Mycobacterium Tuberculosis Infection, Immigration Status, and Diagnostic Discordance: A Comparison of Tuberculin Skin Test and QuantiFERON-TB Gold In-Tube Test Among Immigrants to the U.S

The Challenges of Tuberculosis Management beyond Professional Competence: Insights from Tuberculosis Outbreaks among Ethiopian Immigrants in Israel

Controlling tuberculosis (TB) among immigrants from high-incidence countries presents a public health concern as well as a medical challenge. In this article, we investigate a TB outbreak in a community of people of Jewish descent who emigrated from Ethiopia to Israel (Israeli Ethiopians) that started in June 2022. The index case was a 20-year-old female who had recently immigrated to Israel with her family. Her pre-immigration tuberculin skin test was positive. After excluding active TB, treatment with daily isoniazid for latent TB (LTB) was started shortly after her arrival. A year later, she was diagnosed with smear-positive, culture-positive, pulmonary TB. Investigation of 83 contacts revealed five additional patients with active TB, and three of whom were members were of her household. In this article, we report the current TB outbreak, review previously published TB outbreaks involving Israeli Ethiopians, analyze the factors that triggered each of these outbreaks, and discuss the challenges that face the Israeli TB control program in an era of declining TB incidence and diminishing resources available for TB control.

Challenges in LTBI care in the United States identified using a nationwide TB medical consultation database

BACKGROUND

Identifying and treating individuals with latent TB infection (LTBI) represents a critical and challenging component of national TB elimination. Medical consultations by the Centers for Disease Control and Prevention (CDC) funded TB Centers of Excellence (COEs) are an important resource for healthcare professionals (HCPs) caring for individuals with LTBI. This study aimed to identify the most common clinical concerns regarding LTBI care and to describe epidemiologic and clinical features of patients discussed in these consultations.

METHODS

This mixed-methods study randomly sampled 125 consultation inquiries related to LTBI from the COEs' medical consultation database in 2018. Text from consultation records were reviewed and coded to identify reasons for the inquiries and common epidemiologic and clinical patient characteristics.

RESULTS

The most common topics of inquiry for consultation included accurate LTBI diagnosis (36%), management of LTBI treatment-related issues (22%), and choice of appropriate LTBI treatment regimen (17%). Patients for whom consultations were requested commonly had another medical condition (34%), were non-U.S. born (31%), were children (25%), and had a history of travel to TB-endemic areas (18%).

CONCLUSION

Our findings emphasize the challenge of managing patients with either suspected or confirmed LTBI, highlighting the need for ongoing medical consultation support for nuanced clinical and epidemiologic scenarios.

Tuberculin skin test - Outdated or still useful for Latent TB infection screening?

OBJECTIVE

To make an informed viewpoint on the usefulness of Tuberculin Skin test (TST) compared to Interferon Gamma Release Assays (IGRAs) for diagnosis of Latent TB Infection (LTBI) in different geographical settings.

METHODS

We reviewed the current literature on TST compared to IGRA, including national implementation of WHO LTBI recommendations and retrospective data over the past 7 years at the National Institute for Infectious Diseases "L. Spallanzani" as indirect indicator of usage of both tests under actual programmatic conditions.

RESULTS

Current national guidelines vary considerably, reflecting the uncertainty and rapidly evolving evidence about the potential use of these tests. Data from Institute "L. Spallanzani" showed IGRA concordance in TST positive subjects only in 54.74% of subjects, while there was strong concordance between two tests in TST negative subjects (93.78%).

CONCLUSION

Neither IGRAs nor TST can distinguish active TB from LTBI. TST will continue to be clinically useful in low and high TB endemic areas until more accurate and predictive tests will become available. Clinical judgment remains fundamental in choosing between IGRA/TST tests and interpreting their results.

Disparities in oral health by immigration status in the United States

BACKGROUND

Few investigators have explored differences in oral health status between immigrants and natives. To address this gap, the authors used nationally representative data to characterize disparities in oral health among noncitizens, naturalized citizens, and native adults.

METHODS

The 2013 to 2014 National Health and Nutrition Examination Survey, a nationally representative in-person survey, provides oral health data for US natives, naturalized citizens, and noncitizens. Univariate and multivariate regression analyses were conducted to compare evidence of caries and periodontal disease, as well as recommendations for oral health care, stratified by immigration status for adults.

RESULTS

More than one-half of noncitizens (50.5%) received a diagnosis of periodontal disease, and 38.0% had caries; for natives, these rates were 34.4% and 27.0%, respectively. Differences between natives and naturalized citizens were not statistically significant. After adjusting for age, sex, race or ethnicity, education, poverty, tobacco smoking status, and number of permanent teeth, noncitizens still had 45% higher adjusted odds of periodontal disease and 60% higher odds of receiving recommendations for oral health care than natives. However, differences between noncitizens and natives were no longer important after adjusting for insurance.

CONCLUSIONS

Noncitizen immigrants reported having substantially poorer oral health than natives in the United States. However, disparities between noncitizens and natives are no longer important when accounting for health insurance.

PRACTICAL IMPLICATIONS

Although noncitizen adults have a higher likelihood of poor oral health than native adults, having insurance may close this gap. Health care reform initiatives should provide dental benefits for adults to help mitigate the current economic and legal barriers that many immigrants face when accessing oral health care.

Pulmonary immune responses to Mycobacterium tuberculosis in exposed individuals

BACKGROUND

Blood based Interferon-(IFN)-γ release assays (IGRAs) have a poor predictive value for the development of tuberculosis. This study aimed to investigate the correlation between IGRAs and pulmonary immune responses in tuberculosis contacts in Germany.

METHODS

IGRAs were performed on bronchoalveolar lavage (BAL) cells and peripheral blood from close healthy contacts of patients with culturally confirmed tuberculosis. Cellular BAL composition was determined by flow cytometry. BAL cells were co-cultured with three strains of Mycobacterium tuberculosis (Mtb) and Mtb derived antigens including Purified Protein Derivative (PPD), 6 kD Early Secretory Antigenic Target (ESAT-6) and 10 kD Culture Filtrate Protein (CFP-10). Levels of 29 cytokines and chemokines were analyzed in the supernatants by multiplex assay. Associations and effects were examined using linear mixed-effects models.

RESULTS

There were wide variations of inter-individual cytokine levels in BAL cell culture supernatants. Mycobacterial infection and stimulation with PPD showed a clear induction of several macrophage and lymphocyte associated cytokines, reflecting activation of these cell types. No robust correlation between cytokine patterns and blood IGRA status of the donor was observed, except for slightly higher Interleukin-2 (IL-2) responses in BAL cells from IGRA-positive donors upon mycobacterial infection compared to cells from IGRA-negative donors. Stronger correlations were observed when cytokine patterns were stratified according to BAL IGRA status. BAL cells from donors with BAL IGRA-positive responses produced significantly more IFN-γ and IL-2 upon PPD stimulation and mycobacterial infection than cells from BAL IGRA-negative individuals. Correlations between BAL composition and basal cytokine release from unstimulated cells were suggestive of pre-activated lymphocytes but impaired macrophage activity in BAL IGRA-positive donors, in contrast to BAL IGRA-negative donors.

CONCLUSIONS

In vitro BAL cell cytokine responses to M. tuberculosis antigens or infection do not reflect blood IGRA status but do correlate with stronger cellular responses in BAL IGRA-positive donors. The cytokine patterns observed suggest a pre-activated state of lymphocytes and suppressed macrophage responsiveness in BAL cells from BAL IGRA-positive individuals.