Symptom-based screening of child tuberculosis contacts: improved feasibility in resource-limited settings

Community-based tuberculosis contact management: Caregiver experience and factors promoting adherence to preventive therapy

Delivery of tuberculosis preventive therapy (TPT) for children with household exposure to tuberculosis is a globally supported intervention to reduce the impact of tuberculosis disease (TB) in vulnerable children; however, it is sub-optimally implemented in most high-burden settings. As part of a community-based household contact management program, we evaluated predictors of adherence to community based TPT in children and performed qualitative assessments of caregiver experiences. The Vikela Ekhaya (Protect the Home) project was a community-based household contact management program implemented between 2019 and 2020 in the Hhohho Region of Eswatini. At home visits, contact management teams screened children for TB, initiated TPT when indicated and performed follow-up assessments reviewing TPT adherence. TPT non-adherence was defined as either two self-reported missed doses or a pill count indicating at least two missed doses, and risk factors were evaluated using multivariate clustered Cox regression models. Semi-structured interviews were performed with caregivers to assess acceptability of home visits for TPT administration. In total, 278 children under 15 years initiated TPT and 96% completed TPT through the Vikela Ekhaya project. Risk factors for TPT non-adherence among children initiating 3HR included low family income (adjusted hazard ratio (aHR) 2.3, 95%CI 1.2-4.4), female gender of the child (aHR 2.5, 95% CI 1.4-5.0) and an urban living environment (aHR 3.1, 95%CI 1.6-6.0). Children with non-adherence at the first follow-up visit were 9.1 fold more likely not to complete therapy. Caregivers indicated an appreciation for community services, citing increased comfort, reduced cost, and support from community members. Our results are supportive of recent World Health Organization (WHO) recommendations for decentralization of TB preventive services. Here, we identify populations that may benefit from additional support to promote TPT adherence, but overall demonstrate a clear preference for and excellent outcomes with community based TPT delivery.

Barriers to childhood tuberculosis case detection and management in Cambodia: the perspectives of healthcare providers and caregivers

BACKGROUND

Diagnosis and treatment of tuberculosis (TB) in children remain challenging, particularly in resource-limited settings. Healthcare providers and caregivers are critical in improving childhood TB screening and treatment. This study aimed to determine the barriers to childhood TB detection and management from the perspectives of healthcare providers and caregivers in Cambodia.

METHOD

We conducted this qualitative study between November and December 2020. Data collection included in-depth interviews with 16 healthcare providers purposively selected from four operational districts and 28 caregivers of children with TB and children in close contact with bacteriologically confirmed pulmonary TB residing in the catchment areas of the selected health centers. Data were analyzed using thematic analyses.

RESULTS

Mean ages of healthcare providers and caregivers were 40.2 years (standard deviation [SD] 11.9) and 47.9 years (SD 14.6), respectively. Male was predominant among healthcare providers (93.8%). Three-fourths of caregivers were female, and 28.6% were grandparents. Inadequate TB staff, limited knowledge on childhood TB, poor collaboration among healthcare providers in different units on TB screening and management, limited quality of TB diagnostic tools, and interruption of supplies of childhood TB medicines due to maldistribution from higher levels to health facilities were the key barriers to childhood TB case detection and management. Caregivers reported transportation costs to and from health facilities, out-of-pocket expenditure, time-consuming, and no clear explanation from healthcare providers as barriers to childhood TB care-seeking. Aging caregivers with poor physical conditions, lack of collaboration from caregivers, ignorance of healthcare provider's advice, and parent movement were also identified as barriers to childhood TB case detection and management.

CONCLUSIONS

The national TB program should further invest in staff development for TB, scale-up appropriate TB diagnostic tools and ensure its functionalities, such as rapid molecular diagnostic systems and X-ray machines, and strengthen childhood TB drug management at all levels. These may include drug forecasting, precise drug distribution and monitoring mechanism, and increasing community awareness about TB to increase community engagement.

The Contribution of Chest Radiography to the Clinical Management of Children Exposed to Tuberculosis

Rationale: Although World Health Organization guidelines emphasize contact investigation for tuberculosis (TB)-exposed children, data that support chest radiography as a useful tool are lacking. Objectives: We evaluated the diagnostic and prognostic information of chest radiography in children exposed to TB and measured the efficacy of isoniazid preventive therapy (IPT) in those with relevant radiographic abnormalities. Methods: Between September 2009 and August 2012, we enrolled 4,468 TB-exposed children who were screened by tuberculin skin testing, symptom assessment, and chest radiography. Those negative for TB disease were followed for 1 year for the occurrence of new TB diagnoses. We assessed the protective efficacy of IPT in children with and without abnormal chest radiographs. Measurements and Main Results: Compared with asymptomatic children with normal chest films, asymptomatic children with abnormal radiographs were 25.1-fold more likely to have coprevalent TB (95% confidence interval [CI], 1.02-613.76) and 26.7-fold more likely to be diagnosed with incident TB disease during follow-up (95% CI, 10.44-68.30). Among the 29 symptom-negative and CXR-abnormal child contacts, 20% (3/15) of the isoniazid recipients developed incident TB, compared with 57% (8/14) of those who did not receive IPT (82% IPT efficacy). Conclusions: Our results strongly support the use of chest radiography as a routine screening tool for the evaluation of child TB contacts, which is readily available. Radiographic abnormalities not usually considered suggestive of TB may indicate incipient or subclinical disease, although TB preventive treatment is adequate in most cases.

Alert sign and symptoms for the early diagnosis of pulmonary tuberculosis: analysis of patients followed by a tertiary pediatric hospital

Background

Intercepting earlier suspected TB (Tuberculosis) cases clinically is necessary to reduce TB incidence, so we described signs and symptoms of retrospective cases of pulmonary TB and tried to evaluate which could be early warning signs.

Methods

We conducted a retrospective descriptive study of pulmonary TB cases in children in years 2005–2017; in years 2018–2020 we conducted a cohort prospective study enrolling patients < 18 years accessed to Emergency Department (ED) with signs/symptoms suggestive of pulmonary TB.

Results

In the retrospective analysis, 226 patients with pulmonary TB were studied. The most frequently described items were contact history (53.5%) and having parents from countries at risk (60.2%). Cough was referred in 49.5% of patients at onset, fever in 46%; these symptoms were persistent (lasting ≥ 10 days) in about 20%. Lymphadenopathy is described in 15.9%. The prospective study enrolled 85 patients of whom 14 (16.5%) were confirmed to be TB patients and 71 (83.5%) were non-TB cases. Lymphadenopathy and contact history were the most correlated variables. Fever and cough lasting ≥ 10 days were less frequently described in TB cases compared to non-TB patients (p < 0.05).

Conclusions

In low TB endemic countries, pulmonary TB at onset is characterized by different symptoms, i.e. persistent fever and cough are less described, while more relevant are contact history and lymphadenopathy. It was not possible to create a score because signs/symptoms usually suggestive of pulmonary TB (considered in the questionnaire) were not significant risk factors in our reality, a low TB country.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01288-5.

Vikela Ekhaya: A Novel, Community-based, Tuberculosis Contact Management Program in a High Burden Setting

BACKGROUND

The prevention of tuberculosis (TB) in child contacts of TB cases and people living with human immunodeficiency virus (HIV) is a public health priority, but global access to TB preventive therapy (TPT) remains low. In 2019, we implemented Vikela Ekhaya, a novel community-based TB contact management program in Eswatini designed to reduce barriers to accessing TPT.

METHODS

Vikela Ekhaya offered differentiated TB and HIV testing for household contacts of TB cases by using mobile contact management teams to screen contacts, assess their TPT eligibility, and initiate and monitor TPT adherence in participants' homes.

RESULTS

In total, 945 contacts from 244 households were screened for TB symptoms; 72 (8%) contacts reported TB symptoms, and 5 contacts (0.5%) were diagnosed with prevalent TB. A total of 322 of 330 (98%) eligible asymptomatic household contacts initiated TPT. Of 322 contacts initiating TPT, 248 children initiated 3 months of isoniazid and rifampicin and 74 children and adults living with HIV initiated 6 months of isoniazid; 298 (93%) completed TPT. In clustered logistic regression analyses, unknown HIV status (adjusted odds ratio [aOR] 5.7, P = .023), positive HIV status (aOR 21.1, P = .001), urban setting (aOR 5.6, P = .006), and low income (aOR 5.9, P = .001) predicted loss from the cascade of care among TPT-eligible contacts.

CONCLUSION

Vikela Ekhaya demonstrated that community-based TB household contact management is a feasible, acceptable, and successful strategy for TB screening and TPT delivery. The results of this study support the development of novel, differentiated, community-based interventions for TB prevention and control.

Knowledge, attitude, and practices regarding childhood tuberculosis detection and management among health care providers in Cambodia: a cross-sectional study

BACKGROUND

The World Health Organization (WHO) estimated that 29% of global tuberculosis (TB) and almost 47% of childhood TB cases were not reported to national TB programs in 2019. In Cambodia, most childhood TB cases were reported from health facilities supported by the Global Fund to Fight AIDS, Tuberculosis, and Malaria in 2019. This study aimed to compare the healthcare providers' knowledge, attitude, and practices (KAP) on childhood TB case detection in operational districts (ODs) with high and low childhood TB case detection in Cambodia.

METHODS

We conducted a cross-sectional study between November and December 2020 among healthcare providers in 10 purposively selected ODs with high childhood TB case detection and 10 ODs with low childhood TB case detection. A total of 110 healthcare providers from referral hospitals (RHs) and 220 from health centers (HCs) were interviewed. We collected information on socio-demographic characteristics, training, and KAP on childhood TB. Pearson's Chi-square or Fisher's exact and Student's t-tests were performed to explore the differences in KAP of healthcare providers from ODs with low vs. high childhood TB detection.

RESULTS

Of the 330 respondents, 193 were from ODs with high childhood TB case detection, and 66.67% were from HCs. A significantly higher proportion (46.11%) of respondents from ODs with high childhood TB case detection received training on childhood TB within the past two years than those from low childhood TB case detection ODs (34.31%) (p = 0.03). Key knowledge on childhood TB was not significantly different among respondents from ODs with high and low childhood TB case detection. A significantly higher proportion of respondents from ODs with high childhood TB case detection had a good attitude (98.96 vs. 97.08%, p = 0.002) and performed good practices (58.55 vs. 45.26%, p = 0.02) on contact investigation in the community than those from low childhood TB case detection ODs.

CONCLUSIONS

Healthcare providers from ODs with high childhood TB detection had better attitudes and practices towards childhood TB. The attitudes and practices need to be improved among healthcare providers in ODs with low case detection. Further investment in training and experience sharing on childhood TB case detection among healthcare providers is needed to improve childhood TB case detection.

Diagnostic Challenges in Childhood Pulmonary Tuberculosis-Optimizing the Clinical Approach

The management of childhood tuberculosis (TB) is hampered by the low sensitivity and limited accessibility of microbiological testing. Optimizing clinical approaches is therefore critical to close the persistent gaps in TB case detection and prevention necessary to realize the child mortality targets of the End TB Strategy. In this review, we provide practical guidance summarizing the evidence and guidelines describing the use of symptoms and signs in decision making for children being evaluated for either TB preventive treatment (TPT) or TB disease treatment in high-TB incidence settings. Among at-risk children being evaluated for TPT, a symptom screen may be used to differentiate children who require further investigation for TB disease before receiving TPT. For symptomatic children being investigated for TB disease, an algorithmic approach can inform which children should receive TB treatment, even in the absence of imaging or microbiological confirmation. Though clinical approaches have limitations in accuracy, they are readily available and can provide valuable guidance for decision making in resource-limited settings to increase treatment access. We discuss the trade-offs in using them to make TB treatment decisions.

Clinical standards for the diagnosis, treatment and prevention of TB infection

BACKGROUND: Tuberculosis (TB) preventive therapy (TPT) decreases the risk of developing TB disease and its associated morbidity and mortality. The aim of these clinical standards is to guide the assessment, management of TB infection (TBI) and implementation of TPT.METHODS: A panel of global experts in the field of TB care was identified; 41 participated in a Delphi process. A 5-point Likert scale was used to score the initial standards. After rounds of revision, the document was approved with 100% agreement.RESULTS: Eight clinical standards were defined: Standard 1, all individuals belonging to at-risk groups for TB should undergo testing for TBI; Standard 2, all individual candidates for TPT (including caregivers of children) should undergo a counselling/health education session; Standard 3, testing for TBI: timing and test of choice should be optimised; Standard 4, TB disease should be excluded prior to initiation of TPT; Standard 5, all candidates for TPT should undergo a set of baseline examinations; Standard 6, all individuals initiating TPT should receive one of the recommended regimens; Standard 7, all individuals who have started TPT should be monitored; Standard 8, a TBI screening and testing register should be kept to inform the cascade of care.CONCLUSION: This is the first consensus-based set of Clinical Standards for TBI. This document guides clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage TBI.

Symptom-based Screening Versus Chest Radiography for TB Child Contacts: A Systematic Review and Meta-analysis

BACKGROUND

Accessibility to chest radiography remains a major challenge in high burden and low-income countries. The World Health Organization (WHO) guidelines acknowledge that for child contacts under 5 years, a negative symptom-based screening is sufficient to exclude active tuberculosis (TB), but in child contacts older than 5 years, a chest radiograph should be considered. We performed a systematic review and meta-analysis to assess the performance of symptom-based screening compared with chest radiography in household contacts under 15 years in low-income and middle-income countries.

METHODS

Screening articles published prior 1 October 2020 and data extraction were performed by 2 independent reviewers. The primary outcome was the concordance between symptom screening and chest radiography using the prevalence adjusted bias adjusted kappa coefficient (PABAK) and the proportion of asymptomatic children with negative chest radiography. The analysis was stratified by age group.

RESULTS

Of 639 identified articles, 10 were included. PABAK varied between 0.09 and 0.97 and between 0.22 and 0.98, in children less than 5 years and 5-14 years, respectively. The pooled proportion of children with both non-TB suggestive symptoms and chest radiography findings was 98.7% (96.9-99.8) in children less than 5 years and 98.1% (93.8-100) in children of age 5-14 years.

CONCLUSIONS

Despite low concordance between symptom-based screening and chest radiography, most children without TB suggestive symptoms did not have chest radiography findings suggestive of TB. These results suggest that a negative symptom screening is sufficient to rule out active TB, supporting the WHO recommendation to use symptom-based screening alone when chest radiography is not available.

Subclinical tuberculosis in children: diagnostic strategies for identification reported in a 6-year national prospective surveillance study

BACKGROUND

Subclinical tuberculosis (TB) is well recognized and defined as a disease state with absent or non-recognized symptoms. The study identifies factors associated with subclinical TB and diagnostic strategies in a low-burden, high-resource country.

METHODS

Data was collected between December 2013 to November 2019 through the Swiss Pediatric Surveillance Unit (SPSU). Children with culture/molecular confirmed TB, or who were treated with ≥3 anti-mycobacterial drugs, were included.

RESULTS

A total of 138 (80%) children with TB disease were included in the final analysis, of which 43 (31%) were subclinical. The median age of children with subclinical compared to symptomatic TB was 3.7(IQR 2.2 to 7) and 9.7(IQR 2.7 to 14.3) years, respectively (p=0.003). The cause of investigation for TB was recorded in 31/43 (72.1%) of children with subclinical TB, and included contact exposure in 25 (80.6%). In children with subclinical TB, diagnosis was made by a combination of the following abnormal/confirming results: culture/molecular + immunodiagnostic + chest radiography in 12 (27.9%), immunodiagnostic + chest radiography in 19 (44.2%), culture/molecular + chest radiography in 2 (4.7%), culture + immunodiagnostic in 1 (2.3%), chest radiography only in 8 (18.6%) and immunodiagnostic only in 1 (2.3%) case.

CONCLUSION

A notable proportion of children with TB had subclinical disease. This highlights the importance of non-symptom-based TB case finding in exposed children and refugees from high-TB-prevalence settings. TB screening in these asymptomatic children should therefore include a combination of immunodiagnostic testing and imaging followed by culture and molecular testing.

Screening tests for active pulmonary tuberculosis in children

BACKGROUND

Globally, children under 15 years represent approximately 12% of new tuberculosis cases, but 16% of the estimated 1.4 million deaths. This higher share of mortality highlights the urgent need to develop strategies to improve case detection in this age group and identify children without tuberculosis disease who should be considered for tuberculosis preventive treatment. One such strategy is systematic screening for tuberculosis in high-risk groups.

OBJECTIVES

To estimate the sensitivity and specificity of the presence of one or more tuberculosis symptoms, or symptom combinations; chest radiography (CXR); Xpert MTB/RIF; Xpert Ultra; and combinations of these as screening tests for detecting active pulmonary childhood tuberculosis in the following groups. - Tuberculosis contacts, including household contacts, school contacts, and other close contacts of a person with infectious tuberculosis. - Children living with HIV. - Children with pneumonia. - Other risk groups (e.g. children with a history of previous tuberculosis, malnourished children). - Children in the general population in high tuberculosis burden settings.

SEARCH METHODS

We searched six databases, including the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase, on 14 February 2020 without language restrictions and contacted researchers in the field.

SELECTION CRITERIA

Cross-sectional and cohort studies where at least 75% of children were aged under 15 years. Studies were eligible if conducted for screening rather than diagnosing tuberculosis. Reference standards were microbiological (MRS) and composite reference standard (CRS), which may incorporate symptoms and CXR.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed study quality using QUADAS-2. We consolidated symptom screens across included studies into groups that used similar combinations of symptoms as follows: one or more of cough, fever, or poor weight gain and one or more of cough, fever, or decreased playfulness. For combination of symptoms, a positive screen was the presence of one or more than one symptom. We used a bivariate model to estimate pooled sensitivity and specificity with 95% confidence intervals (CIs) and performed analyses separately by reference standard. We assessed certainty of evidence using GRADE.

MAIN RESULTS

Nineteen studies assessed the following screens: one symptom (15 studies, 10,097 participants); combinations of symptoms (12 studies, 29,889 participants); CXR (10 studies, 7146 participants); and Xpert MTB/RIF (2 studies, 787 participants). Several studies assessed more than one screening test. No studies assessed Xpert Ultra. For 16 studies (84%), risk of bias for the reference standard domain was unclear owing to concern about incorporation bias. Across other quality domains, risk of bias was generally low. Symptom screen (verified by CRS) One or more of cough, fever, or poor weight gain in tuberculosis contacts (4 studies, tuberculosis prevalence 2% to 13%): pooled sensitivity was 89% (95% CI 52% to 98%; 113 participants; low-certainty evidence) and pooled specificity was 69% (95% CI 51% to 83%; 2582 participants; low-certainty evidence). Of 1000 children where 50 have pulmonary tuberculosis, 339 would be screen-positive, of whom 294 (87%) would not have pulmonary tuberculosis (false positives); 661 would be screen-negative, of whom five (1%) would have pulmonary tuberculosis (false negatives). One or more of cough, fever, or decreased playfulness in children aged under five years, inpatient or outpatient (3 studies, tuberculosis prevalence 3% to 13%): sensitivity ranged from 64% to 76% (106 participants; moderate-certainty evidence) and specificity from 37% to 77% (2339 participants; low-certainty evidence). Of 1000 children where 50 have pulmonary tuberculosis, 251 to 636 would be screen-positive, of whom 219 to 598 (87% to 94%) would not have pulmonary tuberculosis; 364 to 749 would be screen-negative, of whom 12 to 18 (2% to 3%) would have pulmonary tuberculosis. One or more of cough, fever, poor weight gain, or tuberculosis close contact (World Health Organization four-symptom screen) in children living with HIV, outpatient (2 studies, tuberculosis prevalence 3% and 8%): pooled sensitivity was 61% (95% CI 58% to 64%; 1219 screens; moderate-certainty evidence) and pooled specificity was 94% (95% CI 86% to 98%; 201,916 screens; low-certainty evidence). Of 1000 symptom screens where 50 of the screens are on children with pulmonary tuberculosis, 88 would be screen-positive, of which 57 (65%) would be on children who do not have pulmonary tuberculosis; 912 would be screen-negative, of which 19 (2%) would be on children who have pulmonary tuberculosis. CXR (verified by CRS) CXR with any abnormality in tuberculosis contacts (8 studies, tuberculosis prevalence 2% to 25%): pooled sensitivity was 87% (95% CI 75% to 93%; 232 participants; low-certainty evidence) and pooled specificity was 99% (95% CI 68% to 100%; 3281 participants; low-certainty evidence). Of 1000 children, where 50 have pulmonary tuberculosis, 63 would be screen-positive, of whom 19 (30%) would not have pulmonary tuberculosis; 937 would be screen-negative, of whom 6 (1%) would have pulmonary tuberculosis. Xpert MTB/RIF (verified by MRS) Xpert MTB/RIF, inpatient or outpatient (2 studies, tuberculosis prevalence 1% and 4%): sensitivity was 43% and 100% (16 participants; very low-certainty evidence) and specificity was 99% and 100% (771 participants; moderate-certainty evidence). Of 1000 children, where 50 have pulmonary tuberculosis, 31 to 69 would be Xpert MTB/RIF-positive, of whom 9 to 19 (28% to 29%) would not have pulmonary tuberculosis; 969 to 931 would be Xpert MTB/RIF-negative, of whom 0 to 28 (0% to 3%) would have tuberculosis. Studies often assessed more symptoms than those included in the index test and symptom definitions varied. These differences complicated data aggregation and may have influenced accuracy estimates. Both symptoms and CXR formed part of the CRS (incorporation bias), which may have led to overestimation of sensitivity and specificity.

AUTHORS' CONCLUSIONS

We found that in children who are tuberculosis contacts or living with HIV, screening tests using symptoms or CXR may be useful, but our review is limited by design issues with the index test and incorporation bias in the reference standard. For Xpert MTB/RIF, we found insufficient evidence regarding screening accuracy. Prospective evaluations of screening tests for tuberculosis in children will help clarify their use. In the meantime, screening strategies need to be pragmatic to address the persistent gaps in prevention and case detection that exist in resource-limited settings.

Post-trial perceptions of a symptom-based TB screening intervention in South Africa: implementation insights and future directions for TB preventive healthcare services

Background

Tuberculosis is a top-10 cause of under-5 mortality, despite policies promoting tuberculosis preventive therapy (TPT). We previously conducted a cluster randomized trial to evaluate the effectiveness of symptom-based versus tuberculin skin-based screening on child TPT uptake. Symptom-based screening did not improve TPT uptake and nearly two-thirds of child contacts were not identified or not linked to care. Here we qualitatively explored healthcare provider perceptions of factors that impacted TPT uptake among child contacts.

Methods

Sixteen in-depth interviews were conducted with key informants including healthcare providers and administrators who participated in the trial in Matlosana, South Africa. The participants’ experience with symptom-based screening, study implementation strategies, and ongoing challenges with child contact identification and linkage to care were explored. Interviews were systematically coded and thematic content analysis was conducted.

Results

Participants’ had mixed opinions about symptom-based screening and high acceptability of the study implementation strategies. A key barrier to optimizing child contact screening and evaluation was the supervision and training of community health workers.

Conclusions

Symptom screening is a simple and effective strategy to evaluate child contacts, but additional pediatric training is needed to provide comfort with decision making. New clinic-based child contact files were highly valued by providers who continued to use them after trial completion. Future interventions to improve child contact management will need to address how to best utilize community health workers in identifying and linking child contacts to care.

Trial registration

The results presented here were from research related to NCT03074799, retrospectively registered on 9 March 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12912-021-00544-z.

Improving Tuberculosis Preventive Therapy Uptake: A Cluster-randomized Trial of Symptom-based Versus Tuberculin Skin Test-based Screening of Household Tuberculosis Contacts Less Than 5 Years of Age

BACKGROUND

Tuberculosis preventive therapy (TPT) is highly effective at preventing tuberculosis disease in household child contacts (<5 years), but is poorly implemented worldwide. In 2006, the World Health Organization recommended symptom-based screening as a replacement for tuberculin skin testing (TST) to simplify contact evaluation and improve implementation. We aimed to determine the effectiveness of this recommendation.

METHODS

We conducted a pragmatic, cluster-randomized trial to determine whether contact evaluation using symptom screening improved the proportion of identified child contacts who initiated TPT, compared to TST-based screening, in Matlosana, South Africa. We randomized 16 clinics to either symptom-based or TST-based contact evaluations. Outcome data were abstracted from customized child contact management files.

RESULTS

Contact tracing identified 550 and 467 child contacts in the symptom and TST arms, respectively (0.39 vs 0.32 per case, respectively; P = .27). There was no significant difference by arm in the adjusted proportion of identified child contacts who were screened (52% in symptom arm vs 60% in TST arm; P = .39). The adjusted proportion of identified child contacts who initiated TPT or tuberculosis treatment was 51.5% in the symptom clinics and 57.1% in the TST clinics (difference -5.6%, 95% confidence interval -23.7 to 12.6; P = .52). Based on the district's historic average of 0.7 child contacts per index case, 14% and 15% of child contacts completed 6 months of TPT in the symptom and TST arms, respectively (P = .89).

CONCLUSIONS

Symptom-based screening did not improve the proportion of identified child contacts evaluated or initiated on TPT, compared to TST-based screening. Further research is needed to identify bottlenecks and evaluate interventions to ensure all child contacts receive TPT.

CLINICAL TRIALS REGISTRATION

NCT03074799.

Measuring and addressing the childhood tuberculosis reporting gaps in Pakistan: The first ever national inventory study among children

INTRODUCTION

Tuberculosis in children may be difficult to diagnose and is often not reported to routine surveillance systems. Understanding and addressing the tuberculosis (TB) case detection and reporting gaps strengthens national routine TB surveillance systems.

OBJECTIVE

The present study aimed to measure the percentage of childhood TB cases that are diagnosed but not reported to the national surveillance system in Pakistan.

DESIGN

The study design was cross sectional. The study was nationwide in 12 selected districts across Pakistan, each representing a cluster. Health facilities that diagnose and treat childhood TB from all sectors were mapped and invited to participate. Lists of child TB cases were created for the study period (April-June 2016) from all study facilities and compared against the list of child TB cases notified to the national TB surveillance system for the same districts and the same period.

RESULTS

All public and private health facilities were mapped across 12 sampled districts in Pakistan and those providing health services to child TB cases were included in the study. From all private health facilities, 7,125 children were found with presumptive TB during the study period. Of them, 5,258 were diagnosed with tuberculosis: 11% were bacteriologically-confirmed and 89% clinically-diagnosed; only 4% were notified to National TB Control Program. An additional 1,267 children with TB were also registered in the National TB Control Program. Underreporting was measured to be 78%.

CONCLUSION

This is the first nationwide childhood TB inventory study globally and confirmed that childhood TB underreporting is very high in Pakistan. TB surveillance in the country must be strengthened to address this, with particular attention to guiding and supporting general practitioners and pediatricians to notify their TB cases.

Challenges and controversies in childhood tuberculosis

Children bear a substantial burden of suffering when it comes to tuberculosis. Ironically, they are often left out of the scientific and public health advances that have led to important improvements in tuberculosis diagnosis, treatment, and prevention over the past decade. This Series paper describes some of the challenges and controversies in paediatric tuberculosis, including the epidemiology and treatment of tuberculosis in children. Two areas in which substantial challenges and controversies exist (ie, diagnosis and prevention) are explored in more detail. This Series paper also offers possible solutions for including children in all efforts to end tuberculosis, with a focus on ensuring that the proper financial and human resources are in place to best serve children exposed to, infected with, and sick from all forms of tuberculosis.

Multidrug-resistant tuberculosis infection and disease in children: a review of new and repurposed drugs

The World Health Organization estimates that 10 million new cases of tuberculosis (TB) occurred worldwide in 2017, of which 600,000 were rifampicin or multidrug-resistant (RR/MDR) TB. Modelling estimates suggest that 32,000 new cases of MDR-TB occur in children annually, but only a fraction of these are correctly diagnosed and treated. Accurately diagnosing TB in children, who usually have paucibacillary disease, and implementing effective TB prevention and treatment programmes in resource-limited settings remain major challenges. In light of the underappreciated RR/MDR-TB burden in children, and the lack of paediatric data on newer drugs for TB prevention and treatment, we present an overview of new and repurposed TB drugs, describing the available evidence for safety and efficacy in children to assist clinical care and decision-making.

Xpert MTB/RIF assay did not improve diagnosis of pulmonary tuberculosis among child contacts in Rwanda

Introduction

To report on the diagnostic yield using the Xpert MTB/RIF assay on gastric lavage samples from children (<15 years) who were household contacts of tuberculosis (TB) cases in Kigali, Rwanda.

Methods

A cross-sectional study was conducted among 216 child contacts of index cases with sputum smear-positive TB over a 7 month period, from 1^st August 2015 to 29^th February 2016. Child contacts with tuberculosis-related symptoms or abnormal chest X-ray had sputum collected by gastric lavage on two consecutive days and samples were examined by smear microscopy, Xpert MTB/RIF assay and solid culture.

Results

Of the 216 child contacts, 94 (44%) were less than 5 years of age. Most of them 84 (89%) were receiving isoniazid preventive therapy at the time of screening. Thirty seven out of 216 children had TB-related symptoms. Only 4 (10.8%) were clinically diagnosed with TB; and none had bacteriologically confirmed tuberculosis.

Conclusion

The use of Xpert MTB/RIF assay did not contribute to bacteriological confirmation of active TB in child contacts in this study. The low prevalence of tuberculosis in child contacts in this study may reflect the high coverage of preventive therapy in young (<5 years) child contacts. The low sensitivity of Xpert MTB/RIF assay in contacts may also suggest likely reflection of paucibacillary disease.

Effectiveness of WHO's pragmatic screening algorithm for child contacts of tuberculosis cases in resource-constrained settings: a prospective cohort study in Uganda

BACKGROUND

Tuberculosis is a leading cause of global childhood mortality; however, interventions to detect undiagnosed tuberculosis in children are underused. Child contact tracing has been widely recommended but poorly implemented in resource-constrained settings. WHO has proposed a pragmatic screening approach for managing child contacts. We assessed the effectiveness of this screening approach and alternative symptom-based algorithms in identifying secondary tuberculosis in a prospectively followed cohort of Ugandan child contacts.

METHODS

We identified index patients aged at least 18 years with microbiologically confirmed pulmonary tuberculosis at Old Mulago Hospital (Kampala, Uganda) between Oct 1, 1995, and Dec 31, 2008. Households of index patients were visited by fieldworkers within 2 weeks of diagnosis. Coprevalent and incident tuberculosis were assessed in household contacts through clinical, radiographical, and microbiological examinations for 2 years. Disease rates were compared among children younger than 16 years with and without symptoms included in the WHO pragmatic guideline (presence of haemoptysis, fever, chronic cough, weight loss, night sweats, and poor appetite). Symptoms could be of any duration, except cough (>21 days) and fever (>14 days). A modified WHO decision-tree designed to detect high-risk asymptomatic child contacts was also assessed, in which all asymptomatic contacts were classified as high risk (children younger than 3 years or immunocompromised [HIV-infected]) or low risk (aged 3 years or older and immunocompetent [HIV-negative]). We also assessed a more restrictive algorithm (ie, assessing only children with presence of chronic cough and one other tuberculosis-related symptom).

FINDINGS

Of 1718 household child contacts, 126 (7%) had coprevalent tuberculosis and 24 (1%) developed incident tuberculosis, diagnosed over the 2-year study period. Of these 150 cases of tuberculosis, 95 (63%) were microbiologically confirmed with a positive sputum culture. Using the WHO approach, 364 (21%) of 1718 child contacts had at least one tuberculosis-related symptom and 85 (23%) were identified as having coprevalent tuberculosis, 67% of all coprevalent cases detected (diagnostic odds ratio 9·8, 95% CI 6·8-14·5; p<0·0001). 1354 (79%) of 1718 child contacts had no symptoms, of whom 41 (3%) had coprevalent tuberculosis. The WHO approach was effective in contacts younger than 5 years: 70 (33%) of 211 symptomatic contacts had coprevalent disease compared with 23 (6%) of 367 asymptomatic contacts (p<0·0001). This approach was also effective in contacts aged 5 years and older: 15 (10%) of 153 symptomatic contacts had coprevalent disease compared with 18 (2%) of 987 asymptomatic contacts (p<0·0001). More coprevalent disease was detected in child contacts recommended for screening when the study population was restricted by HIV-serostatus (11 [48%] of 23 symptomatic HIV-seropositive child contacts vs two [7%] of 31 asymptomatic HIV-seropositive child contacts) or to only culture-confirmed cases (47 [13%] culture confirmed cases of 364 symptomatic child contacts vs 29 [2%] culture confirmed cases of 1354 asymptomatic child contacts). In the modified algorithm, high-risk asymptomatic child contacts were at increased risk for coprevalent disease versus low-risk asymptomatic contacts (14 [6%] of 224 vs 27 [2%] of 1130; p=0·0021). The presence of tuberculosis infection did not predict incident disease in either symptomatic or asymptomatic child contacts: in symptomatic contacts, eight (5%) of 169 infected contacts and six (5%) of 111 uninfected contacts developed incident tuberculosis (p=0·80). Among asymptomatic contacts, incident tuberculosis occurred in six (<1%) of 795 contacts infected at baseline versus four (<1%) of 518 contacts uninfected at baseline, respectively (p=1·00).

INTERPRETATION

WHO's pragmatic, symptom-based algorithm was an effective case-finding tool, especially in children younger than 5 years. A modified decision-tree identified 6% of asymptomatic child contacts at high risk for subclinical disease. Increasing the feasibility of child-contact tracing using these approaches should be encouraged to decrease tuberculosis-related paediatric mortality in high-burden settings, but this should be partnered with increasing access to microbiological point-of-care testing.

FUNDING

National Institutes of Health, Tuberculosis Research Unit, AIDS International Training and Research Program of the Fogarty International Center, and the Center for AIDS Research.

Child contact management in high tuberculosis burden countries: A mixed-methods systematic review

Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide. Considering the World Health Organization recommendation to implement child contact management (CCM) for TB, we conducted a mixed-methods systematic review to summarize CCM implementation, challenges, predictors, and recommendations. We searched the electronic databases of PubMed/MEDLINE, Scopus, and Web of Science for studies published between 1996–2017 that reported CCM data from high TB-burden countries. Protocol details for this systematic review were registered on PROSPERO: International prospective register of systematic reviews (#CRD42016038105). We formulated a search strategy to identify all available studies, published in English that specifically targeted a) population: child contacts (<15 years) exposed to TB in the household from programmatic settings in high burden countries (HBCs), b) interventions: CCM strategies implemented within the CCM cascade, c) comparisons: CCM strategies studied and compared in HBCs, and d) outcomes: monitoring and evaluation of CCM outcomes reported in the literature for each CCM cascade step. We included any quantitative, qualitative, mixed-methods study design except for randomized-controlled trials, editorials or commentaries. Thirty-seven studies were reviewed. Child contact losses varied greatly for screening, isoniazid preventive therapy initiation, and completion. CCM challenges included: infrastructure, knowledge, attitudes, stigma, access, competing priorities, and treatment. CCM recommendations included: health system strengthening, health education, and improved preventive therapy. Identified predictors included: index case and clinic characteristics, perceptions of barriers and risk, costs, and treatment characteristics. CCM lacks standardization resulting in common challenges and losses throughout the CCM cascade. Prioritization of a CCM-friendly healthcare environment with improved CCM processes and tools; health education; and active, evidence-based strategies can decrease barriers. A focused approach toward every aspect of the CCM cascade will likely diminish losses throughout the CCM cascade and ultimately decrease TB related morbidity and mortality in children.

Improving access to tuberculosis preventive therapy and treatment for children

Children suffer a huge burden of disease in tuberculosis (TB) endemic countries. This disease burden was largely invisible when TB control programmes focused exclusively on adults with sputum smear-positive disease. High-level advocacy and better data have improved visibility, but the establishment of functional paediatric TB programmes remains challenging. The key issues that limit children's access to TB preventive therapy and treatment in endemic areas are briefly discussed. Barriers to preventive therapy include (1) the perceived inability to rule out active disease, (2) fear of creating drug resistance, (3) non-implementation of existing guidelines in the absence of adequate monitoring, and (4) poor adherence with long preventive therapy courses. Barriers to TB treatment include (1) perceived diagnostic difficulties, (2) non-availability of chest radiography, (3) young children presenting to unprepared maternal and child health (MCH) services, and (4) the absence of child-friendly formulations. With drug-resistant disease there is currently no guidance on the use of preventive therapy and treatment is usually restricted to cases with bacteriologically confirmed disease, which excludes most young children from care, even if their likely source case has documented drug-resistant TB.

Controlling the seedbeds of tuberculosis: diagnosis and treatment of tuberculosis infection

The billions of people with latent tuberculosis infection serve as the seedbeds for future cases of active tuberculosis. Virtually all episodes of tuberculosis disease are preceded by a period of asymptomatic Mycobacterium tuberculosis infection; therefore, identifying infected individuals most likely to progress to disease and treating such subclinical infections to prevent future disease provides a crucial opportunity to interrupt tuberculosis transmission and reduce the global burden of tuberculosis disease. Programmes focusing on single strategies rather than comprehensive programmes that deliver an integrated arsenal for tuberculosis control might continue to struggle. Tuberculosis preventive therapy is a poorly used method that is essential for controlling the reservoirs of disease that drive the epidemic. Comprehensive control strategies that combine preventive therapy for the most high-risk populations and communities with improved case-finding and treatment, control of transmission, and health systems strengthening could ultimately lead to worldwide tuberculosis elimination. In this Series paper we outline challenges to implementation of preventive therapy and provide pragmatic suggestions for overcoming them. We further advocate for tuberculosis preventive therapy as the core of a renewed worldwide focus to implement a comprehensive epidemic control strategy that would reduce new tuberculosis cases to elimination targets. This strategy would be underpinned by accelerated research to further understand the biology of subclinical tuberculosis infections, develop novel diagnostics and drug regimens specifically for subclinical tuberculosis infection, strengthen health systems and community engagement, and enhance sustainable large scale implementation of preventive therapy programmes.

A prospective evaluation of the symptom-based screening approach to the management of children who are contacts of tuberculosis cases

BACKGROUND

Child tuberculosis contact screening and management can enhance case finding and prevent tuberculosis disease. It is universally recommended but rarely implemented in tuberculosis-endemic settings. The World Health Organization (WHO)-recommended symptom-based screening approach could improve implementation but has not been prospectively evaluated.

METHODS

We conducted a cohort study of children who were close contacts of pulmonary tuberculosis patients in Indonesia from August 2010 to December 2012. We performed clinical assessment, tuberculin skin test, and chest radiography in all eligible children irrespective of symptoms at baseline. Mycobacterial culture and Xpert MTB/RIF assay were performed on sputum from children with persistent symptoms of suspected tuberculosis. Children were managed according to WHO guidelines and were prospectively followed for 12 months.

RESULTS

A total of 269 child contacts of 140 index cases were evaluated. At baseline, 21 (8%) children had tuberculosis diagnosed clinically; an additional 102 (38%) had evidence of infection without disease. Of children with any tuberculosis-related symptoms at baseline, 21% had tuberculosis diagnosed compared with none of the asymptomatic children (P < .001). After 12 months of follow-up, none of the 99 eligible young child contacts (<5 years) who received isoniazid preventive therapy (IPT) had developed disease compared with 4 of 149 (2.6%) asymptomatic older children who did not receive IPT.

CONCLUSIONS

Symptom-based screening is an effective and simple approach to child tuberculosis contact management that can be implemented at the primary healthcare level.

Agreement between QuantiFERON®-TB Gold In-Tube and the tuberculin skin test and predictors of positive test results in Warao Amerindian pediatric tuberculosis contacts

Background

Interferon-gamma release assays have emerged as a more specific alternative to the tuberculin skin test (TST) for detection of tuberculosis (TB) infection, especially in Bacille Calmette-Guérin (BCG) vaccinated people. We determined the prevalence of Mycobacterium tuberculosis infection by TST and QuantiFERON^®-TB Gold In-Tube (QFT-GIT) and assessed agreement between the two test methods and factors associated with positivity in either test in Warao Amerindian children in Venezuela. Furthermore, progression to active TB disease was evaluated for up to 12 months.

Methods

163 HIV-negative childhood household contacts under 16 years of age were enrolled for TST, QFT-GIT and chest X-ray (CXR). Follow-up was performed at six and 12 months. Factors associated with TST and QFT-GIT positivity were studied using generalized estimation equations logistic regression models.

Results

At baseline, the proportion of TST positive children was similar to the proportion of children with a positive QFT-GIT (47% vs. 42%, p = 0.12). Overall concordance between QFT-GIT and TST was substantial (kappa 0.76, 95% CI 0.46-1.06). Previous BCG vaccination was not associated with significantly increased positivity in either test (OR 0.68, 95% CI 0.32-1.5 for TST and OR 0.51, 95% CI 0.14-1.9 for QFT-GIT). Eleven children were diagnosed with active TB at baseline. QFT-GIT had a higher sensitivity for active TB (88%, 95% CI 47-98%) than TST (55%, 95% CI 24-83%) while specificities were similar (respectively 58% and 55%). Five initially asymptomatic childhood contacts progressed to active TB disease during follow-up.

Conclusion

Replacement of TST by the QFT-GIT for detection of M. tuberculosis infection is not recommended in this resource-constrained setting as test results showed substantial concordance and TST positivity was not affected by previous BCG vaccination. The QFT-GIT had a higher sensitivity than the TST for the detection of TB disease. However, the value of the QFT-GIT as an adjunct in diagnosing TB disease is limited by a high variability in QFT-GIT results over time.

Yield of contact tracing from pediatric tuberculosis index cases in Gaborone, Botswana

SETTING

Contact tracing using pediatric index cases has not been adequately investigated in high tuberculosis (TB) and human immunodeficiency virus (HIV) prevalence settings.

OBJECTIVE

To determine the yield of contact tracing in household contacts of pediatric TB index cases in Botswana.

DESIGN

Index cases included all pediatric (age ≤ 13 years) TB admissions from January 2009 to December 2011 to Botswana's largest referral hospital. A contact tracing team identified cases, conducted home visits, symptom-screened contacts and referred those with ≥ 1 TB symptoms. The primary outcome was newly diagnosed TB in a contact.

RESULTS

From 163 pediatric index cases, 548 contacts were screened (median 3 contacts/case, interquartile range [IQR] 2-4). Of these, 49 (9%) were referred for positive symptoms on screening and 27/49 (55%) were evaluated for active TB. Twelve new TB cases were diagnosed (12/548, 2.2%); the median age was 31 years (IQR 23-38); 11 (92%) were smear-positive. Ten (83%) had known HIV status: 7 (70%) were HIV-positive. To find one new TB case, the number needed to contact trace (index cases/new cases) was 13.6, and the number needed to screen (contacts/new cases) was 46.

CONCLUSION

This yield of contact tracing using pediatric index cases is similar to the traditional adult index case approach. Improving the proportion of symptomatic contacts evaluated may increase yield.

Does an isoniazid prophylaxis register improve tuberculosis contact management in South African children?

Setting

We compared the change in child household contact management of pulmonary tuberculosis (TB) cases before and after the implementation of an isoniazid preventive therapy (IPT) register in an urban clinic setting in Cape Town, South Africa.

Objectives

We determined if the presence of an IPT register was associated with an increase in the number of child contacts identified per infectious case and the proportion of identified children who were started on IPT.

Design

We reviewed routine programme data on IPT delivery to children during two time periods (May 2008–October 2008 and May 2011–October 2011), before and after the implementation of an IPT register used by routine clinic personnel.

Results

Adult TB case demographic and clinical characteristics from the two observation periods were similar. During the post-register period, more child contacts per adult case were identified (0.7 (54 children) vs. 0.3 (24 children)), more of the identified children were started on IPT (54 vs. 4) and 37% of those who started, completed six months of treatment compared to the pre-register period where no adherence information was recorded.

Conclusions

After pilot implementation of an IPT register, documented identification of child contacts, IPT initiation and IPT adherence documentation in TB exposed children was improved. Our findings support further exploration of the potential impact of using standardised IPT recording and reporting in routine clinics in high-burden TB settings to improve TB prevention efforts targeted at young children. Future efforts to improve IPT delivery should be systematic and comprehensive in order to support a change in current operational IPT delivery practices in TB programs.

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.

Trends in childhood tuberculosis in Zambia: a situation analysis

OBJECTIVES

To ascertain childhood tuberculosis (TB) trends, human immunodeficiency virus (HIV) co-infection rates and multi-drug resistant TB (MDR-TB) prevalence rates in Zambia.

METHODS

A retrospective review of Zambian annual TB notification data and National TB Programme reports for a 7 year period (2004-2011). TB trends were stratified by age and HIV status.

RESULTS

The total number of children notified during this period with all forms of TB was 40 976. A total of 2670 of 40 976 (6%) were smear-positive cases. Notification rates of all forms of childhood TB show a decline in trends from 135 per 100 000 population in 2004, to 69 per 100 000 population in 2011.

CONCLUSIONS

Childhood TB is an important but neglected problem in Zambia highlighted by the fact that no data exists on HIV co-infection and MDR-TB. Strengthening of the National TB Programme and diagnostics services/algorithms are required to accurately define the TB burden, HIV co-infection and MDR-TB rates in children in Zambia.

The hidden harm of home-based care: pulmonary tuberculosis symptoms among children providing home medical care to HIV/AIDS-affected adults in South Africa

Millions of children in sub-Saharan Africa undertake personal and medical care for family members who are unwell with AIDS. To date, no research has investigated whether such care provision places children at heightened risk for pulmonary tuberculosis. This study aimed to address this gap by identifying risk factors for paediatric pulmonary tuberculosis symptomatology. In 2009-2011, 6002 children aged 10-17 years were surveyed using door-to-door household sampling of census enumeration areas. These were randomly sampled from six urban and rural sites with over 30% HIV prevalence, within South Africa's three highest tuberculosis-burden provinces. Validated scales and clinical tuberculosis symptom checklists were modelled in multivariate logistic regressions, controlling for socio-demographic co-factors. Findings showed that, among children, severe pulmonary tuberculosis symptomatology was predicted by primary caregiver HIV/AIDS-illness [odds ratio (OR): 1.63, confidence interval (CI): 1.23-2.15, p<0.001], and AIDS-orphanhood (OR: 1.44, CI: 1.04-2.00, p<0.029). Three-fold increases in severe tuberculosis symptoms were predicted by the child's exposure to body fluids through providing personal or medical care to an ill adult (OR: 3.12, CI: 1.96-4.95, p<0.001). Symptoms were also predicted by socio-economic factors of food insecurity (OR: 1.52, CI: 1.15-2.02, p<0.003) and household overcrowding (OR: 1.35, CI: 1.06-1.72, p<0.017). Percentage probability of severe tuberculosis symptoms rose from 1.4% amongst least-exposed children, to 18.1% amongst those exposed to all above-stated risk factors, independent of biological relationship of primary caregiver-child and other socio-demographics. Amongst symptomatic children, 75% had never been tested for tuberculosis. These findings identify the risk of tuberculosis among children providing home medical care to their unwell caregivers, and suggest that there are gaps in the health system to screen and detect these cases of paediatric tuberculosis. There is a need for effective interventions to reduce childhood risk, as well as further support for community-based contact-tracing, tuberculosis screening and anti-tuberculosis treatment for children caring for ill adults in contexts with a high burden of HIV and tuberculosis.

Evaluation of new strategies for the diagnosis of tuberculosis among pediatric contacts of tuberculosis patients

BACKGROUND

In young children, underdiagnosis and diagnostic delay have an adverse effect on morbidity and mortality of tuberculosis (TB). This study evaluated new strategies for early TB diagnosis using an outpatient protocol in children between 0 and 5 years of age, with a recent household TB contact.

METHODS

Case recruitment was performed in Manaus, Amazonas, Brazil, from 2008 to 2009. Epidemiologic and clinical data, tuberculin test, chest radiograph and 2 induced sputum respiratory samples from each participant were obtained. Laboratory diagnosis was based on Lowenstein-Jensen (LJ) culture, mycobacteria growth indicator tube (MGIT) and polymerase chain reaction. We conducted a study of comparison of diagnostic tests and a study of cases and controls to identify the clinical characteristics of the population with positive culture and polymerase chain reaction results.

RESULTS

A total of 102 children were evaluated. Thirty-two fulfilled criteria of suspicion of TB. MGIT was more sensitive (P = 0.035) and faster (P < 0.001) than LJ. Clinical score, MGIT, LJ and polymerase chain reaction presented no concordance or slight concordance. A positive MGIT culture was only associated with a strong tuberculin test reaction (P = 0.026). The combination of MGIT with the clinical score allowed the diagnosis of 33% more cases with little or no symptomatology compared with the exclusive use of the clinical classification.

CONCLUSIONS

The sensitivity and speed of MGIT demonstrate the utility of liquid cultures for the diagnosis in children. Furthermore, these results suggest that the use of MGIT in children presenting recent household TB contact and a strong tuberculin test reaction may be a strategy to improve early TB diagnosis.

Contact investigation for tuberculosis: a systematic review and meta-analysis

Investigation of contacts of patients with tuberculosis (TB) is a priority for TB control in high-income countries, and is increasingly being considered in resource-limited settings. This review was commissioned for a World Health Organization Expert Panel to develop global contact investigation guidelines. We performed a systematic review and meta-analysis of all studies reporting the prevalence of TB and latent TB infection, and the annual incidence of TB among contacts of patients with TB. After screening 9,555 titles, we included 203 published studies. In 95 studies from low- and middle-income settings, the prevalence of active TB in all contacts was 3.1% (95% CI 2.2-4.4%, I(2)=99.4%), microbiologically proven TB was 1.2% (95% CI 0.9-1.8%, I(2)=95.9%), and latent TB infection was 51.5% (95% CI 47.1-55.8%, I(2)=98.9%). The prevalence of TB among household contacts was 3.1% (95% CI 2.1-4.5%, I(2)=98.8%) and among contacts of patients with multidrug-resistant or extensively drug-resistant TB was 3.4% (95% CI 0.8-12.6%, I(2)=95.7%). Incidence was greatest in the first year after exposure. In 108 studies from high-income settings, the prevalence of TB among contacts was 1.4% (95% CI 1.1-1.8%, I(2)=98.7%), and the prevalence of latent infection was 28.1% (95% CI 24.2-32.4%, I(2)=99.5%). There was substantial heterogeneity among published studies. Contacts of TB patients are a high-risk group for developing TB, particularly within the first year. Children <5 yrs of age and people living with HIV are particularly at risk. Policy recommendations must consider evidence of the cost-effectiveness of various contact tracing strategies, and also incorporate complementary strategies to enhance case finding.

Preventive therapy in children exposed to Mycobacterium tuberculosis: problems and solutions

Young children living with a tuberculosis patient are at high risk of Mycobacterium tuberculosis infection and disease. WHO guidelines promote active screening and isoniazid (INH) preventive therapy (PT) for such children under 5 years, yet this well-established intervention is seldom used in endemic countries. We review the literature regarding barriers to implementation of PT and find that they are multifactorial, including difficulties in screening, poor adherence, fear of increasing INH resistance and poor acceptability among primary caregivers and healthcare workers. These barriers are largely resolvable, and proposed solutions such as the adoption of symptom-based screening and shorter drug regimens are discussed. Integrated multicomponent and site-specific solutions need to be developed and evaluated within a public health framework to overcome the policy-practice gap and provide functional PT programmes for children in endemic settings.

Training community care workers to provide comprehensive TB/HIV/PMTCT integrated care in KwaZulu-Natal: lessons learnt

OBJECTIVE

To describe a participatory approach to implement and evaluate ways to integrate and train community care workers (CCWs) to enhance collaborative TB/HIV/PMTCT activities, and home-based HIV counseling and testing (HCT) at community level.

METHODS

The intervention study was conducted in Sisonke, a rural district of KwaZulu Natal, South Africa. A baseline household (HH) survey was conducted in 11 villages. Six villages were randomly selected into intervention and control clusters. Training was provided first to CCWs from the intervention cluster (IC) followed by the control cluster (CC). Routine monthly data from CCWs were collected from March-December 2010. The data was subjected to bivariate tests.

RESULTS

The baseline HH survey revealed that of 3012 HH members visited by CCWs in 2008, 21% were screened for TB symptoms, 7% were visited for TB adherence support and 2% for ART adherence, and 1.5% were counselled on infant feeding options. A total of 89 CCWs were trained. Data show that during the study period in IC, 684 adults were offered HCT by CCWs, 92% accepted HCT and tested and 7% tested HIV-positive and were referred to the clinic for further care. Of 3556 adults served in IC, 44% were screened for TB symptoms and 32% for symptoms of sexually transmitted infections (STIs) and 37% of children were traced as TB contact. Out of 6226 adults served in CC, 10% were screened for TB symptoms and 7% for STI symptoms. The differences in uptake of services between IC and CC were statistically significant (p<0.05).

CONCLUSION

The findings of this study suggest higher uptake of TB and STI symptoms screening, TB contact tracing and home based HCT in the intervention clusters. This study suggests that up-skilling CCWs could be one avenue to enhance TB/HIV case finding, TB contact tracing and linkages to care.

Latent tuberculosis infection in children: diagnostic approaches

Tuberculosis (TB) remains an important public health problem and a leading infectious cause of death. Diagnosis and treatment of latent tuberculosis infection (LTBI) is important for TB control and elimination. Nevertheless, the diagnosis of LTBI in both adults and children remains complex, since there is no gold standard. The development of interferon gamma release assays was a major breakthrough in the diagnosis of LTBI. The evaluation of IGRAs in the diagnosis of LTBI in children is proven to be difficult since childhood TB differs from adults as immune responses vary with age. Separate studies assessing IGRAs performance in children are still limited, and only a few of them divide results by narrow age groups Nevertheless, new approaches are being exploited by the ongoing research for the development of more efficient diagnostic tools. It is likely that many changes in both the diagnosis and management of LTBI will occur in the near future. We believe that better understanding of the immunopathology of latency can ultimately lead to the development of more effective strategies in TB control. In the present review we summarize current data on diagnosis of LTBI in children, underscoring the existing challenges and limitations.

Active case finding in contacts of people with tuberculosis

BACKGROUND

Tuberculosis is a major global health challenge that is caused by a bacteria which is spread by airborne droplets. Mostly patients are identified in high-burden countries when they visit health care facilities ('passive case finding'). Contacts of tuberculosis patients are a high-risk group for developing the disease. Actively screening contacts of people with confirmed tuberculosis may improve case detection rates and control of the disease.

OBJECTIVES

This study aims to compare whether active case finding among contacts of people with confirmed tuberculosis increases case detection compared to usual practice.

SEARCH STRATEGY

In April 2011 we searched CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE, EMBASE, LILACS and mRCT. We also checked article reference lists, the International Journal of Tuberculosis and Lung Disease and contacted relevant researchers and organizations.

SELECTION CRITERIA

Randomized and quasi-randomized trials of active case finding to detect tuberculosis disease among close and casual contacts of patients with microbiologically proven pulmonary tuberculosis (by sputum smear and/or culture).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility and the methodological quality of the trials that were extracted using a search method that was outlined previously.

MAIN RESULTS

No trials met the inclusion criteria for this review. One RCT did test the effect of active case finding in contacts, but the intervention in that trial also included screening for, and treatment of, LTBI in contacts; and the separate effect of active case finding could not be estimated.

AUTHORS' CONCLUSIONS

There are currently insufficient data from randomized controlled trials or quasi-randomized controlled trials to evaluate the effect of active case finding for tuberculosis among contacts of patients with confirmed disease. While observational studies show that contacts have a higher risk of developing tuberculosis than the general population, further research is needed to determine whether active case finding among contacts significantly increases case detection rates.

TB and HIV in children - advances in prevention and management

The human immunodeficiency virus (HIV) epidemic has had a major impact on the age and gender profile of adult tuberculosis (TB) patients, resulting in increased exposure of HIV-infected and uninfected children at a very young age. Young and/or HIV-infected children are extremely vulnerable to develop severe forms of TB following recent exposure and infection. There is an urgent need to implement safe and pragmatic strategies to prevent TB in children, especially in TB endemic areas where they suffer the greatest burden of disease. The management of TB in HIV-infected children poses multiple challenges, but recent advances in the implementation of prevention of mother to child transmission (PMTCT) strategies and HIV care of infants offer hope. These include HIV testing and access to PMTCT for all pregnant women, routine testing of all HIV exposed infants and rapid initiation of antiretroviral treatment irrespective of clinical or immunological disease staging. In addition, careful scrutiny for TB exposure should occur at every health care visit, with provision of isoniazid preventive therapy (IPT) following each documented exposure event. Knowing the HIV infection status of child TB suspects is essential to optimize case management. Although multiple difficulties remain, recent advances demonstrate that the management of children with TB and/or HIV can be vastly improved by well focused interventions using readily available resources.

Childhood tuberculosis: an emerging and previously neglected problem

Although awareness is growing, childhood tuberculosis (TB) remains a neglected disease in many resource-limited settings. In part this reflects operational difficulties, lack of visibility in official reports, as well as perceptions that children tend to develop mild disease, contribute little to disease transmission, and do not affect epidemic control. At an international level there is greater appreciation that children contribute significantly to the global TB disease burden and suffer severe TB-related morbidity and mortality, particularly in TB-endemic areas, where the disease often remains undiagnosed. However, this is not always the case at the national or local level and there remains an urgent need for feasible and implementable policies to guide clinical practice. Pediatric TB can be regarded as an emerging epidemic in areas where the adult epidemic remains out of control and Mycobacterium tuberculosis transmission is ongoing. This article reviews important concepts, challenges, and management principles related to childhood TB; it also summarizes the main priorities for future research.

Tuberculosis case-contact research in endemic tropical settings: design, conduct, and relevance to other infectious diseases

The study of the contacts of patients with tuberculosis has a long history. Where tuberculosis is endemic, regular recruitment of tuberculosis cases and their household contacts can be done for research and strategic intervention. This recruitment provides a platform whereby host, pathogen, and environmental factors related to tuberculosis can be investigated and new interventions can be assessed. We describe the types of study possible within a tuberculosis case-contact study platform and its essential components, including recruitment and follow-up of the patients with tuberculosis, their household contacts and community controls, assessments and sampling, and data management and processing. Sample handling and storage, local engagement, ethical challenges, and the strengths and weaknesses of study design are all important issues in case-contact research. A case-contact study platform is a powerful research tool to answer fundamental questions in tuberculosis and has relevance to the study of other major infectious diseases.

Scale-up of services and research priorities for diagnosis, management, and control of tuberculosis: a call to action

The Millennium Development Goal target for tuberculosis control is to halt the spread of tuberculosis by 2015, and begin to reverse the worldwide incidence. After the introduction of standard control practices in 1995, 36 million people were cured and about 6 million deaths were averted. However, substantial scientific advances and innovative solutions are urgently needed together with creative new strategies. Strong international and national political commitment is essential. Urgent action is needed by national governments to fund their own programmes, and for the G8 countries and other donor governments and organisations to support governmental and non-governmental efforts. To foster the global need for urgent action to control the tuberculosis epidemic, The Lancet, in collaboration with the Stop TB Partnership, WHO, Global Fund to Fight AIDS, Tuberculosis and Malaria, and the experts participating in this Series, is launching The Lancet TB Observatory, which will assess and monitor progress in tuberculosis control and research, assess domestic and global financing, regularly disseminate information, and advocate for intensified efforts with stakeholders at all levels.

Pediatric TB: issues related to current and future treatment options

Pediatric TB continues to be a neglected disease in many endemic areas where limited resources restrict the focus of treatment to only the most infectious TB cases. However, recognition that children contribute to a significant proportion of the global TB disease burden and suffer severe TB-related morbidity and mortality is growing. The WHO published guidelines on the management of pediatric TB in 2006 and child-friendly drug formulations have been made available to deserving low-income nations via the Global Drug Fund since 2008. Increased awareness and improved drug availability re-emphasized the considerable programmatic barriers that remain and the difficulty of establishing an accurate diagnosis in resource-limited settings. This article provides an overview of current treatment practices, factors that influence the provision of effective TB therapy to children in endemic areas and potential future advances. It includes a brief summary of the relevant literature and presents the authors’ personal perspectives on issues related to the treatment of pediatric TB.

Validation of 2006 WHO prediction scores for true HIV infection in children less than 18 months with a positive serological HIV test

Introduction

All infants born to HIV-positive mothers have maternal HIV antibodies, sometimes persistent for 18 months. When Polymerase Chain Reaction (PCR) is not available, August 2006 World Health Organization (WHO) recommendations suggest that clinical criteria may be used for starting antiretroviral treatment (ART) in HIV seropositive children <18 months. Predictors are at least two out of sepsis, severe pneumonia and thrush, or any stage 4 defining clinical finding according to the WHO staging system.

Methods and Results

From January 2005 to October 2006, we conducted a prospective study on 236 hospitalized children <18 months old with a positive HIV serological test at the national reference hospital in Kigali. The following data were collected: PCR, clinical signs and CD4 cell count.

Current proposed clinical criteria were present in 148 of 236 children (62.7%) and in 95 of 124 infected children, resulting in 76.6% sensitivity and 52.7% specificity. For 87 children (59.0%), clinical diagnosis was made based on severe unexplained malnutrition (stage 4 clinical WHO classification), of whom only 44 (50.5%) were PCR positive. Low CD4 count had a sensitivity of 55.6% and a specificity of 78.5%.

Conclusion

As PCR is not yet widely available, clinical diagnosis is often necessary, but these criteria have poor specificity and therefore have limited use for HIV diagnosis. Unexplained malnutrition is not clearly enough defined in WHO recommendations. Extra pulmonary tuberculosis (TB), almost impossible to prove in young children, may often be the cause of malnutrition, especially in HIV-affected families more often exposed to TB. Food supplementation and TB treatment should be initiated before starting ART in children who are staged based only on severe malnutrition.