No abstract available.
Paragonimiasis ; Paragonimus westermani ; Stroke

The present study was performed to observe the ultrastructure of the integument of adult Paragonimus westermani. Dogs experimentally infected with 60 metacercariae of P. westermani were autopsied 4 months after the infection. Adult P. westermani were extracted from the dogs and the fine structure was studied by means of scanning and transmission electron microscope. The findings are as follows: Scanning electron microscopic findings showed that the spines and the papillae are distributed at whole body surface but the well developed spines or papaillae are shown around the oral suckrer and ventral sucker. At the end of the body, excretory pore was found, the shape was irregular. Transmission electron microscopic findings showed that plasma membrane, tegument, basal lamina, connective tissue, circular muscle layer, longitudinal muscle layer, nerve axon and tegumental cell were observed. In higher magnification, plasma membrane and bar-shaped granules were found at the outer surface of the tegument.
parasitology-helminth-trematoda ; Paragonimus westermani ; electron microscopy

The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate host of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were excysted and examined with light, scanning and transmission electron microscopes for morphological features. On the surface of metacercariae, three types of sensory papillae were identified. Large domed papillae (3-5 micrometer), which were covered with wrinkled plasma membrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12-13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae (2-3 micrometer), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30-32 pairs) and dorsal surfaces (40-42 pairs). Ciliated papillae (0.8-1.5 micrometer) were observed about 5-6 in number around the oral sucker and 3-5 pairs each on the ventral and dorsal surface of the body. Single pointed spines covered the entire surface of the body except around the excretory pore. Spines on the anterior part of the body were 0.9-2.0 micrometer in length and 45-55/100 square micrometer in number, and were gradually reduced in length (0.4-1.4 micrometer) and in number (12-27/100 square micrometer) toward the posterior part. The body wall of P. westermani metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave (0.15-0.55 micrometer) and spherical (0.08-0.16 micrometer) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and ribosomes, were observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.
parasitolgy-helminth-trematoda ; Paragonimus westermani ; electron microscopy

Metacercariae were found from 6 samples among 4,382 Parlemon nipponensis which were caught at Podu, Kohung, Korea. The metacercaria was inclined as a larval stage of Paragonimus westermani by following reason: Semisulcospira libertina was the only one species which lives in Podu area. No other metacercaria except Paragonimus westermani were found from the craw or cray fish which were caught in the endemic aera. Metacercariae, ovary, testes and cuticular spines resmbled the characteristics of Paragonimus westermani, which have been described by previous workers.
parasitology ; helminth ; trematoda ; Paragonimus westermani ; metacercaria ; epidemiology

This survey was undertaken to determine the recent prevalence of lung fluke, Paragonimus westermani, in the three localities of Wiseong county, Kyungpook Province, Korea and to compare the prevalence among the residents in the same areas between 1924 and 1980. The three localities, Ku-seong, Sam-chun, and Um-ji villages (dong) have been known as the endemic areas of Paragonimus westermani. The surveys were made on the general population. They were examined using intradermal test with Paragonimus westermani antigen, and the diagnosis of paragonimiasis was made depending on the positive intradermal reaction. The sputum examination could not be performed beacause the residents were inaccessible. The prevalence of Paragonimus westermani among the residents in the three communities varied from 1.4 percent to 7.9 per cent, with an average of 4.0 per cent. Whereas, the average reported by Ichinomiya in 1924 was 4.7 percent. There are no significant differences in the sex and age specific rates of infection between 1924 and 1980. With the abundant density of Semisulcospira snails and crayfish in Sam-chun stream and the high rate of infection with Paragonimus westermani among the residents in the village, it is found that Sam-chun village, one of the three localitied in Wiseong county, where Ichinomiya (1924) surveyed, was still the endemic focus of Paragonimus westermani.
parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; epidemiology

A case of Paragonimus westermani cysts found deep inside the spleen is described. This spleen was from a dog that was experimentally infected via oral route with a hundred metacercariae and was killed 3 months after. At autopsy, beside the usual lesions due to Paragonimus in the lungs, the spleen was the site of multiple parasitic cysts. The involved spleen was slightly enlarged and showed an area of hemorrhagic dome on the capsular surface. There found a total of 8 adult worms in four well demarcated parasitic cysts containing a pair of worms each. All of them were found deep into the splenic parenchyme and were surrounded by a well formed connective tissue wall, thus resembling the features of the pulmonary paragonimiasis. The route of infection was assumed to be a direct transcapsular invasion during the phase of larval migration.
parasitology-helminth-trematoda ; paragonimiasis ; Paragonimus westermani ; dog ; case report ; spleen

Among 11,005 inhabitants(61% of total population) surveyed in 13 villages of Che Ju Island in 1964, were identified as paragonimiasis patients, of these 1,355 were treated with 40 mg/kg body weight of bithionol for 10-15 doses. The purpose of the study was to test whether mass chemotherapy of the human host may provie an answer for the control of paragonimiasis in an area where the human host is main source of infection to the intermediate hosts. The efficacy of the mass chemotherapy as control program was measured by the acceptance of the survey and treatment by the inhabitants, the efficacy and the toxicity of the drug applied, and the influence of the infection rates of the intermediate hosts. The acceptance of the survey and the treatment was not entirely satisfactory: an estimate based on data suggests that only fifty to sixty percent of all cases infected were detected, and 93% of detected cases were treated in the primary program. All cases detected during the follow up survey, which could not cover whole population, were treated. The efficacy of bithionol was excellent when the treatment was completed. 40 mg/kg body weight for 10-15 doses was sufficient to turn the sputum egg-negative except in a few cases infected heavily that needed 20 doses. Side reactions were generally mild; the most frequent reaction was gastrointestinal; which spontaneously subsided within a few to several days. The infection rate of intermediate hosts started to decrease from the third year of the mass treatment with a pattern of gradual drop. Follow up studies on general population in three and four years of the mass treatment also showed markedly decreased prevalence of paragonimiasis by intradermal test and sputum examination. It is concluded that a complete mass chemotherapy with bithionol in an area where human is the main source of infection to the intermediate hosts can be the answer for control of paragonimiasis.
parasitology-helminth-trematoda ; Paragonimus westermani ; epidemiology ; chemotherapy ; bithionol

In this study the authors observed the status of water contamination by crayfish, Cambaroides similis, either alive or dead infected with Paragonimus westermani. The crayfish used as materials were infected heavily with metacercariae of Paragonimus westermani. The live crayfish were kept in water for a long time, and then the sediments of the water were examined to find out whether or not the liberation of the metacercariae from the body of the crayfish had caused contamination of the water with metacercariae. Killed crayfish were also preserved in water for some time. Physical stimuli in terms of mederate degree of shaking were added to the preserved water once a day and half amount of the water was replaced with tapped water of same temperature everyday. Status of the decay of the crayfish, liberation of the metacercariae from the body of the crayfish or contamination of the preserved water by the metacercariae, and numbers of metacercariae harboured in the body of the crayfish were examined everyday. The fate of the metacercariae liberated from the crayfish into water was also observed. Status of the decay of the crayfish, liberation of the metacercariae from the body of the crayfish or contamination of the preserved water by the metacercariae, and numbers of metacercariae harboured in the body of the crayfish were examined everyday. The fate of the metacercariae liberated from the crayfish into water was also observed. The results of this study can be outlined as follows: No metacercaria was detected in the water which contained live crayfish infected with Paragonimus westermani. The preserved water with dead or killed crayfish was found to be contaminated by the metacercariae of Paragonimus westemani, which had been caused by the decay and dispersion of the flesh of the crayfish The liberated metacercariae survived for 10 days in the water at 21-27 C. The liberated metacercariae were found to be sinking into water of s.g. 1.000 with average velocity of 35.8 cm per minute.
parasitology-helminth-trematoda ; Paragonimus westermani ; epidemiology ; crayfish ; Cambaroides similis

A total of 52 paragonimiasis patients was treated with praziquantel at three dose levels: 21 patients received 3 x 25.0 mg/kg bwt on a single day, 21 patients were treated with 3 x 25.0 mg/kg for 2 consecutive days and 10 patients were treated with the same dose for 3 consecutive days. Follow-up examination were carried out at monthly up to 4 months (120 days) after treatment. Fifteen (71.4%) out of 21 patients who received the drug 3 x 25.0 mg/kg bwt on a single day were parasitologically cured. Eighteen (85.7%) out of 21 patients who received 3 x 25.0 mg/kg bwt for 2 consecutive days were also cured. Six and 3 of uncured cases in each above groups were treated again with doses of 3 x 25.0 mg/kg bwt for 2 or 3 consecutive days. Two (consisting each one in each group ) of nine retreated cases were failed in parasitological cure. Therefore the overall cure rates of 95.2 % (20 out of 21 cases) in each group were finally obtained. On the other hand, in 10 patients who received 3 x 25.0 mg/kg bwt for 3 consecutive days, complete cure was obtained at 4 months follow-up examinations. Praziquantel is well tolerated and side effects consist particularly of mild and transient headache and dizziness. There was no great difference between the three dosage groups. Extended hematological and biochemical tests, and urinalysis, revealed no abnormal findings which could be related to the compound after therapy. The disappearance of precipitating bands of immunoelectrophoresis together with the disappearance of abnormal shawdows in chest X-ray after treatment gave a potent proof on assuring the cure of paragonimiasis.
parasitology-helminth-trematoda ; chemotherapy ; praziquantel ; paragonimiasis ; Paragonimus westermani

Recent results of mass stool examination for parasitic infections revealed 0.01-0.0001 percent of Paragonimus egg positive rate in Seoul school-children. This survey was carried out to understand the infection status of intermediate hosts and their relations to human paragonimiasis in Seoul. Twelve mountainous streams in the outskirts of Seoul were surveyed. From all streams, Semisulcospira libertina, the snail intermediate host was not detected. From 7 streams 132 crayfishes, Cambaroides similis, the second intermediate host were collected. From them no metacercaria was found. The results indicated that crayfish in district of Seoul is no more an infection source of paragonimiasis. Possible factors related with the ecology of intermediate hosts were briefly discussed from the epidemiological view point.
parasitology-helminth-trematoda ; Paragonimus westermani ; host ; Semisulcospira libertina ; Cambaroides similis