Abstract:

Objective: To analyze the screening result of close contacts of etiologically negative tuberculosis (TB) patients in Yuexiu District, Guangzhou City, and to provide a basis for the screening and management of those close contacts. Methods: The screening results of 1149 close contacts (hereafter referred to as etiologically negative contact group) of 645 cases of etiologically negative TB registered at the TB control facility in Yuexiu District, Guangzhou City diagnosed from January 1, 2019, to December 31, 2022, were collected. Another 1780 close contacts of 920 etiologically positive pulmonary TB patients registered during the same period (hereinafter referred to as the etiologically positive contact group) were used as controls to compare the screening result of close contacts in the two groups. Results: Among 1149 close contacts with etiologically negative TB patients(534 male and 615 female), 45 TB patients were detected (3.92%). Among 1780 close contacts with etiologically positive TB patients (804 male and 976 female), 52 TB patients were detected (2.92%). The difference of TB detection rate was not statistically significant (χ²=2.159, P=0.142). In the etiologically negative contact group, 27 cases (2.35%) got suspicious symptoms and 19 (70.37%) cases were detected with TB from them, while 1122 (97.65%) cases were without suspicious symptoms and 26 (2.32%) cases were detected with TB. In the etiologically positive group, there were 42 (2.36%) cases with suspicious symptoms and 25 (59.52%) cases were detected with TB, while there were 1738 (97.64%) cases without suspicious symptoms and 27 (1.55%) cases were detected with TB. The TB detection rate was higher among symptomatic contacts than asymptomatic contacts in both groups, with statistically significant differences (χ²=324.482,P=0.000, χ²=465.715, P=0.000). Conclusion: TB can be found in close contacts with etiologically negative TB patients. The possibility of detecting TB in close contacts with suspicious symptoms is higher than in close contacts without suspicious symptoms.

Key words: Tuberculosis,pulmonary, Contact tracing, Communicable disease control