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

Abstract

BackgroundTuberculosis (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.MethodsWe 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.ResultsComplete 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).ConclusionsAlthough 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.

Active pulmonary tuberculosis and latent tuberculosis infection among homeless people in Seoul, South Korea: a cross-sectional study

“…The prevalence of active TB as well as LTBI in our study was higher than that reported in New York in the US (31% of LTBI) [10] and in the Airin district in Japan (1.5% and 50.6% rate of active TB and LTBI, respectively) [9]. The higher rate of active TB and LTBI among homeless people in Seoul reflects the higher prevalence of active TB in South Korea (115 per 100 000 persons) compared with the US (4.7 per 100 000 persons) and Japan (27 per 100 000 persons) in 2009 [1].…”

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

“…A survey performed by the Ministry of Health, Labor and Welfare, Japan in 2006 estimated that 35.4% of men and 6.9% of women were habitual drinkers (persons who drink 330 g of ethanol per day on 33 days per week). A recent study of active or latent tuberculosis in the Airin district reported that the proportion of current drinkers (persons who drink 310 g of ethanol nearly every day) was 51.9%, 25 which is similar to the proportion of habitual drinkers in our study (54.7%). The mean alcohol consumption of homeless people in the district was 40.7 1 53.5 g of ethanol per day (unpubl.…”

Prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people: a systematic review and meta-analysis

“…For tuberculosis (excluding a study from Japan 48 ), estimates ranged from 0·2% to 7·7%, with substantial heterogeneity (χ 2 =123, p<0·0001; I 2 =84%, 95% CI 76–89). The random-effects pooled prevalence was 1·1% (95% CI 0·8–1·4).…”