• Title, Summary, Keyword: reinfection

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Biological Control of Crown Gall

  • Kerr, Allen;Biggs, John;Ophel, Kathy
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • pp.11-26
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    • 1994
  • Crown gall of stonefruit and nut trees is one of the very few plant diseases subject to efficient biological control. The disease is caused by the soil-inhabiting bacteria Agrobacterium tumefaciens and Agrobacterium rhizogenes and the original control organism was a non-pathogenic isolate of A. rhizogenes strain K84. Control is achieved by dipping planting material in a cell suspension of strain K84 which specifically inhibits pathogenic strains containing a nopaline Ti plasmid. Because the agrocin 84-encoding plasmid (pAgK84) is conjugative, it can be transmitted from the control strain to pathogenic strains which, as a result, become immune to agrocin 84 and cannot be controlled. To prevent this happening, the transfer genes on pAgK84 were located and then largely eliminated by recombinant DNA technology. The resulting construct, strain K1026, is transfer deficient but controls crown gall just as effectively as does strain K84. Field data from Spain confirm that pAgK84 can transfer to pathogenic recipients from strain K84 but not from strain K1026. The latter has been registered in Australia as a pesticide and is the first genetically engineered organism in the world to be released fro commercial use. It is recommended as a replacement for strain K84 to prevent a breakdown in the effectiveness of biological control of crown gall. Several reports indicate that both strains K84 and K1026 sometimes control crown gall pathogens that are resistant to agrocin 84. A possible reason for this is that both strains produce a second antibiotic called 434 which inhibits growth of nearly all isolates of A. rhizogenes, both pathogens and non-pathogens. Crown gall of grapevine is caused by another species, Agrobacterium vitis. It is resistant to agrocin 84 and cannot be controlled by strains K84 or K1026. It is different from other crown gall pathogens in several characteristics, including the fact that, although a rhizosphere coloniser, its also lives systemically in the vascular tissue of grapevine. Pathogen free propagating material can be obtained from tissue culture or, less surely, by heat therapy of dormant cuttings. A number of laboratories are searching for a biocontrol strain that will prevent, or at least delay, reinfection. A non-pathogenic A. vitis strain F/25 from South Africa looks very promising in this regard.

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Prevalence, Worm Burden and Other Epidemiological Parameters of Ascaris lumbricoides Infection in Rural Communities in Korea (한국 농촌지역의 회충 감염율, 감염량 및 역학적 변수)

  • 채종일;금구진
    • The Korean Journal of Parasitology
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    • v.23 no.2
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    • pp.241-246
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    • 1985
  • The epidemiological status of ascariasis was analyzed in 8 rural villages in Korea, through observation of its epidemiological parameters such as prevalence, worm burden and basic reproductive rate. Total 978 inhabitants were subjected to stool examination and recovery of worms after chemotherapy with pyrantel pamoate. The results were as follows: 1. The worm positive rate in each village was 16.5~79.5%, while the egg positive rate was 9~18% lower, 3.3~66.7%. The average worm burden (among all inhabitants) ranged from O. 21 to 8. 44 by villages and the frequency of cases with each worm burden showed negative binomial distributions with 'k' values of O. 38-0. 54. 2. The prevalence rates (worm) in each village was almost identical with the theoretical ones from Anderson and May's equation; $p=1-(1+M^*/k)^{-k}$, where 'p' is worm prevalence and '$M^*$' equilibrium average worm burden. The basic reproductive rate 'R' was calculated from 1.03 to 2.11. lt is suggested that, although 'R' in lower endemic areas is approaching to the breakpoint of reinfection (R=1), control programs of ascariasis in Korea should be continued until it becomes below the level nationwidely.

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Case Control Study of Recognition level for Dermatomycosis of Dermatomycosis Patient to be Treated in Ulleung Hospital of Ulleung island (울릉도의 일개 병원을 내원한 피부 진균증 환자들의 피부 진균증에 대한 인식도에 관한 사례 연구)

  • Bae, Jung-Min;Jung, Man-Jin;Ha, Dong-Yeup;Jung, Ho-Keun;Jung, Ki-Hun;Jung, Byung-Wook;Oh, Min-Koo;Bae, Sung-Han;An, Woo-Sup
    • Journal of agricultural medicine and community health
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    • v.30 no.2
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    • pp.205-211
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    • 2005
  • Objectives: In Ulleung island, many people was suffered from dermatomycosis. But many patients was not recognized to dermatomycosis due to little symptom. So, public health education was needed. We will plan education direction based on evidence. So, in one way, the recognition level was needed to determine education direction. Methods: From June to July in 2005, 45 patients was made a question. The questionnaire was composed of chief complaint, site, duration, similar disease in family, 5 questiones and so on. If patients was recognized to 1 question, 1 score was added. Remain 4 question was done in same manner. Results: The low score group were that total socre was beyond 2. And The high score group were that total score was above 3. The low score group was 24 persons, average age was 59. The high score group was 21 persons and average age was 42. Male and female ratio was 7 : 17 in low score group and 10 : 11 in high score group. Coinfection was 17 patients in low score group and 2 patients in high score group. There was only 17 patients that wete recognized that dermatomycosis and "Moozom" were same disease. And, many patients was not recognized to possibility of reinfection after treatment of dermatomycosis. Conclusions: In Ulleung island, coinfection rate was higher than other area bacause of low recognition level. And infection rate in family was higher too. So, there was essential to educate of dermatomycosis prevention. Dermatomycosis patient became older and was more female than other area, so there was need to centralize people to be needed of public health education. Finally, many statistical study for dermatomycosis should be needed for many patients and general populations in Ulleung island.

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EFFECT OF POLYPHOSPHATE IN ROOT CANAL SEALERS ON THE GROWTH OF ORAL BACTERIA (Polyphosphate가 함유된 근관충전재가 구강세균의 성장에 미치는 영향)

  • 박석범;최기운;최호영
    • Restorative Dentistry and Endodontics
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    • v.26 no.2
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    • pp.141-152
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    • 2001
  • Eliminating the infecting bacteria of the root canal system and preventing reinfection must be the main objectives of all endodontic works. None of commercially available root canal sealers have the properties of desirable tissue compatibility and strong antibacterial activity. The purpose of this study is to develope an ideal root canal sealer using commercially available polyphosphate (polyP), Calgon, which is known to be antibacterial and safe. For the study. resin type AH26, zinc oxide eugenol type Tubli Seal. Ca(OH)$_2$ type Apexit as base sealers for polyP (0~3%) and para formaldehyde containing N2 as a control base were selected. Specimens (3$\times$4mm) of the sealers were prepared in a 37$^{\circ}C$ incubator for 3 and 10 days and their antibacterial activity against streptococci and black pigmented anaerobic rods was observed using an agar diffusion method. The result were as follows: 1. Among 3 day old root canal sealers. N2 as a positive control showed the strongest antibacterial effect. followed by AH26. Tubli Seal and. Apexit which barely showed antibacterial activity against the test bacteria. In contrast. 10 day old AH26 showed a greater antibacterial activity than 10 day old N2. 2. All sealer specimens showed a greater antibacterial activity against black pigmented anaerobic rods than streptococci. Three day old ones appeared to be more antibacterial than 10 day old ones except for Apexit. 3. As compared to N2, 3 day old AH26 demonstrated a similar antibacterial activity against black pig mented anaerobic rods but to a lesser extent to streptococci. Ten day old AH26 showed a greater antibacterial activity against black pigmented anaerobic rods than 10 day old N2. 4. As compared to AH26. Tubli Seal generally revealed a lower antibacterial activity but it showed a greater antibacterial activity aginst S. gordonii Challis. 5. Enhancement of antibacterial activity by polyP was more clearly observed when it was added to Ca(OH)$^{\circ}C$ based root canal sealers. Tubli Seal and N2. 6. The addition of polyP enhanced the antibacterial activity of 3 day old AH26 against S. gordonii G9B (16%) and Challis (29%), and P. gingivalis 2561 (24%) only. Moreover, polyP failed to increase antibacterial activity of 10 day old AH26 against the test strains but P. gingivalis A7A1 28(13%). 7. The addition of polyP increased the antibacterial effect of 3 day old Tubli Seal on several test bacteria including s. mutans GS 5 (50%). s. gordonii G9B (47%) and Challis (122%). and all the test strains of P. gingivalis (13~35%) except for 9 14K 1. The addition of polyP to 10 day old Tubli Seal increased antibacterial activity of the root canal sealer against most test strains. 8. 3 day old Apexit failed to show antibacterial activity. if any very little against S. mutans GS 5 and Pr. intermedia ATCC 49046. However. polyP increased its antibacterial activity by 50 and 69%, respectively. Increase of antibacterial activity of 10 day old Apexit by polyP was more clearly observed than that of 3 day old one.

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Antibiotic Spacers in Shoulder Arthroplasty: Comparison of Stemmed and Stemless Implants

  • Padegimas, Eric M;Narzikul, Alexia;Lawrence, Cassandra;Hendy, Benjamin A;Abboud, Joseph A;Ramsey, Matthew L;Williams, Gerald R;Namdari, Surena
    • Clinics in Orthopedic Surgery
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    • v.9 no.4
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    • pp.489-496
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    • 2017
  • Background: Antibiotic spacers in shoulder periprosthetic joint infection deliver antibiotics locally and provide temporary stability. The purpose of this study was to evaluate differences between stemmed and stemless spacers. Methods: All spacers placed from 2011 to 2013 were identified. Stemless spacers were made by creating a spherical ball of cement placed in the joint space. Stemmed spacers had some portion in the humeral canal. Operative time, complications, reimplantation, reinfection, and range of motion were analyzed. Results: There were 37 spacers placed: 22 were stemless and 15 were stemmed. The stemless spacer population was older ($70.9{\pm}7.8years$ vs. $62.8{\pm}8.4years$, p = 0.006). The groups had a similar percentage of each gender (stemless group, 45% male vs. stemmed group, 40% male; p = 0.742), body mass index (stemless group, $29.1{\pm}6.4kg/m^2$ vs. stemmed group, $31.5{\pm}8.3kg/m^2$; p = 0.354) and Charlson Comorbidity Index (stemless group, $4.2{\pm}1.2$ vs. stemmed group, $4.2{\pm}1.7$; p = 0.958). Operative time was similar (stemless group, $127.5{\pm}37.1minutes$ vs. stemmed group, $130.5{\pm}39.4minutes$). Two stemless group patients had self-resolving radial nerve palsies. Within the stemless group, 15 of 22 (68.2%) underwent reimplantation with 14 of 15 having forward elevation of $109^{\circ}{\pm}23^{\circ}$. Within the stemmed group, 12 of 15 (80.0%, p = 0.427) underwent reimplantation with 8 of 12 having forward elevation of $94^{\circ}{\pm}43^{\circ}$ (range, $30^{\circ}$ to $150^{\circ}$; p = 0.300). Two stemmed group patients had axillary nerve palsies, one of which self-resolved but the other did not. One patient sustained dislocation of reverse shoulder arthroplasty after reimplantation. One stemless group patient required an open reduction and glenosphere exchange of dislocated reverse shoulder arthroplasty at 6 weeks after reimplantation. Conclusions: Stemmed and stemless spacers had similar clinical outcomes. When analyzing all antibiotic spacers, over 70% were converted to revision arthroplasties. The results of this study do not suggest superiority of either stemmed or stemless antibiotic spacers.

Mitral Valve Repair for Active and Healed Endocarditis (급성 혹은 치유된 심내막염 환자에서의 승모판막성형술)

  • Baek, Man-Jong;Na, Chan-Young;Oh, Sam-Sae;Kim, Woong-Han;Whang, Sung-Wook;Lee, Cheol;Kang, Chang-Hyun;Chang, Yun-Hee;Jo, Won-Min;Kim, Jae-Hyun;Seo, Hong-Ju;Kim, Wook-Sung;Lee, Young-Tak;Kim, Chong-Whan
    • The Korean Journal of Thoracic and Cardiovascular Surgery
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    • v.36 no.11
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    • pp.820-827
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    • 2003
  • Background: Mitral valve repair rather than replacement for mitral regurgitation (MR) offers a number of well-accepted benefits. However, the surgical results of repair for mitral valve endocarditis remain largely unknown. Material and Method: Fourteen patients who underwent mitral valve repair for MR caused by mitral valve endocarditis from April 1995 through October 2001 were reviewed retrospectively. There were 9 male patients and mean age was 32$\pm$10 years. Four patients had previous embolism and 2 had active infections. The grade of MR were III in 6 patients and IV in 8. Operatively, mitral annuloplasty was performed in 12 patients and various valvuloplasty techniques were applied in all patients. One patient had immediate valve replacement due to residual MR after weaning of cardiopulmonary bypass. Result: There was no early operative death. Early postoperative transthoracic echocardiography revealed no or grade I of MR and no or mild mitral stenosis in 13 patients. After the mean follow-up of 36 months, there was no late death, and no or grade I of MR in 11 patients (84.6%) and no or mild mitral stenosis in 12 patients (92.3%). Reoperation required in one patient (7.1%). The cumulative freedom from recurrent MR and valve-related reoperation at 5 years were 91$\pm$9% and 75$\pm$22%, respectively. Conclusion: This study suggests that mitral valve repair for mitral regurgitation caused by endocarditis offers good early and intermediate survival and functional improvement without reinfection, and it is an attractive alternative to valve replacement in selective patients with bacterial endocariditis.

Final Report of China-Korea Collaborative Project of Control Strategies of Clonorchiasis in Heilongjiang Pilot Areas(2001-2004) (중국 흑룡강성 간흡충증 관리사업(2001-2004))

  • Ji, Zhuo;Li, Zhimin;Wang, Shuyu;Yuan, Ren;Ge, Tao;Yuan, Shang;Cui, Changyuan;Ge, Hongan;Feng, Zheng;Xu, Longqi;Hong, Sung-Tae;Choi, Min-Ho;Cho, Seung-Yull;Choi, Dong-Il;Hong, Kwang-Seon;Rim, Han-Jong;Lee, Soon-Hyung
    • Journal of Korea Association of Health Promotion
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    • v.3 no.1
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    • pp.72-83
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    • 2005
  • The present pilot project was executed to recommend a strategy of clonorchiasis control in China. The pilot area of this project was Zhaoyuan, Hailin, and Ningan, Heiloagjiang province. A baseline survey subjecting 4,865 residents in Heilongjiang confirmed Zhaoyuan asa high endemic area and Hailin and Ningan as moderate endemic areas. Six different control strategies were implemented in Zhaoyuan, two were in Hailin, and one was in Ningan. Including the baseline survey and project programs from 2000 to 2004, total 63,274subject-times were examined of their feces for Clonorchiseggs, 26,680 were treated, 10,082 were screened by ELISA, and 6,130 subjects were examined of their liver by sonography. The egg Positive rates in 6 villages of Zhaoyuan were as high as 44.8% 70,0%. Following the protocolof each strategy, the subjected residents were examined of their feces and treated with 25 mg/kg praziquantel, 3 times. Except the control group, all of the villages showed 72.8% to 92.0% reduction of their original egg Positive rates at Zhaoyuan. Mass treatments of all subjected residents in 2001 and 2003 reduced the egg rate from 68.8% to18.7% and 4 annual mass treatments reduced the rate from 44.8% in 2001 to 8.7% in 2004.Selective annual treatments of egg positive subjects reduced the egg rates from 50.8% in2001 to 13.8% in 2004 or from 70.0% in 2001 to 11.6% in 2004, and two treatments in a year reduced the rate from 57.6% in 2001 to 4.6% in 2004. According to repeated treatments, EPG counts decreased remarkably. In moderate endemic areas, the original egg rates were 22.6% and 28.3% in 2001 but were 1.7% and 1.1% after 2 or 3 selective treatments. The present findings of the chemotherapeutic control of clonorchiasis prove that repeated medication is important. The reduction is directly correlated with dose of praziquantel but not with mass or selective treatments. Chemotherapeutic control of reservoirhosts has little effect on reinfection of clonorchiasis because the field along the Songhua-jiang is too wide to be impacted. ELISA confirmed many serologically positive cases to Clonorchisantigen but only a few cases were positive to other antigens (Paragonimus, cysticercus, sparganum). The abdominal soaography visualized intrahepatic bile duct dilatation and periductal echo in 2,002 of 6,070 examined subjects. In addition to these examinations and treatment, health education supplemented tㅗe control activities. The present findings prove clonorchiasis is very widely prevalent and heavily endemic along the rivers in Heiloagjiang. The results suggest that group chemotherapy with praziquantel is effective to reduce endemicity of clonorchiasis. Mass treatment without individual fecal examination is recommended in heavy endemic areas where the egg rate is over 40% while one selective treatment is effective enough in moderate endemic areas.

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Therapeutic Outcome and Recurrence Rate of Helicobacter pylori Infection in Children (소아에서 Helicobacter pylori 감염에 대한 치료결과 및 재발률)

  • Choi, Won-Jun;Kim, Je-Woo;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.1 no.1
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    • pp.37-44
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    • 1998
  • Purpose: This study aimed at evaluating the therapeutic outcome, cost effectiveness and recurrence rate in children with H. pylori infection after the treatment using various medications. Methods: Seventy five children (mean age $11.4{\pm}2.5$ years) were given an endoscopy with biopsy and H. pylori status assessed by CLO test and histologic examination (Warthin Starry stain). Children were given one of following medications such as DA ($Denol^{(R)}$ and amoxycillin), OA (omeprazole and amoxycillin), DC ($Denol^{(R)}$ and clarithromycin) as primary treatment. And one of following medications such as DAM ($Denol^{(R)}$, amoxycillin and metronidazole), DC, OA, OC (omeprazole and clarithromycin) were used in children who failed the eradication of H. pylori. Results: The endoscopic diagnoses were: nodular gastritis (46 cases), gastric ulcer (9), duodenal ulcer (6), superficial gastritis (6), and normal (8). H. pylori eradication rate was 91% (63 of 69 children) on 4 weeks course of DA, 50% (1 of 2 cases who had treatment failure on DA) on DAM, and 75% (3 of 4 cases who treated on DC primarily) and 50% (1 of 2 cases who had treatment failure on DA) on DC, and 100% on OA (all of 2) and on OC (all of 1 who failed on DA). In 3 of 7 children in whom H. pylori had not been eradicated by primary medications (DA 6 and DC 1 case), H. pylori was re-eradicated by secondary medications (DA 1, DAM 1 and DC 1 case). But in remaining 4 cases, H. pylori infection persisted. Reinfection of H. pylori was found in 4 of 75 children between 3 months and 3 years after completion of the treatment of DA, yielding recurrence rate of 5.3%. In 2 of 4 cases who had relapsed, H. pylori was re-eradicated by secondary medications (OC 1 and DA 1 case). But in remaining 2 cases, H. pylori infection persisted. Conclusion: These results suggest that dual therapy with $Denol^{(R)}$ and amoxycillin is the effective medications in treating H. pylori infection in children. Concerning the cost effectiveness, it can be recommended as first line treatment of choice as well.

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Control of Human Clonorchiasis at Gokseong-gun and Sunchang-gun near the Sumjin River in Korea (섬진강 유역 곡성군, 순창군 지역 주민의 간흡충증 관리)

  • Kim, Suk-Il;Yun, Woo-Sang
    • Journal of agricultural medicine and community health
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    • v.29 no.1
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    • pp.163-175
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    • 2004
  • Objectives: This study was carried out to decrease the prevalence of human clonorchiasis and to evaluate the control effect in two Clonorchis sinensis-endemic area of Gokseong-gun and Sunchang-gun adjacent to the Sumjin River in Korea. Methods: The formalin-ether concentration method for stool egg examination or ELISA was applied for the diagnosis of clonorchiasis. As a primary survey, according to the non-probability sampling, a total of 1,2.13 inhabitants at Gokseong-gun were screened through the stool examination, and 1,004 inhabitants at Sunchang-gun were screened through the ELISA. The humans infected with C. sinensis were medicated with praziquantel and educated for the prevention of reinfection with the fluke. After 9 months, as a secondary survey, each prevalence of 616 inhabitants at Gokseong-gun and 2.637 inhabitants at Sunchang-gun was followed-up for the decrease of human clonorchiasis. Results: The prevalence before the mass control was 39.0% at Gokseong-gun and 30.1% at Sunchang-gun in average from 61.5% to 8.9% according to the villages (Myeon) of the survey. In the riverside villages to the Sumjin River the prevalences were higher than other villages located far from the river. The prevalence after the control was decreased to the level of 22.4% at Gokseong-gun(P<0.0001) and 16,3% at Sunchang-gun (P<0.0001). Conclusions: These results suggested that human clonorchiasis was still highly endemic in riverside area of the Sumjin River and could be decreased through the control activities such as diagnosis, medication and education. It was highly recommended that a integrated control such as those of the present study must be adopted in other localities along the Sumjin River for the eradication of human clonorchiasis.

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Growth and Yield Variations among Generations in Field Cultivation of Virus-free Sweet Potato Plants (고구마 바이러스 무병묘의 세대간 생육 및 수량 변이)

  • Lee, Seung Yeob;Lee, Na Ra
    • Protected Horticulture and Plant Factory
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    • v.23 no.4
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    • pp.376-382
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    • 2014
  • This work was conducted to investigate the variation of growth and yield among three generations ($TC_0$, $TC_1$, and $TC_2$) in the field cultivation of virus-free sweetpotato (Ipomoea batatas) plants. Virus-free generations of three cultivars ('Matnami', 'Shinhwangmi', and 'Yeonhwangmi') were cultivated with $75{\times}25cm$ planting density on May 20th, covered with black vinyl film. At 30 days after planting, vine growth in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, and vine length in $TC_0$ showed the highest growth among treatments. At harvesting time after 120 days, vine diameter, number of node, and number of branch in $TC_0$, $TC_1$, and $TC_2$ were more increased than farmer's plant, but were not statistically significant. Fresh weight of shoot in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, but was not statistically significant among generations or cultivars. Number of tuber per plant and mean weight of tuber in $TC_0$ and $TC_1$ showed significant increasement, but that in $TC_2$ did not show significant difference as compared to the farmer's plant. Weight of tuber per plant in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. Marketable yield, percentage of marketable tuber, and percentage of small tuber (40 to 200g) in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. The large tuber over 300g showed the lowest percentage in $TC_0$. Marketable yield in $TC_2$ was significantly decreased as compared to $TC_0$, and was not significantly different as compared to the farmer's plant. Marketable yield in 'Matnami' was highest among cultivars. From this results, Farmers are required to renew every three years to maintain the yield and quality of virus-free plants. However, the exchange period of virus-free plants is desirable to renew every 2 or 3 years according to the degree of virus reinfection.