Epidemiology survey of infectious diseases in North Korean travelers, 2015-2017.

BACKGROUND: Up until now, there are limited studies available on the epidemiology of infectious diseases in Democratic People's Republic of Korea (DPRK, North Korea). However, different types of infectious diseases have been found in North Korean travelers at Dandong port. Entry surveillance data of those North Korean travelers may provide some insight into the probable epidemiology of some infectious diseases in DPRK. METHODS: We actively analyzed the medical test result of North Korean travelers entering China through Dandong port. Detection of hepatitis B virus (HBV), tuberculosis (TB), syphilis and malaria was made by specific laboratory tests according to the national technical guidelines. Infectious diseases surveillance data for 2015-17 was analyzed and compared among subgroups. RESULTS: Between Jan 1, 2014, and Dec 31, 2016, 557 cases of infectious diseases were identified among 18,494 North Korean travelers, HBV active infection (466 cases), active TB infection (33 cases), current active syphilis infection (57) cases, Plasmodium falciparum (P.falciparum) malaria infection (1 case). The incidence of HBV, TB and syphilis in North Korean travelers was high. Incidence of TB increased from 11.7256 (1/10,000) in 2015 to 28.2738 (1/10,000) in 2017. HBV immunization rate in in North Korean travelers was relatively high in 0-10 age group. CONCLUSION: This report is the first to characterize the profile of infectious diseases among arriving North Korean travelers in mainland China. Our findings suggest high incidence of HBV, TB and syphilis among North Korean travelers. The screening for TB in North Korean workers should be strengthened in order to prevent infections imported into China.

Performance of genetic risk factors in prediction of trichloroethylene induced hypersensitivity syndrome.

Trichloroethylene induced hypersensitivity syndrome is dose-independent and potentially life threatening disease, which has become one of the serious occupational health issues and requires intensive treatment. To discover the genetic risk factors and evaluate the performance of risk prediction model for the disease, we conducted genomewide association study and replication study with total of 174 cases and 1761 trichloroethylene-tolerant controls. Fifty seven SNPs that exceeded the threshold for genome-wide significance (P < 5 × 10(-8)) were screened to relate with the disease, among which two independent SNPs were identified, that is rs2857281 at MICA (odds ratio, 11.92; P meta = 1.33 × 10(-37)) and rs2523557 between HLA-B and MICA (odds ratio, 7.33; P meta = 8.79 × 10(-35)). The genetic risk score with these two SNPs explains at least 20.9% of the disease variance and up to 32.5-fold variation in inter-individual risk. Combining of two SNPs as predictors for the disease would have accuracy of 80.73%, the area under receiver operator characteristic curves (AUC) scores was 0.82 with sensitivity of 74% and specificity of 85%, which was considered to have excellent discrimination for the disease, and could be considered for translational application for screening employees before exposure.

Cytokine expression in trichloroethylene-induced hypersensitivity dermatitis: an in vivo and in vitro study.

The purpose of this study was to address the association between cytokine expression and the hypersensitivity dermatitis induced by trichloroethylene (TCE) exposure. 28 TCE-induced hypersensitivity dermatitis patients, 22 TCE exposed workers and 22 non-exposed controls were enrolled in the study. The serum levels of interleukin (IL)-1ß, IL-6, IL-8 and tumor necrosis factor (TNF)-α were analyzed using a magnetic colorbead-based multiplex assay. The patients showed significantly higher levels of serum IL-1ß (p=0.033 and p=0.015), IL-6 (p<0.001), IL-8 (p<0.001 and p=0.002) and TNF-α (p=0.009 and p=0.005) than the TCE exposed workers and non-exposed controls. There was a significantly positive correlation among these cytokine concentrations, but no significant correlation was found between these cytokine concentrations and the disease duration in patient group. We further compared the effects of trichloroethanol (TCOH) and trichloroacetic acid (TCA), two major metabolites of TCE, on cytokine expression in keratinocyte cell line (HaCaT). IL-1α, IL-6, IL-8 and TNF-α concentrations were tested using enzyme-linked immunosorbent assay (ELISA) after HaCaT cells were treated with different concentrations of TCOH or TCA for 24h. We found that TCOH, but not TCA, increased the levels of IL-1α and IL-6 in a dose-dependent manner. We also found that TCOH activated the nuclear factor kappa B (NF-κB) pathway. Bay 11-7082 (NF-κB inhibitor) significantly attenuated the TCOH-induced production of IL-6 in HaCaT cells, but IL-1α production was not affected. In conclusions, it is suggested that IL-1ß, IL-6, IL-8 and TNF-α were associated with TCE-induced hypersensitivity dermatitis. TCOH induced IL-6 expression through activation of the NF-κB pathway in HaCaT cells and may play an integral role in TCE-induced skin hypersensitivity.

[Analysis of subgroups of lymphocyte in peripheral blood among dermatitis medicamentosa-like of trichloroethylene patients and healthy exposed workers].

OBJECTIVE: To study the effects of trichloroethylene (TCE) to lymphocyte subsets among exposed workers, and explore the early immunological effect biomarkers for prevention of hypersensitivity dermatitis induced by TCE. METHODS: Twenty-eight patients with TCE-induced hypersensitivity dermatitis, 56 healthy TCE-exposed workers from the same workshops with patients, and 28 comparable unexposed controls were recruited in this study. The total lymphocyte count and the major lymphocyte subsets including T cell, CD4(+) T cell, CD8(+) T cell, B cell, NK cell in peripheral blood were measured by Flow Cytometer analysis and Standard blood count analysis. RESULTS: The total lymphocyte count and T cell, CD4(+) T cell, CD8(+) T cell among patients (median at 2810.00, 1846.17, 831.87, 904.05 cell counts/µl blood) were significantly increased compared with TCE-exposed workers (median at 2101.00, 1218.59, 643.87, 482.81 cell counts/µl blood, Z = -3.19, -4.96, -3.22, -4.99, P < 0.001) and unexposed controls (median at 1900.00, 1223.60, 558.60, 325.80 cell counts/µl blood, Z = -3.30, -4.46, -3.45, -5.03, P < 0.001), the NK cell and CD3(+)CD4(+)/CD3(+)CD8(+) ratio among patients (median at 255.50 cell counts/µl blood and 1.11) were significantly decreased compared with the unexposed controls (median at 642.60 cell counts/µl blood and 1.96, Z = -3.56 and -3.11, P < 0.01). Meanwhile, for the exposed workers, the CD8(+) T cell (median at 482.81 cell counts/µl blood) was significantly increased and the NK cell and CD3(+)CD4(+)/CD3(+)CD8(+) ratio (median at 318.76 cell counts/µl blood and 1.27) were significantly decreased compared with unexposed controls (median at 325.80 and 642.60 cell counts/µl blood and 1.96, Z = -2.63, -3.52, -2.29, P < 0.05). CONCLUSION: Occupational exposure to TCE could affect the lymphocyte subsets, especially T cell and NK cell. The total lymphocyte count, T cell and CD4(+) T cell might be effect biomarkers for subjects with hypersensitivity dermatitis among TCE-exposed workers.

[Study on the influence factors of human peripheral blood B lymphocyte transformation by Epstein-Barr virus].

OBJECTIVE: To investigate the influence factors of human peripheral blood B lymphocyte transformation by epstein-barr virus (EBV). METHODS: EB virus was obtained from B95-8 supernatant and quantitated by quantitative PCR amplification. The concentration of cyclosporine A (CSA) concentration of lymphocytes and different time of adding CSA to culture media were selected to examine the effects on the lymphocyte transformation, and the condition of lymphocyte transformation of worker exposed to trichloroethylene was further confirmed. RESULTS: The titer of two virus samples were 5.45 x 10(6) and 1.06 x 10(6) copies/ml. Peripheral blood mononuclear cells (PBMCs) was transformed by using CSA at different concentration and adding time to culture fluid. The concentration of PBMCs being transformed was 2 x 10(6)/ml for normal people, but 1 x 10(6)/ml for worker exposed to trichloroethylene. Cell transformation was confirmed by the gradual increase of cell size and cellular clusters. CONCLUSION: The results suggest the key issue is PBMCs being transformed at a concentration of 2 x 10(6)/ml, rather than using CSA at different concentration and adding time to culture fluid. The PBMCs at concentration of 1 x 10(6)/ml for worker exposed to trichloroethylene were transformed, which may be associated with sensitized status of lymphocytes.