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

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 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

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

parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; ELISA ; immunology

As epidemiological parameters of human paragonimiasis, the positive rates of intradermal test and the sputum/stool examination have long been employed in population surveys. However, both the specificity of the intradermal test and the sensitivity of sputum/stool examination have been gradually declined as the endemicity was lowered; thus the gap between above two parameters widened. In such context, the development of a new epidemiological parameter or tool which makes it possible to accurately discriminate the active paragonimiasis cases was necessary. In the present study, the detection rate of Paragonimus-specific IgG antibody by micro-ELISA was evaluated as an indicator of epidemiologic status of human paragonimiasis in a population. A total of 4,285 students and inhabitants living in Bukpyeong Myeon and Bukil Myeon, Haenam Gun, Jeonlanam Do was surveyed in October 1983 by intradermal test first. Out of them, 244 case (5.7 percent) were found positively reacted to VBS antigen of P. wetermani. Out of 168 positive reactors, 7 cases (4.2 percent) were egg positive either by two times of sputum examination or by one stool examination. That indicated that only 0.16 percent of total surveyed were confirmed as active paragonimiasis by egg detection. When sera collected from 239 positive reactors of intradermal test were tested by micro-ELISA for their specific IgG antibody, 40 cases (16.7 percent) were found to be positive. All of 7 eggs positive cases were again positive for specific IgG antibody. Among remaining 232 intradermal test positive cases, 33 cases were positive for IgG antibody. In contrast to those, none of 42 positive reactors to intradermal test for Clonorchis and of 128 intradermal test negative cases showed positive for Paragonimus- specific IgG antibody. The rate of specific IgG antibody as detected by micro-ELISA appeared to be increased with the wheal size of the intradermal test. When the wheal size was over 13 mm in diameter, about 50 percent of them were positive for specific IgG antibody. Thirty-one specific antibody positive cases were clinically evaluated by laboratory examinations (repeated sputum examination, peripheral eosinophil count and chest roentgenogram) and by history taking. Out of them 24 cases were associated with one or more positive laboratory findings; thus considered as active paragonimiasis cases. Out of 7 lab. finding-free cases 3 revealed past history of typical paragonimiasis symptoms, suggesting that they were in chronic or in convalescent stages. The remaining 4 cases were considered as either mild or ectopic infection cases; the possibility of cross-reaction with other helminthiases could not be ruled out. From the above results, it was inferred that the detection of Paragonimus-specific IgG antibogy by micro-ELISA was very much helpful in detecting the active cases as well as in proper evaluation of the endemicity of human paragonimiasis in a population. The convenience of mass handling of sera in micro-ELISA was considered another superiority as an epidemiologic tool.
parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; ELISA ; immunology ; diagnosis ; IgG

: In order to observe the antigenic fractions in saline extract of adult Paragonimus westermani, proteins in the crude extract were separated by sodium dodecyl sulfate-polyacylamide gel electrophoresis (SDS-PAGE) in reducing conditions. The separated protein fractions were transferred to nitrocellulose paper on which 20 sera from human paragonimiasis were reacted and immunoblotted. Out of 15 stained protein bands in SDS-PAGE, 7 reacted with the sera. Of 14 reacted bands, 30 kilodalton(kDa) band was the most frequently reacted (95%) and was a strong antigen. Protein bands of 23 and 46 kDa were also strong antigens. Bands of over 150 kDa, 120 kDa, 92 kDa, 86 kDa, 74 kDa, 62 kDa, 51 kDa, 32 kDa, 28 kDa, 16.5 kDa and 15.5 kDa were also reactive but their frequencies of the reaction were variable.
parasitology-helminth-trematoda ; Paragonimus westermani ; immunology ; antigen ; electrophoresis

This study was undertaken to evaluate the status of human paragonimiasis in Kang Hwa Gun, Kyunggi Do, Korea from March 1973 to October 1975 by the use of intradermal screening test with Veronal buffered saline antigen. A total number of 7,352 (male 3,936; female 3,4l6) consisting of 3,447 primary school children, 2,689 middle school students, l,008 high school students of 9 Myuns out of 13 Myuns of this County and 208 residents of all age group in Kilgeong-Ri, Yangdo Myun were examined by the intradermal test with Paragonimus antigen. In order to detect Paragonimus egg, the sputum and the stool examinations were undertaken on the residents in Kilgeong-Ri. The infestation rate of crayfish with Paragonimus metacercaria was also examined in Konneung and Jeongha village in Kilgeong-Ri. The following results were obtained in this survey: As a whole, 16.6 per cent of the examiners showed positive reaction with sexual difference of 16.1% in male and 14.8 per cent in female. In age groups, the highest positive rate showed in middle school age group (17.1 per cent) than primary school (14.0 per cent) and high school age group (11.4 per cent). In regional differences of positive rates, the highest rate (28.4 per cent) showed at Yangdo Myun followed by Kilsang Myun (27.0 per cent), Hwado Myun (25.0 per cent), and Naega Myun(20.8 per cent). In the result of 208 residents Kilgeong-Ri, the positive of 36.1 per cent in male and 20.2 per cent in female. The highest positive rate showed in 10 to 19 age group (41.5 per cent). Among the residents in Kilgeong-Ri, Paragonimus eggs were detected in 11 residents by the sputum and the stool examinations. The infestation rate of crayfsh with Paragonimus metacercariae was 100 per cent (41 out of 41 crayfishes) in Konneung village, and 84.6 per cent (9 out of 13 crayfishes) in Jeongha village, Kilgeong-Ri The fluctuation of the infection rate of crayfish with Paragonimus metacercariae was decreased in Konneung village in 2 years after the treatment with Bilevon against 10 paragonimiasis patients.
parasitology-helminth-trematoda ; epidemiology-paragonimiasis ; Paragonimus westermani ; crayfish-Cambaroides similis

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