[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.

Prevalence of arrhythmias and conduction disturbances in large population-based samples of children.

The aim of our study is to provide data on the prevalence of disturbances of rhythm in the general population of children. Accurate estimates of true prevalence of such disturbances of rhythm from large samples are mandatory if we are to interpret properly electrocardiographic abnormalities. We analysed prevalence of disturbances of rhythm in a population of 152,322, comprised of 71,855 elementary school students, 36,692 males and 35,163 females, aged from 5 to 6 years, and 80,467 students of junior high school, 41,842 males and 38,625 females, aged from 12 to 13 years. We analysed the prevalence of premature atrial and ventricular contractions, first, second and third degree atrioventricular block, incomplete and complete right bundle branch block, Wolff-Parkinson-White syndrome, and prolongation of the QT interval. The prevalence of disturbances of rhythm in total rose with age, being found in 1.25% of elementary school students and 2.32% of junior high school students, and was higher in males than females, at 2.00% as opposed to 1.38%, both values being statistically significant at a level of less than 0.0001. Prevalences of all types of rhythmic disturbances were higher in junior high school students than elementary school students (p < 0.0001). Premature atrial and ventricular contractions and prolongation of the QT interval were higher in female than male students, at percentages of 0.089, 0.497, and 0.02 for males, and 0.123, 0.534 and 0.027 in females (p < 0.0001). In contrast, incomplete and complete right bundle branch blocks were higher in males than females, at 0.983% and 0.083% in males versus 0.410% and 0.161% in females (p < 0.0001). Disturbances of rhythm increased with age, and conduction disturbances were higher in male students than female, although premature atrial and ventricular contractions and prolongation of the QT interval were more frequent in female. These data may be useful for future comparative studies of disturbance of rhythm in children.

Relationship between CT findings of pulmonary tuberculosis and the number of acid-fast bacilli on sputum smears.

PURPOSE: To investigate the relationship between computed tomography (CT) findings in patients with active pulmonary tuberculosis (PTB) and the number of acid-fast bacilli (AFB) on sputum smears. METHODS: We reviewed CT scans of 173 patients with active PTB. The patients were divided into groups according to the number of AFB on sputum smears as follows: A, negative (n = 40); B, doubtful (n = 21); C, + (n = 34); and D, ++ or greater (n = 78). The presence or absence and the number of lobes that included micronodules, nodules, consolidation and cavitation, the number of cavities and the maximum diameter of the cavity lumen were noted. RESULTS: The frequency of micronodules and nodules did not significantly differ among the four groups. In contrast, the frequency of consolidation and cavitation increased with the number of AFB (P < .0001). Differences in the number of lobes involving micronodules, nodules, consolidation and cavitation were significant between Group D and the other groups (P < .0001), but not between Groups A or B and C. The number and maximum size of cavities significantly differed between Group D and the other groups (P < .0001). CONCLUSIONS: CT findings correlated with the number of AFB in sputum smears to some extent. However, CT findings do not reliably discriminate between smear-negative patients and those with very few AFB excreting smear-positive patients.

[Problems about tuberculin skin test raised from consultations and countermeasures--influence to the interpretation of tuberculin skin test in case of the stoppage of BCG revaccination abolition and the introduction of induration measurement].

Since people have very limited access to informations on TB, Chiba Anti-TB Association started "Chiba Kekkaku Dial 110", free TB consultation service through telephone, fax and e-mail, since October 1997. We received 1453 consultations during three years by September 2000. The most frequent consultations was about tuberculin skin test (TST) that amounted to 383, 26.4% of the all consultations. We reviewed the consultations on TST to know why consultations on TST are so frequent and what are problems clients want to know. We categorized the consultations according to the professions of clients and three periods of TST, that is, before testing, during testing and reading, and post reading. There were 178 (46.5%) consultations from health professionals, 134 (35.0%) from general citizens and the rest of them were from those unknown job. The health professionals were 94 physicians, 34 public health nurses, 23 school nurses, 19 nurses, 2 medical technicians, 2 radiographers and 4 others. Consultation after tuberculin reading was the most frequent: 93 out of 178 consultations from health professionals and 97 out of 134 from general citizens. Especially, difficulty in the interpretation of the reading result was common reason of the consultations in both health professionals (69/93) and general citizens (89/97). They feel difficulties in TST result because of widely practiced BCG revaccination and booster phenomenon due to the repetition of TST. Furthermore, TST reading results vary very much between readers especially in double redness (erythema), and it sometimes affects the diagnosis of tuberculosis infection. Therefore, if repeated TST and BCG revaccination practices in children are abolished, most of those consultations might be solved. When induration measurement is used in TST according to the international standard, the complexity of the classifications of the result seems to be dissolved. Considering the current practices in Japan, we recommend that the size of TST induration should be measured and recorded as we measure and record erythema. And induration should be referred in interpretation when they diagnose TB infection with TST.

[Tuberculosis control of construction workers living in Hanba].

Construction workers living in temporal quarters, HANBA, rarely have opportunity to receive the routine health screening program such as that for general inhabitants organized by the local government or that for permanent employees by the employer. Long delay in detecting TB and high drop-out rate from TB treatment among them have been reported. We carried out the following interventions to cope with the problems: In 1999 and 2000, we organized TB screening with X-ray and further examination in the same day when necessary among workers in 6 HANBA in Chiba City. A total of 382 workers were screened, and they also received structured interviews to assess their health-related behaviors and conditions. Four active pulmonary TB cases were detected, and the incidence of 1,047/1,000,000 was forty times higher than that of Chiba City. All four patients were treated and cured. According to the experiences through our intervention, we developed the following recommendations on TB control of construction workers living in HANBA: 1) A system carry out the health examination routinely in the HANBA should be provided, and its implementation be supervised by the public health center and the Labor Standards Inspection Office. 2) It is necessary to guarantee worker's minimum living conditions and medical treatment, and for this regular purpose, close cooperation should be established between clinical service providers and public health, social welfare, and work management authorities. 3) We should start "DOTS" (Directly Observed Treatment Short-Course) not only to the patients in the hospital but also to the outpatients and in the HANBA. To control TB among those workers, further effort is necessary to motivate them to receive basic regular health screening program that is provided in free of charge in Japan.