Redescription of Macroorchis spinulosus Ando, 1918 (Digenea: Nanophyetidae) encysted in the fresh water crayfish, Cambaroides similis

Macroorchis spinulosus Ando, 1918 (Digenea: Nanophyetidae) is redescribed based on adult flukes recovered from experimental mice, rats and cats which were fed with metacercariae encysted in the muscle of the crayfish. Cambaroides similis. A total of 117 adult flukes were harvested from the small intestine of the experimental animals at 5-21 days post-infection. The worm recovery rate was 31-37%, not significantly different among the three kinds of animals. The metacercariae were round, 0.18 mm in average diameter, encysted with two layers of thick walls, and possessing a stylet on the oral sucker and Y-shaped excretory bladder. The adult flukes were oval, 0.66-0.71 mm long and 0.36-0.41 mm wide, and characterized by the presence of a stylet on the oral sucker, variable location of the ovary near the mid-portion of the body, bilobed seminal vesicle, and anterolateral location of two testes. These morphological features were a little different from the original description, hence, an emended version of M. spinulosus was given. M. spinulosus is a new intestinal trematode of animals and possibly man in Korea.

A human case of invasive fascioliasis associated with liver abscess

A 56 year-old Korean housewife/farmer/goat keeper suffered from right upper quadrant pain and fever with chills. In the abdominal sonogram and computerized tomography, multiple, 2-3 cm, irregular shaped cavities were observed in the right lobe of liver. A liver biopsy revealed extensive central necrosis with Characot-Leyden crystals surrounded by palisading histiocytes, eosinophil-rich inflammatory infiltration. Worm was not observed. However, the serologic test for Fasciola-specific IgG antibody by micro-ELISA was positive. Prior antibody levels did not differ and eosinophilia persisted 6 and 16 months after praziquantel treatment although the cavitary lesions in the liver disappeared 6 months after the treatment. Reported herein is a human case of invasive fascioliasis diagnosed clinically by a combination of radiological, histopathological and serological studies.

Helminths in Rattus norvegicus captured in Chunchon, Korea

We report helminthic infections in the liver and intestine of Rattus norvegicus captured in Chunchon, Korea from April to October, 1994. Out of 43 examined rats, eggs of Capillaria hepatica were found in 11, Hymenolepis diminuta in 14 and Taenia taeniaeformis metacestodes in 28. Those rats can be sources of zoonotic infections in the surveyed area.

Head louse infestation in vagrants and children admitted to public welfare facilities, Republic of Korea

From December 1992 to February 1993, all vagrants and children admitted to public welfare facilities supported by the Government of Republic of Korea were examined for the presence of nit, nymph or adult of head louse. Of 36,055 persons examined, the number of positive was 7,393 (20.5%). Intensive control measures are needed to control this ectoparasitic infestation.

Intestinal parasitic infections in the residents of an emigration camp in Tijuana, Mexico

We examined stool specimens of the residents in the emigration camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entamoeba coli (29.3%) Giardia lamblia (9.8%), Entamoeba histolytica (7.6%), and eggs of Taenia spp. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.

Infestation rate of lice in patients in a mental hospital, Seoul, Korea

We examined the infestation rate of head and/or body lice in patients in a mental hospital, Seoul, Korea on June 27-28, 1988. Of 438 women, 146 (33.3%) were positive with nits or worms of louse. Of 143 men, 22 (15.4%) were positive with those of louse. Regular control programs were necessary to this hospital.

[Chronological observation on intestinal histopathology and intraepithelial lymphocytes in the intestine of rats infected with Metagonimus yokogawai]

The relationship between the intestinal histopathology and number and position of intraepithelial lymphocytes (IEL) was observed chronologically in the small intestine of rats experimentally infected with Metagonimus yokogawai. Fifteen Sprague-Dawley rats were orally infected each with 3,000 metacecariae, and 3 were kept uninfected for controls. Three rats each were sacrificed on the day 5, 10, 15, 24 and 70 post-infection (PI) and samples of the small intestine, 5 cm, 10 cm, 20 cm and 70 cm posterior to the pylorus were taken. The samples were processed routinely and stained with Giemsa. The intestinal histopathology was severe during the day 5-15 PI and characterized by villous atrophy, crypt hyperplasia, and decrease of villus/crypt height ratio. After the day 24 PI, the intestinal lesions showed some tendency of recovery. The number of IEL increased at the early stage of infection, but decreased thereafter to a lower level than that of controls, with progression of the pathological changes. Then, the IEL number began to increase again after the day 24 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, a considerable proportion of IEL was found to have moved to the intermediate or apical region of the epithelium. From the above results, it is suggested that the change of IEL number and position during the course of M. yokogawai infection should be closely related to the progression and recovery of the intestinal histopathology.

Intestinal trematode infections in the villagers in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea

An epidemiological study for the intestinal trematode infection of the villagers was done in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea in March, 1994. Of 116 stool specimens examined, total helminthic ova positive cases were 13 (11.2%) and cumulative ova positive cases 21 (18.1%): Echinostoma hortense 11 cases (9.5%), Metagonimus sp. 6 cases (5.2%), and Clonorchis sinensis 4 cases (3.4%). After the treatment and purgation, variable numbers of E. hortense, 6 to 227 per person, were collected from 7 echinostome egg positive cases, together with M. takahashii in 6 cases. Three adult flukes of E. cinetorchis were collected from one person and one Stellantchasmus falcatus was recovered from another case. This mountainous village was proved to be one of the endemic foci of echinostomiasis in Korea.

Two rare cases of Diphyllobothrium latum parvum type infection in Korea

Two rare cases of human infection with parvum (dwarf) type of Diphyllobothrium latum [syn. D. parvum (Stephens, 1908)], were discovered in Korea. The first case was a 46-year old housewife, from whom a kind of pseudophyllidean tapeworm eggs was detected in the feces. She was treated with praziquantel and purged, and a complete strobila with scolex, 120 cm in total length, was recovered. She recalled that she had eaten raw trouts at a raw-fish restaurant near the Chungju Lake. Another patient was a 22-year old medical student (male), who used to eat raw sea-foods. He discovered a chain of tapeworm proglottids, 15 cm in length, discharged spontaneously in his stool and brought it for identification. The worms from the two cases were compatible with D. parvum (Stephens, 1908) of which the taxonomic significance has long been questioned. After a detailed morphological study and review of literature, we designated the worms as D. latum parvum type. This is the first report on the occurrence of this rare type of D. latum infection in Korea.

A follow-up examination of intestinal parasitic infections of the Army soldiers in Whachon-gun, Korea

A follow-up stool examination was done to know the status of intestinal parasitic infections in Army soldiers who were stationing in Whachon-gun, Kangwon-do, Korea in 1993. Of 233 examined soldiers, Infections with Clonorchis sinensis (0.4%), Metagonimus spp. (0.9%), Echinostoma hortense (0.4%), Neodiplostomum seoulensis (0.4) and Giardia lamblia (3/233) were found. E. hortense and N. seoulensis infections were each 75th, and 27th cases in Korea. Regular control program of intestinal parasitic infections might be able to contribute to diminish the prevalence rate in young Army soldiers in Korea.

Intestinal parasite infections in the inhabitants along the Hantan River, Chorwon-gun

The prevalence of intestinal parasite infections in inhabitants at the reaches of the Hantan River, Chorwon-gun, Korea, was observed from August 12 to September 14, 1993. Of 465 people observed by cellophane thick smear and formalin-ether concentration method, 2 Ascaris lumbricoides (unfertilized), 1 Trichuris trichiura, 39 Clonorchis sinensis and 16 Metagonimus egg positive cases were found. After treatment, the Metagonimus egg positive cases passed out flukes of Metagonimus Miyata type. Of 68 fish caught in the Hantan River, 14 (20.6%) were infected with metacercariae of Metagonimus, while no metacercaria of C. sinensis was found. At this area, soil-transmitted nematodes are very low, but clonorchiasis and metagonimiasis are prevalent by modernate endemicity.

Histopathological changes of the cat brain in experimental sparganosis

Histopathological changes of the brain were observed in 22 mongrel cats each of which was subjected to intracranial inoculation of 3 or 5 plerocercoids of Spirometra erinacei. The brains were examined at 2 weeks, 1, 3, and 6 months post-inoculation (PI). Grossly, the brain lesion consisted of a mass of worm capsule and/or hemorrhagic tract. Microscopically hypertrophied astrocytes, lymphocytes, plasma cells, RBCs, polymorphonuclear leukocytes, and hemosiderin laden macrophages were found around the worms or tracts in all groups. The number of reactive astrocytes increased mainly in the white matter. In the lesions 3 months PI, the sectioned worms were encircled with fibrous tissue along with numerous RBCs, inflammatory cells, and necrotic debris. Collagenous fibers were also demonstrated. Outside the inflammation, a wide edematous zone developed and numerous neuroglial fibers were also found. The location of the worms or the tracts was random in the brain lobes, but the worm seemed to migrate mainly along the white matter.

Transmission electron microscopic findings of the tribocytic organ of Fibricola seoulensis

We observed ultra-structure of the tribocytic organ of Fibricola seoulensis with transmission electron microscope. Microvilli are observed on the surface of the tribocytic organ. Below the muscle layer, we can find three types of cells. Type I cell has electron lucent cytoplasm with a few granules, while type II cell shows electron dense cytoplasm and the particulate granules. Type III cell's electron dense cytoplasm possesses many granules. Of the above three cells, Type I and II cells are believed as tegumental cells. Type III cells are thought as glandular cells specific to the tribocytic organ. This finding can also explain the secretory function of the tribocytic organ of F. seoulensis.

Intestinal parasites of cats purchased in Seoul

Fecal samples of cats purchased in Seoul were examined for helminth ova or protozoan oocysts from December 1987 to March 1988. Out of the 41 samples, 31 (75.6%) were positive and 60 (146.3%) were cumulative positive for parasites. The followings were identified in the samples: Eggs of Toxocara cati, Clonorchis sinensis, Metagonimus sp., Pharyngostomum cordatum, Spirometra erinacei, Taenia taeniaeformis and oocysts of Isospora sp. From nine autopsied cats, larvae of Anisakis simplex, adults of C. sinensis, M. yokogawai, P. cordatum, S. erinacei and T. taeniaeformis were identified. This is the first report on the detection of Anisakis larvae from cats in Korea. The possible role of cats as a source of human infection with each parasite was discussed.

Intestinal parasitic infections of Korean Army soldiers in Whachon-gun, Korea

We examined stools of 113 soldiers of Korean Army in Whachon-gun, Korea in 1992. The eggs of Clonorchis sinensis (7/113) and Metagonimus sp. (3/113), and cysts of Giardia lamblia (4/113) were detected. No eggs of soil-transmitted helminths were found. Most of the Clonorchis-infected soldiers (6/7) were recruited from Kyongsangnam-do.

An epidemiological study of metagonimiasis along the upper reaches of the Namhan River

An epidemiological study of Metagonimus infection was undertaken along the upper reaches of the Namhan River, with special consideration on the species (type) of the worms collected from humans. Eggs of Metagonimus spp. were detected from 15 (9.7%) of 154 people examined in Umsong-gun, and from each infected person (5 cases) 6,015-24,060 worms (mean 13,233) were recovered after treatment with praziquantel (10 mg/kg). Eggs were also detected from 37 (48.1%) of 77 people in Yongwol-gun, from whom (27 cases) 1-4,965 worms (means 1,215) were collected. The worm from Umsong-gun consisted of both Metagonimus Miyata type and Metagonimus takahashii, whereas those from Yongwol-gun consisted of only Metagonimus Miyata type. When the uterine eggs of the two kinds and M. yokogawai (obtained from people in Tamjin River basin) were morphologically compared, it was suggested that the egg size should be a good indicator for discrimination of the species or type. The source of human infection was proved to be fresh water fishes; 49 of 52 Zacco platypus examined, 6 of 8 Hemibarbus longirostris, 13 of 15 Pseudogobio esocinus, 4 of 6 Odontobutis obscura interrupta, and 17 of 18 Carassius carassius were found infected with Metagonimus metacercariae. From the results, it is concluded that the upper reaches of the Namhan River are endemic foci of Metagonimus Miyata type and M. takahashii.

Activities of acid phosphatase and non-specific esterase are present in the tribocytic organ and the caecum of Fibricola seoulensis

In order to know the enzyme activities of Fibricola seoulensis, an intestinal trematode of human and rodent in Korea, the enzyme histochemical method is applied. Activities of acid phosphatase (E.C.3.1.3.2) and non-specific esterase (E.C.3.1.1) were present in microvilli and glandular cells of tribocytic organ and the epithelium of the caecum.

Prevalence of head louse infestation in primary school children in Kangwon-do, Korea

We tried to reveal the prevalence rates of the head louse infestation in school children in Kangwon-do, Korea in December 1990. A total of 912 children in four primary schools was examined. The positive rate for adults and/or nits of Pediculus humanus capitis was 37.2%. One school was followed-up without specific intervention. There was no significant change of the prevalence rate 6 months after the first examination from 66.0% to 57.3%. We could see the persistent infestation rate if there was no intervention. We are emphasizing the significance of worm positive rate because it represents the potentiality of active transmission.

Secretions of the biliary mucosa in experimental clonorchiasis

The histological change of the biliary mucosa in clonorchiasis is characterized as adenomatous hyperplasia, and cross-sectioned mucosa looks like intestinal mucosa. In addition to the glandular hyperplasia, the metaplasia of mucin secreting cells is also known. The present study investigated the presence of intestinal secretion from the biliary mucosal cells of rabbits and rats with Clonorchis sinensis infection. The rabbit was infected with 300 and the rat was infected with 100 metacercariae of C. sinensis. A part of the animals were followed up after praziquantel treatment. The rabbit livers were prepared for histochemistry to observe any endocrine secretion and the bile duct mucosa of the mice was processed for the activity of brush border membrane (BBM)-bound enzymes of the small intestine. Immunohistochemistry with the polyclonal antibodies and biotin-streptavidin-peroxidase staining kit showed no positive cells for gastrin and secretin, but a few cells were positive for serotonin. The proliferated biliary mucosa of the mice revealed no activity of disaccharidases and aminopeptidase. Only alkaline phosphatase activity was found both in the control and the infected. The hyperplastic biliary mucosal cells showed no gastrointestinal secretory functions. The serotonin secreting cells may be one of the inflammatory cells.

Histochemical findings of the tribocytic organ and tegument of Fibricola seoulensis

The tribocytic organ and tegument of Fibricola seoulensis were examined histochemically for the detection of carbohydrates, mucosubstances, amyloid, collagen and alkaline phosphatase. The surface, secretes, gland cells of the tribocytic organ, and the tegument of the worms were positive to periodic acid Schiff (PAS) and PAS with diastase stain but negative to other stains. It was inferred that the tribocytic organ and tegument of F. seoulensis comprise neutral mucopolysaccharides, which may take a protective role against host enzymes. The surface and secretes of the tribocytic organ, and the tegument of the worms were also positive to double bridge PAP for alkaline phosphatase. This fact suggests that they may play a role as both self protective and host tissue lytic functions.

The fate of spargana inoculated into the cat brain and sequential changes of anti-sparganum IgG antibody levels in the cerebrospinal fluid

To establish an animal model of intracranial sparganosis, the fate and behavior of the experimentally inoculated spargana were observed. A total of 102 scolices of spargana were injected into 22 cat brains, and the cats were sacrificed at 2 weeks, 1 month, 3 months and 6 months after the inoculation. Neurosparganosis was established in 77% of the cats. Of 43 recovered worms, 19 (44%) were located in the subdural or subarachnoid space, 16 (37%) in the brain parenchyme, and 2 (5%) in the lateral ventricle. One was detected at the diploic space of the skull and 5 were outside the cranial cavity. All but one were alive, and had grown tails. They were distributed in the brain parenchyme randomly. There was no place which they could not invade. No adult was found in the intestine. Cerebrospinal fluid (CSF) was collected before inoculation, 1 week, 2 weeks, 1 month, 3 months and 6 months after inoculation. The level of anti-sparganum IgG antibody in CSF measured by ELISA began to increase above the criteria of positivity 1 month after inoculation. Three months after inoculation, the values markedly increased. The present findings reveal that intracranial inoculation of spargana into the brains of cats would be a good animal model of experimental neurosparganosis.

The changes of histopathology and serum anti-sparganum IgG in experimental sparganosis of mice

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with five spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, lymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3. The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection.(ABSTRACT TRUNCATED AT 250 WORDS)

[Seven cases of Diphyllobothrium latum infection]

Seven cases of Diphyllobothrium latum infection were proved by collection of worms after praziquantel treatment between October, 1986 and July, 1987. The patients were all males aged 20-44 years residing in Seoul or Ulungdo, Kyungpook Province. All of them had the history of eating several kinds of raw marine fishes, and they had never been to abroad. One of them experienced abdominal pain and 6 experienced natural discharge of a chain of worm segments, but none revealed any sign of anemia. Total 12 worms (1-3/patient) were collected after praziquantel treatment. The worms were 85-423 cm in length, and revealed the characteristic rosette-shape uterus in their gravid proglottides. The average egg size varied 61.0-65.3 x 41.7-46.1 microns. The eggs were yellowish-brown, and ovoid to elliptical. Including the present 7 cases, the total number of human D. latum infections proven by worms in Korea becomes 28 cases.

A case of unilocular hydatid disease imported from Saudi Arabia

A 39-year-old Korean man with general malaise was found to have two hepatic cysts by computed tomography. He had the history of close contact with domesticated wild dog in Saudi Arabia in 1976. Two cysts, 15cm and 10cm in diameter which contained clear fluid, were excised from both lobes of the liver. He was pathologically diagnosed as unilocular hydatid disease. This case is regarded as an imported case from Saudi Arabia.

Egg laying capacity of Fibricola seoulensis in mice and rats

The egg laying capacity of Fibricola seoulensis was observed in mice and rats. In mice, the mean number of eggs produced by an adult worm a day was 116 at the first week after infection, 123 at the 2nd week and 42 at the 3rd week. Thereafter, the capacity of about 20 eggs/worm/day was maintained up to one year period. In rats, it generally produced more eggs; 49 at 1 week, 250 at 2 weeks, 216 at 4 weeks, 327 at 6 months and 11 at one year after infection. It survived longer than a year in mice and rats.

Clinical and histopathological findings in mice heavily infected with Fibricola seoulensis

To observe the clinical course and intestinal histopathology in heavy infection of Fibricola seoulensis, an experimental study was performed in mice. Clinical, hematological and histopathological observation was done on 1, 3, 7 and 12 days after experimental infection with l,000 metacercariae. On the 11th day after infection, the mice began to die and all of the infected mice were dead by the 16th day. The infected mice showed gradual weight loss. Occult blood was detected after the 10th day. Diarrhea occurred after the 9th day and was recognized in all of the infected mice on the 12th day. Hemoglobin and mean corpuscular hemoglobin decreased significantly after the 12th day, and mean corpuscular hemoglobin concentration decreased in all infected mice. The histopathological changes were more marked in the duodenum than in the jejunum or ileum. Major changes were villous atrophy and crypt hyperplasia, with decreased villus/crypt ratio, inflammatory cell infiltration and stromal edema. The present results suggest that the cause of death of mice heavily infected with F. seoulensis should be malnutrition and severe fluid loss due to malabsorption, together with intestinal bleeding.

[Head louse infestation among school children in Sanbuk-myon, Mungyong-gun, Kyongsangbuk-do (1985)]

In order to know the prevalence of head louse among the school children in rural area, we visited 3 primary schools and a kindergarten in Sanbuk-myon, Mungyong-gun, Kyongsangbuk-do in July 1985, and examined the children to identify the adult worms of head louse and/or its nits on the hair. The overall infestation rate was 91.9% among 420 children examined, and there was a difference between schools (P< 0.05). the school girls' rate, 96.1% was higher than that of bods' 88.9%(P< 0.05). By grade, the rate of infant school was 88.5% and 1st to 6th grade were 100, 100, 95.8, 90.4 89.7, 80.0% respectively. Above result indicates that the head louse is an important health problem in this community. Therefore, the chemotherapy and the effort to improve the hygiene are necessary in this community by physicians, teachers and health administrators.

The effect of temperature and salinity on maturation and hatching of Fibricola seoulensis eggs

This study was carried out to reveal the effect of temperature, salinity and aeration on maturation and hatching of Fibricola seoulensis eggs. The eggs were incubated and were observed daily for the appearance of eyespots and hatching. The results were summerized as follows: From 4-5 days after incubation in distilled water at 28C or at 11-26C, the eyespots began to appear and the rate of eggs with eyespots were over 90% in 28C on the 7th or 8th day. However, eyespots did not appear in 5-15C or 4C by the 18th day. The mature eggs began to hatch at the 8th day, and hatching rate 2 weeks after incubation was over 90% at 28C, but it was below 5% at 11-26C, and 0% at 5-15C and 4C. Aeration did not influence the appearance of eyespots nor hatching. In saline under 0.6%, the rates of eyespots were over 90% on the 7th day. The rate was 55.0% in 0.9% at 20 days, and 0% in 1.2%. The hatching rates in salines below 0.3% concentration were over 90% by 14 days of incubation. However, the rate decreased to 44% in 0.6% saline and to 0% over 0.9% salinity. The eggs incubated in the dark hatched in 12.5% on the 10th day, but hatching rate of maturation eggs increased to 85.7% within 2 hours after exposure to light. Above results demonstrated that the best temperature for maturation and hatching of F. seoulensis eggs was 28C, and the miracidia began to hatch at 8-9 days after incubation. In the field hatching and invasion into snails of the miracidia may occur from May to September in Korea. In salines under 0.3 percent concentration maturation and hatching were not influenced, but as salinity increased hatching was inhibited more than maturation was.