[An epidemiological study of tuberculosis in Guangzhou in the year of 2005]

Abstract

Objective: To investigate the epidemiological trend of tuberculosis, and therefore to provide information for the Guangzhou Tuberculosis Control Program 2006 to 2010.

Methods: Random population sampling and proportion sampling were used with a sample to population ratio of 1 to 158. There were 24 investigation sites in Guangzhou, and in each site 1656 people should be studied. For children 0 - 14 years old, tuberculin testing was carried out, the BCG inoculation history was obtained and the BCG scar was checked. Fluoroscopy was carried out for population aged 15 years or older and for children with a tuberculin reaction >or= 10 mm or < 10 mm but with blister formation. Chest X-ray film, sputum smear and culture were performed for those with an abnormal fluoroscopy or with symptoms suggesting tuberculosis (persistent cough for 3 weeks or more).

Results: The prevalence of active pulmonary tuberculosis was 201/100 000, the prevalence of smear positive pulmonary tuberculosis was 33/100 000, and the prevalence of bacteriological positive pulmonary tuberculosis was 43/100 000 in Guangzhou. No active pulmonary tuberculosis was found in children younger than 14 years. The prevalence of active pulmonary tuberculosis was 72.5/100 000 - 176.8/100 000 in the population 15 - 50 years old, and was the highest in the population older than 80 years. The prevalence was highest in old males (2341/100 000). The rates of active pulmonary tuberculosis, smear positive and culture positive tuberculosis were 35.0%, 61.5% and 47.1% respectively. The rates of first-time treatment active pulmonary tuberculosis, smear positive and culture positive tuberculosis were 81.3%, 69.2% and 58.8%, respectively. The re-treatment active pulmonary tuberculosis in the group older than 55 years was 80.0% (chi(2) = 2.4123, P > 0.05).

Conclusion: The epidemic of tuberculosis is still serious in Guangzhou, and smear positivity was high in old patients.