Tuberculosis is the leading cause of death in patients living with HIV/AIDS, and HIV infection is also a major risk factor for latent tuberculosis infection (LTBI) developing to tuberculosis. So screening and treatment of LTBI is an important measure to prevent the incidence of tuberculosis to reduce the mortality rate in this population.

To examine the prevalence of LTBI and associated factors, and to identify the high-risk individuals among HIV/AIDS patients in Yinchuan urban areas, Ningxia Hui Autonomous Region, providing a scientific basis for the preventive treatment of tuberculosis in this population.

A total of 546 HIV/AIDS patients who were treated in designated institutions for HIV/AIDS management in the urban area of Yinchuan, Ningxia Hui Autonomous Region from March to August 2021 were selected. By use of an on-site survey in combination with reviewing management files, general information (including demographic characteristics such as sex, age, ethnic group, education level, marital status, annual household income per capita, occupation, BMI, smoking and drinking) and clinical information (chronic disease prevalence, closely contacting with tuberculosis patients, time since the HIV/AIDS diagnosis, duration of antiviral treatment, other co-infections, recent CD₄⁺ T cell count) were collected. LTBI was screened by the tuberculin skin test (TST) . The general information was compared between those with LTBI (n=133) and those without (n=413) . Multivariate Logistic regression analysis was used to explore the influencing factors of LTBI in HIV/AIDS patients. R software was used to establish a restricted cubic spline model to fit the dose-effect relationship between CD₄⁺ T cell count and the risk of LTBI.

The prevalence of LTBI detected by TST was 24.4%. Married 〔OR=0.544, 95%CI (0.321, 0.922) , P<0.05〕was associated with decreased risk of LTBI in HIV/AIDS, while smoking〔OR=1.919, 95%CI (1.213, 3.037) , P<0.05〕, and closely contacting with tuberculosis patients 〔OR=11.100, 95%CI (2.889, 42.648) , P<0.05〕were associated with increased risk of LTBI in HIV/AIDS. The fitting results of the restricted cubic spline model showed that the CD₄⁺ T cell count and LTBI risk had an approximate "n" -shaped nonlinear relationship (non-linear test χ²=29.080, P<0.001) .

To reduce the incidence of LTBI in people living with HIV/AIDS, more attention and timely preventive treatment should be given to those unmarried, smokers, and close contacts of tuberculosis patients. In addition, multiple methods are recommended for screening for LTBI in those with low CD₄⁺ T cell count.