Effectiveness of short-course, intermittent chemotherapy for tuberculosis in young infants aged less than 6 months

Post-tuberculosis sequelae in children and adolescents: a systematic review

In 2020, an estimated total of 155 million people had survived tuberculosis. Among this number, a sizable proportion have considerable post-tuberculosis morbidity, as shown for the adult population. This systematic review aims to identify the spectrum and prevalence of post-tuberculosis sequelae in children and adolescents. Four databases were systematically searched from database inception to Feb 7, 2022, for literature on post-treatment outcomes of tuberculosis acquired during childhood. Of the 4613 identified publications, 71 studies were included in this systematic review. Studies on cohorts with comparably rare (most of which were extrapulmonary) tuberculosis presentations, such as spinal tuberculosis and tuberculous meningitis were over-represented; however, no study assessed long-term sequelae in a cohort with an average childhood tuberculosis spectrum. The descriptive analysis includes long-term outcomes of 3529 paediatric patients 1 month to 36 years after confirmed (47%) or clinical (53%) tuberculosis. In a considerable proportion of children, a broad spectrum of post-tuberculosis sequelae were identified, ranging from radiological residua after pulmonary tuberculosis, to disabling deformities after musculoskeletal and cutaneous tuberculosis, to somatic and psychosocial impairment after tuberculous meningitis. A better understanding and comprehensive assessment of post-tuberculosis sequelae in children are needed to improve tuberculosis care beyond antituberculous treatment.

Intermittent versus daily therapy for treating tuberculosis in children

BACKGROUND

Childhood tuberculosis (TB) is a neglected global public health problem. Short treatment courses with rifampicin-containing anti-TB drugs given daily for six-months cure over 90% of infected children, but poor adherence reduces treatment success. Intermittent, short-course anti-TB regimens, given two or three times a week under direct observation, are associated with higher adherence in observational studies; but how they compare with daily treatment in relation to cure is unclear. Current international and national recommendations differ on use of intermittent regimens to treat TB in children.

OBJECTIVES

To compare the efficacy and safety of intermittent, short-course anti-TB regimens (twice- or thrice-weekly) with daily short-course anti-TB regimens in treating childhood TB.

SEARCH METHODS

We searched the Cochrane Infectious Disease Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, clinical trials registries, regional databases, conference proceedings, and references without language restrictions up to 30 May 2013; and contacted experts for relevant published, unpublished, and on-going trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs of children aged 15 years or younger, diagnosed with TB (according to the World Health Organization diagnostic categories 1, 2, or 3), who were treated with intermittent twice-weekly or thrice-weekly, short-course anti-TB regimens compared to daily short-course anti-TB treatment regimens. All regimens had to contain rifampicin for at least the first two months.

DATA COLLECTION AND ANALYSIS

The review authors independently screened and selected trials, assessed risk of bias, and extracted data. We sought clarifications from trial authors. We pooled relative risks with their 95% confidence intervals and used a random-effects model where there was significant heterogeneity. We assessed overall evidence-quality using the GRADE approach.

MAIN RESULTS

We included four trials published between 1996 to 2000 that randomized 563 children (465 evaluable) aged five months to 15 years to intermittent twice-weekly versus daily anti-TB treatment. Two trials were from India, one from South Africa, and one from Turkey. All trials used rifampicin and isoniazid, three trials used pyrazinamide, and one trial used streptomycin. The drug combination, and the duration of intermittent and daily treatments differed between trials, and no trials used drug combinations and schedules currently recommended for childhood TB. No trial reported if any child was HIV-positive.In comparisons of twice-weekly versus daily anti-TB treatment regimens, the trials did not detect differences in the number of patients cured, but trials were small, and the comparator regimens were not standard (four trials, 465 children; very low quality evidence). Trials were underpowered to provide estimates for death (two trials, 213 participants, very low quality evidence), relapse (one trial, 214 participants,very low quality evidence), and treatment limiting adverse events (four trials, 441 participants, very low quality evidence)Reported adherence to treatment was similar (87% versus 84%; four trials, 458 children, very low quality evidence)We did not find trials comparing the commonly used thrice-weekly anti-TB short-course regimen with the daily treatment regimen.

AUTHORS' CONCLUSIONS

Trials conducted to date are insufficient to support or refute the use of intermittent twice- or thrice-weekly, short-course treatment regimens over daily short-course treatment in children with TB. Further randomized trials conducted in high TB-transmission settings will help inform policy and practice.

Tuberculosis in neonates and infants: epidemiology, pathogenesis, clinical manifestations, diagnosis, and management issues

Tuberculosis is one of the leading infectious causes of death and as such represents a major global health problem. Infants may develop congenital tuberculosis from an infectious mother or, most commonly, they may acquire postnatal disease by contact with an infectious adult source. Important epidemiologic, pathogenetic, and clinical data regarding the management of infantile disease are reviewed. Diagnostic evaluation includes tuberculin skin tests, chest radiography and other imaging studies, smears and cultures, examination of the cerebrospinal fluid, and polymerase chain reaction, as well as the more recent interferon-gamma assay. Pregnant women with a positive Mantoux skin test but normal chest x-ray should either start chemoprophylaxis during gestation or after delivery depending on the likelihood of being recently infected, their risk of progression to disease, as well as their clinical evidence of disease. Pregnant women with a positive Mantoux skin test and chest x-ray or symptoms indicative of active disease should be treated with non-teratogenic agents during gestation; all household contacts should also be screened. When tuberculosis is suspected around delivery, the mother should be assessed by chest x-ray and sputum smear; separation of mother and offspring is indicated only if the mother is non-adherent to medical treatment, needs to be hospitalized, or when drug-resistant tuberculosis is involved. According to the American Academy of Pediatrics, treatment of latent infection is highly effective with isoniazid administration for 9 months. This regimen may be extended to 12 months for immunocompromised patients. When drug resistance is suspected, combination therapies, which usually consist of isoniazid with rifampin (rifampicin), are administered until the results of susceptibility tests become available. Organisms resistant to isoniazid only may be treated with rifampin alone for a total of 6-9 months. All infants with tuberculosis disease should be started on four agents (isoniazid, rifampin, pyrazinamide, and ethambutol or streptomycin) until drug susceptibility is assessed. For susceptible intrathoracic tuberculosis, isoniazid, rifampin, and pyrazinamide are administered for a total of 2 months, at which point pyrazinamide is withdrawn and the other two agents are continued for another 4-10 months depending on the severity of the disease. The same regimen may be applied in extrapulmonary tuberculosis with the exception of skeletal, miliary, and CNS disease, which require daily administration of isoniazid, rifampin, pyrazinamide, and streptomycin for 1-2 months, followed by isoniazid and rifampin daily or twice weekly for another 10 months. When drug-resistant tuberculosis is suspected, a regimen of isoniazid, rifampin, and pyrazinamide plus either streptomycin or ethambutol should be initially prescribed, until the results of susceptibility tests become available. HIV-seropositive infants with pulmonary tuberculosis should receive isoniazid, rifampin, pyrazinamide, and ethambutol or an aminoglycoside for 2 months, followed by isoniazid and rifampin for a total of at least 12 months. Apart from conventional antimycobacterial agents, novel therapeutic modalities, which stimulate the host immune system such as interleukin-2 (IL-2), IL-12, interferon-gamma, and tumor necrosis factor antagonists have been tested with promising results.

Newer diagnostic modalities for tuberculosis

The gold standard for diagnosis of tuberculosis is demonstration of mycobacteria from various body fluids. This is often not possible in children due to pauci-bacillary nature of illness. Significant improvement in understanding of molecular biology of Mycobacterium tuberculosis has led to development of newer diagnostic techniques of tuberculosis. Polymerase chain reaction (PCR) is an emerging diagnostic tool for diagnosis of TB in children. However, its role in day-to-day clinical practice needs to be defined. A negative PCR never eliminates possibility of tuberculosis, and a positive result is not always confirmatory. The PCR may be useful in evaluating children with significant pulmonary disease when diagnosis is not readily established by other means, and in evaluating immunocompromised children (HIV infection) with pulmonary disease. In the absence of good diagnostic methods for tuberculosis, a lot of interest has been generated in serodiagnosis. ELISA has been used to detect antibodies to various purified or complex antigens of M. tuberculosis in children. Despite a large number of studies published over the past several years, serology has found little place in the routine diagnosis of tuberculosis in children, even though it is rapid and does not require specimen from the site of disease. Sensitivity and specificity depend on the antigen used, gold standard for the diagnosis of tuberculosis and the type of tubercular infection. Though most of these tests have high specificity, their sensitivity is poor. In addition, these tests may be influenced by factors such as age, prior BCG vaccination and exposure to environmental mycobacteria. The serological tests, theoretically, may not be able to differentiate between infection and disease. At present, serodiagnosis does not appear to have any role in diagnosis of childhood pulmonary tuberculosis. A new test (QuantiFERON-TB or QFT) that measures the release of interferon-gamma in whole blood in response to stimulation by purified protein derivative is comparable with the tuberculin skin testing to detect latent tubercular infection, and is less affected by BCG vaccination. It can also discriminate responses due to nontuberculous mycobacteria, and avoids variability and subjectivity associated with placing and reading the tuberculin skin test. Polymerase chain reaction based test for identification of katG and rpoB mutation which are associated with isoniazid and rifampicin resistance may help in early identification of drug resistance in mycobacterium.