[Tuberculosis annual report 2008--Series 5. Case finding]

Abstract

Regarding current case findings, the mode of detection, delays in detection, the patient's occupation and so on were observed using the tuberculosis (TB) surveillance database. 81.3% of 24,760 TB patients newly notified in 2008 were detected at medical institutions. However, 10.8% of TB patients were detected during hospitalization with a disease other than TB and 8.5% of TB patients were detected under outpatients with a disease other than TB. The proportion of TB patients detected during inpatient or outpatient increased with age. On the other hand, significant proportion of adolescents and young adults were also detected by active case finding such as periodic school mass-screening and periodic health examination for employees. 22.5% of TB patients aged 15-19 years were detected by periodic school mass-screening, and 24.9% of TB patients aged 25-34 years were detected by periodic health examination for employees. Although active case finding generally detects bacillary negative cases, 14.1% of sputum smear positive pulmonary TB patients aged 20-49 years were detected by periodic health examination for employees. Although the proportion of TB patients detected by contact examination was only 3.0%, they were large among younger TB patients, e.g. 53.7% of those aged 0-14 years, 19.4% of those aged 15-19 years, 9.2% of those aged 20-24 years and 6.7% of those aged 25-29 years. According to the symptoms of 19,393 pulmonary TB patients, 28.7% had respiratory symptoms, 30.4% had both respiratory and other symptoms, and 15.1% had symptoms other than respiratory symptom. 24.8% of pulmonary TB patients had no symptoms and 0.9% had no data about symptoms. The proportion of TB patients only having other symptoms without respiratory symptoms increased among the elderly TB patients, e.g. 13.7% of those aged 65-69 years, 16.2% of those aged 70-74 years, 18.0% of those aged 75-79 years, 19.7% of those aged 80-84 years, 22.1% of those aged 85-89 years and 26.5% of those aged 90 years and over. Regarding the delay of case detection among 14,400 symptomatic pulmonary TB patients, patient's delay was longer in those aged 20-64 years and shorter in those aged 65 years and over. While, doctor's delay showed an inverse relationship with patient's delay. Total delay combining patient's delay and doctor's delay was strongly influenced by patient's delay. The sputum smear positive symptomatic pulmonary TB patients showed much longer total delay, and the proportion of total delay exceeding 3 months was 27.5% in those aged 20-64 years. Regarding occupation, the proportion of service workers and nurses/public health nurses were large among young TB patients. 8.4% of male TB patients aged 20-24 years and 10.8% of female TB patients aged 20-24 years were service workers. 10.7% of female TB patients aged 25-49 years were nurses/public health nurses. TB control for nosocomial infection is still important in Japan.