A case of sparganosis mimicking a varicose vein

Recent advances in radiological and serological techniques have enabled easier preoperative diagnosis of sparganosis. However, due to scarcity of cases, sparganosis has been often regarded as a disease of other etiologic origin unless the parasite is confirmed in the lesion. We experienced a case of sparganosis mimicking a varicose vein in terms of clinical manifestations and radiological findings. Sparganosis should be included among the list of differential diagnosis with the varicose vein.

Nosocomial submandibular infections with dipterous fly larvae

In September 1998, a case of nosocomial cutaneous myiasis caused by Lucilia sericata (Meigen, 1826) in a 77-year-old male was found. The patient had been receiving partial maxillectomy due to the presence of malignant tumor on premaxilla. This is the first verified case involving Lucilia sericata in Taegu, Korea. In the present paper, the salient morphological features of the third instar larvae involved have been studied.

Myiasis in a submandibular metastatic squamous cell carcinoma: a case report

We report a case of myiasis on the left submandibular area after radiation therapy for squamous cell carcinoma. A 77-year-old man visited our hospital, 7 weeks after complicating a course of radiation therapy, had a 7cm diameter necrotic ulcer on the left submandible. The margin of the lesion were undermined by numerous interlinking passages containing 20 maggots. The maggots were removed by simple extraction and were identified as Calliphoridae Lucilia. The probable origin of the myiasis in this case was attributed to poor environmental condition and general weakness of the patient. Oppotunistic cutaneous myiasis can be prevented by protecting open wounds from flies, wound should not be left without a covering capable of excluding flies, especially in the summer month.

Changing patterns of infection with digenetic larval trematodes from fresh-water fish in river Taewha, Kyongnam province

Recent patterns of infection with digenetic larval trematodes in fresh-water and brackish-water fish were studied in three locations of the river Taewha during the period from April to October 1988, and compared with the data reported previously in the same river. Of 16 species of fish examined, the encysted larvae of Cyathocotyle orientalis were found most frequently from 9 species of fresh-water fish. The metacercariae of Echinochasmus sp., Metacercaria hasegawai and Metagonimus yokogawai were found 8 species, those of Clonorchis sinensis from 7 species, and Exorchis oviformis and Metorchis orientalis from 5 species of fish. The infection rates of fish with C. sinensis metacercariae were not lower than those reported in 1980, wheres their intensity of infection was found lowered in 3 species, Coreobagrus brevicorpus, Gnathopogon atromaculatus, and Puntungia herzi. The infection rates of 3 species of fish with M. yokogawai metacercariae were lower than the results in 1982, while the rate was higher in 2 species, Zacco platypus, and Z. temmincki, and rather stationary in Plecoglossus altivelis. The intensity of infection in several species of fish appeared rather higher than in 1980. the encysted larvae of C. orientalis, Echinochasmus sp., E. oviformis and Metacercaria hasegawai showed variations in infection rates of fish in 1980 and in the present study. It was found that the rate of infection with digenetic larval trematodes in fresh-water fish was still relatively high in the river Taewha, and the metacercarial burden in the fish varied greatly by different fish in 1980 and in the present study.

Infestation status of Paragonimus westermani metacercariae in the second intermediate host in Ulchin county, Kyungpook Province

A study on the population density of crayfish intermediate hosts and infestation status of crayfish with encysted larvae of Paragonimus westermani in Ulchin county, Kyungpook province, Korea was conducted from May to October in 1986. The population density of the crayfish ranged from 1 to 13, with an average of 4 per manhour. Among the six habitats, Ducheon had a somewhat higher density than that of the others. Of eight hundred and seventeen crayfish examined, 127 or 15.5 per cent harboured the metacercarial larvae of Paragonimus westermani. The majority of the larvae were found in three parts of the body: most frequently in the cephalothorax, next in the gills, and then in the liver. The average number of metacercarial larvae per infected crayfish ranged from 1.0 to 1.9, with an average of 1.7. Summarizing the results, this study indicates that the population density of crayfish intermediate host and infestation rates for the crayfish with encysted larvae of Paragonimus westermani in Ulchin county of Kyungpook province is relatively high.

Epidemiological studies on malayan filariasis in an inland area in Kyungpook, Korea 3. Ecological survey of vector mosquitoes of Brugia malayi

The species composition, population density, and seasonal prevalence of vector mosquitoes in an inland area of Kyungpook province were studied, based on light trap and human bait trap collections, and the recent patterns of infestation for infective larvae of Brugia malayi in these vector hosts were investigated from May to November in 1985. Nine species in four genera of mosquitoes were collected by light trap, human bait trap, and/or by nets. Anopheles sinensis Wiedemann was the most abundant species collected by light traps during this year. Culex tritaeniorhychus Giles was the second abundant species, and Aedes vexans nipponii(Theobald) ranked third in total abundance. The earlist time when A. sinensis were found was the middle of May. At that time the temperature ranged from 14.3 C to 22.8 C and the humidity 53-90 per cent. The month of highest average nightly catch was July, when the temperature was betweeen 21.5 C and 30.6 C and the humidity 72-91 per cent. The peak time of biting activity of mosquitoes was different in each month, i.e. between 22:00-23:00 in July, and 20:00-21:00 hours in September, when the temperature was between 24.3 C and 26.5 C and the humidity 73-88 per cent in the field. While infective larvae of B. malayi were reported to have been found in one species of mosquito in 1975, no larvae were found in any species collected in this survey.

Seasonal prevalence of the vector mosquitoes of Japanese encephalitis virus in Kyungpook Province, Korea

In order to determine the seasonal prevalence and population density of vector mosquitoes in Kyungpook province, a survey based on average number of female mosquito per trap-night, were carried out during the period from May to November in 1984. Among the 34,571 mosquitoes collected in Kyungsan county in animal shelters and human dwellings by light traps, approximately 45.0 % were Culex tritaeniorhynchus, 34. 0 % per cent Culex pipiens pallens, and 19.0 per cent Anopheles sinensis. By comparison, distribution of mosquito species in Ankang town, in which Japanese encephalitis had been reported in the past, were quite different and A. sinensis was the most abundant species, being constituted in 75.8 per cent, followed by C. tritaeniorhynchus(23. 2 percent), and C. pipiens pallens(0. 6 per cent). In the general patten of seasonal prevalence, C. tritaeniorhynchus first appeared in mid-June, and trapped in large numbers during the periods from mid-August to early September, showing a simple sharply pointed one-peaked curve, while C. pipiens pallens was found to be active through almost the entire season showing irregular curves with several peaks. The trend of seasonal distribution of A. sinensis was similar to that of C. tritaeniorhynchus, but the earliest dates of appearance and disappearance different form that of C. tritaeniorhynchus. The results of hourly catches of mosquitoes by human baited traps have clearly shown the differences in the biting rhythm among the vector mosquitoes of this province, such as the facts that C. tritaeniorhynchus and A. sinensis are rather constantly active all through a night with more or less inconspicuous peaks twice a night, while C. pipiens pallens exhibits an irregular curve, and the numbers of A. vexans nipponii, C. vagans and Armigeres subalbatus are very small and are not sufficient for estimating the biting rhythm. Four genera and fourteen species of larval mosquitoes collected from eighteen kinds of habitats which classified according to the categories followed by Bates(1949). The main breeding sites contributing to peak C. tritaeniorhynchus adult densities in this surveyed areas were evidently ricefields, ground pools, puddles and swamps and marshes, etc. Summarizing the results, this study indicated that the highest population density of C. tritaeniorhynchus was encountered in late August and early September, showing simple sharply pointed one-peaked curve.

Epidemiological survey of Paragonimus westermani in Ulchin County, Kyungpook Province, Korea

In order to determine the epidemiological pattern of the Paragonimus westermani, the infestation rates of the cercarial and metacercarial larvae of digenetic trematodes in the snail and crayfish host, and the prevalence of Paragonimus westermani among the residents in the vicinity of the stream Namdae, Wyangpi, and Kwang, in the Ulchin county, Kyungpook province were studied from March to October in 1984. The population density of the snails per square meter of the habitats ranged form 5 to 25, with average of 15. Among the seven habitats, one, Ducheon, had snails infested with the cercariae of Paragonimus westermani, and the proportion of infested snails was very low, the average being 0.152 per thousand. Of six hundred and four crayfish examined, 113 or 18.7 per cent harboured the encysted larvae of Paragonimus westermani. A high infestation rate for the metacercariae in the crayfish was found in two habitats; 39.0 per cent in the Ducheon and 21.6 per cent in the Sokwang. The prevalence of Paragonimus westermani among the residents in Ulchin county was relatively high, 25.8 per cent by the Paragonimus intradermal tests and the difference in the rate of infection between males and females was found to be significant(t>2). The results obtained in this study indicate that endemic foci of Paragonimus westermani exist in Ulchin county and the prevalence of this lung fluke among the residents is relatviely high.

Recent patterns of intestinal helminth infections among the residents in Taegu City, Korea

In order to estimate the recent pattens of intestinal helminth infections among the residents in Taege City, Korea, a survey based on discovery of helminth eggs by formalin-ether sedimentation and modified Graham's scotch-tape anal swab techniques, were performed during the period from March to September in 1983. A total of 1,697 fecal specimens were collected from 854 male and 843 female residents from 5 villages(Dong), each of whom were selected randomly to represent 1,000 persons referred to the census in 1982. Among the specimens examined, one or more species of helminth parasites were found in 473, revealing the overall positive rate of 27.9 pre cent. Of them, Trichuris trichiura was found most frequently, in 13.2 percent, followed by Enterobius vermicularis in 7.0 per cent. Hookworm was the least prevalent. The sex-specific rate of overall helminth infections was a little higher in females than in males, while in cases of Clonorchis sinensis, Metagonimus yokogawai and Taenia species, the infection rates in males was higher than in females. T.trichiura was most prevalent in the 20~29 age group and showed about the same prevalence in males and females of all age groups. C. sinensis infection rate increased with age while those of Ascaris lumbricoides decreased. Single infections were 82.5 per cent of all positive cases. Of cource, T. trichiura revealed the highest prevalence in 31.7 per cent followed by E. vermicularis in 20.1 per cent and A. lumbricoides in 14.8 per cent. Of the double infections, the percentage of T. trichiura in combination with other intestinal helminths was higher than that of A. lumbricoides. It was concluded that although the infection rates of intestinal helminths among the residents in Taegu City, Korea is still high, eradication of these parasitic diseases seems to be possible with twice-a-year administration of specific anthelmintics, in combination with extensive public health education and improvement of the dietary life.

Infestation of larval trematodes from fresh-water fish and brackish-water fish in River Hyungsan, Kyungpook Province, Korea

In order to determine the infestation patterns for metacercaria of digenetic trematodes, several kinds of fresh-water and brackish-water fish were caught in River Hyungsan, Kyungpook Province, Korea and examined from March to October in 1983. They were collected by netting, fishig with rod and line, or using the bait of crushed oil cake in transparent plastic bowls, and were dissected into the flesh, scales and fins with tail, and then examined for the presence and infestation density of larval trematodes. Of the 11 kinds of fish examined, the encysted larvae of Exorchis oviformis were found all of them, Metagonimus yokogawai from 9 kinds, Cyathocotyle orientalis, Metacercaria hasegawai and Metorchis orientalis from 6 kinds, and Clonorchis sinensis from 4 kinds in the present study. In the intensity of infestation with Clonorchis sinensis, the Korean shiner, Gnathopogon atromaculatus Nichols et Pope, was the most heavily infected species, the average number of metacercariae per gram of fish flesh being 45.5, followed by the striped shiner, Puntungia herzi Herzenstein 11.6, and Southern top-mouthed minnow, Pseudorasbora parva (Temminck et Shlegel), 9.7. The intensity of infestation with the Metagonimus larvae in 8 species of fresh-water fish was relatively low, and the average number per gram of flesh varied from 0.23 to 9.1. In comparison, the brackish-water fish were more heavily infected and the mean number of cysts per gram of flesh in the sweetfish, Plecoglossus altivelis, was 32.9. The results of this study generally indicate that Clonorchis sinensis and Metagonimus yokogawai infection may occur by consuming raw fresh-water fish caught in the river Hyungsan, Kyungpook Province, Korea.

Infestation of larval trematodes from fresh-water fish and brackish-water fish in river Taechong, Kyungpook province, Korea

: A study of infestation patterns for larval trematodes from fresh-water fish and brackish-water fish was carried out during the period from June to October in 1982. They were collected by netting, fishing with rod and line, and using the bait of crushed oil cake in a transparent plastic bowls at the three localities, Daebon-dong, Kugil-dong, and Hoam-dong in the river Taechong, Kyungpook Province, Korea. Five species of fresh-water fish, the crussian carp, Carassius carassius Linnaeus, the bullhead, Coreobagrus brevicorpus Mori, the fat minnow, Moroco oxycephalus (Bleeker), the flat bitterling, Paracheilognathus rhombea(Temminck et Schlegel), and the catfish, Parasilurus asotus (Linnaeus), and two kinds of brackish-water fish, the grey mullet, Mugil cephalus (Linnaeus) and the sweetfish, Plecoglossus altivelis (Temminck et Schlegel) were examined. Four species of the metacercariae, Exorchis oviformis, Metacercari hasegawai, Metorchis orientalis and undetermined larvae were found. Of these, the encysted larvae of the human intestinal fluke, Metagonimus yokogawai, were found from three kinds of fresh-water fish, the crussian carp, the bullhead and the fat minnow and one species of brackish-water fish, the sweetfish and the infestation rates for the larvae varied appreciably from fish to fish. The intensity of infestation with the Metagonimus larvae in the three species of fresh-water fish as low, and the average number of the larvae per gram of flesh varied from 0.5 to 0.2. By comparison, the brackish-water fish was more heavily infested and the mean number of cysts per gram of flesh in Plecoglossus altivelis was 109.2. It was found that infection with Metagonimus yokogawai is caused by consuming raw fresh-water fish and brackish-water fish caught in the river Taechong, Kyungpook Province, Korea.

Epidemiological studies of Clonorchis sinensis in vicinity of river Taewha, Kyungnam province, Korea

In order to determine the epidemiological patten of the liver fluke, Clonorchis sinensis, the locality where the snail, Parafossarulus manchouricus, is abundant, the infestation rates for the cercarial and metacercarial larvae of digenetic trematodes in the snail and fish hosts, and the prevalence of Clonorchis sinensis among the residents in the vicinity of river Taewha, Kyungnam Province, Korea were studied from March 1979 to September 1980. Four snail habitats were found in the river Taewha. The population density of the snail per square meter of the habits ranged from 10 to 500, with an average of 150. Among the 4 snail habitats, three, Baek-cheon, Sa-yeon and Taewha had snails infected with the cercaria of Clonorchis sinensis, and the proportion of infested snails in the three habitats was very low, the average being 0.59 per thousand. Four species of fresh-water fish, the bullhead, Coreobagrus brevicorpus, the Korean shiner, Gnathopogon atromaculatus, the flat bitterling, Paracheilognathus rhombea, and the striped shiner, Pungtungia herzi among ten species of fish examined harbored the metacercaria of Clonorchis sinensis. The intensity of infestation with the cyst of Clonorchis sinensis in the four species of fish was low. The approximate number of the cysts per gram of flesh was between 3.5 in Paracheilognathus rhombea and 21.5 in Gnathopogon atromaculatus. Seven kinds of laval tremathodes, Clonorchis sinensis, Cyathocotyle orientalis, Echinochasmus species, Exorchis oviformis, Metacercaria hasegawai, Metagonimus yokogawai and Metorchis orientalis were found from ten species of fish examined. In general, the infestation rates for the encysted larvae of digenetic trematodes varied from fish to fish. The infection rate for Clonorchis sinensis among the residents in the vicinity of river Taewha was relatively high, 22.2 percent by the formalin-ether sedimentation technique, and the difference in the rate of infection between males and females found to be siginificant(t>2). Of these, the rate was 12.4 per cent in 483 elementary school children and 17.7 percent in 761 middle and high school students. The results obtained in the present study indicate that endemic foci of Clonorchis sinensis exist in the river Taewha and the prevalence of the liver fluke among the residents is still high.

Seasonal variation of snail population of Parafossarulus manchouricus and larval trematode infection in river Kumho, Kyungpook province, Korea

Studies were conducted to determine the ecology of the snail, Parafossarulus manchouricus, the seasonal variation of the snail population, and the infestation rates of these snails with the cercariae of digenetic trematodes, in the snail habitat of river Kumho, in Dongchon of Taegu city, in Kyungpook Province, Korea, from 1975 to 1979. The earliest time the snails were found was early in April every year. At that time the water temperature ranged from 13 to 14 degrees C. The population density of snails ranged from 2 to 8 per square meter. The highest population density of snails was encountered in late June and the water temperature was between 24 and 26 degrees C. The snails disappeared in early and mid-November, when the water temperature dropped to 10-13 degrees C. The average snail population in June was 115.9 per square meter in 1975 but in 1976 dropped abruptly to 30.5 and remained at approximately the same level in 1977. It then decreased at considerably lower rates, with the average of 18.7 in 1978 and 14.5 in 1979. The snails collected in the habitat were examined for the presence of cercariae of digenetic trematodes. Of these, four species, Clonorchis sinensis, Cyathocotyle orientalis, Exorchis oviformis, and Loxogenes liberum were found. The most frequently liberated cercaria was L. liberum 43.3 per cent, followed by E. oviformis 6.2 per cent and C. orientalis 1.5 per cent. The least frequently liberated was C. sinensis 0.1 per cent. In the monthly liberation rates for larval trematodes, the higher rates were observed in June, July and August every year, and the cercarial rates for Clonorchis sinensis, Cyathocotyle orientails and Exorchis oviformis demonstrate a fairly consistently fluctuating downward trend over the five-year period, except for Loxogenes liberum. Summarizing the results, this study indicated that the population density of snails in the habitat and the infection of the snail with the cercariae of digenetic trematodes has decreased over the five-year period from 1975 to 1979.

Newly found endemic foci of Clonorchis sinensis in Kyungpook Province, Korea

Nishimura in 1943 indicated for the first time that a serious endemic focus of Clonorchis sinensis is located in the vicinity of Yeong-cheon(Kyungpook Province, Korea). Later, numerous surveys of this fluke in the Province have been made, but no additional report on the endemic focus of the fluke has been available. The overall percentage of Clonorchis sinensis infections, based on the discovery of eggs by the formalin-ether sedimentation technique, was found to be 54.8 percent from 851 residents in Nakjeon ri (village), Danmil myun, Uiseong gun (county), Kyungpook Province and no significant difference was observed in the sex specific rate of the individuals infected. There is a high incidence of infection with Clonorchis sinensis. The infection rate in the age group from 0 to 4 years was 14.6 per cent, 5 to 9 years was 35.7 per cent and 10 to 14 years was 51.7 per cent. In the worn burdens for residents, the average number of egg-counts was 41,800. It is found that a serious endemic focus of Clonorchis sinensis exists in the vicinity of Nakjeon village.

Changing pattern of Clonorchis sinensis infection among school children in the Gumho basin, Kyungpook Province, Korea

A study was required to evaluate the prevalence of clonorchiasis among school children in the 7 differnet schools located near the Gumho basin and to determine the effectiveness of the anticlonorchis campaign conducted in that area. Surveys for Clonorchis sinensis and the worm burden in the same areas were compared for the period 1960-1970. Both surveys concentrated on children in grades 1-3 ranging from 6-11 years old. They were examined using primarily intradermal tests with Clonorchis antigen and followed by stool examinations. Stool examinations consisting of the formalin-ether sedimentation(Ritchie, 1948 ) and the Stoll egg-count techniques were performed in those cases which revealed positive and doubtful intradermal reactions. The overall prevalence rate for clonorchiasis was reduced from 13.4 per cent to 4.1 per cent. There was also a significant reduction in the worm burden, suggesting that no clonorchiasis will be found among chileren in the near future. In connection with this survey, the prevalence rate for intestinal helminths in 1960 was compared with 1970. The rate for Ascaris lumbricoides had decreased, while the rates for Trichuris trichiura and Trichostrongylus species had increased. No fluctuation in the rate of hookworm was observed during the past 10 years. Clearly, the present survey denotes a requirement for a combined procedure of health education and mass survey with intradermal testing. It has been found that these methods not only greatly reduce the prevalence of clonorchiasis but also is followed by the marked reductions of the worm burdens of the children examined.

Further observations on the prevalence of Ancylostoma duodenale and Necator americanus in the Taegu area

In order to determine the prevalence of Necator americanus, 182 fecal samples were collected from school children in the Taegu vicinity. These sample were subsequently cultured by the Harada-Mori technique. Necator americanus was differentiated from Ancylostoma duodenale using the bases of morphological characteristics of filariform larvae. Necator americanus was not found in the vicinity of Taegu.

Survival of adult Clonorchis sinensis in the biliary passages of dead human bodies

Adult Clonorchis sinensis were collected from the biliary passage of nine cases of medico-legal autopsies. The worms were washed repeatedly with tap water and rinsed twice with physiological saline. Incubation took place in Tyrode's medium in order to recover live worms. The number of worms surviving in the medium was determined. The rate of surviving worms showed an unexpectedly high percentage (22.8%) in those cases autopsied 2 days after death. The surviving worm burden dropped sharply to 6.3 and 9.2 percent for those samples taken 5 days after death.