Latent tuberculous infection testing among HIV-infected persons in clinical care, United States, 2010-2012

Estimated rates of progression to tuberculosis disease for persons infected with Mycobacterium tuberculosis in the United States

BACKGROUND

In the United States, over 80% of tuberculosis (TB) disease cases are estimated to result from reactivation of latent TB infection (LTBI) acquired more than 2 years previously ("reactivation TB"). We estimated reactivation TB rates for the US population with LTBI, overall, by age, sex, race-ethnicity, and US-born status, and for selected comorbidities (diabetes, end-stage renal disease, and HIV).

METHODS

We collated nationally representative data for 2011-2012. Reactivation TB incidence was based on TB cases reported to the National TB Surveillance System that were attributed to LTBI reactivation. Person-years at risk of reactivation TB were calculated using interferon-gamma release assay (IGRA) positivity from the National Health and Nutrition Examination Survey, published values for interferon-gamma release assay sensitivity and specificity, and population estimates from the American Community Survey.

RESULTS

For persons aged ≥6 years with LTBI, the overall reactivation rate was estimated as 0.072 (95% uncertainty interval: 0.047, 0.12) per 100 person-years. Estimated reactivation rates declined with age. Compared to the overall population, estimated reactivation rates were higher for persons with diabetes (adjusted rate ratio [aRR] = 1.6 [1.5, 1.7]), end-stage renal disease (aRR = 9.8 [5.4, 19]), and HIV (aRR = 12 [10, 13]).

CONCLUSIONS

In our study, individuals with LTBI faced small, non-negligible risks of reactivation TB. Risks were elevated for individuals with medical comorbidities that weaken immune function.

Screening for tuberculosis infection and effectiveness of preventive treatment among people with HIV in low-incidence settings

OBJECTIVE

To determine the yield of screening for latent tuberculosis infection (LTBI) among people with HIV (PWH) in low tuberculosis (TB) incidence countries (<10 TB cases per 100 000 persons).

DESIGN

A systematic review and meta-analysis were performed to assess prevalence and predictive factors of LTBI, rate of TB progression, effect of TB preventive treatment (TPT), and numbers needed to screen (NNS).

METHODS

PubMed and Cochrane Library were searched for studies reporting primary data, excluding studies on active or paediatric TB. We extracted LTBI cases, odds ratios, and TB incidences; pooled estimates using a random-effects model; and used the Newcastle-Ottawa scale for bias.

RESULTS

In 51 studies with 65 930 PWH, 12% [95% confidence interval (CI) 10-14] had a positive LTBI test, which was strongly associated with origin from a TB-endemic country [odds ratio (OR) 4.7] and exposure to TB (OR 2.9). Without TPT (10 629 PWH), TB incidence was 28/1000 person-years (PY; 95% CI 12-45) for LTBI-test positive versus 4/1000 PY (95% CI 0-7) for LTBI-test-negative individuals. Among 625 PWH (1644 PY) receiving TPT, 15 developed TB (6/1000 PY). An estimated 20 LTBI-positive individuals would need TPT to prevent one case of TB, and numbers NNS to detect LTBI or prevent active TB varied according to a-priori risk of LTBI.

CONCLUSION

The relatively high prevalence of LTBI among PWH and the strong correlation with origin from a TB-endemic country support risk-stratified LTBI screening strategies for PWH in low-incidence countries and treating those who test positive.

Single-Cell Transcriptomics of Mtb/HIV Co-Infection

Tuberculosis (TB) and Human Immunodeficiency Virus (HIV) co-infection continues to pose a significant healthcare burden. HIV co-infection during TB predisposes the host to the reactivation of latent TB infection (LTBI), worsening disease conditions and mortality. There is a lack of biomarkers of LTBI reactivation and/or immune-related transcriptional signatures to distinguish active TB from LTBI and predict TB reactivation upon HIV co-infection. Characterizing individual cells using next-generation sequencing-based technologies has facilitated novel biological discoveries about infectious diseases, including TB and HIV pathogenesis. Compared to the more conventional sequencing techniques that provide a bulk assessment, single-cell RNA sequencing (scRNA-seq) can reveal complex and new cell types and identify more high-resolution cellular heterogeneity. This review will summarize the progress made in defining the immune atlas of TB and HIV infections using scRNA-seq, including host-pathogen interactions, heterogeneity in HIV pathogenesis, and the animal models employed to model disease. This review will also address the tools needed to bridge the gap between disease outcomes in single infection vs. co-infection. Finally, it will elaborate on the translational benefits of single-cell sequencing in TB/HIV diagnosis in humans.

Practices and attitudes towards tuberculosis and latent tuberculosis infection screening in people living with HIV/AIDS among HIV physicians in Japan

Background

Tuberculosis (TB) continues to be the leading cause of death for people living with HIV/AIDS (PLHIV), and HIV is the strongest known risk factor for progression to active TB disease for persons with latent TB infection (LTBI). Screening for active TB and LTBI, and TB preventive therapy (TPT) is recommended, however, clinical practices regarding LTBI screening for HIV positive population have not been uniform, resulting in low rates of LTBI screening and TPT uptake, in both low and high TB-burden countries. We sought to explore the practices and attitudes towards TB and LTBI screening in PLHIV among HIV physicians in Japan.

Methods

We conducted a cross-sectional survey whereby an on-line questionnaire was administered to physicians who are currently, or have the experience of, providing care and treatment for PLHIV in Japan.

Results

The questionnaire was sent to a total of 83 physicians, of which 59 responded (response rate; 71.1%). 52.5% (31/59) conducted routine screening and 44.0% (26/59) conducted selectively screening for active TB among HIV/AIDS patients. As for LTBI, 54.2% (32/59) conducted routine screening and 35.6% (21/59) conducted selective screening for LTBI among PLHIV. “T-SPOT only” was the most frequently used method of screening (n = 33), followed by “QFT only” (n = 11). Criteria for LTBI screening included TB burden in the country of birth of the patient, previous contact with a TB patient, and CD4+ cell count. 83.1% (49/59) either “always” or “selectively” offered TPT to PLHIV diagnosed with LTBI, and among the 49 respondents who did provide TPT, 77.6% (38/49) chose 9-months isoniazid as their first choice. None chose regimen including rifampicin.

Conclusions

Our study revealed that practices regarding TB and LTBI screening and treatment for PLHIV among HIV physicians were mixed and not necessarily in accordance with the various published guidelines. Building and disseminating scientific evidence that takes into consideration the local epidemiology of TB and HIV in Japan is urgently needed to assist physicians make decisions.

Testing and treatment for latent tuberculosis infection in people living with HIV and substance dependence: a prospective cohort study

OBJECTIVE

To quantify the proportion of people living with HIV (PLWH) with other tuberculosis (TB) risk factors that completed the latent tuberculosis infection (LTBI) care cascade and describe factors associated with attrition. The care cascade was defined as follows: (1) receipt of an LTBI test and result, (2) initiation of LTBI treatment and (3) completion of LTBI treatment.

DESIGN

Prospective cohort study.

SETTING

Reactivation of LTBI remains a large source of active TB disease in the USA. PLWH and those who use substances are at greater risk and are harder to engage and retain in care.

PARTICIPANTS

Participants enrolled in a Boston cohort of PLWH from 2012 to 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome was the number and proportion of participants who completed each stage of the cascade and the factors associated with completing each stage. Our secondary outcomes were differences between participants tested with an interferon gamma release assay (IGRA) versus tuberculin skin test and differences between participants who tested positive versus negative for LTBI.

RESULTS

Only 189 of 219 (86.3%) participants completed testing. Five of the 11 with LTBI initiated and three completed treatment. Participants tested with an IGRA were more likely to complete testing (OR 3.87, 95% CI 1.05 to 14.30) while among participants successfully tested, being foreign-born was associated with a positive test result (OR 3.95; 95% CI 1.13 to 13.77).

CONCLUSIONS

Although the majority completed LTBI testing, our findings warrant further investigation in a larger cohort to better understand factors that lead to suboptimal treatment initiation and completion in a low-burden country.

The latent tuberculosis cascade-of-care among people living with HIV: A systematic review and meta-analysis

BACKGROUND

Tuberculosis preventive therapy (TPT) reduces TB-related morbidity and mortality in people living with HIV (PLHIV). Cascade-of-care analyses help identify gaps and barriers in care and develop targeted solutions. A previous latent tuberculosis infection (LTBI) cascade-of-care analysis showed only 18% of persons in at-risk populations complete TPT, but a similar analysis for TPT among PLHIV has not been completed. We conducted a meta-analysis to provide this evidence.

METHODS AND FINDINGS

We first screened potential articles from a LTBI cascade-of-care systematic review published in 2016. From this study, we included cohorts that reported a minimum of 25 PLHIV. To identify new cohorts, we used a similar search strategy restricted to PLHIV. The search was conducted in Medline, Embase, Health Star, and LILACS, from January 2014 to February 2021. Two authors independently screened titles and full text and assessed risk of bias using the Newcastle-Ottawa Scale for cohorts and Cochrane Risk of Bias for cluster randomized trials. We meta-analyzed the proportion of PLHIV completing each step of the LTBI cascade-of-care and estimated the cumulative proportion retained. These results were stratified based on cascades-of-care that used or did not use LTBI testing to determine eligibility for TPT. We also performed a narrative synthesis of enablers and barriers of the cascade-of-care identified at different steps of the cascade. A total of 71 cohorts were included, and 70 were meta-analyzed, comprising 94,011 PLHIV. Among the PLHIV included, 35.3% (33,139/94,011) were from the Americas and 29.2% (27,460/94,011) from Africa. Overall, 49.9% (46,903/94,011) from low- and middle-income countries, median age was 38.0 [interquartile range (IQR) 34.0;43.6], and 65.9% (46,328/70,297) were men, 43.6% (29,629/67,947) were treated with antiretroviral therapy (ART), and the median CD4 count was 390 cell/mm3 (IQR 312;458). Among the cohorts that did not use LTBI tests, the cumulative proportion of PLHIV starting and completing TPT were 40.9% (95% CI: 39.3% to 42.7%) and 33.2% (95% CI: 31.6% to 34.9%). Among cohorts that used LTBI tests, the cumulative proportions of PLHIV starting and completing TPT were 60.4% (95% CI: 58.1% to 62.6%) and 41.9% (95% CI:39.6% to 44.2%), respectively. Completion of TPT was not significantly different in high- compared to low- and middle-income countries. Regardless of LTBI test use, substantial losses in the cascade-of-care occurred before treatment initiation. The integration of HIV and TB care was considered an enabler of the cascade-of-care in multiple cohorts. Key limitations of this systematic review are the observational nature of the included studies, potential selection bias in the population selection, only 14 cohorts reported all steps of the cascade-of-care, and barriers/facilitators were not systematically reported in all cohorts.

CONCLUSIONS

Although substantial losses were seen in multiple stages of the cascade-of-care, the cumulative proportion of PLHIV completing TPT was higher than previously reported among other at-risk populations. The use of LTBI testing in PLHIV in low- and middle-income countries was associated with higher proportion of the cohorts initiating TPT and with similar rates of completion of TPT.

The Impact of HIV Infection on TB Disparities Among US-Born Black and White Tuberculosis Patients in the United States

BACKGROUND/OBJECTIVES

US-born non-Hispanic black persons (blacks) (12% of the US population) accounted for 41% of HIV diagnoses during 2008-2014. HIV infection significantly increases TB and TB-related mortality. TB rate ratios were 6 to 7 times as high in blacks versus US-born non-Hispanic whites (whites) during 2013-2016. We analyzed a sample of black and white TB patients to assess the impact of HIV infection on TB racial disparities.

METHODS

In total, 552 black and white TB patients with known HIV/AIDS status were recruited from 10 US sites in 2009-2010. We abstracted data from the National TB Surveillance System, medical records, and death certificates and interviewed 477 patients. We estimated adjusted odds ratios (AORs) with 95% confidence intervals (CIs) for associations of TB with HIV infection, late HIV diagnosis (≤3 months before or any time after TB diagnosis), and mortality during TB treatment.

RESULTS

Twenty-one percent of the sample had HIV/AIDS infection. Blacks (AOR = 3.4; 95% CI, 1.7-6.8) and persons with recent homelessness (AOR = 2.5; 95% CI, 1.5-4.3) had greater odds of HIV infection than others. The majority of HIV-infected/TB patients were diagnosed with HIV infection 3 months or less before (57%) or after (4%) TB diagnosis. Among HIV-infected/TB patients, blacks had similar percentages to whites (61% vs 57%) of late HIV diagnosis. Twenty-five percent of HIV-infected/TB patients died, 38% prior to TB diagnosis and 62% during TB treatment. Blacks did not have significantly greater odds of TB-related mortality than whites (AOR = 1.1; 95% CI, 0.6-2.1).

CONCLUSIONS

Black TB patients had greater HIV prevalence than whites. While mortality was associated with HIV infection, it was not significantly associated with black or white race.

Latent tuberculosis infection screening in persons newly-diagnosed with HIV infection in Italy: A multicentre study promoted by the Italian Society of Infectious and Tropical Diseases

BACKGROUND

The Italian Society of Infectious and Tropical Diseases performed a survey on the application of guidelines for the management of persons living with HIV (PLWH), to evaluate current practice and the yield of screening for latent tuberculosis infection (LTBI) in newly-diagnosed PLWH; in addition, the offer of preventive therapy to LTBI individuals and the completion rate were analysed.

MATERIALS AND METHODS

Newly-diagnosed PLWH in nine centres were evaluated retrospectively (2016/2017) using binary and multinomial logistic regression to identify factors associated with LTBI diagnostic screening and QuantiFERON (QFT) results.

RESULTS

Of 801 patients evaluated, 774 were studied after excluding active TB. LTBI tests were performed in 65.5%. Prescription of an LTBI test was associated with being foreign-born (odds ratio (OR) 3.19, p < 0.001), older (for 10-year increments, OR 1.22, p = 0.034), and having a CD4 count <100 cells/mm³ vs ≥500 cells/mm³ (OR 2.30, p = 0.044). LTBI was diagnosed in 6.5% of 495 patients evaluated by QFT. Positive results were associated with being foreign-born (relative risk ratio (RRR) 30.82, p < 0.001), older (for 10-year increments, RRR 1.78, p = 0.003), and having a high CD4 count (for 100 cells/mm³ increments, RRR 1.26, p < 0.003). Sixteen LTBI individuals started TB preventive therapy and eight completed it.

CONCLUSIONS

LTBI screening is inconsistently performed in newly-diagnosed PLWH. Furthermore, TB preventive therapy is not offered to all LTBI individuals and compliance is poor.

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.

Combining surveillance systems to investigate local trends in tuberculosis-HIV co-infection

Alameda County has some of the highest human immunodeficiency virus (HIV) and tuberculosis (TB) case rates of California counties. We identified TB-HIV co-infected patients in 2002-2015 by matching county TB and HIV registries, and assessed trends in TB-HIV case rates and estimated prevalence ratios for HIV co-infection. Of 2054 TB cases reported during 2002-2015, 91 (4%) were HIV co-infected. TB-HIV case rates were 0.29/100,000 and 0.40/100,000 in 2002 and 2015, respectively, with no significant change (P = 0.85). African-American TB case-patients were 9.77 times (95% confidence interval [CI] 5.90-16.17) more likely than Asians to be HIV co-infected, and men 2.74 times (95% CI 1.66-4.51) more likely co-infected than women. HIV co-infection was more likely among TB case-patients with homelessness (6.21, 95% CI 3.49-11.05) and injection drug use (11.75, 95% CI 7.61-18.14), but less common among foreign-born and older case-patients (both P < 0.05). Among foreign-born case-patients, 42% arrived in the U.S. within 5 years of TB diagnosis. TB-HIV case rates were low and stable in Alameda County, and co-infected patients were predominantly young, male, U.S.-born individuals with traditional TB risk factors. Efforts to reduce TB-HIV burden in Alameda County should target persons with traditional TB risk factors and recently arrived foreign-born individuals.