A relook at preventive therapy for tuberculosis in children

Tuberculosis Preventive Treatment

Some individuals exposed to Mycobacterium tuberculosis develop a latent infection and remain at a lifelong risk of developing tuberculosis (TB) disease, a state called as TB infection (TBI). TB preventive treatment (TPT) aims to treat TBI and prevent progression to active TB in an exposed or infected person. Currently, it is not possible to confirm TBI microbiologically, but can be identified indirectly by means of immune-based tests [Tuberculin skin test (TST), interferon-gamma release assays (IGRAs)]. It is crucial to rule out active TB before initiating TPT. TPT regimens have evolved with time. The most widely used regimen is 6 mo of daily Isoniazid (INH) (6H). Another regime in pipeline for persons >2 y, but not yet widely available, is 3HP (3 mo of weekly Isoniazid and Rifapentine). TPT to contacts of drug resistant TB (DR-TB) patients needs to be tailored depending on the resistance pattern in the index case, and relies on a bacteriological confirmation of the same. Individuals receiving TPT should be closely monitored for emergence of any signs or symptoms suggestive of active TB disease while on TPT.

Systematic review with network meta-analysis on the treatments for latent tuberculosis infection in children and adolescents

BACKGROUND

We aimed to synthesize the evidence on the efficacy and safety of different treatment regimens for latent tuberculosis infection (LTBI) in children and adolescents.

METHODS

A systematic review with network meta-analysis was performed (CRD142933). Searches were conducted in Pubmed and Scopus (Nov-2021). Randomized controlled trials comparing treatments for LTBI (patients up to 15 years), and reporting data on the incidence of the disease, death or adverse events were included. Networks using the Bayesian framework were built for each outcome of interest. Results were reported as odds ratio (OR) with 95% credibility intervals (CrI). Rank probabilities were calculated via the surface under the cumulative ranking analysis (SUCRA) (Addis-v.1.16.8). GRADE approach was used to rate evidence's certainty.

RESULTS

Seven trials (n = 8696 patients) were included. Placebo was significantly associated with a higher incidence of tuberculosis compared to all active therapies. Combinations of isoniazid (15-25 mg/kg/week) plus rifapentine (300-900 mg/week), followed by isoniazid plus rifampicin (10 mg/kg/day) were ranked as best approaches with lower probabilities of disease incidence (10% and 19.5%, respectively in SUCRA) and death (20%). Higher doses of isoniazid monotherapy were significantly associated to more deaths (OR 18.28, 95% ICr [1.02, 48.60] of 4-6 mg/kg/day vs. 10 mg/kg/3x per week).

CONCLUSIONS

Combined therapies of isoniazid plus rifapentine or rifampicin for short-term periods should be used as the first-line approach for treating LTBI in children and adolescents. The use of long-term isoniazid as monotherapy and at higher doses should be avoided for this population.

Preventive therapy compliance in pediatric tuberculosis - A single center experience

INTRODUCTION

Despite its importance, there are some barriers to patient compliance in preventive therapy (PT) of tuberculosis (TB). The purpose of this study was to evaluate the compliance to appointments, PT and follow-up in a pediatric population after TB exposure, followed in a single TB outpatient center, and the subsequent identification of compliance determinants.

METHODS

Retrospective analysis of all pediatric patients who underwent PT in Gaia TB outpatient center from January 2015 to June 2016. Patients were divided into two groups: compliant and non-compliant, according to adherence to screening, visits and medication. The data collection was based on review of medical records.

RESULTS

A total of 72 patients were enrolled, 33 (45.8%) on chemoprophylaxis and 39 (54.2%) on latent tuberculosis infection (LTBI) treatment. The majority of patients were compliant (63.9%, n=46). Non-compliance was found in 36.1% (n=26): in 12 patients to contact screening, in 11 patients to PT and 22 patients did not attend medical appointments in the first place. In 10 patients, non-compliance was related to social problems/family dysfunction (low socioeconomic status and parent's unemployment). After putting in place several strategies, such as telephone contact, activating social services and direct observation of therapy, a compliance of 98.6% was achieved. Isoniazid was the main drug used (91.7%), during 9 months for LBTI.

CONCLUSION

PT compliance in TB can be challenging, probably related to the lack of risk perception and caregiver's reluctance to undergo a prolonged treatment to an asymptomatic condition. We conclude that implementing interventions can considerably improve treatment compliance and reduce the risk of future tuberculosis development. We emphasize the success in compliance to a 9 month regimen of isoniazid in the vast majority of patients with LTBI.

Contact investigation for active tuberculosis among child contacts in Uganda

BACKGROUND

Tuberculosis is a large source of morbidity and mortality among children. However, limited studies characterize childhood tuberculosis disease, and contact investigation is rarely implemented in high-burden settings. In one of the largest pediatric tuberculosis contact investigation studies in a resource-limited setting, we assessed the yield of contact tracing on childhood tuberculosis and indicators for disease progression in Uganda.

METHODS

Child contacts aged <15 years in Kampala, Uganda, were enrolled from July 2002 to June 2009 and evaluated for tuberculosis disease via clinical, radiographic, and laboratory methods for up to 24 months.

RESULTS

Seven hundred sixty-one child contacts were included in the analysis. Prevalence of tuberculosis in our child population was 10%, of which 71% were culture-confirmed positive. There were no cases of disseminated tuberculosis, and 483 of 490 children (99%) started on isoniazid preventative therapy did not develop disease. Multivariable testing suggested risk factors including human immunodeficiency virus (HIV) status (odds ratio [OR], 7.90; P < .001), and baseline positive tuberculin skin test (OR, 2.21; P = .03); BCG vaccination was particularly protective, especially among children aged ≤5 years (OR, 0.23; P < .001). Adult index characteristics such as sex, HIV status, and extent or severity of disease were not associated with childhood disease.

CONCLUSIONS

Contact tracing for children in high-burden settings is able to identify a large percentage of culture-confirmed positive tuberculosis cases before dissemination of disease, while suggesting factors for disease progression to identify who may benefit from targeted screening.

Tuberculin Skin Test, chest radiography and contact screening in children ≤5 y: relevance in Revised National Tuberculosis Control Programme (RNTCP)

OBJECTIVES

To ascertain the status of Tuberculin Skin Test (TST) in the children aged 0-5 y who are household contacts of adults having sputum smear positive pulmonary tuberculosis and also to study the relationship of TST and Chest X-Ray (CXR) and their relevance in contact screening under RNTCP setup.

METHODS

This prospective hospital based clinical study was conducted at a tertiary level referral medical college in Northern India. Study subjects were 200 children ≤5 y of age who were household contacts of adults with sputum smear positive pulmonary tuberculosis. All these adult index cases were registered and taking regular treatment at RNTCP centre attached to a medical college. Demographic data collection, detailed clinical history along with clinical examination, growth assessment, TST and chest radiography (CXR) was done for every child.

RESULTS

TST was positive in 39 % children and out of these 68 % of child contacts had CXR findings suggestive of tuberculosis. This correlation was found to be highly significant (p < 0.001), especially in children less than 1 y of age. A high percentage of clinically asymptomatic children also had positive TST and CXR consistent with definition of TB disease.

CONCLUSIONS

Contact screening must be prioritized in RNTCP. Unlike presently, TST and CXR should be actively employed in RNTCP for contact screening.