Epidemiological Characteristics of Asymptomatic Tuberculosis - China, 2021-2024.

INTRODUCTION

Tuberculosis (TB) remains a major public health challenge in China, which ranks fourth among the 30 high-burden countries worldwide. Individuals with asymptomatic Pulmonary TB (aPTB) may act as "silent transmitters", contributing to undetected community transmission and hindering progress toward the End-TB goals. This study examined the epidemiological characteristics of patients with aPTB in China from 2021 to 2024 to inform targeted control strategies.

METHODS

Data were obtained from the China Information System for Disease Control and Prevention for the period 2021-2024 and included TB cases with complete symptom records. aPTB was defined as cases without recorded cough symptoms, whereas symptomatic TB was defined as cases with recorded cough symptoms. Descriptive statistical analyses compared the demographic, clinical, and healthcare-seeking characteristics of patients with aPTB and symptomatic TB.

RESULTS

Among 973,299 PTB cases with complete symptom records, 16.66% were classified as aPTB. This proportion remained relatively stable throughout the study period, with a slight peak observed in 2022. Higher proportions of aPTB were observed among individuals aged 55-64 years (17.07%), 65-74 years (15.51%), and 15-24 years (14.03%), and among farmers and herders (50.87%). A mild seasonal trend was observed. Geographically, high-incidence areas were concentrated in western and southwestern China.

CONCLUSIONS

aPTB constitutes a substantial component of the total TB burden in China. Strengthening active case detection in high-risk populations, optimizing medical resources in western China, and integrating aPTB control programs into national prevention and control plans for TB to mitigate hidden transmissions and advance national End-TB objectives.