BACKGROUND
There are few data on the treatment of children and adolescents with multidrug-resistant (MDR) or rifampicin-resistant (RR) tuberculosis, especially with more recently available drugs and regimens. We aimed to describe the clinical and treatment characteristics and their associations with treatment outcomes in this susceptible population.
METHODS
We conducted a systematic review and individual participant data meta-analysis. Databases were searched from Oct 1, 2014, to March 30, 2020. To be eligible, studies must have included more than five children or adolescents (0-19 years of age) treated for microbiologically confirmed or clinically diagnosed MDR or RR tuberculosis within a defined treatment cohort, and reported on regimen composition and treatment outcomes. Abstracts were screened independently by two authors to identify potentially eligible records. Full texts were reviewed by two authors independently to identify studies meeting the eligiblity criteria. For studies meeting eligiblity criteria, anonymised individual patient data was requested and individiual level data included for analysis. The main outcome assessed was treatment outcome defined as treatment success (cure or treatment completed) versus unfavourable outcome (treatment failure or death). Multivariable logistic regression models were used to identify associations between clinical and treatment factors and treatment outcomes. This study is registered with Prospero (CRD42020187230).
FINDINGS
1417 studies were identified through database searching. After removing duplicates and screening for eligibility, the search identified 23 369 individual participants from 42 studies, mostly from India and South Africa. Overall, 16 825 (72·0%) were successfully treated (treatment completed or cured), 2848 died (12·2%), 722 (3·1%) had treatment failure, and 2974 (12·7%) were lost to follow-up. In primary analyses, the median age was 16 (IQR 13-18) years. Of the 17 764 (87·1%) participants with reported HIV status, 2448 (13·8%) were living with HIV. 17 707 (89·6%) had microbiologically confirmed tuberculosis. After adjusting for significant factors associated with treatment outcome, the use of two (adjusted odds ratio [OR] 1·41 [95% CI 1·09-1·82]; p=0·008) or three (2·12 [1·61-2·79]; p<0·0001) WHO-classified group A drugs (bedaquiline, moxifloxacin, levofloxacin, and linezolid) compared with the use of no group A drugs at all was positively associated with treatment success.
INTERPRETATION
Younger and clinically diagnosed children are underrepresented among those treated for MDR and RR tuberculosis and should be a focus for case-finding efforts. Overall treatment outcomes in our analysis were better than in adults but lower than the international targets of 90% or more individuals successfully treated. Treatment with more group A drugs was associated with better treatment outcomes in children and adolescents, highlighting the need for more rapid access to these drugs and improved regimens.
Background
Isoniazid (INH, H) resistance is the most common drug-resistant TB pattern, with treatment success rates lower than those in drug-susceptible TB. The WHO recommends a 6-month regimen of rifampicin (RIF, R), ethambutol (EMB, E), pyrazinamide (PZA, Z), and levofloxacin (Lfx) (6REZLfx) for INH-resistant, RIF-susceptible TB (HRRS-TB). Uzbekistan has a high burden of TB (62/100,000 population) and multidrug-resistant TB (12/100,000 population).
Methods
We conducted a retrospective, descriptive study of microbiologically confirmed HRRS-TB using routinely collected programmatic data from 2009 to 2020.
Results
We included 854 HRRS-TB cases. Treatment success was 80.2% overall. For REZLfx, the treatment success rate was 92.0% over a short treatment duration, with no amplifications to RIF or second-line anti-TB drug resistance. We documented 46 regimens with REZLfx plus linezolid (success 87.0%) and 539 regimens using kanamycin or capreomycin (success 76.6%). We identified 37 treatment failures (4.3%), 30 deaths (3.5%), 25 resistance amplifications (2.9%), including eight to RIF (0.9%), and 99 lost to follow-up (LTFU) cases (11.6%). Unsuccessful outcomes were more common with older age, diabetes, chest X-ray cavities, smear positivity, smear-positive persistence, and male sex. LTFU was more common with injection-containing regimens.
Conclusions
REZLfx is a safe and effective first-line treatment for INH-resistant, RIF-susceptible TB. Treatment success was lower and LTFU was higher for injection-containing regimens.
The Global Drug Facility (GDF) of the Stop TB Partnership was launched in 2001 with the goal of increasing access to quality-assured tuberculosis (TB) drugs and products. We aimed to describe the TB drugs and prices available from the GDF over time and to assess trends.
METHODS
We searched the internet, including an internet archive, for past and recent GDF Product Catalogs and extracted the listed TB drugs and prices. We calculated the lowest price for the most common drug formulations assuming drugs with similar active pharmaceutical ingredients (APIs) are substitutes for each other. We assessed time trends in the TB drugs and prices offered by the GDF in univariable regressions over the longest possible period.
RESULTS
We identified 43 different GDF Product Catalogs published between November 2001 and May 2024. These product catalogs included 122 single medicines (31 APIs), 28 fixed-dose combinations (9 API combinations), and 8 patient kits (8 API regimens and other materials). The number of TB drugs listed in the GDF Product Catalog increased from 9 (8 APIs) to 55 (32 APIs). The price decreased for 17, increased for 19, and showed no trend for 12 APIs. The price of 15 (53.6%) of 28 APIs used against drug-resistant TB decreased, including the price of drugs used in new treatment regimens. The decreasing price trend was strongest for linezolid (-16.60 [95% CI: -26.35 to -6.85] percentage points [pp] per year), bedaquiline (-12.61 [95% CI: -18.00 to -7.22] pp per year), cycloserine (-11.20 [95% CI: -17.40 to -4.99] pp per year), pretomanid (-10.47 [95% CI: -15.06 to -5.89] pp per year), and rifapentine (-10.46 [95% CI: -12.86 to -8.06] pp per year). The prices of 16 (61.5%) of 23 APIs for standard drug-susceptible TB treatment increased, including rifampicin (23.70 [95% CI: 18.48 to 28.92] pp per year), isoniazid (20.95 [95% CI: 18.96 to 22.95] pp per year), ethambutol (9.85 [95% CI: 8.83 to 10.88] pp per year), and fixed-dose combinations thereof.
CONCLUSIONS
The number of TB drugs available from the GDF has substantially increased during its first 23 years of operation. The prices of most APIs for new TB treatments decreased or remained stable. The prices of most APIs for standard drug-sensitive TB treatment increased.
Tajikistan has a high burden of rifampicin-resistant TB (RR-TB), with 2,700 new cases estimated for 2021 (28/100,000 population). TB is spread among household members through close interaction and children exposed through household contact progress to disease rapidly and frequently.
METHODS
We retrospectively analysed programmatic data from household contact tracing in Dushanbe over 50 months. We calculated person-years of follow-up, contact tracing yield, number needed to screen (NNS) and number needed to test (NNT) to find one new case, and time to diagnosis.
RESULTS
We screened 6,654 household contacts of 830 RR-TB index cases; 47 new RR-TB cases were detected, 43 in Year 1 and 4 in Years 2 or 3. Ten were aged <5 years; 46/47 had TB symptoms, 34/45 had chest radiographs consistent with TB, 11/35 were Xpert Ultra-positive, 29/32 were tuberculin skin test-positive and 28/47 had positive TB culture and phenotypic drug susceptibility results. The NNS to find one RR-TB case was 141.57 and the NNT was 34.49. The yields for different types of contacts were as follows: 0.7% for screened contacts, 2.9% for tested contacts, 17.0% for symptomatic contacts and 12.1% for symptomatic contacts aged below 5 years.
CONCLUSION
RR-TB household contact tracing was feasible and productive in Tajikistan, a low middle-income country with an inefficient healthcare delivery system.
These clinical standards aim to provide guidance for diagnosis, treatment, and management of drug-susceptible TB in children and adolescents.
METHODS
Fifty-two global experts in paediatric TB participated in a Delphi consensus process. After eight rounds of revisions, 51/52 (98%) participants endorsed the final document.
RESULTS
Eight standards were identified: Standard 1, Age and developmental stage are critical considerations in the assessment and management of TB; Standard 2, Children and adolescents with symptoms and signs of TB disease should undergo prompt evaluation, and diagnosis and treatment initiation should not depend on microbiological confirmation; Standard 3, Treatment initiation is particularly urgent in children and adolescents with presumptive TB meningitis and disseminated (miliary) TB; Standard 4, Children and adolescents should be treated with an appropriate weight-based regimen; Standard 5, Treating TB infection (TBI) is important to prevent disease; Standard 6, Children and adolescents should receive home-based/community-based treatment support whenever possible; Standard 7, Children, adolescents, and their families should be provided age-appropriate support to optimise engagement in care and clinical outcomes; and Standard 8, Case reporting and contact tracing should be conducted for each child and adolescent.
CONCLUSION
These consensus-based clinical standards, which should be adapted to local contexts, will improve the care of children and adolescents affected by TB.
IMPORTANCE
The importance of this report is that it provides further support for WHO’s recent recommendation that fresh stool is an acceptable sample for GeneXpert TB testing in children, especially small children who often cannot produce an adequate sputum sample. Diagnosing TB in this age group is difficult, and many cases are missed, leading to unacceptable rates of TB illness and death. In our large cohort of children from Dushanbe, Tajikistan, the GeneXpert stool test was positive in 69% of proven cases of TB, and there were very few false-positive tests. We also showed that this diagnostic strategy was feasible to implement in a low-middle-income country with an inefficient health care delivery system. We hope that many more programs will adopt this form of diagnosing TB in children.
Tuberculosis (TB) drugs and their import are costly. We assessed how shorter TB drug regimens, which were non-inferior or superior in recent TB trials, can affect the costs for purchasing and importing TB drugs.
METHODS
We estimated the drug costs and import costs of 39 longer and shorter TB drug regimens using TB drug prices from the Global Drug Facility and import cost estimates for a TB program in Karakalpakstan, Uzbekistan. Drug regimens from recent TB trials were compared with TB drug regimens following present or past World Health Organization recommendations.
RESULTS
We estimated an import cost of $4.19 and a drug cost of $43 per standard 6-month drug-sensitive (DS)-TB regimen. A new 17-week DS-TB regimen from the TBTC Study 31 currently requires more tablets and is more expensive to import ($6.08) and purchase ($233). The TB program can substantially decrease import costs ($2.26–14) and drug costs ($391–2308) per multidrug-resistant (MDR)-TB regimen when using new 6-month or shorter drug regimens from the Nix-TB, NExT, TB PRACTECAL, ZeNix, or BEAT TB trials instead of 9–20-month regimens with import costs of $9.96–507 and drug costs of $354–15 028. For a commonly used 20-month all-oral, bedaquiline-containing MDR-TB regimen, we estimated costs of $41 for drug import and $1773 for drug purchase.
CONCLUSIONS
The implementation of a new and shorter DS-TB regimen may increase the costs for drug purchase and import. The implementation of new and shorter MDR-TB regimens may decrease the costs for drug purchase and/or drug import.
Tuberculosis (TB) programs depend on a continuous supply of large amounts of high-quality TB drugs. When TB programs procure TB drugs from international suppliers, such as the Global Drug Facility, they can incur import costs for international transport, customs clearance, and national transport. We assessed the drug costs and import costs of 18 longer (≥18 months), 10 shorter (9–12 months), and 8 short (≤6 months) drug regimens for drug-sensitive (DS) and multidrug-resistant (MDR)-TB treatment. Costs per regimen were estimated by multiplying recommended drug amounts with 2021 Global Drug Facility prices and drug import costs of a TB program in Karakalpakstan, Uzbekistan. The standard short-course treatment of DS-TB requires taking 730 fixed-dose combination tablets, which weigh 0.79 kg and cause an import cost of $4.19 (9.8% of the regimen’s drug cost of $43). A new 4-month DS-TB regimen requires taking 1358 tablets, which weigh 1.1 kg and cause an import cost of $6.07 (2.6% of the regimen’s drug cost of $233). MDR-TB regimens that last between 24 weeks and 20 months involve 546–9368 tablets and injections. The drugs for these MDR-TB regimens were estimated to weigh 0.42–96 kg and cause an import cost of $2.26–507 per drug regimen (0.29–11% of a regimen’s drug cost of $360–15,028). In a multivariable regression analysis, an additional treatment month increased the import cost of a drug regimen by $5.45 (95% CI: 1.65 to 9.26). Use of an injectable antibiotic in a regimen increased the import cost by $133 (95% CI: 47 to 219). The variable and potentially sizable import costs of TB regimens can affect the financial needs of TB programs. Drug regimens that are shorter and all-oral tend to reduce import costs compared to longer regimens and regimens including an injectable drug.