Childhood tuberculosis - global epidemiology and the impact of HIV

Childhood Tuberculosis and Isoniazid Preventive Therapy Among Household Contacts of Sputum Positive Pulmonary Tuberculosis Patients: A Descriptive Observational Study

Background

The prevalence of tuberculosis (TB) disease among household contacts of adult TB patients is very high. Contact screening and isoniazid preventive therapy (IPT) are recommended for household contacts, but their uptake by families and implementation by the national TB program are poor. This study was performed to estimate the yield of tuberculosis disease, risk factors associated with disease development, and coverage of IPT in household contacts of sputum-positive pulmonary tuberculosis patients in the Aurangabad district of Maharashtra.

Methods

A cross-sectional study was conducted at MGM Medical College Hospital Aurangabad. Sputum-positive adult TB patients were enrolled in the study. Their household contacts were screened for TB disease, and the status of IPT in eligible contacts was studied. Serial screening and follow-up of these contacts were performed for one year.

Results

A total of 82 contacts of 55 index cases were studied. At the one-year follow-up, 15 (18%) patients developed TB disease. Twelve had pulmonary TB, and three had extrapulmonary TB. The mean age of diseased contacts was 5.5 years. The disease was more common in contacts under six years of age. Sixty-four percent of eligible contacts received IPT. There was a statistically significant association between disease development and noncompliance with IPT (p-value 0.005913).

Conclusions

The yield of tuberculosis disease is high in children contacts with sputum-positive pulmonary TB cases. IPT implementation is inadequate in child contact.

Tuberculosis research conducted over the years at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT)

This review article highlights some of the key research conducted at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT) over the years since its inception in 1956 till the present. The research carried out in the field of tuberculosis at ICMR-NIRT has been a joint effort between the ICMR, NIRT, the TB control program in India with assistance from World Health Organization (WHO) and the National Institutes of Health (NIH), USA. The research carried out at ICMR-NIRT has helped to formulate the national guidelines for the control and the management of tuberculosis in India. The major highlights of the research carried out at ICMR-NIRT are provided in this manuscript.

The burden of vaccine-preventable diseases among HIV-infected and HIV-exposed children in sub-Saharan Africa: a systematic review and meta-analysis

There are knowledge gaps regarding evidence-based research on the burden of vaccine-preventable diseases among human immunodeficiency virus (HIV)-infected and HIV-exposed children aged <18 years in sub-Saharan Africa. It is therefore essential to determine the trend and burden of vaccine-preventable diseases. We completed a systematic review and meta-analysis to identify the incidence, prevalence and case-fatality rates (CFR) attributed to various vaccine-preventable diseases among HIV-infected and HIV-exposed children in sub-Saharan Africa. The trends in the prevalence of vaccine-preventable diseases among HIV-infected and HIV-exposed children were also determined. Nine studies on tuberculosis (TB) were pooled to give an overall incidence rate estimate of 60 (95% confidence interval [CI] 30-70) per 1,000 child-years. The incidence of pneumococcal infections varied between 109-1509 per 100,000 while pertussis was between 2.9 and 3.7 per 1000 child-year. Twenty-two TB prevalence studies reported an estimated prevalence of 16%. Fifteen prevalence studies on hepatitis B infection were pooled together with an estimated prevalence of 5%. The pooled prevalence for pneumococcal infections was 2% while rotavirus diarrhoea reported a prevalence of 13%. Twenty-nine studies on TB were pooled to give an overall CFR estimate of 17% while pneumococcal infections in HIV-infected and exposed children were pooled together with a resultant rate of 15%. Some of the vaccine-preventable diseases still have high incidences, prevalence and CFR among HIV-infected and HIV-exposed children. There is also a dearth of research data on the burden of several vaccine-preventable diseases among HIV-infected and exposed children and a need for more studies in this area.

Incidence of tuberculosis in children on antiretroviral therapy: a retrospective cohort study

Objectives

Be aware of the burden of tuberculosis among high-risk population is important. Three hundred fifty-two children were participated in this study. Survival analysis was conducted. We assessed the incidence of tuberculosis and its predictors in children on ART.

Results

Tuberculosis incidence rate in children on ART was 2.63 per 100 person-years. Those children who were on baseline World Health Organization clinical stages 3 and 4 (AHR (adjusted hazard ratio) = 3.0; 95% CI 1.2–7.7), “fair” and “poor” ART adherence (AHR = 4.0; 95% CI 1.5–10.8), late initiation of ART (AHR = 4.0; 95% CI 1.5–10.6), and less than 6 months duration on ART (AHR = 5.5; 95% CI 1.5–20.6) were more likely to develop tuberculosis infection. The incidence rate of TB in children on ART was high. This study suggests a need to give attention to advanced AIDS stages and improve timely initiation of ART and level of adherence to ART.

Characterizing Pediatric Tuberculosis with and without Human Immunodeficiency Virus Coinfection in Harare, Zimbabwe

Pediatric tuberculosis (TB) represents a major barrier to reducing global TB mortality, especially in countries confronting dual TB and human immunodeficiency virus (HIV) epidemics. Our study aimed to characterize pediatric TB epidemiology in the high-burden setting of Harare, Zimbabwe, both to fill the current knowledge gap around the epidemiology of pediatric TB and to indicate areas for future research and interventions. We analyzed de-identified data of 1,051 pediatric TB cases (0-14 years) found among a total of 11,607 TB cases reported in Harare, Zimbabwe, during 2011-2012. We performed Pearson's χ² test and multivariate logistic regression analysis to characterize pediatric TB and to assess predictors of HIV coinfection. Pediatric TB cases accounted for 9.1% of all TB cases reported during 2011-2012. Approximately 50% of pediatric TB cases were children younger than 5 years. Almost 60% of the under-5 age group were male, whereas almost 60% of the 10-14 age group were female. The overall HIV coinfection rate was 58.3%. Odds for HIV coinfection was higher for the 5-9 age group (adjusted odds ratio [AOR]: 2.77, 95% confidence interval [CI]: 1.97-3.94), the 10-14 group (AOR: 3.57, 95% CI: 2.52-5.11), retreatment cases (AOR: 6.17, 95% CI: 2.13, 26.16), and pulmonary TB cases (AOR: 2.39, 95% CI: 1.52, 3.75). In conclusion, our study generated evidence that pediatric TB, compounded by HIV coinfection, significantly impacts children in high-burden settings. The findings of our study indicate a critical need for targeted interventions.

The challenges of pharmacokinetic variability of first-line anti-TB drugs

INTRODUCTION

Inter-individual variations in the pharmacokinetics (PK) of anti-TB drugs are known to occur, which could have important therapeutic implications in patient management. Areas covered: We compiled factors responsible for PK variability of anti-TB drugs reported from different settings that would give a better understanding about the challenges of PK variability of anti-TB medications. We searched PubMed data base and Google scholar from 1976 to the present using the key words 'Pharmacokinetics', 'pharmacokinetic variability', 'first-line anti-TB therapy', 'Rifampicin', 'Isoniazid', 'Ethambutol', 'Pyrazinamide', 'food', 'nutritional status', 'HIV', 'diabetes', 'genetic polymorphisms' and 'pharmacokinetic interactions'. We also included abstracts from scientific meetings and review articles. Expert commentary: A variety of host and genetic factors can cause inter-individual variations in the PK of anti-TB drugs. PK studies conducted in various settings have adopted different designs, PK sampling time points, drug estimation methodologies. Hence comparison and interpretation of these results should be done with caution More phamacogenomic studies in different patient populations are needed for further understanding.

High prevalence of primary drug resistance in children with intrathoracic tuberculosis in India

BACKGROUND

Drug susceptibility testing (DST) of Mycobacterium tuberculosis (Mtb) isolates is crucial for the effective treatment of tuberculosis. Data on DST patterns in Mtb isolates in childhood tuberculosis are scanty.

AIMS

To determine drug resistance patterns in Mtb isolates from a paediatric TB cohort in North India.

METHODS

403 children aged 6 months to14 year with probable intrathoracic tuberculosis were enrolled prospectively. All were treatment-naïve. 802 ambulatory-induced sputa (IS) and 787 gastric aspirate (GA) samples were cultured in BACTEC-MGIT960 system, and DST of the Mtb isolates was undertaken using the automated BACTEC-MGIT960 SIRE kit.

RESULTS

Of the 403 children, 147 (36.4%) were culture-confirmed: 132 (89.8%) isolates were Mtb and 15 (10.2%) non-tuberculous mycobacteria (NTM). Five Mtb isolates were contaminated and the remaining 127 were subjected to in-vitro drug susceptibility testing against streptomycin, isoniazid, rifampicin and ethambutol. Twenty-six (20.47%) isolates were resistant to one or more drugs, seven (5.5%) were resistant to rifampicin singly or in combination, and 11 (8.7%) were resistant to isoniazid singly or in combination. Mono-resistance to isoniazid, rifampicin, streptomycin and ethambutol was detected in four (3.1%), one (0.8%), four (3.1%) and two (1.6%), respectively. Five children (3.9%) had MDR-TB; 101 (79.9%) children had Mtb isolates which were sensitive to all four drugs.

CONCLUSIONS

The rifampicin and isoniazid resistance rates were much higher than those in the adult TB population in India.

A systematic review of published literature describing factors associated with tuberculosis recurrence in people living with HIV in Africa

BACKGROUND

A summary of factors associated with recurrent tuberculosis (TB) in the African HIV-infected population is lacking. We performed a systematic review to address this.

METHODS

We performed a literature search within PubMed and The WHO Global Library with specific inclusion and exclusion criteria to identify manuscripts emanating from the African continent which potentially described factors associated with recurrent TB in persons living with HIV.

RESULTS

The literature search yielded 52 unique manuscripts, of which only 4 manuscripts were included in the final systematic review following application of the inclusion and exclusion criteria. Baseline CD4 count, baseline HIV viral load, a positive tuberculin skin test, prior active TB disease, cutaneous hypersensitivity reaction to treatment, having < 3 lung zones affected by prior TB disease, and anaemia were associated with recurrent TB in HIV-infected individuals, whilst age and antiretroviral status were not.

CONCLUSION

The lack of studies describing recurrent TB in Africa which stratify results by HIV-status is a hindrance to understanding risk factors for recurrent TB in this population. This might be overcome by implementing guidelines related to the publishing of data from observational studies in peer-reviewed medical journals reporting recurrent TB in populations with a high-burden of HIV infection.

Epidemiology of tuberculosis in children in Kampala district, Uganda, 2009-2010; a retrospective cross-sectional study

Background

The global tuberculosis (TB) estimate in 2011 was 500,000 cases among children under 15 years representing 5.7 % of all cases and 64, 000 deaths among HIV negative children representing 6.5 % of the total deaths. In Uganda, the child TB cases reported in 2012 made up less than 3 % of the total cases while recent modelling estimates it at 15–20 % of adult cases. Mapping of these cases in Kampala district most especially for the children under five years would reflect recent transmission in the various communities in the district. We therefore conducted a retrospective study of reported child TB cases in Kampala district Uganda for 2009–2010 to provide an estimate of child TB incidence and map the cases.

Methods

This was a retrospective cross-sectional study on data collected from the health unit TB registers in the five divisions of Kampala district, Uganda. The data was a starting point in preparation for a TB Vaccine study in children. The extracted data spanned a period from 1st January 2009 to 31st December 2010. The projected population of children below 15 years was 637,922 in 2009 and 744,750 in 2010 for Kampala district. We based our projections on the National Bureau of Statistics most recent census report of 2002 before the study duration while assuming a population growth rate of 3.7 % each year. We captured the data into EPI DATA 3.1 and analysed it using STATA version 12.

Results

We accessed 15,499 records and analysed 1167 records that were of children below 15 years old. The child TB cases represented 7.5 % (7.3 in 2009 & 7.6 % in 2010) of all the registered cases in Kampala district. The females were 47 % and the median age was 4 years (IQR 1, 10). The percent of children less than 5 years old was 54 %. The percent of pulmonary TB cases was 89 % (1041/1167) with 15 % smear positive. The proportion of extra-pulmonary TB cases was 11 % (126/1167). Among those that tested for HIV, 60 % (359/620) had test results available with an HIV co-infection rate of 47 % (168/359). Antiretroviral treatment uptake was 24 % among the co-infected. The incidence of child TB in Kampala was 56 (95 % CI 50–62) per 100,000 in 2009 and 44 (95 % CI 40–49) per 100,000 in 2010. Most of the TB cases (60 % (410/685)) in Kampala live in slum areas.

Conclusion

There was a higher child TB incidence of 56 per 100,000 in 2009 compared with 44 per 100,000 in 2010. The percentage of child TB cases was much higher at 7.5 % of all the reported TB cases than the WHO reported national average. For the review period, the TB cases clustered in particular slums in Kampala district.

Pharmacokinetics of first-line antituberculosis drugs in HIV-infected children with tuberculosis treated with intermittent regimens in India

The objective of this report was to study the pharmacokinetics of rifampin (RMP), isoniazid (INH), and pyrazinamide (PZA) in HIV-infected children with tuberculosis (TB) treated with a thrice-weekly anti-TB regimen in the government program in India. Seventy-seven HIV-infected children with TB aged 1 to 15 years from six hospitals in India were recruited. During the intensive phase of TB treatment with directly observed administration of the drugs, a complete pharmacokinetic study was performed. Drug concentrations were measured by high-performance liquid chromatography. A multivariable regression analysis was done to explore the factors impacting drug levels and treatment outcomes. The proportions of children with subnormal peak concentrations (Cmax) of RMP, INH, and PZA were 97%, 28%, and 33%, respectively. Children less than 5 years old had a lower median Cmax and lower exposure (area under the time-concentration curve from 0 to 8 h [AUC0-8]) of INH (Cmax, 2.5 versus 5.1 μg/ml, respectively [P=0.016]; AUC0-8, 11.1 versus 22.0 μg/ml·h, respectively [P=0.047[) and PZA (Cmax, 34.1 versus 42.3 μg/ml, respectively [P=0.055]; AUC0-8, 177.9 versus 221.7 μg/ml·h, respectively [P=0.05]) than those more than 5 years old. In children with unfavorable versus favorable outcomes, the median Cmax of RMP (1.0 versus 2.8 μg/ml, respectively; P=0.002) and PZA (31.9 versus 44.4 μg/ml, respectively; P=0.045) were significantly lower. Among all factors studied, the PZA Cmax influenced TB treatment outcome (P=0.011; adjusted odds ratio, 1.094; 95% confidence interval, 1.021 to 1.173). A high proportion of children with HIV and TB had a subnormal RMP Cmax. The PZA Cmax significantly influenced treatment outcome. These findings have important clinical implications and emphasize that drug doses in HIV-infected children with TB have to be optimized.

How to manage TB in children? Problems and solutions in four cases

Children bear a substantial part of the tuberculosis (TB) epidemic worldwide, and it is estimated that there were ≅ 500.000 childhood TB cases globally in 2010, although accurate data are problematic to obtain given the many difficulties associated with TB diagnosis in children and the weaknesses of surveillance systems in countries where TB is endemic. The World Health Organization is working hard in order to reduce the TB prevalence rates and deaths by half by 2015. In this challenge, general practitioners and pediatricians play a key role in detecting early cases of suspected TB and sending them to experts in infectious diseases. This will reduce delayed diagnosis and the spread of disease, which is especially important now that the prevalence of multidrug resistant TB is increasing. For this reason, the purpose of this report was to delineate the characteristic clinical features of the most common forms of pediatric TB and to suggest a rational and practical approach to the disease underlining the role of patients and parents personal and clinical history.

Drug-resistant tuberculosis: pediatric guidelines

The World Health Organization estimates that there are 650,000 prevalent cases of multidrug-resistant (MDR) tuberculosis (TB) globally, and since children (<15 years of age) constitute up to 20 % of the TB caseload in high-burden settings, the number of children with drug-resistant (DR) TB is likely to be substantial. Because bacterial burden at the site of disease is often low, diagnosis involves collection of multiple specimens and a laboratory capable of performing culture, although the Xpert MTB/RIF assay has improved sensitivity over smear examination. The basic principles of treatment for children are the same as those for adults with MDR-TB; however, the treatment regimen is often empiric and based on the drug susceptibility pattern of the source case, if available, or on past history of treatment. Additional challenges arise when MDR-TB is diagnosed and managed in the context of HIV coinfection. HIV-infected children are also treated with antiretroviral therapy medications, which have the potential to interact with second-line anti-TB drugs. Lack of pediatric formulations of second-line drugs and paucity of pharmacokinetic data make dosage challenging. However, when treated appropriately, children with DR TB have good outcomes.

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.

Estimates of tuberculosis progression rate of children in China

In this paper, a discrete mathematical model is formulated to describe tuberculosis (TB) progression from latent infection to active disease. The data of national TB epidemiology surveys in China are taken to estimate the TB progression rate for children aged 0-14 years. The progression rate obtained in this paper gives a detailed and better estimate of TB progression rate among children.

Contact investigation of children exposed to tuberculosis in South East Asia: a systematic review

Background. Screening of children who are household contacts of tuberculosis (TB) cases is universally recommended but rarely implemented in TB endemic setting. This paper aims to summarise published data of the prevalence of TB infection and disease among child contacts in South East Asia. Methods. Search strategies were developed to identify all published studies from South East Asia of household contact investigation that included children (0-15 years). Results. Eleven studies were eligible for review. There was heterogeneity across the studies. TB infection was common among child contacts under 15 years of age (24.4-69.2%) and was higher than the prevalence of TB disease, which varied from 3.3% to 5.5%. Conclusion. TB infection is common among children that are household contacts of TB cases in South East Asia. Novel approaches to child contact screening and management that improve implementation in South East Asia need to be further evaluated.

Pharmacokinetics of anti-tuberculosis drugs in children

Tuberculosis (TB) is among the top 10 causes of death among children worldwide. Recent reports suggest that the currently recommended dosages of first-line anti-TB drugs are not adequate in children, particularly younger children. The objective of this review was to synthesize available pharmacokinetic data of anti-TB drugs in children from different settings that would help determine optimal doses of anti-TB drugs, in order to provide evidence-based recommendations. A PubMed database was searched from 1970 to present using the terms rifampicin, isoniazid, pyrazinamide, ethambutol, pharmacokinetics, HIV, TB, nutrition and children. References from identified articles were also reviewed and abstract from recent meetings were included. Available pharmacokinetic data from different settings suggest that age, nutritional status, HIV infection and gene polymorphisms in drug metabolising enzymes could significantly influence the pharmacokinetics of first-line anti-TB drugs. However, most of the pharmacokinetic studies conducted so far in children have failed to associate drug concentrations with treatment outcomes. Hence, more studies to examine the relationship between drug pharmacokinetics and response to anti-TB treatment are required. Studies to examine the impact of nutritional status and HIV infection on the pharmacokinetics of anti-TB drugs in children are needed.

Treatment and disease progression in a birth cohort of vertically HIV-1 infected children in Ukraine

Background

Ukraine has the highest HIV prevalence (1.6%) and is facing the fastest growing epidemic in Europe. Our objective was to describe the clinical, immunological and virological characteristics, treatment and response in vertically HIV-infected children living in Ukraine and followed from birth.

Methods

The European Collaborative Study (ECS) is an ongoing cohort study, in which HIV-1 infected pregnant women are enrolled and followed in pregnancy, and their children prospectively followed from birth. ECS enrolment in Ukraine started in 2000 initially with three sites, increasing to seven sites by 2009.

Results

A total of 245 infected children were included in the cohort by April 2009, with a median age of 23 months at most recent follow-up; 33% (n = 77) had injecting drug using mothers and 85% (n = 209) were infected despite some use of antiretroviral prophylaxis for prevention of mother-to-child transmission. Fifty-five (22%) children had developed AIDS, at a median age of 10 months (IQR = 6-19). The most prevalent AIDS indicator disease was Pneumocystis jiroveci pneumonia (PCP). Twenty-seven (11%) children had died (median age, 6.2 months). Overall, 108 (44%) children had started highly active antiretroviral treatment (HAART), at a median 18 months of age; median HAART duration was 6.6 months to date. No child discontinued HAART and 92% (100/108) remained on their first-line HAART regimen to date. Among children with moderate/severe immunosuppression, 36% had not yet started HAART. Among children on HAART, 71% (69/97) had no evidence of immunosuppression at their most recent visit; the median reduction in HIV RNA was 4.69 log₁₀ copies/mL over a median of 10 months treatment. From survival analysis, an estimated 94%, 84% and 81% of children will be alive and AIDS-free at 6, 12 and 18 months of age, respectively. However, survival increased significantly over time: estimated survival rates to 12 months of age were 87% for children born in 2000/03 versus 96% for those born in 2004/08.

Conclusion

One in five children had AIDS and one in ten had died. The half of children who received HAART has responded well and survival has significantly improved over time. Earlier diagnosis and prompt initiation of HAART remain key challenges.

The HIV-associated tuberculosis epidemic--when will we act?

Despite policies, strategies, and guidelines, the epidemic of HIV-associated tuberculosis continues to rage, particularly in southern Africa. We focus our attention on the regions with the greatest burden of disease, especially sub-Saharan Africa, and concentrate on prevention of tuberculosis in people with HIV infection, a challenge that has been greatly neglected. We argue for a much more aggressive approach to early diagnosis and treatment of HIV infection in affected communities, and propose urgent assessment of frequent testing for HIV and early start of antiretroviral treatment (ART). This approach should result in short-term and long-term declines in tuberculosis incidence through individual immune reconstitution and reduced HIV transmission. Implementation of the 3Is policy (intensified tuberculosis case finding, infection control, and isoniazid preventive therapy) for prevention of HIV-associated tuberculosis, combined with earlier start of ART, will reduce the burden of tuberculosis in people with HIV infection and provide a safe clinical environment for delivery of ART. Some progress is being made in provision of HIV care to HIV-infected patients with tuberculosis, but too few receive co-trimoxazole prophylaxis and ART. We make practical recommendations about how to improve this situation. Early HIV diagnosis and treatment, the 3Is, and a comprehensive package of HIV care, in association with directly observed therapy, short-course (DOTS) for tuberculosis, form the basis of prevention and control of HIV-associated tuberculosis. This call to action recommends that both HIV and tuberculosis programmes exhort implementation of strategies that are known to be effective, and test innovative strategies that could work. The continuing HIV-associated tuberculosis epidemic needs bold but responsible action, without which the future will simply mirror the past.

Childhood tuberculosis in the Kilimanjaro region: lessons from and for the TB programme

OBJECTIVE

To determine the magnitude of childhood TB and treatment outcome in Kilimanjaro region.

METHODS

Retrospective review of registration-based data on TB notifications in Kilimanjaro region for the period 2002-2006.

RESULTS

Between 2002 and 2006, there were 1615 patients of childhood TB in Kilimanjaro region constituting 13% of total TB burden and the average case detection rate was 147/100 000 for urban and 41.8/100 000 for rural populations. Of them, 54.2% were men and 75.2% had pulmonary TB (PTB); 24.9% were tested for acid-fast bacilli (AFB) by Ziehl-Neelsen staining showing that 5.8% of all patients with TB were AFB smear positive. The remaining 94.2% were presumptively treated for TB. Treatment success rate was 79.9%, mortality 10.9% and default rate was 7%. Unfavourable outcome was more common among unconfirmed TB patients. HIV testing was very rare but increased after 2004 (<2% before 2005, 11-16% afterwards.)

CONCLUSION

The rate of childhood TB in Kilimanjaro region is among the highest in the world. Microbiological diagnosis for TB and AFB smear positivity is very low. Treatment outcome in this region is poor. These findings argue for specific TB control strategies to be designed for children such as more AFB testing using new tools such as induced sputum and laryngeal swabs, active case finding, HIV testing of all suspected TB children, promoting and monitoring adherence. Regular epidemiological studies are also needed.

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.

The clinical burden of tuberculosis among human immunodeficiency virus-infected children in Western Kenya and the impact of combination antiretroviral treatment

CONTEXT

The burden of tuberculosis (TB) disease in children, particularly in HIV-infected children, is poorly described because of a lack of effective diagnostic tests and the emphasis of public health programs on transmissible TB.

OBJECTIVES

The objectives of this study were to describe the observed incidence of and risk factors for TB diagnosis among HIV-infected children enrolled in a large network of HIV clinics in western Kenya.

DESIGN

Retrospective observational study.

SETTING

The USAID-Academic Model Providing Access to Healthcare (AMPATH) Partnership is Kenya's largest HIV/AIDS care system. Since 2001, the program has enrolled over 70,000 HIV-infected patients in 18 clinics throughout Western Kenya.

PATIENTS

This analysis included all HIV-infected children aged 0 to 13 years attending an AMPATH clinic.

MAIN OUTCOME MEASURE

The primary outcome was a diagnosis of any TB, defined either by a recorded diagnosis or by the initiation of anti-TB treatment. Diagnosis of TB is based on a modified Kenneth Jones scoring system and is consistent with WHO case definitions.

RESULTS

There were 6535 HIV-infected children aged 0 to 13 years, eligible for analysis, 50.1% were female. Of these, 234 (3.6%) were diagnosed with TB at enrollment. There were subsequently 765 new TB diagnoses in 4368.0 child-years of follow-up for an incidence rate of 17.5 diagnoses (16.3-18.8) per 100 child-years. The majority of these occurred in the first 6 months after enrollment (IR: 106.8 per 100 CY, 98.4-115.8). In multivariable analysis, being severely immune-suppressed at enrollment (Adjusted Hazard Ratio [AHR]: 4.44, 95% CI: 3.62-5.44), having ever attended school AHR: 2.65, 95% CI: 2.15-3.25), being an orphan (AHR: 1.57, 95% CI: 1.28-1.92), being severely low weight-for-height at enrollment (AHR: 1.46, 95% CI: 1.32-1.62), and attending an urban clinic (AHR: 1.39, 95% CI: 1.16-1.67) were all independent risk factors for having an incident TB diagnosis. Children receiving combination antiretroviral treatment were dramatically less likely to be diagnosed with incident TB (AHR: 0.15, 95% CI: 0.12-0.20).

CONCLUSIONS

These data suggest a high rate of TB diagnosis among HIV-infected children, with severe immune suppression, school attendance, orphan status, very low weight-for-height, and attending an urban clinic being key risk factors. The use of combination antiretroviral treatment reduced the probability of an HIV-infected child being diagnosed with incident TB by 85%.

Mycobacterium tuberculosis and Mycobacterium africanum in stools from children attending an immunization clinic in Ibadan, Nigeria

BACKGROUND

Tuberculosis is a major cause of childhood morbidity and mortality in Nigeria. Diagnosis of childhood tuberculosis is a global challenge making early treatment a mirage. In this study we investigated the stools of children for the presence of mycobacteria.

METHODS

Stool samples from children aged 3 days to 3 years who presented for postnatal immunization at a large university-based clinic in Nigeria, were subjected to Ziehl-Neelsen staining. Samples with acid-fast bacilli were further processed using mycobacterial culture, spoligotyping, and deletion typing.

RESULTS

One hundred and ninety-two stool samples from different children were collected and processed. Thirty (15.6%) had acid-fast bacilli. Of these, eight had Mycobacterium tuberculosis and one had Mycobacterium africanum.

CONCLUSIONS

Approximately 5% (9/192) of apparently well children had evidence of potentially serious tuberculosis infection. The usefulness of stool specimens for diagnosing pediatric tuberculosis warrants further investigation.