High Prevalence of Tuberculosis Infection and Disease in Child Household Contacts of Adults With Rifampin-resistant Tuberculosis

Timing of maternal isoniazid preventive therapy on tuberculosis infection among infants exposed to HIV in low-income and middle-income settings: a secondary analysis of the TB APPRISE trial

BACKGROUND

Infants born to women with HIV in settings with a high tuberculosis burden are at risk of tuberculosis infection and rapid progression to active disease. Maternal isoniazid preventive therapy might mitigate this risk, but optimal timing of therapy remains unclear. The TB APPRISE trial showed that initiation of isoniazid during pregnancy resulted in more frequent adverse pregnancy outcomes than when initiated postpartum. We aimed to determine the proportion of infants testing positive for tuberculosis infection born to mothers who initiated isoniazid therapy antepartum compared with postpartum using two commonly used tests, the test agreement, and predictors of test positivity.

METHODS

TB APPRISE was a randomised, double-blind, placebo-controlled, non-inferiority trial done at 13 study sites across eight countries (Botswana, Haiti, India, South Africa, Tanzania, Thailand, Uganda, and Zimbabwe). Pregnant women with HIV on antiretroviral therapy were randomly assigned to receive immediate isoniazid preventive therapy (28 weeks isoniazid [300 mg daily], then placebo until week 40 after delivery) or deferred treatment (placebo until week 12 after delivery, then isoniazid [300 mg daily] for 28 weeks). Mother-infant pairs were followed up until 48 weeks after delivery. We included all liveborn infants with a tuberculin skin test or interferon-γ release assay (IGRA) at 44 weeks. The outcomes assessed in this secondary analysis were tuberculosis test positivity by study group, test agreement, and predictors of test positivity. This study was registered with ClinicalTrials.gov, NCT01494038.

FINDINGS

Between Aug 19, 2014, and April 4, 2016, 956 mothers were randomly assigned, and 749 mother-child pairs were included in this secondary analysis. Of 749 infants, 694 (93%) received Bacille Calmette-Guérin (BCG) vaccination, 675 (90%) were born to mothers who had completed isoniazid treatment, 20 (3%) were exposed to tuberculosis, seven (1%) became HIV positive, and one (<1%) developed probable tuberculosis. 43 (6%; 95% CI 4-8]) of 732 infants had a positive IGRA test result and 55 (8%; 6-10) of 727 infants had a positive tuberculin skin test result. Test positivity did not differ by study group (p=0·88 for IGRA; p=0·44 for tuberculin skin test). Test agreement was poor (κ=0·107 [95% CI 0·002-0·212]). Infant tuberculin skin test positivity was associated with breastfeeding (adjusted odds ratio 6·63 [95% CI 1·57-27·9]), BCG vaccination (4·97 [1·50-16·43]), and maternal tuberculin skin test positivity at delivery (3·28 [1·70-6·33]); IGRA positivity was associated with female sex (2·09 [1·06-4·14]).

INTERPRETATION

Deferral of maternal isoniazid preventive therapy to early postpartum had no effect on infant tuberculosis acquisition in our trial population, regardless of the diagnostic test used; however, tuberculosis test agreement is poor during infancy.

FUNDING

US National Institutes of Health.

What's new in childhood tuberculosis

PURPOSE OF REVIEW

The current review identifies recent advances in the prevention, diagnosis, and treatment of childhood tuberculosis (TB) with a focus on the WHO's updated TB management guidelines released in 2022.

RECENT FINDINGS

The COVID-19 pandemic negatively affected global TB control due to the diversion of healthcare resources and decreased patient care-seeking behaviour. Despite this, key advances in childhood TB management have continued. The WHO now recommends shorter rifamycin-based regimens for TB preventive treatment as well as shorter regimens for the treatment of both drug-susceptible and drug-resistant TB. The Xpert Ultra assay is now recommended as the initial diagnostic test for TB in children with presumed TB and can also be used on stool samples. Point-of-care urinary lipoarabinomannan assays are promising as 'rule-in' tests for children with presumed TB living with HIV. Treatment decision algorithms can be used to diagnose TB in symptomatic children in settings with and without access to chest X-rays; bacteriological confirmation should always be attempted.

SUMMARY

Recent guideline updates are a key milestone in the management of childhood TB, and the paediatric TB community should now prioritize their efficient implementation in high TB burden countries while generating evidence to close current evidence gaps.

Factors associated with prevalent Mycobacterium tuberculosis infection and disease among adolescents and adults exposed to rifampin-resistant tuberculosis in the household

BACKGROUND

Understanding factors associated with prevalent Mycobacterium tuberculosis infection and prevalent TB disease in household contacts of patients with drug-resistant tuberculosis (TB) may be useful for TB program staff conducting contact investigations.

METHODS

Using data from a cross-sectional study that enrolled index participants with rifampin-resistant pulmonary TB and their household contacts (HHCs), we evaluated HHCs age ≥15 years for factors associated with two outcomes: Mycobacterium tuberculosis infection and TB disease. Among HHCs who were not already diagnosed with current active TB disease by the TB program, Mycobacterium tuberculosis infection was determined by interferon-gamma release assay (IGRA). TB disease was adjudicated centrally. We fitted logistic regression models using generalized estimating equations.

RESULTS

Seven hundred twelve HHCs age ≥15 years enrolled from 279 households in eight high-TB burden countries were a median age of 34 years, 63% female, 22% current smokers and 8% previous smokers, 8% HIV-positive, and 11% previously treated for TB. Of 686 with determinate IGRA results, 471 tested IGRA positive (prevalence 68.8% (95% Confidence Interval: 64.6%, 72.8%)). Multivariable modeling showed IGRA positivity was more common in HHCs aged 25-49 years; reporting prior TB treatment; reporting incarceration, substance use, and/or a period of daily alcohol use in the past 12 months; sharing a sleeping room or more evenings spent with the index participant; living with smokers; or living in a home of materials typical of low socioeconomic status. Forty-six (6.5% (95% Confidence Interval: 4.6%, 9.0%)) HHCs age ≥15 years had prevalent TB disease. Multivariable modeling showed higher prevalence of TB disease among HHCs aged ≥50 years; reporting current or previous smoking; reporting a period of daily alcohol use in the past 12 months; and reporting prior TB treatment.

CONCLUSION

We identified overlapping and distinct characteristics associated with Mycobacterium tuberculosis infection and TB disease that may be useful for those conducting household TB investigations.

Trends in Rifampicin Resistance Among Children With Presumptive TB in the Pre-COVID and COVID-Era

Publications on COVID-19's impact on the global tuberculosis burden are from adult cohorts, pediatric data are lacking for inform decision. We compared the TB trends in southern Nigerian children in the pre-COVID-19 and COVID-19 era. This was a retrospective, cross-sectional study of early morning sputum/gastric washing or stool samples from children with presumptive TB evaluated using GeneXpert in a tertiary hospital from January 2016 to May 2022. Of the 20 589 persons screened for presumed TB in the pre-COVID-19 and the COVID-19 era, only 1104 (88.7%) of 1245 children had complete data for analysis. In the COVID era, a significantly higher number of children were presumed to have TB 755 (68.4%), P < .001. The overall incidence of MTB detected by Xpert MTB/RIF during the study period was 6.4% (71/1104). The incidence of MTB in the pre-COVID-19 era was 24/349 (6.9%), which was slightly higher than the COVID-19 era (47/755; 6.2%), P > .05). The annual trends of MTB detected peaked in 2019 [18/115; 15.7%] in the pre-COVID-19 era, then plummeted to 12/228 (5.3%) in 2020 in the COVID-19 era, and reached its all-time low of 6/160 (3.8%) in the first half of 2022, (P < .001). The overall incidence of Rifampicin-resistant TB (RR-TB) was 2.8% among the MTB detected cases and all occurred in the COVID-19 era. This study found a significant decline in MTB diagnosis and in the emergence of RR-TB in the COVID-19 era. This necessitates re-prioritizing worldwide efforts to manage childhood tuberculosis, including increased testing, if the aim of eliminating tuberculosis by 2035 is to be met.

Tuberculosis Infection in Pregnant People: Current Practices and Research Priorities

Women are significantly more likely to develop tuberculosis (TB) disease within the first 90 days after pregnancy than any other time in their lives. Whether pregnancy increases risk of progression from TB infection (TBI) to TB disease is unknown and is an active area of investigation. In this review, we discuss the epidemiology of TB and TBI in pregnancy, TBI diagnostics, and prevalence in pregnancy. We also review TBI treatment and highlight research priorities, such as short-course TB prevention regimens, drug-resistant TB prevention, and additional considerations for safety, tolerability, and pharmacokinetics that are unique to pregnant and postpartum people.

Mycobacterium tuberculosis Transmission in High-Incidence Settings-New Paradigms and Insights

Tuberculosis has affected humankind for thousands of years, but a deeper understanding of its cause and transmission only arose after Robert Koch discovered Mycobacterium tuberculosis in 1882. Valuable insight has been gained since, but the accumulation of knowledge has been frustratingly slow and incomplete for a pathogen that remains the number one infectious disease killer on the planet. Contrast that to the rapid progress that has been made in our understanding SARS-CoV-2 (the cause of COVID-19) aerobiology and transmission. In this Review, we discuss important historical and contemporary insights into M. tuberculosis transmission. Historical insights describing the principles of aerosol transmission, as well as relevant pathogen, host and environment factors are described. Furthermore, novel insights into asymptomatic and subclinical tuberculosis, and the potential role this may play in population-level transmission is discussed. Progress towards understanding the full spectrum of M. tuberculosis transmission in high-burden settings has been hampered by sub-optimal diagnostic tools, limited basic science exploration and inadequate study designs. We propose that, as a tuberculosis field, we must learn from and capitalize on the novel insights and methods that have been developed to investigate SARS-CoV-2 transmission to limit ongoing tuberculosis transmission, which sustains the global pandemic.

Preventive Therapy for Contacts of Drug-Resistant Tuberculosis

Preventing the progression of a drug-resistant tuberculosis (DR-TB) infection to disease is an important pillar of the DR-TB elimination strategy. International guidelines have recently proposed fluoroquinolones for tuberculosis preventive therapy (TPT) in DR-TB contacts, although the available evidence is low quality. The pooled data from small observational studies suggest that a fluoroquinolone-based TPT is safe, effective and cost-effective as a preventive treatment in DR-TB contacts. Three clinical trials are currently ongoing to generate higher quality evidence on the efficacy of levofloxacin and delamanid as a DR-TB preventive therapy. Additional evidence is also needed, regarding TPT treatment in fluoroquinolone-resistant-TB contacts, patient and health care worker perceptions on DR-TB preventive therapy for contacts, and the service delivery models to increase DR-TPT access. This state-of-the-art review presents the current literature on TPT for contacts of DR-TB cases, focusing on the available evidence and international guidelines.