• Title, Summary, Keyword: reinfection

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Bile duct changes in rats reinfected with Clonorchis sinensis

  • Choi, Dong-Il;Hong, Sung-Tae;Li, Shun-Yu;Chung, Byung-Suk;Lim, Jae-Hoon;Lee, Soon-Hyung
    • The Korean Journal of Parasitology
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    • v.42 no.1
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    • pp.7-17
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    • 2004
  • This study describes an evaluation of the sonographic, cholangiographic, pathological, and immunological findings, and the protective effect shown by rats reinfected with Clonorchis sinensis. Eight experimental rat groups were, namely, a normal control, a primary infection control, a reinfection I (reinfection 7 week after treatment following 3-week infection), a reinfection II (reinfection 2 week after treatment following 8-week infection), a reinfection III (exploration of the intrahepatic bile ducts 1 week after reinfection 4 week after treatment following 4-week infection), a superinfection, a secondary infection control, and an infection following immunization group. Sonographic and cholangiographic findings showed moderate or marked dilatation of the bile duct confluence in the primary infection control, reinfection II, and secondary infection control groups. Juvenile worms survived in the intrahepatic bile ducts 1 week after reinfection following treatment in the reinfection III group. It was concluded that reinfecting juvenile worms found during the first week following reinfection failed to survive or grow further. Anatomical, pathophysiological, or immunological changes may induce protection from reinfection in rats.

Reinfection by Opisthorchis Viverrini after Treatment with Praziquantel

  • Saengsawang, Phubet;Promthet, Supannee;Bradshaw, Peter
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.857-862
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    • 2016
  • Background: The prevalence of infection by the liver fluke, Opisthorchis viverrini (O. viverrini), has remained high in Northeast Thailand where it is a major risk factor for the eventual development of cholangiocarcinoma (CCA). The infection is acquired by the consumption of dishes containing unsafely prepared freshwater fish, a dietary tradition which has proved resistant to change. Since many people are aware that dosing with praziquantel (PZQ) is a successful treatment for an episode of the infection, there is a risk that, to avoid the long term consequences, they will engage in a cycle of infection, dosing and reinfection. Objectives: There is a dearth of studies of reinfection by O. viverrini, and the aims of this study were to assess re-infection rates in a typical province of Northeastern Thailand where O. viverrini infection is likely and to investigate factors associated with reinfection. Materials and Methods: A total of infected 607 villagers were treated with PZQ, and those found to be no longer infected were followed up at six-monthly intervals over 12 months. Results: At the end of this period data on 457 subjects were available for analysis using descriptive statistics and logistic regression, and 50 were found to have become reinfected, giving a cumulative reinfection rate of 10.9%. The results of a multiple logistic regression analysis showed that the only factor found to be associated with reinfection was past use of PZQ. Conclusions: Recommendations are made for future larger scale and better designed reinfection studies in the light of limitations of the current study. Further efforts are needed to discourage people from eating fish dishes likely to contain viable metacariae.

Susceptibility of experimental animals to reinfection with Clonorchis sinensis

  • Sohn, Woon-Mok;Zhang, Hong-Man;Choi, Min-Ho;Hong, Sung-Tae
    • The Korean Journal of Parasitology
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    • v.44 no.2
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    • pp.163-166
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    • 2006
  • The present study observed the resistance to reinfection with Clonorchis sinensis in various experimental animals including mice, guinea pigs, rabbits, and dogs, as well as rats and hamsters. The resistance rates to reinfection in rats, mice, hamsters, guinea pigs, rabbits, and dogs were 79.7%, 58.0%, -12.6%, 54.8%, 62.6%, and 6.0%, respectively. Worms recovered from reinfected rats and mice were immature, and significantly smaller than those from the primarily infected (P < 0.01), whereas those from other animals were fully matured to adults. These findings indicate that the protective response against reinfection with C. sinensis is prominent in rats and mice, and that they may be a good animal model to investigate the mechanism of resistance to reinfection with C. sinensis.

Epidemiological Studies on Ascaris lumbricoides Reinfection in Rural Communities in Korea II. Age-specific Reinfection Rates and Familial Aggregation of the Reinfected Cases (한국 농촌지역의 회충재감염에 대한 역학적 조사연구 ll. 연령별 재감염률 및 재감염의 가족집적성)

  • 채종일;서병양이순형조승열
    • The Korean Journal of Parasitology
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    • v.21 no.2
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    • pp.142-149
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    • 1983
  • Epidemiological studies on the reinfetion pattern of Ascaris lumbricoides were undertaken by means of blanket mass chemotherapy and worm collection in a rural village in Korea, during 1977~1980. The study objectives were to determine the age (sex)-specific reinfection rate during 2, 4, 6 and 12 months through repeated mass chemotherapy with pyrantel pamoate, and to observe the familial aggregation tendency of the reinfected cases. The results obtained are as follows: 1. The age (sex)-reinfection curve revealed that the reinfection rate is much higher in younger individuals than in olders in all of 4 kinds of interval chemotherapy groups. The highest reinfection rate and the highest burden of reinfected worms were observed in preschool children, followed by primary school students. Such fluctuation in the age-specific reinfection rates was more pronounced in males than in females. 2. There was noted a significant tendency of familial aggregation among the reinfected cases. It is suggested that reinfection occurs never randomly but preferably to the members of certain household families. From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmiSSIOn in the surveyed rural area is likely to be of 'dooryard type', in which case children and certain family members are more preferably reinfected. It is also suggested that the preschool children should be included in the primary targets of mass control programme.

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Helicobacter pylori reinfection rate by a 13C-urea breath test and endoscopic biopsy tests in Korean children (한국 소아에서 Helicobacter pylori 박멸 후 13C-요소 호기 검사와 내시경적 생검을 이용한 재감염률 연구)

  • Shim, Jeong Ok;Seo, Jeong Kee
    • Clinical and Experimental Pediatrics
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    • v.49 no.3
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    • pp.268-272
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    • 2006
  • Purpose : The reinfection rate of H. pylori reported before $^{13}C$-urea breath test($^{13}C$-UBT) era was higher than that of the post $^{13}C$-UBT era. Children are usually reluctant to receive invasive endoscopic evaluation for the reinfection of H. pylori, particularly when they are asymptomatic. The aim of the study is to discover the reinfection rate by different diagnostic tests, and to find out what causes the difference. Methods : Children confirmed to be eradicated from H. pylori were included in the study. Reinfection was evaluated by endoscopic biopsy based tests(n=34, mean age $11.5{\pm}3.7$ years) and/or a $^{13}C$-UBT(n=38, mean age $10.0{\pm}3.6$ years) at the time of 18 months after eradication. At first visit, H. pylori infection had been diagnosed by positive results from a rapid urease test, Giemsa stain and Warthin-Starry stain and/or a positive culture. Eradication was defined as negative results from all above tests 1-3 months after eradication therapy. Results : Reinfection rate by endoscopic biopsy based tests was 35.3 percent(12/34). All patients had abdominal symptoms(P=0.000). Reinfection rate was 13.2 percent(5/38) by a $^{13}C$-UBT. Reinfection rate was higher in children with abdominal symptoms(P=0.008). There was no evidence that reinfection rate depended on the sex(P=0.694), age(P=0.827), diseases(peptic ulcers vs gastritis, P=0.730) and eradication regimen(P=0.087). Conclusion : Helocibacter pylori reinfection rate in Korean children was 13.2 percent per 18 months by a non-invasive test or $^{13}C$-UBT. Accurate determinations of the reinfection rate in children is affected by the compliance of the diagnostic tests. Non-invasive tests should be considered to investigate the reinfection rate in children.

Studies on the Comparative Migration Patterns of Ascaris suum Larvae between Primary and Re-infected Mice (돼지회충(Ascaris suum) 유충 감염력이 재감염에 미치는 영향)

  • 송종술;김재진
    • The Korean Journal of Parasitology
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    • v.23 no.2
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    • pp.247-252
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    • 1985
  • In the present study, the effect of primary infection to reinfection with Ascaris suum larvae was experimented in mouse model. Mice were challenged with 1,000 infective stage eggs of Ascaris suum. The embryonated eggs were directly introduced into stomach of mice. Reinfection was performed at 50 days after the primary infection with same method as primary infection. Mice were sacrificed 3, 5, 7, 10, 15 and 20 days after infection in both groups respectively. Larvae collected from livers and lungs with Baermann's apparatus were enumerated and measured after sacrifice. Sera of mice were also collected at same time. The results of the experiment were as follows: With antigen prepared from coelomic fluid of adult Ascaris suum and sera collected from mice before reinfection, the production of antibody in experimental mice was confirmed by the gel-diffusion technique. In the livers of reinfected mice, the larvae were recovered up to 10 days after challenge, otherwhile in the primary infected mice, the larvae were observed up to 7 days. The maximum number of larvae were observed in the lungs of primary infected mice on 10 days after inoculation. In the lungs of reinfected mice, maximum number of larvae were recovered on 7 days after, only few larvae were recovered on 10 days after reinfection. As regards the growth of the larvae, the third stage larvae, over $500{\mu\textrm{m}}$ in length, appeared in livers at 5 days after reinfection, but it couldn't be found on 7 days and 10 days after challenge. The third stage larvae continuously developed were observed in lungs of mice from 5 days after reinfection. In conclusion, it was found that development of larvae in livers of immune mice were probably repressed by the immune mechanisms being rises in livers and defence mechanism is also acting by interfering with the process of larval penetration into the lung from the liver.

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Prospective Study of Helicobacter pylori Reinfection Rate and Its Related Factors (전향적 연구에 의한 Helicobacter pylori 재감염률 및 관련요인)

  • Kang, Pock-Soo;Lee, Kyeong-Soo;Kim, Chang-Yoon
    • Journal of agricultural medicine and community health
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    • v.28 no.1
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    • pp.79-92
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    • 2003
  • Objectives: To investigate the reinfection rate of Helicobacter pylori and the factors related to reinfection of H. pylori, 86 persons were examined in April 2000 after 1 year follow-up period and 77 persons were examined in October 2001 after two and a half-year follow-up period in Gyeongju-si, Gyeongsangbuk-do, Korea. Methods: The subjects were confirmed as H. pylori negative by urea breath test(UBT), and asked to answer the questionnaire regarding demographic characteristics, dyspepsia symptoms, health-related behaviors and family history. Results: The reinfection rate on the first year of the eradication of H. pylori was 15.6%, when the 77 subjects have finished follow-up observation for one year. In the urea breath test performed after two and a half year, 13 out of 77 were positive, with the reinfection rate of 16.9%. Age, sex, socio-economical status, educational level and family history were not associated with the reinfection, while there was significant association between the reinfection and postprandial fullness and epigastric bloating in subjective dyspepsia that the subjects who were determined to be negative in the urea breath test for the following year. The treatment compliance and drinking were significant variables in univariate analysis. Meanwhile, the cases in which the dyspepsia symptom scores for the recent year were 2 to 3 points served as the only statistically significant variable in multiple logistic regression analysis, with the odds ratio of 4.5. The cases in which salt intake during meals was exceeded were 8.7 in the odds ratio, but statistically insignificant. Conclusions: Conclusively, the first-year reinfection rate was 15.6%, and the second-year reinfection rate was 16.9%. Thecomplaints of subjective dyspeptic symptoms and the treatment compliance, as the basis for predicting the H. pylori reinfection in communities, can be used as the basis to screen the subjects for follow-up examination to find out H. pylori infection.

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The effect of reinfection with Neodiplostomum seoulensis on the histopathology and activities of brush border membrane bound enzymes in the rat small intestine (서울주걱흡충의 재감염이 흰쥐 소장의 조직병리 및 미소융모막효소 활성도에 미치는 영향)

  • 유재란;홍성태
    • The Korean Journal of Parasitology
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    • v.33 no.1
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    • pp.37-44
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    • 1995
  • Neodiplostomum seoulensis, one of the human intestinal trematodes , was reinfected to albino rats, and worm recovery rates, histopathology and activity changes of the intestinal brush border membrane bound enzymes were observed. The experimental groups were three: uninfected, primary infection and reinfection. The worm recovery rate in the reinfection group was much lower than in the primary infection group 14 days after infection. The duodenal histopathology showed villous atrophy during the first and second week in the primary infection group. In the reinfection group, however. villous changes occurred as early as 3 days after the infection, and the lesion was found healed 7 days after infection. The activities of alkaline phosphatase and sucrase in the duodenum of primary infection rats decreased nearly half of the controls 2 weeks after infection, whereas the activities were unchanged in the reinfection group. However, no changes in the activities were observed in the proximal jejunum between the experimental groups. These findings suggested that a secondary infection of N. seouLensis in rats should make less damage on the intestinal mucosa than a primary infection. Key words: Neoniplostomum seoulensis, albino rats, reinfection, worm recovery, histopathology, brush border membrane bound enxyines.

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Cell Death and Proliferation after Treatment and Reinfection of Clonorchis sinensis in the Sprague-Dawley Rat Bile Duct

  • Min, Byoung-Hoon;Ahn, Ka-Young;Lee, Haeng-Sook;Kim, Soo-Jin;Joo, Kyoung-Hwan
    • Applied Microscopy
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    • v.45 no.2
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    • pp.80-88
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    • 2015
  • The structural change and distribution of mitochondrial enzyme (ATPase, cytochrome-c-oxidase), cell proliferation (proliferating cell nuclear antigen, PCNA), cell death (caspase-3) and cell growth factor (fibroblast growth factor 8, FGF-8) in the Sprague-Dawley rat bile duct during Clonorchis sinensis infection was investigated. Experimental groups were divided into C. sinensis infection, superinfection and reinfection of C. sinensis after 'praziquantel' treatment group. As a result, C. sinensis infected rat bile ducts showed the features of chronic clonorchiasis, i.e., connective tissue thickening, ductal fibrosis and epithelial tissue dilatation. PCNA for cell proliferation increased in the infection group, and decreased after praziquantel treatment. Caspase-3 was distributed in reinfection group only. FGF-8 was distributed in the rat bile duct after praziquantel treatment but not distributed in infection and reinfection group. Overall, C. sinensis infection causes physical and chemical irritations and then brings on the abnormalities of intracellular energy metabolism and cellular growth factors, which hinders bile duct tissue from functioning properly, and resultingly, fibrosis occurs and epithelial cells dilated abnormally. More intense infection makes tissue fibrosis chronical and activates apoptosis factors.

Epidemiological Studies on Ascaris lumbricoides Reinfection in Rural Communities in Korea 1. The Relationship between Prevalence and Monthly Reinfection Rate (한국 농촌지역의 회충재감염에 대한 역학적 조사연구 I. 현재감염률과 월재감염률의 상관관계)

  • 채종일
    • The Korean Journal of Parasitology
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    • v.21 no.2
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    • pp.135-141
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    • 1983
  • The epidemiological relationship between the current prevalence and monthly reinfection rate of Ascaris lumbricoides was observed in rural communities in Korea by means of blanket mass chemotherapy and worm collection for measurement of the prevalence and reinfection rates. During the period from 1975 to 1980, a total of 4,466 inhabitants in 10 different localities were treated with 10 mg/kg of pyrantel pamoate and 2 days' whole stools were collected from 2,547 inhabitants. The stools were examined for the presence of expelled adult and/or young worms, which represent the prevalence and reinfection rates for past 2 months respectively. After then, the obtained rates were correlated each other applying the timeprevalence curve proposed by Hayashi. It was observed that the prevalence (overall worm positive rate) and worm burden per individual ranged by areas from 13. 6 to 72. 3% and 1.4~10. 2 respectively. The calculated monthly reinfection rates (X) (from young worm positive rates) according to areas were in the range, 2.6~16.2%, and clearly correlated with the current prevalence (Y) under the equation, $Y=1-(l-X)^{7.2}$ where 7.2 is time in month. The equation means that after one time mass chemotherapy the period needed to attain equilibrium of prevalence again would be about 7~8 months. And it is inferred that the majority of reinfected worms in human host turn over every 7~8 months.

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