradiated group was mild compared to the control group. The direct sunlight destroyed the infective stage larvae within three hours. In general, the ultraviolet ray showed the inhibitory action in the hatching, development, pathogenicity and egg-productivity of the hookworm. The grade was paralleled with the period of irradiation and reversed to the distance between the light and samples.
parasitology-helminth-nematoda-hookworm-Ancylostoma caninum ; irradiation ; development ; infectivity ; ultraviolet ray

One hundred and two stray dogs in Ejungbu City of Kyunggi-Do, Korea were examined to reveal out the degree of natural helminthic infection of small intestine. Helminthes were collected at autopsy, by scraping the intestinal contents. The collected worms were classified by their morphological characteristics. Out of 102 examined, 72 dogs were infected with any helminthes. The common helminthes were Dipylidium caninum (47 percent), Ancylostoma caninum (26 percent), Toxascaris leonina (16 percent) and Toxocara canis (13 percent). Taenia pisiformis (9 percent), Echinostoma hortense (4 percent), E. cinetorchis (2 percent), Spirometra mansoni (2 percent) were also found. One dog was incidentally found to be infected with Clonorchis sinensis. The prevalence of Toxascaris leonina was relatively high in this study over Toxocara canis, and its significance was discussed. Dogs were firstly described as the reservoir hosts of Echinostoma hortense and E. cinetorchis in Korea.
parasitology-helminth-nematoda-trematoda ; cestoda ; dog ; epidemiology ; morphology ; Dipylidium caninum ; Ancylostoma caninum ; Toxascaris leonina ; Toxocara canis ; Taenia pisiformis ; Echinostoma hortense ; Echinostoma cinetorchis ; Spirometra mansoni ; reservoir host ; intermediate host

In order to confirm whether the migrating larvae of parasites could carry pathogenic organisms into liver and cause hepatitis, a series of experiments has been carried out. Clonorchis sinensis: Recovery rate of larvae in the abdominal cavity of rabbits: One to seven days after the administration adolescariae were recovered from the abdominal cavity in less than l percent of the total number of metacercariae given. Generally, 1-6 larvae were found from each animal which was given 900-1,000 metacercariae, though many larvae were already found in the common bile ducts or remained still in intestine. Fate of Clonorchis sinensis in abdominal cavity: The young or mature worms which were introduced directly into the abdominal cavity were examined l5, 32, 40 and 42 days after the inoculation. Several larvae were found on the surface of liver in four animals. All the worms on the surface of the liver were dead and the biopsied liver tissues on the area where the worms were attached showed no pathological changes. Two of them were between bile duct and liver tissue but pus cell infiltration surrounding them was observed. In every case, pus cell infiltration was found in the peripheral portion of the liver and pus nodules on the surface of intestine and mesentery. The nodule in the intestinal wall contained the eggs of Clonorchis sinensis. Two worms in the abdominal cavity were still alive. From the above results it is suggested that the larvae of Clonorchis sinensis were capable of penetrating the intestinal wall and reaching the organs in the abdominal cavity and surviving for l5-42 days, but they were unable to penetrate the organs. No bacterial flora appeared from the lesion by culture method. Fate of Clonorchis sinensis which was inoculated into the peripheral region of liver: Small abscess was observed at the same area. Microscopically, the area became edematous and the vessels in the peripheral region were dilated. The parasites became necrotic and amorphous. Pathologically the lesions appeared as eosinophilic masses and neutrophile leukocytes were infiltrated surrounding the masses. In some cases, the dead worms were found apart from the original place of inoculation but no leukocyte infiltration was found. There was linear infiltration between the original site and the portion where the dead worm was found. The distance from the capsule varied from 0 to 4 mm. Sometimes, the eggs of Clonorchis sinensis were also found. In all cases, there were no living worms in liver tissues and hepatic ducts. In all case,. the bacteriological examination was negative. Do clonorchis sinensis transfer the microorganism? Five adult worms of clonorchis sinensis were incubated in the saline solution containing Staphylococcus aureus. The intestinal contents of these worms were cultured in the Nutient-agar plate and examined by Methylene Blue and Gram's stain. The area of liver tissue where the Clonorchis sinensis were inoculated showed no inflammatory changes after the 3 days of inoculation but no living Staphylococcus aureus was found in the culture media with which the pieces of liver tissues were smeared. Hookworm: Cutaneous infection: Four to eight days after the cutaneous infection of Ancylostoma caninum, the mice were sacrificed. Grossly, there was no abnormal finding in liver. The pieces of liver tissues were smeared on the Nutrient-agar plate, and cocci were found in four out of six examined. The microorganism were confirmed as the same species of Diplococcus pneumoniae which were grown in the hookworm culture media. Oral infection: 1,000 filariform larvae of Ancylostoma caninum were given orally. 24 hours later, the mice were sacrificed and the pieces of liver tissue were smeared on the Nutrient-agar plate. After 50 hours at 36 C, the bacterial colonies were examined bacteriologically. Staphylococcus albus was found from two out of four samples. Grossly there was no abnormality on the surface of liver, but microscopically there were spots like microabscesses which were infiltrated by leukocytes. The larvae were also found from other portions of liver tissues and they were surrounded by yellow colored material. In another experiment, a combination of Ancylostoma duodenale and Staphylococcus aureus was fed to mice. The mice sacrificed five days after the oral administration of Ancylostoma duodenale cultivated in the media containing Staphylococcus aureus. The liver pieces were examined routinely. The larvae cultivated in normal tap water which contained no Staphylococcus aureus was used as control. In the experimental mouse, the cocci appeared in the liver. Pathologically, microabscesses infiltrated with neutrophile leukocytes were found, but there was no manifestation of inflammatory change due to Staphylococcus aureus. There was only mechanical trauma due to the larvae penetration. Haemorrhage appeared only where the larvae were found.
parasitology-helminth-trematoda-nematoda ; Clonorchis sinensis ; Ancylostoma caninum ; pathogenicity ; Staphyllococcus aureus ; Staphyllococcus albus ; Diplococcus pneumoniae ; rabbit-liver

Helminthic zoonoses are of significant importance to the public health and to the socioeconomic consequences especially in lost-meat, animal products and animal labor. For past several decades in Korea, it has been recognized that endoparasitic infections among domestic animals are extremely common and many of the helminth parasites of man have been acquired from, or are shared with domestic animals. However, there was no survey of a nationwide scale on the prevalence of animal helminthiasis; and control measures are also not satisfactory. Furthermore, because of the remarkable increase in the demand, number of domestic animals and pets is rapidly increasing in these days. Therefore, an extensive study on zoonotic helminths was carried out from July 1980 throughout August 1981 to understand the present status and parasite-host relationship from the epidemiological viewpoont. A total of 13,685 fecal specimens of cattles, sheeps, pigs, dogs and cats was collected from 26 localities in the country. The specimens were examined by formalin-ether centrifugal sedimentation technique. The results are summarized as follows: Of 13,685 specimens examined, 9,808(71.7 percent) were positive for helminth parasites. The positive rates were 99.0 percent in cattles, 86.5 percent on sheeps, 85.4 percent in pigs, 35.4 percent in dogs, 15.1 percent in cats. Single infection showed the highest rate (60.0 percent), and double infection(27.5 percent), triple(8.1 percent), quadruple(2.8 percent), quintuple(1.5 percent) and hexad(0.1 percent) were in decreasing order. In the present study, 18 species zoonotic helminths were found: 11 nematodes, 6 trematodes and 1 cestode. According to province, Cheju revealed the highest rate 84.8 percent, then Kyungnam 77.5 percent, Jeonnam 75.6 percent, Jeonpuk 75.4 percent, Kyonggi 75.2 percent, Chungnam 71.7 percent, Chungpuk 70.6 percent and Kangwon 64.2 percent were in decreasing order and Busan and Seoul showed 70.4 percent and 58.1 percent, respectively. Rural area showed slightly higher rate (74.7 percent) than urban area (68.5 percent), and rates of mountainous area (70.4 percent) and plain area (71.1 percent) are very similar. According to animal, helminths species and positive rates appeared in: Cattles: 6 nematodes and 3 trematodes; Strongyles 26.4 percent, Neoascaris vitulorum 24.1 percent, Trichuris ovis 12.0 percent, Nematodirus sp. 6.3 percent, Srongyloides papillosus 5.1 percent, Capillaria bovis 0.02 percent, Paramphistomum sp. 41.5 percent, Fasciola hepatica 33.2 percent and Eurytrema pancreaticum 29.7 percent. Sheeps: 3 nematodes and 2 trematodes: Strongyles 33.0 percent, S. papillosus 26.9 percent, Nematodirus sp. 14.6 percent, F. hepatica 31.7 percent and E. pancreaticum 19.6 percent. Pigs: 5 nematodes and 2 trematodes: Strongyles 43.1 percent, Ascaris suum 29.0 percent, Metastrongylus apri 20.3 percent, Trichuris suis 14.0 percent, Strongyloides ransomi 12.1 percent, Clonorchis sinensis 1.4 percent and Paragonimus westermani 0.9 percent, Dogs: 4 nematodes and 3 trematodes and 1 cestode: Toxocara canis 14.4 percent, Trichuris vulpis 9.5 percent, Ancylostoma caninum 8.0 percent, Toxascaris leonina 4.0 percent, C. sinensis 2.4 percent, Metagonimus yokogawai 1.3 percent, P. westermani 0.8 percent and Spirometra sp. 0.9 percent, Cats: 2 nematodes, and 3 trematodes and 1 cestode: Toxocara cati 7.7 percent, Ancylostoma tubaeforme 3.1 percent, C. sinensis 1.9 percent, P. westermani 1.4 percent, M. yokogawai 1.2 percent and Spirometra sp. 0.7 percent.
parasitology-helminth-nematoda-trematoda-cestoda ; cattle ; sheep ; pig ; dog ; cat ; epidemiology ; zoonosis ; Fasciola hepatica ; Eurytrema pancreaticum ; Paramphsitomum sp. ; Neoascaris vitulorum ; Trichuris ovis ; Strongyloides papillosus ; Nematodirus sp. ; Capillaria bovis ; Clonorchis sinensis ; Paragonimus westermani ; Ascaris suum ; Trichuris suis ; Strongyloides ransomi ; Metastrongylus apri ; Spirometra sp. ; Metagonimus yokogawai ; Toxocara canis ; Toxocara leonina ; Ancylostoma caninum ; Trichuris vulpis ; Ancylostoma tubaeforme ; Strongyles

This study was undertaken to evaluate the present status of hookworm infections in Korea from October 1976 through September 1978. The stool specimens of 5,632 persons(male 3,689: female 1,943) collected from primary and middle schools, foundling asylums, and the general populations of various parts in Korea were examined The methods employed were brine floatation technique for the prevalence rate of hookworm infections, Kato's cellophane thick smear technique for the other helminthic infections, and Stoll's dilution egg counting technique for the intensity of hookworm infections. Ancylostoma duodenale and Necator americanus infections were classified by polyethylene tube coproculture method and by the evacuated adult worms after administration of anthelmintics against the patients infected with hookworms. The following results were obtained in this study. The prevalence rate of hookworm infections in rural area was higher than in urban area in the ratio of 2.4:1. And in the age group of over 20, the prevalence rate in significantly higher than that in urban area in the ratio of 5.8:1. In the urban area, difference in the prevalence rate of hookworm infections between the age group of over 20 and that of under 19 was not observed. But in the rural area, the ratio of the prevalence rate between the age group of over 20 to that of under 19 was 8:1. The prevalence rate of hookworm infections in female was higher than that in male in all age group except the age group of under 9 and 20-29. The ratio of the prevalence rate between female to male was 1.5:1 in total population. The area which showed the mean E.P.G. of over 1,000 was not found and almost all of the patients who were infected with hookworms gave the mean E.P.G. between l-999. Necator americanus was newly found in Dangjin Gun, Boseong Gun, Habcheon Gun and Weonseong Gun. In these 4 newly found areas, Dangjin Gun and Boseong Gun showed the composition rate of 25.5 percent and 83.4 percent respectively.
parasitology-helminth-nematoda ; hookworm-epidemiology ; Ancylostoma duodenale ; Necator americanus

The anthelminthic effect of phenylene-diisothiocyanate-(1,4)(=Jonit) was studied on the eighty three cases infected with Ancylostoma duodenale. For the evalution, the number of eggs per gram of feces on all these cases was calculated before treatment. The follow-up for the egg reduction was carried out over a period of four weeks. The sixty-seven cases were treated in dosage schedule of 3 x 100 mg every 12 hours. The cure rates - the rate of negative conversion of eggs - was 74.6 percent and the total egg reduction rate of 94.2% was obtained. The ten out of 14 cases treated in the dosage schedule of 2 x 100 mg every 12 hours showed 100% egg reduction and the cure rate was 71.4%. In this group. the total egg reduction rate of 78.6% was noted. In the dosage schedule of 2 x 50 mg every 12 hours the remainder, two out of total 83 cases showed 100% egg reduction. Side effects were observed as being mild, 51 cases (56.6%) were free of side reactions and the most frequently noted side effects were vertigo and diarrhea. From the above results, it is concluded that Jonit is an effective antheminthic against Ancylostoma duodenale and its effectiveness is quite equivalent to that of a known recommended anti-hookworm products.
parasitology-helminth-nematoda ; Ancylostoma duodenale ; chemotherapy ; phenylene-diisothiocyanate ; Jonit

Present trial was carried out to evaluate the anthelmintic efficacy of oxantel/pyrantel tablets against intestinal nematode infections, and to determine the efficacy of oxantel tablels against Trichuris infection. A total of 34 subjects with the mixed infections were treated with oxantel/pyrantel tablets (100 mg/tablet each) in a single dose of 15 mg/kg body weight, and another group of 22 Trichuris infected cases received oxantel pamoate tablets (125 mg/tablet) in a single dose of 15 mg/kg. All stool examinations were done before the treatment and 3 weeks after the treatment. The cellophane thick smear (Kato's technique) and Stoll's dilution egg counting method were employed. The results of the trial were summarized as follows: The cure rates (egg negative conversion rates) and egg reduction rates for oxantel/pyrantel tablets were 85.3 percent and 97 percent in trichuriasis, 100 percent each in ascariasis and ancylostomiasis. The oxantel tablet treated group demonstrated a cure rate of 90.9 percent and an egg reduction rate of 96.3 percent in the treatment of Trichuris. There were no detectable objective and subjective side effects in this trial. Both oxantel/pyrantel and oxantel pamoate tablets were readily accepted and well tolerated.
parasitology-helminth-nematoda ; Enterobius vermicularis ; Ancylostoma duodenale ; Trichuris trichiura ; chemotherapy-oxantel/pyrante ; oxantel pamoate

A new anthelmintic, amidantel(Bay d 8815), an acetylated p-amino-phenyl-acetamidine was tried in 140 patients with Ancylostoma duodenale and other helminth infections. In the first trial, each 16 cases in 64 patients with A. duodenale were treated with 3.0, 6.0 and 9.0 or 10.0 mg/kg body weight of amidantel including placebo control. Another 76 patients infected with hookworms and other helminths were treated with 5.0, 6.0 and 8.0 mg/kg body weight of amidantel in the second trial. In order to assess the efficacy and safety of the drug, follow-up examination by repeated and replicated examinations over three consecutive days were performed at 14 to 16 days and 28 to 30 days after treatment, And complete laboratory studies including ECG were carried out before and one day after the medication. In the results, it was confirmed that amidantel is very effective against A. duodenale as well as Ascaris lumbricoides. With regard to dosage, a single dose of 6.0 mg/kg body weight of amidantel was found to be the most effective and well tolerated than the other dosages employed. In a single dose of 6.0 mg/kg body weight the cure rates were 93.8 and 96.6 per cent for A. duodenale infection and 90.9 and 93.1 per cent for ascariasis in the first and second trials respectivley. Relatively significant activity was also observed against Necator americanus at the dosages employed, however it was not superior to other drugs currently use. No significant activity was noted against Trichuris trichiura. Side effects including headache, nausea, dizziness and abdominal discomfort were usually mild and transient. No significant changes attributable to therapy were observed in hematology, blood biochemistry and urinalysis as well as ECG.
parasitology-helminth-nematoda ; amidantel ; acetylated p-amino-phenyl-acetamidine ; chemotherapy-Ancylostoma duodenale ; Necator americanus