Classification of Type 2 Diabetes Incidence Risk and the Health Behavior of the 30-50-Year-Old Korean Adults: Latent Class Analysis.

This study aimed to categorize the risk of type 2 diabetes mellitus development (T2DD) in the 30-50-year-old (3050) Korean adults and establish a baseline framework of customized management to prevent the progression to diabetes. A total of 9515 participants were enrolled in the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2019. Latent class analysis (LCA) was performed based on the health behaviors that were obtained from the secondary data source and were considered to affect T2DD. The major results were compared by latent class, multinomial regression analysis was performed, and the predicted risk of T2DD was evaluated using a self-assessment tool for Korean adults. Data analysis was performed using SPSS (ver. 25.0) and Mplus (ver. 8.6). The latent classes were divided into four categories: negative abdominal obesity and high-risk health behavior (Class A) (28.2%), negative abdominal obesity and low-risk health behavior (Class B) (37.1%), positive abdominal obesity and high-risk health behavior (Class C) (10.7%), and positive abdominal obesity and low-risk health behavior (Class D) (23.9%). The predicted risk scores for T2DD were 6.27 (Class C), 4.50 (Class D), 3.58 (Class A), and 2.16 (Class B), with a higher score indicating a worse state. Significant differences were observed in the predicted risk of T2DD between the latent classes, and abdominal obesity increased the risk. When managing the 30s-50s Korean generation physical activity and abdominal obesity control are strongly recommended.

COVID-19 and mental health: Anxiety disorders among immigrants due to COVID-19 outbreak in South Korea.

BACKGROUND: The COVID-19 pandemic has affected various facets of health. While mental health became a major concern during the COVID-19 outbreak, the impact on the migrants' mental health has still been neglected. The purpose of this study was to examine the COVID-19 outbreak's impact on the mental health of immigrants in South Korea. METHODS: A total number of 386 immigrants in South Korea participated in this quantitative cross-sectional study. The standardized e-questionnaire, including the General Anxiety Disorder (GAD-7) scale, was used to measure the anxiety level. Logistic regression analysis was performed to find out the determinants of anxiety disorders among immigrants. RESULTS: The prevalence of severe anxiety among immigrants was found to be 47.2%. Female immigrants (28.6%) had a lower anxiety disorder than males (71.4%). Immigrants who were married, living alone, had a low income, had a history of health problems were suffered from moderate to severe anxiety. Immigrants who were unemployed (OR 2.302, 95% CI = 1.353-3.917) and lost their jobs due to the COVID-19 outbreak (OR 2.197, 95% CI = 1.312-3.678) have a higher anxiety disorder. Immigrants aged over 30 years were found to suffer from a high level of anxiety (OR 2.285, 95% CI = 1.184-4.410). Relief support from the government was significantly associated with anxiety disorder among immigrants (p < 0.01, OR = 3.151, 95% CI = 1.962-5.061). CONCLUSION: With very limited studies on immigrants' mental health during the COVID-19 pandemic, this paper provides scientific research evidence of the COVID-19 outbreak's impact on the mental health of migrants. Our study has consequences for implementing integrated psychological interventions and health promotion strategies for the well-being of immigrants' mental health.

The influence of regional deprivation index on personal happiness using multilevel analysis.

OBJECTIVES: The objective of the present study was to identify the factors that influence the happiness index of community residents, by considering personal and regional aspects, and to use as evidence of efforts for improvement of the happiness index. METHODS: The study was conducted based on information from 16,270 participants who met the data requirement among those who participated in the 2011 South Gyeongsang Community Health Survey. Of the factors that can influence the happiness index, socioeconomic characteristics, health behavior, morbidity, and healthcare use, social contact, and participation in social activities were classified as personal factors; for regional factors, data from the 2010 census were used to extrapolate the regional deprivation indices at the submunicipal-level (eup, myeon, and dong) in South Gyeongsang Province. The happiness index for each characteristic was compared to that for others via t-test and ANOVA, and multilevel analysis was performed, using four models: a basic model for identification of only random effects, model 1 for identification of personal factors, model 2 for identification of regional factors, and model 3 for simultaneous consideration of both personal and regional factors. RESULTS: The mean happiness index was 63.2 points (64.6 points in males and 62.0 points in females), while the mean deprivation index was -1.58 points. In the multilevel analysis, the regional-level variance ratio of the basic model was 10.8%, confirming interregional differences. At the personal level, higher happiness indices were seen in groups consisting of males with high educational level, high income, high degree of physical activity, sufficient sleep, active social contact, and participation in social activities; whereas lower happiness indices were seen in people who frequently skipped breakfast, had unmet healthcare needs, and had accompanying diseases, as well as those with higher deprivation index. CONCLUSIONS: The study confirmed that the happiness index of community residents was influenced by not only personal aspects but also various regional characteristics. To increase the happiness index, interests at both personal and regional levels, as well as community emphasis on creating social rapport and engaging in selective efforts, are needed in vulnerable regions with relatively high deprivation index.

Poor agreement between QuantiFERON-TB Gold test and tuberculin skin test results for the diagnosis of latent tuberculosis infection in rheumatoid arthritis patients and healthy controls.

BACKGROUND/AIMS: We investigated the agreement between the QuantiFERON-TB Gold (QFT-Gold) test and the tuberculin skin test (TST) in the diagnosis of latent tuberculosis infection in patients with rheumatoid arthritis (RA), compared with healthy controls, in Korea. METHODS: We recruited 64 patients with RA and 79 healthy controls at two university hospitals in South Korea. The participants underwent both the QFT-Gold test and the TST simultaneously between August 2006 and February 2009. All patients were diagnosed using the classification criteria for RA revised in 1987 by the American College of Rheumatology. Bacillus Calmette-Guérin vaccination status and current medications were evaluated, and disease activities were assessed using the Disease Activity Score in 28 joints. Eleven patients with RA produced indeterminate QFT-Gold test results and were thus excluded from the kappa analysis. RESULTS: Based on an induration of 10 mm in diameter as the TST cutoff value, the QFT-Gold test and TST demonstrated 75.0% agreement (κ = 0.23) in patients with RA and 75.9% agreement (κ = 0.19) in healthy controls. Among the 56 patients with RA who had negative TST results, 11 patients (17.2%) also yielded indeterminate QFT-Gold results. CONCLUSIONS: Our study showed poor agreement between the results of the QFT-Gold test and the TST in both RA patients and healthy controls. Based on these findings, we emphasize the importance of making clinical decisions in the diagnosis of latent tuberculosis in Koreans with or without RA.

Happiness, subjective and objective oral health status, and oral health behaviors among Korean elders.

OBJECTIVES: This study aims to comprehensively assess the association of subjective and objective oral health status and oral health behaviors with happiness, under consideration of demographic, socioeconomic, and general health-related factors. This study also aims to test whether subjective oral health outcomes are better predictors of happiness compared with objective oral health outcomes. METHODS: The data were collected from 479 community-dwelling elders aged 65 years or over selected by a cluster sampling method. A questionnaire and an oral examination were implemented. A multiple regression method was conducted to assess associations with happiness index (HI). RESULTS: The mean age of the elders was 74.6 years. Mean (standard deviation, SD) HI, EuroQol-visual analog scale (EQ-VAS) and 14-item oral health impact profile (OHIP-14) index were 5.7 (SD 2.3), 59.8 (SD 21.1), and 16.3 (SD 13.1). In the final model, a significant association with HI of the OHIP-14 index (P = 0.091) among all the participants and significant associations of oral symptoms (P = 0.038), wearing a removable denture (P = 0.039), and of the oral health behavior of daily toothbrushing (P = 0.007) among poorer oral health QoL group were confirmed under consideration of other related factors. While correlations of HI to subjective measures of health, EQ-VAS and OHIP-14 score were moderate to weak, those to objective measures of health were only weak or insignificant. CONCLUSIONS: Oral impacts which might persistently affect one's daily life need to be considered in designing and delivering public services aimed to promote people's happiness. With oral health impacts and behaviors accounting for 10% of happiness among elders, public and community services for the elderly that support oral health and daily toothbrushing for the dentate are critical for the well-being of our elders.

The effect of cilostazol on the expression of matrix metalloproteinase-1 and type I procollagen in ultraviolet-irradiated human dermal fibroblasts.

AIM: Cilostazol is a selective inhibitor of type III phosphodiesterase that inhibits platelet aggregation. Cilostazol is a useful vasodilator, antithrombotic, and cardiotonic agent. Ultraviolet B (UVB) irradiation increases the production of matrix metalloproteinase-1 (MMP-1) during skin photoaging. The UVB-induced increase of MMP-1 results in connective tissue damage, and the skin becomes wrinkled and aged. Here, we investigated the capacity of cilostazol to inhibit MMP-1 expression in UVB-irradiated human dermal fibroblasts. MAIN METHODS: Cultured human dermal fibroblasts were irradiated with UVB, followed by the addition of cilostazol to the culture medium. KEY FINDINGS: Post-treatment with cilostazol attenuated UVB-induced production of MMP-1 and prevented the reduction of type I procollagen. Cilostazol inhibited UVB irradiation-induced phosphorylation of the mitogen-activated protein kinase (MAPK) signaling molecules Jun-N-terminal kinase (JNK) and p38 kinase, as well as activator protein-1 (AP-1) in dermal fibroblasts. SIGNIFICANCE: Overall, these results demonstrate that cilostazol regulates UVB-induced MMP-1 expression and type I procollagen synthesis by inhibiting MAPK signaling and AP-1 activity. Therefore, we suggest that cilostazol may be useful for the prevention and treatment of skin photodamage caused by UVB-irradiation.

Meta-analysis of three randomized trials and nine observational studies comparing drug-eluting stents versus coronary artery bypass grafting for unprotected left main coronary artery disease.

Clinical outcomes for unprotected left main coronary artery (ULMCA) disease between coronary artery bypass grafting (CABG) and drug-eluting stents (DESs) remain controversial. We aimed to compare the safety and efficacy of percutaneous coronary intervention (PCI) using DESs with CABG in patients with ULMCA disease. Databases were searched for clinical studies that reported outcomes after PCI with DESs and CABG for treatment of ULMCA disease. End points of this meta-analysis were mortality; composite of death, myocardial infarction (MI), or stroke; and target vessel revascularization at 1-year follow-up. Pooled effects were calculated using fixed-effects model (Mantel-Haenszel method) or random-effects models (Dersimonian-Laird method). Twelve clinical studies (3 randomized trials and 9 observational studies) with 5,079 patients were involved in this study. At 1-year follow-up, there were trends toward lower risk of death (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.45 to 1.02) and the composite end point of death, MI, or stroke (OR 0.70, 95% CI 0.49 to 1.00) in the DES group compared to the CABG group. However, target vessel revascularization was significantly higher in the DES group compared to the CABG group (OR 3.52, 95% CI 2.72 to 4.56). In conclusion, PCI with DESs is associated with favorable outcomes for mortality; composite end point of death, MI, or stroke; and a higher risk of target vessel revascularization compared to CABG in patients with ULMCA disease.

Clinicopathological significance of altered Notch signaling in extrahepatic cholangiocarcinoma and gallbladder carcinoma.

AIM: To investigate the role and clinicopathological significance of aberrant expression of Notch receptors and Delta-like ligand-4 (DLL4) in extrahepatic cholangiocarcinoma and gallbladder carcinoma. METHODS: One hundred and ten patients had surgically resected extrahepatic cholangiocarcinoma (CC) and gallbladder carcinoma specimens examined by immunohistochemistry of available paraffin blocks. Immunohistochemistry was performed using anti-Notch receptors 1-4 and anti-DLL4 antibodies. We scored the immunopositivity of Notch receptors and DLL4 expression by percentage of positive tumor cells with cytoplasmic expression and intensity of immunostaining. Coexistent nuclear localization was evaluated. Clinicopathological parameters and survival data were compared with the expression of Notch receptors 1-4 and DLL4. RESULTS: Notch receptor proteins showed in the cytoplasm with or without nuclear expression in cancer cells, as well as showing weak cytoplasmic expression in non-neoplastic cells. By semiquantitative evaluation, positive immunostaining of Notch receptor 1 was detected in 96 cases (87.3%), Notch receptor 2 in 97 (88.2%), Notch receptor 3 in 97 (88.2%), Notch receptor 4 in 103 (93.6), and DLL4 in 84 (76.4%). In addition, coexistent nuclear localization was noted [Notch receptor 1; 18 cases (18.8%), Notch receptor 2; 40 (41.2%), Notch receptor 3; 32 (33.0%), Notch receptor 4; 99 (96.1%), DLL4; 48 (57.1%)]. Notch receptor 1 expression was correlated with advanced tumor, node, metastasis (TNM) stage (P = 0.043), Notch receptor 3 with advanced T stage (P = 0.017), tendency to express in cases with nodal metastasis (P = 0.065) and advanced TNM stage (P = 0.052). DLL4 expression tended to be related to less histological differentiation (P = 0.095). Coexistent nuclear localization of Notch receptor 3 was related to no nodal metastasis (P = 0.027) and Notch receptor 4 with less histological differentiation (P = 0.036), while DLL4 tended to be related inversely with T stage (P = 0.053). Coexistent nuclear localization of DLL4 was related to poor survival (P = 0.002). CONCLUSION: Aberrant expression of Notch receptors 1 and 3 play a role during cancer progression, and cytoplasmic nuclear coexistence of DLL4 expression correlates with poor survival in extrahepatic CC and gallbladder carcinoma.

Therapeutic evaluation of sustained-releasing praziquantel (SRP) for clonorchiasis: phase 1 and 2 clinical studies.

Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers). In the phase 1 clinical study, blood concentrations of both tablets showed wide individual variation. The AUClast of SRP was 497.9 +/- 519.0 ng * hr/ml (mean +/- SD) and PZQ of 628.6 +/- 695.5 ng * hr/ml, and the AUCinf of SRP was 776.0 +/- 538.5 ng * hr/ml and of PZQ 658.6 +/- 709.9 ng * hr/ml. Cmax values of SRP and PZQ were 90.7 +/- 82.2 ng/ml and 214.9 +/- 251.9 ng/ml, and Tmax values were 3.42 +/- 1.43 hr and 1.96 +/- 1.23 hr, respectively. SRP tablets showed similar AUC values, but lower Cmax and longer Tmax values than PZQ. In the phase 2 study, SRP at 30 mg/kg (single dose) achieved a 60% cure rate and a 95.5% egg reduction rate. The cure rate of a single dose SRP was unsatisfactory compared with that of the conventional PZQ dose, but much better than that achieved by a single dose PZQ.

Interleukin-4 C-590T polymorphism is associated with protection against nasal polyps in a Korean population.

BACKGROUND: Although many studies have implicated interleukin (IL)-4 promoter polymorphisms as potential determinants of disease susceptibility, there are no reports on the association between IL-4 promoter polymorphisms and nasal polyps. The aim of this study was to investigate the relationship between an IL-4 promoter polymorphism and nasal polyps. METHODS: The C-590T promoter polymorphism of the IL-4 gene was genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis in 106 Korean chronic rhinosinusitis patients with or without nasal polyps and 70 healthy Korean subjects. RESULTS: The frequency of the T allele at position -590 of the IL-4 gene in a Korean population was 0.85, which was significantly higher than those of other ethnic groups, and the T/T allele at position -590 of IL-4 was associated with protection against nasal polyps if compared with the C/C allele (relative risk, 0.529; 95% confidence interval, 0.307-0.912; p = 0.028). CONCLUSION: T-590, which is dominant at position -590 of the IL-4 promoter, appears to be associated with a protective mechanism against nasal polyps in Korean populations.

[Determining factors of intention to actual use of charged long-term care services for the aged].

OBJECTIVES: To help develop strategies to cope with the changes arising from the rapid aging process by predicting the determining factors of intention to actual use of the charged long-term care services for elderly as perceived by the middle aged who play the major role of supports. METHODS: Subjects were the parents (men 177, women 507) in their 40s of the students selected from a university of Busan city. A questionnaire survey was conducted for 4 weeks in October 2003 about the knowledge for long-term care service, the intention of actual use, and the preferences about the type of service suppliers. Data analysis was performed with frequency, chi-square test, and t-test using SPSS program (ver 10.0K), along with data mining using decision tree of Enterprise Miner V8.2 by SAS. RESULTS: About half of the subjects (53.7%) had the actual experiences of elderly supports. Intentions to use the charged services were relatively high in home visiting nursing care service (40.1%) and long-term care facilities service (40.4%), and were influenced by previous knowledge about the services. The intentions were stronger in women, those with higher education, and those with greater income levels. Actual elderly supports were mc (80%) done by women, and the perceived burdens for supports were bigger in women and those of lower s economic level. Desired charges were about 10,000 for the bath service, 20,000 won for the rests services day, and about 500,000 won for the long-term care facil service per month. From the result of decision analysis, the job professionalism was the most impol determining factor of intention to actual use of the serv with validation as 63-71%. Health and welfare mixed facilities were preferred, and the most impor consideration was the level of professionalism. CONCLUSIONS: Intention to actual use of the chad services was largely determined by the aspects of time cost. Polices to increase the number of service supp and to decrease the burdens perceived by ac supporters were strongly recommended.

Effects of Chromium (VI) Exposure on the Placental Function and Reproduction in Rats.

OBJECTIVE: This study aimed to investigate the toxic effects of chromium (VI) on the placental function and reproduction in rats. For the study, the placental prolactin-growth hormone (PRL-GH) gene expression, placental trophoblast cell differentiation and reproductive data were analyzed. METHODS: The pregnancies of F344 Fisher rats were checked by the presence of a copulatory plug or sperm in the vaginal smear, which was defined as day 0 of the pregnancy. Pregnant rats were divided into the three groups. The control group was given tap water (chromium level < 0.001 ppm) and the remaining groups were given 250 or 750 ppm of chromium (VI) [as potassium dichromate], from day 7 to 19 of the pregnancy. Rats were sacrificed at days 11 and 20 of pregnancy. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcriptionpolymerase chain reaction (RT-PCR). The hormonal concentration was analyzed by radioimmunoassay, and the differentiation of placental trophoblast cells were observed by histochemical studies. Reproductive data, such as placental and fetal weights, pregnancy period, and litter size, were surveyed at day 20 of pregnancy and after birth. A statistical analysis was carried out using the SAS program (version 8.1). RESULTS: The mRNA levels of the prolactin-growth hormone (PRL-GH) family of genes were dose dependently reduced by chromium exposure. The mRNA levels of Pit-1a and b isotype genes that induce the expression of the PRL-GH family of genes were also reduced by chromium exposure. The PRL-GH hormonal concentration in the rat placenta, fetus and maternal blood were decreased by chromium exposure. In the middle stage of pregnancy (day 11), a high dose of chromium suppressed the differentiation of spongiotrophoblast cells that secret the PRLGH hormones. In the last stage of pregnancy (day 20), a high dose of chromium induced apoptosis of placental cells. Reproductive data, such as placental and fetal weights, litter size, were reduced, but the pregnancy period was extended in the group exposed to chromium compared with the controls. CONCLUSIONS: Chromium (VI) disrupts the ordered functions of the placenta, which leads to reproductive disorders in rats.

Evaluation of field epidemiology specialist training program based on the satisfaction and the changes of educational needs.

OBJECTIVE: To evaluate the learning achievement and satisfaction levels for the Field Epidemiology Specialist Training Program (FESTP), on infectious disease control between March 19 and October 31, 2002. METHODS: The FESTP was designed as a set of 84 hours curricula including lectures, discussions, self-studies, and field practicals, and organized both centrally and locally by the Division of Communicable Disease Control of the National Institute of Health and 11 universities. Before and after the program, a questionnaire survey on the educational need (49 items) and satisfaction (15 items) was conducted on 484 trainees, who were responsible for communicable disease control and immunization at 242 regional health centers. The data were analyzed with paired t-tests for comparison of the educational needs between the pre and post scores. RESULTS: The average score for satisfaction was 3.06 out of 5.0; with relatively higher scores for sincerity (4.10) and professionalism (4.01) of the tutors, adequacy (3.54) and clearness (3.51) of the evaluation criteria, usefulness (3.54) and fitness (3.52) of the contents, but with relatively lower satisfaction for schedule (2.96) and self-studies (2.91). The average for requirement for education improved, as shown by the decrease from 2.72 to 2.22 (p< .0001) with the biggest decrease in the outbreak investigation from 2.60 to 2.08. CONCLUSIONS: The FESTP was evaluated as being effective, the trainees showed moderate satisfaction and decrease educational needs. However, the actual schedules and self-studies should be rearranged to improve the satisfaction level.

Stereoselective metabolism of lansoprazole by human liver cytochrome P450 enzymes.

The stereoselective metabolism of lansoprazole enantiomers was evaluated by incubation of human liver microsomes and cDNA-expressed cytochrome p450 (p450) enzymes to understand and predict their stereoselective disposition in humans in vivo. The intrinsic clearances (Clint) of the formation of both hydroxy and sulfone metabolites from S-lansoprazole were 4.9- and 2.4-fold higher than those from the R-form, respectively. The sums of formation Clint of both metabolites were 13.5 and 57.3 microl/min/mg protein for R- and S-lansoprazole, respectively, suggesting that S-lansoprazole would be cleared more rapidly than the R-form. The p450 isoform selective inhibition study in liver microsomes, and the incubation study of cDNA-expressed enzymes, demonstrated that the stereoselective sulfoxidation is mediated by CYP3A4 and that the hydroxylation is mediated by CYP2C9 and CYP3A4 as well as by CYP2C19. Total Clint values of hydroxy and sulfone metabolite formation catalyzed by all these p450 enzymes were consistently higher for S-lansoprazole than for the R-form. The CYP3A4 produced the greatest difference of Clint between S- and R-enantiomers, mainly due to a difference of sulfoxidation metabolism (Clint 76.5 versus 10.8 microl/min/nmol of p450, respectively), whereas CYP2C19-catalyzed hydroxylation resulted in a minor difference of Clint between S- and R-enantiomers (179.6 versus 143.3 microl/min/nmol of p450, respectively). However, the affinity of CYP2C19 on hydroxylation was 5.7-fold higher for S-enantiomer than for the R-form (Km 2.3 versus 13.1 microM), suggesting that the role of CYP2C19 on stereoselective hydroxylation would be more prominent at concentrations around the usual therapeutic level. These findings suggest that both CYP2C19 and CYP3A4 are major enzymes contributing to the stereoselective disposition of lansoprazole, but stereoselective hydroxylation of lansoprazole enantiomers is mainly influenced by CYP2C19, especially at the usual therapeutic doses.

The prevalence of dementia in a metropolitan city of South Korea.

BACKGROUND: There are few studies on the prevalence of dementia in South Korea. This study was designed to estimate the prevalence rate of dementia in a metropolitan city of South Korea, Busan. METHODS: This was a cross-sectional epidemiological study of 1101 residents aged 65 or over in a metropolitan city (Busan) as of 31 December 2001 who were selected with the stratified three-stage cluster sampling. Dementia was assessed by two-stage examination with Mini-Mental State Examination-Korean version (MMSE-K), psychometric measures and the Barthel index. Crude and sex-age adjusted prevalence rate were obtained. RESULTS: The crude rate was 7.4% (men 2.4%, women 10.5%). The sex-age adjusted rate was 7.0% (men 2.5%, women 9.0%) and 8.0% (men 2.7%, women 10.0%) when adjusted with Busan and whole Korean population, respectively. CONCLUSION: These results were lower than those of other domestic studies. This is the first well-designed total-population based epidemiologic study on the prevalence rate of dementia of the aged residing in Busan city. Further studies for evaluating the relationships with type and severity of dementia are needed.

Analysis of the Plasmodium vivax apical membrane antigen-1 gene from re-emerging Korean isolates.

Apical membrane antigen-1 is a candidate vaccine component for malaria. In the present study, we investigated the polymorphism of the Plasmodium vivax apical membrane antigen-1 gene ( PvAMA-1) in 30 Korean isolates. The polymorphic region of the PvAMA-1 gene, corresponding to nucleotides 324-735 (aa 108-245), was amplified using polymerase chain reaction followed by cloning and sequencing. Two genotypes ( SKA and SKG) were identified on the basis of amino acid substitution. These were identical to those of the Chinese isolates. The Korean isolates showed sequence variation at six positions on the basis of the sequence of the Sal1 strain. Of these, variation at position 189 (Glu/Lys) was found only in SKA. These two genotypes were related to the genotype of the circumsporozoite and Duffy binding protein of the Korean isolate. These findings suggest that two genotypes of P. vivax coexist in the endemic area and that the re-emerging parasite in Korea may be related to or have originated in East Asia.