High prevalence of hepatitis C virus infection in Airin district, Osaka, Japan: A hospital-based study of 1162 patients.

AIM: The Airin district, located in Nishinari-ku, Osaka, is known as Japan's largest slum area, and has the largest concentration of day laborers in the country. We conducted a large hospital-based study to determine the prevalence of hepatitis C virus (HCV) infection in the district. METHODS: The subjects were 1162 men (mean age, 57 ± 9 years) admitted to the Osaka Socio-Medical Center Hospital between April 2005 and March 2008. Their case records were retrospectively reviewed. RESULTS: Anti-HCV antibodies were found in 218 (18.8%) patients; in contrast, only 24 (2.1%) patients had hepatitis B surface antigen. The prevalence of anti-HCV antibodies was 59% among the 122 patients admitted for liver diseases and 14% among the 1040 patients with other diseases. Among 927 patients with normal alanine aminotransferase levels (≤40 IU/L), 128 (13.8%) had anti-HCV antibodies. The prevalence of anti-HCV antibodies increased with age significantly (P < 0.001). At least 33 of the 218 (15%) patients with anti-HCV antibodies admitted to having a history of injection drug use. Interferon therapy was initiated in 26 patients (11 with genotype 1, 14 with genotype 2 and one unclassifiable), but only six completed their scheduled regimens. Hepatocellular carcinoma was diagnosed in 20 patients, but only seven had early-stage disease in which curative treatment, such as surgical hepatectomy or percutaneous ablation, was indicated. CONCLUSION: The prevalence of HCV infection in the Airin district is extremely higher than that in the Japanese general population. Patient education and strict action against illegal drug use are indispensable to prevent the spread of HCV infection from the district.

Tuberculosis infection among homeless persons and caregivers in a high-tuberculosis-prevalence area in Japan: a cross-sectional study.

BACKGROUND: Tuberculosis (TB) is a major public health problem. The Airin district of Osaka City has a large population of homeless persons and caregivers and is estimated to be the largest TB-endemic area in the intermediate-prevalence country, Japan. However, there have been few studies of homeless persons and caregivers. The objective of this study is to detect active TB and to assess the prevalence and risk factors for latent TB infection among homeless persons and caregivers. METHODS: We conducted a cross-sectional study for screening TB infection (active and latent TB infections) using questionnaire, chest X-ray (CXR), newly available assay for latent TB infection (QuantiFERON-TB Gold In-Tube; QFT) and clinical evaluation by physicians at the Osaka Socio-Medical Center Hospital between July 2007 and March 2008. Homeless persons and caregivers, aged 30-74 years old, who had not received CXR examination within one year, were recruited. As for risk factors of latent TB infection, the odds ratios (OR) and 95% confidence intervals (95% CI) for QFT-positivity were calculated using logistic regression model. RESULTS: Complete responses were available from 436 individuals (263 homeless persons and 173 caregivers). Four active TB cases (1.5%) among homeless persons were found, while there were no cases among caregivers. Out of these four, three had positive QFT results. One hundred and thirty-three (50.6%) homeless persons and 42 (24.3%) caregivers had positive QFT results. In multivariate analysis, QFT-positivity was independently associated with a long time spent in the Airin district: ≥10 years versus <10 years for homeless (OR = 2.53; 95% CI, 1.39-4.61) and for caregivers (OR = 2.32; 95% CI, 1.05-5.13), and the past exposure to TB patients for caregivers (OR = 3.21; 95% CI, 1.30-7.91) but not for homeless persons (OR = 1.51; 95% CI, 0.71-3.21). CONCLUSIONS: Although no active TB was found for caregivers, one-quarter of them had latent TB infection. In addition to homeless persons, caregivers need examinations for latent TB infection as well as active TB and careful follow-up, especially when they have spent a long time in a TB-endemic area and/or have been exposed to TB patients.

[Significance of tuberculosis screening of outpatients in areas with high prevalence of tuberculosis].

OBJECTIVE: The Osaka Socio-Medical Center Hospital is a medical care facility located in the Airin area of Osaka city where the prevalence of tuberculosis is high, and treats day laborers and homeless people mainly, either free of charge or with a small fee. To investigate whether this hospital can play a role to reduce the prevalence of tuberculosis in this area, we investigated the case rate of active tuberculosis in outpatients of the hospital. SUBJECTS AND METHODS: Of 1673 patients who first visited the Orthopaedic Outpatient Clinic between March 31, 2005 and June 15, 2006, 538 patients consented to undergo screening and underwent chest X-ray examination (screening group). We also analyzed chest X-ray examination in 2000 patients examined at the Department of Internal Medicine during the same period (control group). RESULTS: Of the 538 patients in the screening group (523 males and 15 females), 13 male patients (2.4%) requiring treatment were detected. Of the 2000 patients in the control group, 85 patients (84 males and 1 female) (4.3%) requiring treatment were detected. CONCLUSION: The tuberculosis case rate (2.4%) in the screening group was similar to that of tuberculosis screenings (1.1-1.8%) in the Airin area in 2004. The case rate in the control group was two times higher. Since the prevalence is very high in patients of this hospital, the hospital should play a significant role in the health care of tuberculosis patients in this community by reinforcing the screening system and enriching the outpatient clinic system.