Impact of the COVID-19 pandemic on gastric surgery in Japan: A nationwide study using interrupted time-series analyses.

BACKGROUND AND AIM: Changes in the number of surgeries for gastric cancer during the coronavirus disease 2019 (COVID-19) pandemic have been reported, but data are insufficient to understand the impact at the national level. This study aimed to determine the impact of the COVID-19 pandemic on gastric surgery in Japan. METHODS: Insurance claims data registered from January 2015 to January 2021 were used. Changes in the number of endoscopic resections and gastrectomies for gastric cancer were estimated using an interrupted time-series analysis. RESULTS: The number of endoscopic resections significantly decreased in July 2020 (-1565; 95% confidence interval [CI]: -2022, -1108) and January 2021 (-539; 95% CI: -970, -109), and the number of laparoscopic surgeries significantly decreased in July 2020 (-795; 95% CI: -1097, -492), October 2020 (-313; 95% CI: -606, -19), and January 2021 (-507; 95% CI: -935, -78). Meanwhile, the number of open gastrectomies remained unchanged, and the number of robot-assisted gastrectomies steadily increased since their coverage by public health insurance in April 2018. CONCLUSIONS: The decreased number of endoscopic resections and laparoscopic surgeries in Japan suggests a decline in early-stage gastric cancer diagnosis, likely due to the suspension of gastric cancer screening and diagnostic testing during the pandemic. Meanwhile, the number of open and robot-assisted gastrectomies remained unchanged and increased, respectively, indicating that these applications were not affected by the pandemic-related medical crisis. These findings highlight that procedures for cancer diagnosis, including screening, should still be provided during pandemics.

Prevalence of positive IGRAs and innate immune system in HIV-infected individuals in Japan.

INTRODUCTION: Human immunodeficiency virus (HIV) infected individuals are at increased risk of developing active tuberculosis (TB). TB incidence remains higher than in non-HIV subjects after antiretroviral therapy (ART) initiation. This study was conducted to estimate the prevalence of positive IGRA, reflecting latent tuberculosis infection and/or a history of active TB, in HIV-infected individuals after ART initiation in Japan. METHODS: Two IGRAs (Interferon (IFN)-γ release assays), QuantiFERON®-TB Gold Plus (QFT-Plus) and T-Spot®.TB (TSPOT), were used. We also analyzed the TB associated risk factors for the IGRAs results and the role of CD4+ T-cells, CD8+ T-cells and NK cells for producing IFN-γ. We also analyzed the risk factors for positive IGRA responses and the role of CD4+ T-cells, CD8+ T-cells and NK cells for producing IFN-γ. RESULTS: One hundred eight-four subjects were prospectively enrolled. Median age was 49 years. The positivity rates of QFT-Plus and TSPOT were 7.6% [95%CI 4.6-12.4] and 2.7% [95%CI 1.2-6.2], respectively, with significant difference. TB-associated risk factors and NK cells ≥300/µL were selected as independently significant factors by multivariate logistic regression. The NK cell count revealed significant linear regression with IFN-γ production responding to TB-specific antigens. CONCLUSIONS: The prevalence of positive IGRAs was 2.7%-7.6%. QFT-Plus would be practical for a higher positivity rate and reflect TB risk factors. The innate immune system, referring to IFN-γ production, plays an important role in the immune response to TB-specific antigens even after initiating ART.

Handheld flow meter improves COPD detectability regardless of using a conventional questionnaire: A split-sample validation study.

BACKGROUND AND OBJECTIVE: Improved detectability of chronic obstructive pulmonary disease (COPD) using a handheld flow meter (HFM) with symptom-based questionnaires has not been sufficiently evaluated. This study aimed to identify the benefit of using an HFM in COPD screening. METHODS: A total of 2008 participants, who were ≥ 40 years of age, from Isumi City, Japan, were recruited. We developed two novel point systems for detecting COPD, one incorporated score of HFM alone (sHFM) and the other incorporated the score of International Primary Care Airway Group questionnaire (IPAG) and HFM (sIPAG + HFM). Validation using random sample allocation (split-sample validation) was carried out to assess the predictive performance of these models. RESULTS: Participants were assigned to a data set for model creation (n = 1007) or a data set for model assessment (n = 1001) to perform split-sample validation. Decision curve analysis showed that the net benefits of sHFM and sIPAG + HFM were higher than that of the IPAG score (sIPAG) and specificity of the former two were also significantly higher than that of sIPAG. However, the curves of sHFM and sIPAG + HFM were crossing and practically the same with no significant difference in sensitivity and specificity. CONCLUSION: This study confirms that HFM is significantly advantageous in detecting COPD despite the use of a conventional questionnaire.

Role of CD8 T-cell in immune response to tuberculosis-specific antigen in QuantiFERON-TB Gold Plus.

Recent contacts with active TB (tuberculosis) patients were screened for latent tuberculosis infection (LTBI) because of their greater relative risk for developing active TB. QuantiFERON®-TB Gold Plus (QFT-Plus) offers two TB-specific antigen tubes (TB1 and TB2). TB1 elicits CD4 T-cell responses, and TB2 is designed to elicit both CD4 and CD8 T-cell responses. These mechanisms could be useful for estimating the role of CD8 T-cell immune responses to TB-specific antigens. To estimate the QFT-Plus capability to diagnose LTBI, a prospective cross-sectional study was conducted. A total of 412 TB contacts (median age 44 years) were enrolled. The positivity rates of QFT-Plus, TB1 and TB2 were 7.5%, 6.3% and 7.2%, respectively. TB2 showed a higher positivity rate compared to TB1, but without significant difference. The interferon (IFN)-γ productions of TB1 and TB2 were well correlated (r = 0.934, P < 0.001). The ratio of IFN-γ production between TB1 and TB2 showed a median (interquartile range) of IFN-γ[QFT-Plus TB2]/IFN-γ[QFT-Plus TB1] of 1.09 (0.91-1.36). CD8 T-cell immune response to TB-specific antigens varied among subjects. CD8 T-cell potentially boosts IFN-γ productions in QFT-Plus and results in the detection of more persons with LTBI. However, there was no significant difference in the positivity rates of QFT-Plus TB1 and TB2 in our TB contact investigation. The contribution of CD8 T-cells might be small for the diagnosis of LTBI. The analysis of IFN-γ production in both TB1 and TB2 would lead to further analysis of the TB immune response, and especially that caused by CD8 T-cells.

Positivity rate of interferon-γ release assays for estimating the prevalence of latent tuberculosis infection in renal transplant recipients in Japan.

Renal transplant recipients are at increased risk of reactivating latent tuberculosis infection (LTBI) and developing active tuberculosis. QuantiFERON®-TB Gold Plus (QFT-Plus) has two TB-specific antigens tubes (TB1 and TB2). TB1 elicits CD4 T-cell response, and TB2 elicits both CD4 and CD8 T-cells responses, with expected increased sensitivity. The aim of this study was to estimate the prevalence of LTBI in renal transplant recipients in Japan. We conducted a cross-sectional study by using two interferon-γ release assays (IGRAs), QFT-Plus and T-SPOT®.TB (TSPOT). One hundred thirty-five recipients were prospectively enrolled. The median age was 49 years (range: 20 to 79). The positivity rates of QFT-Plus and TSPOT were 5.9% (95%CI 3.0-11.3) and 3.7% (95%CI 1.6-8.4), respectively, with no significant difference. The concordance rate was 95.5% (κ coefficient, 0.76). Age of 60 years and higher was related to the higher positivity rate in both QFT-Plus and TSPOT. The positivity rates of TB1 and TB2 were 5.1% (95%CI 2.5-10.2) and 5.9% (95%CI 3.0-11.2), respectively, with no significant difference. The concordance rate was 99.3% (κ coefficient, 0.93). TB2 did not show a higher positivity rate compared with TB1. The estimated prevalence of LTBI by using the both IGRAs was 3.7-5.9% in renal transplant recipients. These results were equivalent to the IGRAs positivity rate in the general Japanese population, even under the condition of immunosuppressive therapy. In consideration of the higher risk of developing active TB from LTBI, we can use both IGRAs as acceptable tools for LTBI diagnosis in renal transplant recipients.

Lymphocyte subset analysis in QuantiFERON-TB Gold Plus and T-Spot.TB for latent tuberculosis infection in rheumatoid arthritis.

Rheumatoid arthritis (RA) is an immune mediated inflammatory disorder, and immune suppressive drugs are prescribed. RA patients receiving treatments are in a kind of immunosuppressive condition that presents increased risk of developing active tuberculosis. Accurate diagnosis of latent tuberculosis infection (LTBI) is recommended for RA. QuantiFERON®-TB Gold Plus (QFT-Plus), a novel IGRA, has two tubes (TB1 and TB2). TB2 is designed to elicit both CD4 and CD8 T-cell responses, with expected increased sensitivity. We conducted a cross-sectional study to compare two IGRAs, QFT-Plus and T-SPOT®.TB (TSPOT), in RA. One hundred fifty-two RA patients (median age: 66.5 yrs) were enrolled. QFT-Plus and TSPOT were concurrently conducted. Lymphocyte subsets (CD4 T-cell and CD8 T-cell) were also measured. The positivity rates of QFT-Plus and TSPOT were 9.7% and 4.5%, respectively, with the difference being significant (P < 0.01). The positivity rates in TB1 and TB2 were 9.1% and 7.1%, respectively; the difference was not significant (P = 0.18). Patients with CD4 T-cell ≥650/µL and CD8 T-cell ≥400/µL had significantly higher positivity rates in both QFT-Plus and TSPOT in comparison with other groups (P < 0.01 and P < 0.05, respectively). QFT-plus demonstrated a higher positivity rate than TSPOT. However, there was little additional effect for detecting LTBI by TB2. Lymphocyte subsets were strongly associated with immune response in both QFT-Plus and TSPOT. LTBI should not be ruled out even with a negative IGRA result in patients with CD4 T-cell <650/µL or CD8 T-cell <400/µL.

Comparison of interferon-γ release assays, QuantiFERON TB-GIT and T-Spot.TB, in renal transplantation.

Renal transplant recipients are at increased risk of reactivating latent tuberculosis infection (LTBI) and progressing to active tuberculosis (TB). This study was conducted in National hospital for tuberculosis and renal transplantation (RT) in Japan. The purpose is to compare two interferon-γ release assays (IGRAs), QuantiFERON®-TB Gold in Tube (QFT) and T-SPOT®.TB (TSPOT), in patients after renal transplantation for detecting latent TB infection (LTBI). Total 92 renal transplant recipients (median age 46 years, range 17-75) were prospectively enrolled, and QFT and TSPOT were concurrently examined. Total subjects were 92 patients (median age 46 years, range 17-75). The positive rate in QFT and TSPOT were 6.5% (95% confidence interval (CI) 3.0-13.5) and 2.2% (95% CI 1.0-7.6), respectively. There was a significant difference in IGRAs positivity (P < 0.05). The negative rate in QFT and TSPOT were 91.3% (95% CI 83.8-95.5) and 95.7% (95% CI 89.3-98.3), respectively. There was no significant difference in IGRAs negativity. No patients among either IGRAs negative patients developed active TB during median follow-up of 994 days. Neither QFT nor TSPOT reaches estimated TB infection rate in Japan, especially elderly recipients aged 60 year-old or more. Therefore, both IGRAs might underestimate LTBI owing to immune suppressive therapy and aging. Physicians for renal transplantation need to understand the characteristics of both IGRAs and pay attention to the possibility of developing active TB even in patients of negative IGRAs results.

Detection of chronic obstructive pulmonary disease in community-based annual lung cancer screening: Chiba Chronic Obstructive Pulmonary Disease Lung Cancer Screening Study Group.

BACKGROUND AND OBJECTIVE: Detection of chronic obstructive pulmonary disease (COPD) is crucial in the management of COPD. The aim of this study was to establish the utility of a community-based lung cancer screening for detecting COPD. METHODS: In Japan, community-based lung cancer screening for residents who are 40 years or older using chest radiography is well established. A screening system in Chiba City, Japan, was used to detect COPD. The criteria to consider COPD at screening included age of 60 years or older, a smoking history and chronic respiratory symptoms. Participants fulfilling these criteria were referred for diagnostic evaluation consisting of pulmonary function testing (PFT) and chest computed tomography (CT). RESULTS: Of 89,100 Chiba City residents who underwent lung cancer screening, 72,653 residents were 60 years or older. Among them, 878 (1.0%) were identified with suspected COPD and referred for further evaluation. Of those identified, a total of 567 residents (64.6%, 567/878) underwent further evaluations, and 161 (28.4%) were reported to have COPD, with 38.5% of them requiring COPD treatment. To verify the diagnoses from the secondary evaluation centres, PFT and CT data were collected from 228 study participants, and 24.9% were diagnosed with COPD. CT findings classified according to the Goddard classification revealed that 20.1% of these participants had moderate to severe emphysema. CONCLUSIONS: COPD screening added to a community-based lung cancer screening programme may be effective in the detection of patients with COPD.

Impact of the coronavirus disease 2019 pandemic on primary and metastatic lung cancer treatments in Japan: A nationwide study using an interrupted time series analysis.

BACKGROUND: The coronavirus disease 2019 pandemic prompted healthcare providers to use different approaches from the current standards of care. We aimed to identify the changes in the number of treatments for primary non-small cell lung cancer (NSCLC) and metastatic lung cancer during the pandemic. METHODS: We used nationwide insurance claims data from January 2015 to January 2021, and estimated changes in the number of treatments using an interrupted time series analysis. RESULTS: The number of surgical resections for primary NSCLC significantly decreased in April 2020 (-888; 95% confidence interval [CI]: -1530 to -246) and July 2020 (-1314; 95% CI: -1935 to -694), while the number of stereotactic body radiotherapies (SBRTs) increased in April 2020 (95; 95% CI: 8-182) and July 2020 (111; 95% CI: 24-198). The total number of treatments for primary NSCLC remained unchanged; however, non-significant decreases were observed in 2020. The number of surgical resections for metastatic lung cancer significantly decreased in April 2020 (-201; 95% CI: -337 to -65), but it eventually increased in July 2020 (170; 95% CI: 32-308). Additionally, the number of SBRTs significantly increased in April 2020 (37; 95% CI: 3-71) and October 2020 (57; 95% CI: 23-91). The total number of treatments for metastatic lung cancer was maintained, with an initial decrease in April 2020 followed by a subsequent increase in July and October 2020. CONCLUSION: In Japan, surgical triage for primary and metastatic lung cancer are likely to have been implemented during the pandemic. Despite these proactive measures, patients with primary NSCLC may have been untreated, likely owing to their undiagnosed disease, potentially leading to a deterioration in prognosis. By contrast, patients diagnosed with cancer prior to the pandemic are presumed to have received standard management throughout the course of the pandemic.

Impact of the COVID-19 Pandemic on Hypofractionated Radiation Therapy Use for Breast Cancer in Japan: A Nationwide Study.

Purpose: Hypofractionated radiation therapy (RT) was recommended for several cancer sites to reduce outpatient visits during the COVID-19 pandemic. This study aimed to identify the impact of the pandemic on hypofractionated RT for breast cancer in Japan. Methods and Materials: The monthly number of courses for hypofractionated and conventional RTs was counted using sample data sets from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, a nationwide database accumulating insurance claims data comprehensively. Changes in the number of hypofractionated and conventional RTs were estimated using an interrupted time-series analysis. Results: The number of hypofractionated RT courses gradually increased before the pandemic in contrast to that of conventional RT courses, which gradually decreased. However, conventional RT remained outnumbered by hypofractionated RT throughout the observation period. After the outbreak of the pandemic, the use of hypofractionated RT significantly increased in April 2020 (1312 courses; 95% CI, 801-1823) but decreased in October 2020 (-601; 95% CI, -1111 to -92). Subgroup analysis by age and the number of beds in medical institutions revealed similar trends. Conclusions: Although conventional RT for breast cancer has been gradually replaced by hypofractionated RT, it remains predominant. The use of hypofractionated RT increased briefly early in the COVID-19 pandemic; however, this increase was not sustained, unlike in other countries. Considering the benefits of hypofractionated RT for breast cancer, its use should be encouraged in Japan.

Lifestyle and osteoporosis in middle-aged and elderly women: Chiba bone survey.

Osteoporosis causes an enormous health and economic impact in Japan. We investigated the relation between lifestyle and bone fracture in middle-aged and elderly women. This was a population-based, multicenter, cross-sectional survey for postmenopausal osteoporosis in Chiba City, Japan (Chiba bone survey). This survey included 64,809 Japanese women aged > 40 years. All participants underwent anthropometric measurements including bone mineral density (BMD) and completed a structured, nurse-assisted, self-administered questionnaire also including patient lifestyle. Bone fracture during the recent 5 years was observed in 5.3%, and the fracture group had significantly higher age, BMI, and prevalence of delivery, family histories of kyphosis and hip fracture, diabetes mellitus (DM), dyslipidemia, kidney disease, exercise, fall, and osteoporosis, and had significantly lower BMD and proportion of menstruating participants. Logistic regression analysis revealed that bone fracture was closely associated with not only low bone mass but also age, fall, family histories of kyphosis and hip fracture, DM, kidney disease, menopause, and lifestyle factors of dieting, exercise, and alcohol. Women's health care focusing on lifestyle-related fracture risks such as dieting, exercise, and alcohol appears necessary to prevent bone fracture in postmenopausal osteoporosis.

Changes in colorectal cancer treatment during the COVID-19 pandemic in Japan: Interrupted time-series analysis using the National Database of Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic forced us to accept changes in our usual diagnostic procedures and treatments for colorectal cancer. This study aimed to determine the impact of the pandemic on colorectal cancer treatment in Japan. METHODS: The number of colorectal surgeries, stoma constructions, stent placements or long tube insertions, and neoadjuvant chemoradiotherapies were determined each month using sampling datasets from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. The observation periods before and during the pandemic were January 2015 to January 2020 and April 2020 to January 2021, respectively. An interrupted time-series analysis was used to estimate the changes in the number of procedures during the pandemic. RESULTS: The number of endoscopic surgeries for colon cancer significantly decreased in April and July 2020 and for rectal cancer in April 2020. Additionally, the number of laparoscopic and open surgeries for colon cancer significantly decreased in July 2020 and October 2020, respectively. The number of stoma constructions and stent placements or long tube insertions did not increase during the observation period. Neoadjuvant chemoradiotherapy for rectal cancer significantly increased in April 2020 but levels returned shortly thereafter. These results suggest that the recommendations to overcome the pandemic proposed by expert committees, including the replacement of laparoscopic surgery with open surgery, stoma construction to avoid anastomotic leak, and replacement of surgery on the ileus with stent placement, were not widely implemented in Japan. However, as an exception, neoadjuvant chemoradiotherapy for rectal cancer was performed as an alternative treatment to delay surgery in small quantities. CONCLUSION: A declining number of surgeries raises concerns about cancer stage progression; however, we found no evidence to suggest cancer progression from the trajectory of the number of stoma constructions and stent placements. In Japan, even during the pandemic, conventional treatments were performed.

Changes in the number of cancer diagnosis practices due to the COVID-19 pandemic: interrupted time-series analysis using the National Database of Japan.

PURPOSE: This study aimed to reveal the impact of coronavirus disease 2019 on the number of practices commonly used for cancer diagnosis in Japan. METHODS: The sampling dataset of the National Database of Japan from January 2015 to January 2021 was used to generate 25-point time-series data for the number of practices (21 points before and 4 points during the pandemic outbreak). The decreased number was estimated by interrupted time-series analysis using a seasonal autoregressive integrated moving average model. Using the pre-pandemic data, expected counterfactual numbers during the pandemic were predicted, and decreased rate was calculated. RESULTS: In most practices, the number dramatically decreased in the early stage of the pandemic and recovered rapidly thereafter. As of April 2020, gastric endoscopy decreased at the top of the practices (- 42.1%, with 95% confidence intervals of - 50.5% and - 33.7%), followed by gastric biopsy (- 38.6%, with 95% confidence intervals of - 46.7% and - 30.6%). The period of declined practices for lung cancer was relatively prolonged. The number of sentinel lymph node biopsies for breast cancer and colposcopies and biopsies for cervical cancer did not decrease in April 2020, but significantly decreased later in July 2020, which is assumed to be the time lapse after the primary testing before surgical treatment or intense scrutiny. CONCLUSION: In general, the number of practices for cancer diagnosis in Japan showed only a temporary decline, which was concordant with reports from several other countries.

Impact of coronavirus disease 2019 pandemic on breast cancer surgery using the National Database of Japan.

Various countries have reported a decrease in breast cancer surgeries during the coronavirus disease 2019 (COVID-19) pandemic; however, inconsistent results have been reported in Japan. This study revealed changes in the number of surgeries during the pandemic using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) from January 2015 to January 2021, where insurance claims data from Japan as a whole are comprehensively accumulated. The number of breast-conserving surgeries (BCS) without axillary lymph node dissection (ALND) significantly decreased in July (- 846; 95% confidence interval (CI) - 1190 to - 502) and October 2020 (- 540; 95% CI - 861 to - 218). No decrease was observed for other types of surgery, BCS with ALND, and mastectomy with or without ALND. In the age-specific subgroup analysis, significant and transient reduction in BCS without ALND was observed in all age groups (0-49, 50-69, and ≥ 70 years). The number of BCS without ALND significantly decreased for a relatively short period in the early pandemic stages, suggesting reduced surgery for patients with a relatively low stage of cancer. Some patients with breast cancer might have been left untreated during the pandemic, and an unfavorable prognosis would be a concern.

[Tuberculosis among construction workers in dormitory housing in Chiba City].

BACKGROUND: Tuberculosis (TB) control in a low socio-economic society is an important program for urban area of industrialized countries. Some construction workers live in Hanba, a kind of dormitory housings that have crowded living conditions, and possibly give rise to Mycobacterium tuberculosis transmission. The pulmonary tuberculosis detection rate by chest X-ray screening in Hanba is higher than the general population, and therefore TB incidence among Hanba construction worker is also estimated to be as high as that of homeless. PURPOSE: To analyze the ratio of the TB patients from Hanba in Chiba City from 1993 through 2006, and analyze the treatment outcome and speculate the factors affecting them, especially the effects of the inpatients DOTS (Directly Observed Treatment Short-course) policy introduction after 2001. METHODS: TB registration records in the Public Health Center, Chiba City, Japan, were retrospectively analyzed. RESULTS: Pulmonary TB patients from Hanba were 121 (male: 121, female: 0), representing 3.8% of the total 3179 TB patients from 1993 through 2006. Restricting to male patients aged 40-59 years-old, TB patients from Hanba were 78, representing 10.7% of 729 male TB patients of the same age groups. All of TB patients from Hanba developed pulmonary TB (PTB) and treatment outcome of chemotherapy was cured or completed: 69 (57%), defaulted or failed: 43 (36%), and died 9 (7%) respectively. When compared with PTB in Chiba and Japan, defaulted or failed was higher. In the multi-variated analysis, extensive lesions more than one lung (Adjusted odds ratio [AOR]: 0.13, 95% confidence interval [CI]: 0.04-0.37, P < 0.001) and smear-positive (AOR: 0.17, 95% CI: 0.04-0.65, P = 0.009) were negative factor for cured and completed. However, hospitalization during initial period of treatment was positive factor (AOR: 7.92, 95% CI: 1.73-36.2, P = 0.008). After inpatients DOTS introduction, the rate of cured or completed increased from 50% to 67%, and the rate of failed or defaulted decreased from 46% to 22% (P < 0.05). CONCLUSION: TB patients from Hanba, a kind of dormitory housings for construction workers, occupied 3.8% of total TB patients in Chiba City. Higher rate of defaulted or failed cases leads to poor treatment outcome in TB patients of Hanba construction workers who were possibly associated with an elevated risk of urban tuberculosis. DOTS might improve adherence to treatment and result in a decrease of failed or defaulted cases.

Variation in interferon-γ production between QFT-Plus and QFT-GIT assays in TB contact investigation.

BACKGROUND: Individuals with recent contact with active tuberculosis (TB) patients were screened for latent tuberculosis infection (LTBI) considering their greater relative risk for developing active TB. QuantiFERON®-TB Gold Plus (QFT-Plus) assay offers two TB-specific antigen tubes (TB1 and TB2). TB2 is designed to elicit both CD4 and CD8 T-cell responses. This mechanism could lead to increased sensitivity as compared to the QuantiFERON®-TB Gold In-Tube (QFT-GIT) assay. Our objective was to compare the LTBI diagnostic capability of QFT-Plus with that of QFT-GIT. METHODS: A total of 412 TB contacts (median age 44 years) were prospectively enrolled. We conducted both QFT-Plus and QFT-GIT assays concurrently. We also analyzed production of interferon-γ (IFN-γ) in response to TB-specific antigens. RESULTS: The positivity rates in QFT-Plus and QFT-GIT were 7.5% (95% confidence interval (CI), 5.4-10.5) and 5.8% (CI, 3.9-8.5), respectively, showing a significant difference (P < 0.05). The median (inter-quartile range [IQR]) of IFN-γ[QFT-Plus]/IFN-γ[QFT-GIT] was 1.41 (1.00-2.00). QFT-Plus produced 1.4 times IFN-γ. CONCLUSIONS: QFT-Plus revealed significantly higher positivity rate compared with QFT-GIT, which might be attributed to increased IFN-γ production. The cut-off in both QFT-Plus and QFT-GIT was 0.35 IU/mL. These effects might resulted in the higher positivity rate in QFT-Plus.

Lung cancer screening--comparison of computed tomography and X-ray.

Recent studies on lung cancer screening with CT disclosed a discrepancy between its efficiency in detecting early lung cancer and a lack of proof for decreasing mortality from lung cancer. The present study, in a city in Japan where an X-ray screening program is provided, bi-annual CT screening was performed for X-ray screening negative subjects for 4 years. Ten patients with lung cancer were detected among 22,720 person-year subjects (0.044%) through the X-ray screening. Among the X-ray screening-negative subjects, 3305 subjects participated in a CT screening program resulting in the detection of 15 patients with lung cancer (0.454%). All 15 cases detected by CT screening and 5 of the 10 cases detected by X-ray screening were at stage IA. In respect of gender, histological type and CT findings, patients detected by CT screening had a better prognostic profile than those detected by X-ray screening. Survival was significantly better in the former than the latter, both in its entirety comparison and in a comparison limited to patients who underwent surgery. In conclusion, CT screening might have the potential to detect lung cancer with good prognostic factors not limited to early detection. Sufficiently long follow-up time, therefore, would be required to evaluate the efficacy for decreasing lung cancer mortality with CT screening.

[Preventive measures against tuberculosis in working facilities and companies].

The health care program in working facilities and companies have played a significant part in prevention of tuberculosis. However, the ordinary national tuberculosis survey policy was abolished in April, 2005 and the tuberculosis survey for salary-earners is on the brink of drastic change. In this symposium the current status of the prevailing survey of tuberculosis in working facilities and companies was reviewed and the future direction of the tuberculosis survey in comparison to that in lung cancer survey was discussed. 1. Epidemiological trends of tuberculosis from the tuberculosis surveillance data: Masako OHMORI (Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association). The estimated rate of tuberculosis case discovery by periodical mass screening in the working facilities was 0.033% and it was higher than that in general adult population. The detection rate of tuberculosis in nurses who suffered from tuberculosis reached 40.4% by an aid of mass X-ray screening and 8.7% by contact tracing. The risk of onset of the disease was 4.3 times higher nurses than in general at the same years of age. The importance of infection control measures in the medical facilities was emphasized. 2. Current status and problems in tuberculosis control in a large-sized company: Yusuke NAKAOKA (Department of Occupational Health, Osaka Railway Hospital, West Japan Railway Company). Some preventive modalities against TB such as periodical medical check-up and awareness programs have been done for the purpose of prevention in our company. The prevalence of the disease has significantly reduced in number. The specific circumstances in large-sized company should be taken into consideration, and it is important for company workers and health professionals to recognize their roles in preventing the infectious disease. 3. Are there any differences between clinical cases and control people working for small-sized companies in the onset of tuberculosis?: Osamu NAKASHIMA, Kohei IMOTO (Taito Health Center, Tokyo) and Toru MORI (Research Institute of Tuberculosis, JATA). We surveyed environmental conditions in working places and domestic conditions of employees who were working for small-sized companies located in Taito ward, based on written questionnaires. The companies were selected as those which had the patients of tuberculosis in the past one-year period, and the number of employees was less than ten. Compared with control people, TB patients had more frequent smoking habit (p < 0.05), and tended to have been less exposed to the sunshine at their residency and to have nutritionally poor meals and deficits of their meals. These results suggest that these factors alone or in combination may contribute to accelerated onset of tuberculosis. 4. Current status and problems in tuberculosis management among high prevalence population and in health check-up for personnel with unspecified and high occupational contact with tuberculosis patients: Hidetoshi IGARI (Division of Control and Treatment of Infectious Diseases, Chiba University Hospital), Kiminori SUZUKI (Chiba Foundation for Health Promotion and Disease Prevention). Tuberculosis prevalence is as high as 500-1500 per 100,000 peoples among the homeless and construction workers living in "Hanba", a bunkhouse. We surveyed their medical conditions through periodical or extraperiodical health check-up. We retrospectively analyzed some medical factors contributing to successful treatment of the disease. Hospital admission and enhancement of counseling opportunities were two factors leading to the success of the treatment. The ambulance attendants have a significant possibility to contact patients with TB and are high at risk of acquiring the infection. As there are often limited information on TB in patients in an emergency condition, it is difficult to protect themselves from its contagion properly. Periodical and extraperiodical health check-up is important for these personnel and application of QuantiFERON-TB 2nd generation to the personnel is new and useful for diagnosis of the latent tuberculosis infection. 5. A role of chest X-ray examination for lung cancer detection among company workers: Takeo TESHIMA (Koseikan Clinic, Miyagi Branch, Japan Anti-Tuberculosis Association). Detection rates of lung cancer in company workers and in general population under the age of 60 years were compared. Chest X-ray survey was done using 10 cm x 10 cm indirect chest X-ray films of the chest. The detection rates of lung cancer in patients with definite or suspicious diagnosis in 265,620 company workers were 2.3 and 2.6 per 100,000, respectively. On the other hand the rates were 9.9 and 8.8 per 100,000 in a general population of 811,391. Twenty-four percent of patients with suspicious diagnosis were eventually made a definite diagnosis. The corrected detection rate reached to 21.0 for male patients and 8.3 for female patients and 12.1 totally. The detection rates of lung cancer in company workers and in general population under the age of 60 years exceeded the rate of pulmonary tuberculosis. Chest X-ray examination for the detection of lung cancer and pulmonary tuberculosis is still recommended under various working and social circumstances.

[Outbreak of pulmonary tuberculosis in which tuberculosis developed from QuantiFERON-TB second generation (QFT-2G) test negative persons].

PURPOSE: To clarify the points to be considered when QFT-2G tests are used in the contacts examination by public health center. OBJECT & METHOD: We analyzed the results of contacts examination on 43 workplace colleagues (39 y/o and younger) of a pulmonary tuberculosis patient (bII2, Gaffky 9, cough for 1.5 months). RESULTS: After two months of the last contact with the index case, tuberculin skin tests, QFT-2G tests and chest X-rays were undertaken. After 6 months, chest X-rays were taken, and after 9 months, QFT-2G tests and chest CT scans were also undertaken. The tuberculin skin tests after two months showed a bimodal distribution, and 10 were QFT-2G positive and 2 showed doubtful reaction. The latter 12 persons underwent chemoprophylaxis. After 6 months, however, out of 31 QFT-2G negative persons, 2 developed pulmonary tuberculosis. Moreover, after 9 months, chest CT scans revealed 5 pulmonary tuberculosis patients. Three out of 7 new patients showed positive or doubtful reactions in QFT-2G tests undertaken after 9 months. DISCUSSION AND CONCLUSION: The sensitivity of QFT-2G tests is reported to be 80 to 90%, and the possibility of false negative is not negligible. We propose measures for public health center to conduct the contacts examination as follows; In case of high QFT-2G positive (including doubtful reaction) rate and/or a bimodal distribution of tuberculin skin test result, many infected persons are likely to be included in the group; and the following measures are recommended; 1) Necessity of chemoprophylaxis should be judged considering both tuberculin skin test results and the situation of contact with the index case, and not only by QFT-2G test results. 2) QFT-2G negative persons also need to be followed with chest X-rays.