International Travel and Imported Parasitic Diseases / 한양의대학술지

International travel has become increasingly common as travelers of various purposes. It is estimated that there are 900 million international tourist arrivals alone each year. Unfortunately, some health impairments were reported in about 50% of short term travelers to the tropics or sub-tropics, usually due to infectious agents. In this paper, the author reviewed imported parasitic diseases in Korea from 1970 to 2009 with literature and data collected by Korea Centers for Disease Control and Prevention (KCDC). The author also reviewed warning points about parasitic disease in pregnant and immune deficit travelers. Most prevalent imported parasitic disease was malaria. About 30~70 travelers infected with malaria are returned home anually from abroad, mostly South East Asia and Africa. Subtype of malaria classified from 2003~2006 surveillance data showed Plasmodium falciparum infection in about 55% of patients identified. Over 20 cases of hydatid disease and cutaneous leishmaniasis cases were reported respectively. Visceral leishmaniasis (5 cases), babesiosis (7 cases), loiasis (3 cases), cutaneous myiasis (1 case), pentastomiasis (1 case), gnathostomiasis (4 cases, 41 people), angiostrongylosis (1 case, 10 people), heterophyiasis (2 cases), schistosomiasis (13 cases), cyclosporiasis (1 case), cutaneous larva migrans (4 cases), ancylostomiasis (1 case) and syngamosis (1 case) were reported. Prevention and surveillance plan of imported parasitic diseases is organized and conducted by KCDC since 2001. According to increasing travel to developing or under developed countries, retraining of doctor and technician, systematization of consulting system for diagnosis of parasitic disease, supply of medication, supplement of the personnel, and financial supports are needed.

Changes of cytokine mRNA expression and IgG responses in rats infected with Capillaria hepatica

The mRNA expression of several cytokines was evaluated in splenocytes and mesenteric lymph node (MLN) cells of rats infected with Capillaria hepatica by reverse-transcription (RT)-PCR until week 12 after infection. IgG1 and IgG2a, which are associated with Th1 and Th2 response, respectively, were also assessed by ELISA. The results indicated that the majority of cytokines, including the Th1 (IL-2 and IFN-gamma) and Th2 cytokines (IL-4, IL-5 and IL-10) were expressed at maximal levels during the early stage of infection (after week 1-2), and the ELISA data also evidenced a similar pattern of changes in IgG1 and IgG2a. Th1 and Th2 cytokines responded in a similar fashion in this rat model. The expression of cytokines in splenocytes was significantly higher than that in MLN cells, thereby indicating that cytokine production is controlled more by spleen than by MLN. In addition, the observation that IFN-gamma expression increased unexpectedly at the time of maximal egg production (6 weeks after infection) indicated that IFN-gamma is a cytokine reacting against egg production. However, increased IL-5 expression occurring in tandem with worm activity indicated that the activity of C. hepatica might be controlled by IL-5 expression.

An outbreak of trichinellosis caused by ingestion of raw wild boar / 대한내과학회지

Trichinellosis is one of the most widespread helminthic zoonoses. Unlike other parasitic infestation, it has been reported in advanced countries where there is a great amount of meat consumption such as Europe and America. In Korea, trichinellosis has been suspected to be prevalent for a long time, but it had not been reported up to 1997. However, three reports of human trichinellosis were published recently. An outbreak of trichinellosis caused by ingestion of raw wild boar occurred in Inje-gun, Gangwon-do, Korea, in Mar 2003. 13 people ate raw wild boar meat together, and then they had high fever, myalgia, facial edema, etc. Hematologic and biochemical examinations revealed leukocytosis, eosinophilia, and elevated AST, ALT, LDH, CPK. Muscle biopsy in rectus femoralis was performed in one index case, we detected two parasites in muscle fibers. And we measured specific antibody titers against Trichinella spiralis ES Ag in 12 patients. More than 3~4 fold higher antibody titer was noted in 11 patients compared with normal controls. We treated these cases with albendazole and steroid for 5 days.

Influence of calcium ion on host cell invasion and intracellular replication by Toxoplasma gondii

Toxoplasma gondii is an obligate intracellular protozoan parasite, which invades a wide range of hosts including humans. The exact mechanisms involved in its invasion are not fully understood. This study focused on the roles of Ca2+ in host cell invasion and in T. gondii replication. We examined the invasion and replication of T. gondii pretreated with several calcium modulators, the conoid extrusion of tachyzoites. Calmodulin localization in T. gondii were observed using the immunogold method, and Ca2+ levels in tachyzoites by confocal microscopy. In light microscopic observation, tachyzoites co-treated with A23187 and EGTA showed that host cell invasion and intracellular replication were decreased. The invasion of tachyzoites was slightly inhibited by the Ca2+ channel blockers, bepridil and verapamil, and by the calmodulin antagonist, calmidazolium. We observed that calcium saline containing A23187 induced the extrusion of tachyzoite conoid. By immunoelectron microscopy, gold particles bound to anti-calmodulin or anti-actin mAb, were found to be localized on the anterior portion of tachyzoites. Remarkably reduced intracellular Ca2+ was observed in tachyzoites treated with BAPTA/AM by confocal microscopy. These results suggest that host cell invasion and the intracellular replication of T. gondii tachyzoites are inhibited by the calcium ionophore, A23187, and by the extracellular calcium chelator, EGTA.

Identification of Functionally Different Rat IgE in RBL-2H3 Exocytosis

BACKGROUND: IgE is closely related to the development of allergies. However, the poor relationship between the specific IgE level and the severity of allergic diseases suggests the possibility of functionally different IgE isoforms. With this in mind, rat basophilic leukemia (RBL)-2H3 activation was analyzed with each type of rat IgE for two parameters, exocytosis and IL-4 mRNA production. RBL-2H3 has been well documented in the rat mucosal mast cell line. METHODS: RBL-2H3 cells sensitized with each kind of rat IgE was activated by cross-linking FcRI with B5 (monoclonal anti-rat IgE mouse IgG antibodies). The RBL-2H3 exocytosis was measured by analyzing the beta-hexosaminidase level, and the level of IL-4 mRNA synthesis was analyzed using semi- quantitative RT-PCR. Rat IgE, which was produced by a parasite infection (REP), was prepared using either Paragonimus westermani metacercariae (REP-PW) or Anisakis simplex third stage larvae (REP-AS). A rat IgE prototype of IR162 was prepared by a peritoneal injection of immunocytoma. RESULTS: The level of exocytosis showed a linear relationship with the rat IgE concentration when REP-PW or REP-AS was applied. However, it exhibited a biphasic response with IR162. In addition, the time course of heating at 56oC illustrated the similarity between REP-PW and REP-AS, which differed from that of IR162. In contrast, the level of IL-4 mRNA synthesis in the RBL-2H3 cells with IR162 was comparable to that of either REP-PW or REP-AS. CONCLUSION: These results suggest that functionally different rat IgE isoforms exists in RBL-2H3 exocytosis.

PCR-RFLP patterns of four isolates of Trichinella for rDNA ITS1 region

We have studied the genetic differences among four isolates of Trichinella including a new strain of Trichinella spiralis (ISS 623) recently found from a human case who took a badger in Korea. Because they have a different host origin and came from geographically separated regions, we supposed the genetic pattern of the isolates might be different as had been previously reported. It was analysed by PCR-RFLP analysis of the rDNA repeat that can readily distinguish a species or strain from others. Isolated genomic DNA of each isolate of Trichinella larvae was amplified with ITS1 specific primers and digested with restriction endonucleases. The PCR product of ITS1 was confirmed using Southern blot analysis to be a 910 bp fragment. The restriction fragments of each isolate had variable patterns when it was digested with Rsa 1 only. According to the RFLP patterns, the estimated genetic divergence between each isolate was different. In conclusion, four isolates of Trichinella including a new strain of T. spiralis obtained from a Korean patient may have genetic differences in the ITS1 region and the Shanghai isolate was genetically more similar to the Japanese unknown isolate than others in the ITS1 region.

A Case of Serologically Confirmed Ocular Toxocariasis with Peripheral Granuloma in a 34-year Old Woman

No Abstract Available.

Endoscopic Findings of Acute Gastric Anisakiasis: Thirty-nine cases in Inchon City / 대한소화기내시경학회지

BACKGROUND AND AIMS: When acute gastric anisakiasis is clinically suspected, endoscopic removal of larva is the only definite treatment method. However, there has been little known for endoscopic findings of gastric anisakiasis. METHODS: In 39 patients with gastric anisakiasis, the ingested species of marine products and clinical findings were investigated. The form of larvae, the mucosal changes of the insertion site, close and distant area were also analysed during endoscopic examination. RESULTS: Twelve patients (30.8%) ate raw Astroconger myriaster solely, and the most frequent mucosal insertion site of larvae was around the greater curvature of the body (59.5%). Endoscopic findings of erosion (33.3%), hemorrhagic erosion (33.3%) and redness of the mucosa (11.9%) were observed at the insertion site. The adjacent mucosal changes were edema and fold enlargement. All patients were treated medically. CONCLUSIONS: When acute gastric anisakiasis is suspected, the careful endoscopic examination of larva was necessary for confirmatory diagnosis and definite treatment of the disease.

Therapeutic field trial with praziquantel (Biltricide) in a rural population infected with Clonorchis sinensis

The present study was undertaken to determine the acceptablility, tolerance and effectiveness of praziquantel in a rural population infected with Clonorchis sinensis and to suggest the suitable dosages of praziquantel for the field use on a large scale. A total of 121 patients with proven C. sinensis infection were treated by two dosages with praziquantel at a single dose of 40 mg/kg bwt and 2 doses of 30 mg/kg bwt in a single day. A single dose of 40 mg/kg bwt were given to 60 patients and 2 x 30mg/kg bwt were given to 61 patients. Follow-up examinations were carried out at about 30 and 60 days after treatment. Two months after therapy, 13(21.7%) of 60 patients who received a single dose of 40 mg/kg bwt were cured completely. Among these cured patients, 9(75.0%) out of 12 cases of light and only 4 out of 48 cases of moderate or heavy infection groups were cured. But in the non-cured cases the overall egg reduction rate was 89.1%. On the other hand, 36(59.0%) out of 61 patients treated with 2 x 30mg/kg bwt were cured at 60 days after treatment. Among these cured patients, all of the 13 cases of light infection and 18(69.2%) out of 26 cases of moderate and 5(23.8%) out of 21 cases of heavy infection groups were cured completely at 60 days after therapy. However the overall egg reduction rate was 95.2% in the non-cured cases. Praziquantel is well tolerated and side effects consist particularly of mild and transient headache, dizziness and abdominal discomfort, etc. However there was no difference in regard to frequency and intensity of untoward side effects between the two dosage groups. The results obtained in this study suggest that a single dose of 40 mg/kg bwt for light infection, 2 x 30mg/kg bwt for moderate infection and 3 x 25mg/kg bwt for heavy infection groups will be recommended for the field use on a large scale.

Therapeutic trial of praziquantal (Embay 8440; Biltricide) on the dermal and cerebral human cysticercosis

A total of 28 adult cases who were confirmed cysticercosis with or without cerebral involvements were treated with praziquantel at the daily dose of 3 x 25mg/kg for 3 to 7 consecutive days and was evaluated for tolerance and therapeutic effects in the trials clinically performed.The assessment of drug efficacy of praziquantel in the dermal cysticercosis was made by comparing the numbers of cysticercus nodules and histopathological findings of the biopsied parasites by means of light, scanning and transmission electron microscope. In the cerebral cysticercosis, the assessment was considered by the frequency of the episodes of convulsive seizure before and after treatment with praziquantel and by the findings of the disapearance or decreased densities of the lesions in C.T. scan in comparison with those of before and after treatment. The results were as follows: The cysticerci in the subcutaneous tissues began to disappear within one month of drug administration of 3 x 25mg/kg praziquantel over 3 to 7 days. Within 3 to 6 months most of the cysticerci had disappeared, although in some case a small number of cysticercus nodules remained even one year after treatment. Histological observation of the cysticerci biopsied at different times during the course of treatment revealed that morphological changes were already taking place within two weeks after the treatment. At the early stage of the treatment, small vacuoles were scattered along the basement layer in the tegumental syncytium of the scolex and neck regions. In the scanning electron microscopic observation, marked surface changes were present in the neck region with many bleb-like structures formed by the bursting of the large vacuoles in the tegumental syncytium. In the specimens biopsied at 2 or 5 weeks after treatment, the degenerations and necrosis of the tegumental syncytium were seen in all parts of cysticercus. In 12 cases of cerebral cysticercosis treated with praziquantel at the daily dose of 3 x 35 mg/kg for 3 or 4 consecutive days, there were no ceasing of the convulsive seizures during the 6 months follow-up. Among them 9 cases were given again the same doses of the drug for 4 or 7 days. In 7 of 9 cases, no more convulsive seizure was experienced over one or two years after the second time. At the same treatment the lesions of the brain C.T. scan disappeared, decreasd in size or calcified after treatment. In other 3 cerebral cysticercosis cases, complete cure was also obtained after the oral medication of praziquantel at the daily dose of 3 x 25 mg/kg for 7 consecutive days. In the treatment of cerebral cysticercosis with praziquantel, it was found that the concomitant oral medication of dexamethasone during the course of treatment was effective for preventing and minimizing the side-effects.

Clinical evaluation of praziquantel(Embay 8440; Biltricide) in the treatment of Paragonimus westermani

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.

An epidemiological note on the taeniasis in Korea

The present study was undertaken to evaluate the prevalence rate of Taenia spp. infection and distribution of taeniasis caused by T. solium among Koreans in several localities in Korea during the period from 1977 to 1980. A total of 1,946 stool specimens collected from students and inhabitants of Chungcheong Bug Do and Gyeongsang Nam Do were examined by cellophane thick smear method. Among them, 40 persons were detected as Taenia egg positive cases. The overall positive rate of Taenia spp. shows 2.1 percent. The prevalence rate of male (2.3 percent) is relatively higher than that of female (1.4 percent). In order to observe the distribution of Taenia solium infection, the whole worms or a part of proglottids of Taenia spp. were collected from the stools of egg positive cases by normal defecation or anthelmintic treatment. For the species identification, expelled proglottids were examined microscopically by the number of branches of the uterus, presence of a vaginal sphincter or the accessory ovarian lobe etc. Among 199 egg detected cases in this study 59 (39.1 percent) out of 151 cases in Seoul, 12(40.0 percent) of 30 cases in Gyeongsang Nam Do and 2 (25.0 percent) from 8 taeniasis cases in Cheju Do were infected with T. solium. But none of T. solium infection was found from 10 egg positive cases in Chungcheong Bug Do. As a whole, the composition of species shows 36.7 per cent of T. solium infection and 55.8 percent of T. saginata infection, and in 7.5 per cent the species were not identified.

Anthelmintic effect of amidental (Bay d 8815) against Ancylostoma duodenale infection

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.

In vitro activities of various drugs against adult worms of Clonorchis sinensis

The present study was undertaken to evaluate in vitro activities of following drugs against adult worms of Clororchis sinensis: i.e., stibnal, chloroquine diphosphate, Hetol (1,4-bis-trichloromethylbenzol), dehydroemetine 'Roche' (Ro 1-9334), niridazole (Ambilhar), bisbendazole, gentian violet, dithiazanine iodide, hexachlorophene, bithionol, niclofolan (Bilevon, Bayer 9015) and praziquantel (Embay 8440, Biltricide). After isolation from bile ducts of experimentally infected rabbits (3 months infection), the parasites were rinsed in sterilized Tyrode's solution and incubated for 24 hours at 37 C in TC 199 medium with Earle's balanced salt solution containing 0, 0.01, 0.1, 1.0, 10 and 100 microgram/ml concentrations of each above drugs. The activities of each concentrations with each drugs were evaluated by the motility of the worms in culture tubes observing at 15, 30, 60 minutes and 2, 4, 6, 12, 18 and 24 hours by stereomicroscope. In the results, no effect was found at the adult worms of C. sinensis in all concentrations with stibnal, chloroquine diphosphate, Hetol, dehydroemetine, niridazole and bisbendazole. However, moderate activities were observed in the concentrations of 1.0 and 0.1 microgram/ml of gentian violet, dithiazanine iodide, hexachlorophene and bithionol. The highest activities were observed in all concentrations of niclofolan and praziquantel.

Therapeutic effects of praziquantel (Embay 8440) against Taenia solium infection

A total of 53 patients infected with Taenia solium were treated with praziquantel in two different dose levels. Twenty-six cases were treated with praziquantel in a single oral dose of 5 mg/kg body weight. All cases except one were completely cured. The cure rate was 96.2 per cent. The other 27 cases were treated with a single dose of 10 mg/kg body weight. All cases were completely cured and revealed a cure rate of 100 per cent. Side effects were mild and transient. About half of the cases complained of a mild abdominal pain. Soft stool or diarrhea and dizziness were observed in some cases. Tests on clinical hematology, serum biochemistry and urinalysis were performed immediately before and one day after treatment in all cases. There were no significant abnormalities detected in these tests.

Anthelmintic effects of various drugs against metagonimiasis

The infection of Metagonimus yokogawai has been known to be present nationwidely and endemic in some parts in Korea. In order to select a highly effective compound against Metagonimus infections, the therapeutic effects were observed in 156 cases who were treated with several anthelmintic i.e. bithionol, niclosamide, niclofolan and praziquantel. All of the above drugs showed highly effective to the treatment of metagonimiasis by a single or two medication days. The egg reduction rates were in the range of 80.2 to 100 per cent. However, relatively low cure rates(8.3 to 37.5 percent) were observed in the groups treated by two doses of 30 mg/kg of bithionol, a single day treatment with 100 mg/kg of niclosamide and two doses of 1.0 mg/kg of niclofolan. On the other hand, the high cure rates were observed at the following dose rates of each drugs, i.e. the cure rate of 66.7 percent was obtained at two doses of 100 mg/kg of niclosamide, 88.9 percent of cure rate was observed at two doses of 2.0 mg/kg of niclofolan and a single dose of 10 and 20 mg/kg of praziquantel were shown as 85.0 percent and 88.0 percent of cure rates respectively. But the complete radical cure was obtained in the group treated by two doses of 20 mg/kg of praziquantel in 10 metagonimiasis cases. From the above results praziquantel was shown as the most highly effective against metagonimiasis and it was well tolerated without any side effect. Therefore, praziquantel is a very promising drug for mass treatment against metagonimiasis.

Epidemiological study on the hookworm infections in Korea

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.

Therapeutic effects of praziquantel (Embay 8440) against Hymenolepis nana infection

A total of 60 patients with Hymenolepis nana infection were treated with a single oral dose of praziquantel in two different dose levels. Twenty-nine cases treated with praziquantel in a single dose of 15 mg/kg body weight produced a 100% cure rate. On the otehr hand, 30 out of 31 patients who received a single dose of 25 mg/kg body weight cured completely, but only one case had counts of 200 EPG of feces in each tests on the 20th and 21st days after treatment. The cure rate was 96.8% and the mean egg reduction rate of 99.8 per cent was obtained. Side effects were mild and transitory. In a few cases, abdominal pain, vertigo, headache and diarrhea were complained in a few hours after medication. Clinial hematology, serum biochemistry and urinalysis were performed immediately before and the next day after treatment in all cases. There were no significant abnormalities detected in these tests.