A longitudinal study on latent TB infection screening and its association with TB incidence in HIV patients.

Latent TB infection (LTBI) in HIV patients, its treatment, and immunological recovery following highly active antiretroviral therapy (HAART) could interact and impact TB disease progression. We aim to examine the factors associated with LTBI and TB disease development among HIV patients. Longitudinal clinical and laboratory data were accessed from the largest HIV specialist clinic in Hong Kong, where HAART and yearly LTBI screening are routinely provided for HIV patients. Between 2002 and mid-2017, among 2079 HIV patients with 14119 person-years (PY) of follow-up, 32% of LTBI screened patients (n = 1740) were tested positive. The overall TB incidence was 1.26/100 PY from HIV diagnosis to HAART initiation, falling to 0.37/100 PY. A lower risk of TB disease progression was associated with local residence, Chinese ethnicity, negative baseline LTBI result, being on HAART, LTBI treatment, higher baseline CD4 and CD4/CD8 ratio. A positive test at baseline, but not subsequent testing results, was significantly associated with TB disease development. Baseline LTBI screening is an important strategy for identifying HIV patients at risk of TB disease progression. Routine repeat LTBI screening on an annual basis might not give additional benefits to patients on HAART with good immunological responses. Such practice should require re-evaluation.

Latent Tuberculosis Infection Testing Strategies for HIV-Positive Individuals in Hong Kong.

Importance: With immune recovery following early initiation of antiretroviral therapy (ART), the risk of tuberculosis (TB) reactivation among individuals with HIV could be reduced. The current strategy of annual latent TB infection (LTBI) testing should be revisited to increase cost-effectiveness and reduce the intensity of testing for individuals. Objective: To analyze the cost-effectiveness of LTBI testing strategies for individuals in Hong Kong with HIV who had negative LTBI test results at baseline. Design, Setting, and Participants: This decision analytical model study using a cost-effectiveness analysis included 3130 individuals with HIV in Hong Kong, China, which has an intermediate TB burden and a low incidence of HIV-TB coinfection. A system dynamics model of individuals with HIV attending a major HIV specialist clinic in Hong Kong was developed and parameterized by longitudinal clinical and LTBI testing records of patients during a 15-year period. The study population was stratified by age group, CD4 lymphocyte level, ART status, and right of abode. Alternative strategies for LTBI testing after a baseline test were compared with annual testing under different coverages of ART, LTBI testing, and LTBI treatment scenarios in the model. An annual discounting rate of 3.5% was used in cost-effectiveness analysis. Main Outcomes and Measures: Proportion of new TB cases averted above base case scenario, discounted quality-adjusted life-years gained (QALYG), incremental cost, and incremental cost-effectiveness ratios in 2017 to 2023. Results: A total of 3130 patients with HIV (2740 [87.5%] male and 2800 [89.5%] younger than 50 years at HIV diagnosis) with 16 630 person-years of follow-up data from 2002 to 2017 were analyzed. Of these, 94 patients (0.67 [95% CI, 0.51-0.91] per 100 person-years) developed TB. Model estimates of cumulative number of TB cases would reach 146 by 2023, with the annual number of new TB diagnoses ranging from 6 to 8. For patients who had negative LTBI test results at baseline, subsequent LTBI testing strategies were ranked by ascending effectiveness as follows: (1) no testing, (2) test by risk factors, (3) biennial testing for all, (4) up to 3 tests for all, and (5) annual testing for all. Applying a willingness-to-pay threshold of $50 000 per QALYG, none of the subsequent testing strategies were cost-effective. Test by risk factors and up to 3 tests for all were cost-effective only if the willingness-to-pay threshold was increased to $100 000 per QALYG and $200 000 per QALYG, respectively. More new TB cases would be averted by expanding LTBI testing and/or treatment coverage. Conclusions and Relevance: Changing the current testing strategy to less intense testing strategies is likely to be cost-effective in the presence of an increased coverage of baseline LTBI testing and/or treatment.

More safer sex intervention needed for HIV-positive MSM with higher education level for prevention of sexually transmitted hepatitis C.

INTRODUCTION: The epidemiology of hepatitis C virus (HCV) infections in Chinese HIV-infected men who have sex with men (MSM) remains obscure. More data is required to understand the epidemic and set up preventive strategy. MATERIALS AND METHODS: Baseline and annual testing of anti-HCV was in place for all HIV-infected MSM in the largest HIV clinic in Hong Kong. Logistic regression was used to compare those with HCV seroconversion (seroconverters) with those remained tested anti-HCV negative (non-seroconverters) to identify factors associated with incident HCV. RESULTS: From 1999 to 2013, 1311 patients were tested for anti-HCV seroconversion, contributing to 6295 patient-years of observation. Fourteen (1.1%) patients seroconverted, with genotype 3 being most commonly detected. The overall incidence rate of HCV infection was 0.22 per 100 patient-years (PY) in the cohort. The incidence rate increased from 0.13 per 100PY before 2002 to 0.19 per 100PY in 2002-2007 and 0.47 per 100PY in 2008-2013. All the seroconverters were Chinese, with median age of anti-HCV seroconversion at 38 years (range: 28-53 years). None of them were injecting drug users. As compared with the non-seroconverters, seroconverters were of higher education level (85.7% vs 50.7% tertiary education or above, OR 5.28, p=0.021) and had prior history of sexually transmitted infection (92.9% vs 60.9%, OR 8.34, p=0.041). More seroconverters were found to have history of syphilis infection (57.1% vs 37.2%, p=0.134) but the difference was not statistically significant. Baseline CD4 count and HIV viral load, proportion on antiretroviral therapy and duration of antiretroviral therapy were not different between two groups. CONCLUSIONS: The incidence of HCV has been increasing among HIV-infected MSM non-injecting drug users in Hong Kong. More education and intervention on safer sex is required to be targeted on those with higher education level.