Tuberculosis in children and adolescents: California, 1985 to 1995

The impact of screening for tuberculosis exposure in the household in children with tuberculosis disease: A difficult riddle to solve

BACKGROUND

Tuberculosis (TB) infection is transmitted by sharing the same airway with people with active TB. Children are often not considered the source of TB bacilli, and index case investigation is carried out after diagnosis. Here, we describe the impact of the presence of a household index case on childhood TB disease.

METHODS

The data of patients aged between 1 month and 18 years who were diagnosed with TB were collected. We compared patients according to whether they had an index case in the household or not.

RESULTS

A total of 202 TB patients were enrolled, of whom 62 (30.7%) had a household index case. There was no significant difference in having a household index case between TB patients under the age of five (23.3%) and older children (33.8%) (p = .140). Pulmonary TB was present in 61.4% of the cases, and extrapulmonary TB was present in 38.6% of the cases. The rate of patients who had a household index case was significantly higher in pulmonary TB (46.8%) compared to extrapulmonary TB (5.1%) (p < .001). Pulmonary TB patients with a history of household contact were more likely to have diagnostic radiological findings (93.1%) compared to those without (75.8%) (p = .009). However, pulmonary TB patients without household contact history had a higher rate of diagnostic microbiological findings (59.1%) and constitutional symptoms (63.6%) (p = .019 and p = .013, respectively).

CONCLUSION

Household contact research is an important epidemiological tool. However, considering the contact rates in the household, new and more comprehensive public health programs are required to prevent the spread of childhood tuberculosis.

Incidence and Mortality of Extrapulmonary Tuberculosis in Ukraine: Analysis of National Surveillance Data

BACKGROUND

Improved understanding of the epidemiology and mortality risk factors of extrapulmonary tuberculosis (EPTB) may facilitate successful diagnosis and management.

METHODS

We analyzed national surveillance data from Ukraine to characterize EPTB subtypes (i.e., localized in different anatomic sites). We calculated annual reported incidence, stratified by age, sex, and HIV status. Using Cox regression, we estimated mortality risk factors.

RESULTS

Between January 2015-November 2018, 14,062 adults/adolescents (≥15 years old) and 417 children (<15 years old) had extrapulmonary TB with or without concomitant pulmonary TB. The most commonly reported EPTB subtypes were pleural, peripheral lymph node, and osteoarticular. Most EPTB subtype notifications peaked at age 30-39 years and were higher in males. In adults/adolescents, most peripheral TB lymphadenitis, central nervous system (CNS) TB, and abdominal TB occurred in those with untreated HIV. CNS TB notifications in people without HIV peaked before age five years. Adults/adolescents with CNS TB (adjusted hazard ratio (aHR) 3.22, 95% CI: 2.89-3.60) and abdominal TB (aHR 1.83, 95% CI: 1.59-2.11) were more likely to die than those with pulmonary TB. Children with CNS TB were more likely to die (aHR 88.25, 95% CI: 43.49-179.10) than those with non-CNS TB. Among adults/adolescents, older age and HIV were associated with death. Rifampicin resistance was associated with mortality in pleural, peripheral lymph node, and CNS TB.

CONCLUSION

We have identified the most common EPTB subtypes by age and sex; patterns of EPTB disease by HIV status; and mortality risk factors. These findings can inform diagnosis and care for people with EPTB.

Data-driven model for the assessment of Mycobacterium tuberculosis transmission in evolving demographic structures

In the case of tuberculosis (TB), the capabilities of epidemic models to produce quantitatively robust forecasts are limited by multiple hindrances. Among these, understanding the complex relationship between disease epidemiology and populations' age structure has been highlighted as one of the most relevant. TB dynamics depends on age in multiple ways, some of which are traditionally simplified in the literature. That is the case of the heterogeneities in contact intensity among different age strata that are common to all airborne diseases, but still typically neglected in the TB case. Furthermore, while demographic structures of many countries are rapidly aging, demographic dynamics are pervasively ignored when modeling TB spreading. In this work, we present a TB transmission model that incorporates country-specific demographic prospects and empirical contact data around a data-driven description of TB dynamics. Using our model, we find that the inclusion of demographic dynamics is followed by an increase in the burden levels predicted for the next decades in the areas of the world that are most hit by the disease today. Similarly, we show that considering realistic patterns of contacts among individuals in different age strata reshapes the transmission patterns reproduced by the models, a result with potential implications for the design of age-focused epidemiological interventions.

Role of PCR method using IS6110 primer in detecting Mycobacterium tuberculosis among the clinically diagnosed childhood tuberculosis patients at an urban hospital in Dhaka, Bangladesh

OBJECTIVE

Better methods are needed for the accurate detection of child tuberculosis (TB). This study compared different laboratory tests and evaluated IS6110 PCR for the detection of Mycobacterium tuberculosis (MTB) among clinically diagnosed child TB patients.

METHODS

A total of 102 paediatric patients (<15 years old) with clinically diagnosed TB were enrolled in this study. The patients were admitted to the icddr,b hospital in Dhaka between 2003 and 2005. Sputum/gastric lavage samples were collected for smear microscopy, culture (solid/Lowenstein-Jensen medium and liquid/MGIT), and IS6110 PCR testing. The sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of smear microscopy and PCR were compared to the two culture methods.

RESULTS

Three patients were positive on smear microscopy (2.9%). MTB was detected by conventional culture in 15.7% (16/102), liquid culture in 14% (14/100), and IS6110 PCR in 61.8% (63/102). PCR detected an additional 45 patients who were undetected with the three other tests. Compared to conventional and liquid culture, respectively, smear microscopy showed sensitivity of 18.8% and 21.4%, specificity of 100% individually, PPV of 100% individually, and NPV of 86.9% and 88.7%, whereas PCR had sensitivity of 87.5% and 92.9%, specificity of 43% individually, PPV of 22.2% and 21%, and NPV of 94.9% and 97.4%.

CONCLUSIONS

PCR can be useful compared to smear microscopy and culture methods and is applicable as a rapid screening test for child TB. A larger scale study is required to determine its diagnostic efficacy in improving the detection of child TB in the presence and absence of severe malnutrition.

Risk Factors for Central Nervous System Tuberculosis

OBJECTIVES

To describe the epidemiology and factors associated with pediatric central nervous system (CNS) tuberculosis (TB) in California from 1993 to 2011.

METHODS

We analyzed California TB registry data for persons aged ≤18 years, comparing CNS TB cases versus non-CNS TB cases reported from 1993 to 2011. Factors associated with CNS TB and TB deaths were identified by using multivariate logistic regression.

RESULTS

A total of 200 CNS TB cases were reported. Compared with non-CNS TB case patients, CNS TB case patients were more likely to be aged <5 years (72.0% vs 43.6%; odds ratio [OR]: 3.8 [95% confidence interval (CI): 2.4-5.9]), US-born (82.0% vs 58.2%; OR: 3.3 [CI: 2.3-4.7]), and Hispanic (75.0% vs 63.2%; OR: 1.7 [CI: 1.3-2.4]). Among US-born CNS TB case patients (during 2010-2011), 76.5% had a foreign-born parent. Tuberculin skin test results were negative in 38.2% of 170 CNS TB cases tested. In multivariate analysis, age <5 years (adjusted odds ratio [aOR]: 3.3 [CI: 2.0-5.4]), US birth (aOR: 1.8 [CI 1.2-2.7]), and Hispanic ethnicity (aOR: 1.5 [CI: 1.1-2.1]) were associated with an increased risk of developing CNS TB. For deaths, CNS TB (aOR: 3.8 [CI: 1.4-9.9]) and culture positivity (aOR: 6.2 [CI: 2.2-17.3]) were associated with increased risk of death, whereas tuberculin skin test positivity (aOR: 0.1 [CI: 0.04-0.2]) was associated with decreased risk.

CONCLUSIONS

Subsets of children are at increased risk for CNS TB in California and may benefit from additional prevention efforts.

The burden and outcomes of childhood tuberculosis in Cotonou, Benin

SETTING

The National Tuberculosis Programme (NTP) and the paediatric ward of the General Hospital (GH), Cotonou, Benin.

OBJECTIVE

To describe the burden of tuberculosis (TB), characteristics and outcomes among children treated in Cotonou from 2009 to 2011.

DESIGN

Cross-sectional cohort study consisting of a retrospective record review of all children with TB aged <15 years.

RESULTS

From 2009 to 2011, 182 children with TB were diagnosed and treated (4.5% of total cases), 153 (84%) by the NTP and 29 (16%) by the GH; the latter were not notified to the NTP. The incidence rate of notified TB cases was between 8 and 13 per 100 000 population, and was higher in children aged >5 years. Of 167 children tested, 29% were HIV-positive. Treatment success was 72% overall, with success rates of 86%, 62% and 74%, respectively, among sputum smear-positive, sputum smear-negative and extra-pulmonary patients. Treatment success rates were lower in children with sputum smear-negative TB (62%) and those with HIV infection (58%).

CONCLUSION

The number of children being treated for TB is low, and younger children in particular are underdiagnosed. There is a need to improve the diagnosis of childhood TB, especially among younger children, and to improve treatment outcomes among HIV-TB infected children, with better follow-up and monitoring.

High caseload of childhood tuberculosis in hospitals on Java Island, Indonesia: a cross sectional study

BACKGROUND

Childhood tuberculosis (TB) has been neglected in the fight against TB. Despite implementation of Directly Observed Treatment Shortcourse (DOTS) program in public and private hospitals in Indonesia since 2000, the burden of childhood TB in hospitals was largely unknown. The goals of this study were to document the caseload and types of childhood TB in the 0-4 and 5-14 year age groups diagnosed in DOTS hospitals on Java Island, Indonesia.

METHODS

Cross-sectional study of TB cases recorded in inpatient and outpatient registers of 32 hospitals. Cases were analyzed by hospital characteristics, age groups, and types of TB. The number of cases reported in the outpatient unit was compared with that recorded in the TB register.

RESULTS

Of 5,877 TB cases in the inpatient unit and 15,694 in the outpatient unit, 11% (648) and 27% (4,173) respectively were children. Most of the childhood TB cases were under five years old (56% and 53% in the inpatient and outpatient clinics respectively). The proportion of smear positive TB was twice as high in the inpatient compared to the outpatient units (15.6% vs 8.1%). Extra-pulmonary TB accounted for 15% and 6% of TB cases in inpatient and outpatient clinics respectively. Among children recorded in hospitals only 1.6% were reported to the National TB Program.

CONCLUSION

In response to the high caseload and gross under-reporting of childhood TB cases, the National TB Program should give higher priority for childhood TB case management in designated DOTS hospitals. In addition, an international guidance on childhood TB recording and reporting and improved diagnostics and standardized classification is required.

Tag SNP polymorphism of CCL2 and its role in clinical tuberculosis in Han Chinese pediatric population

BACKGROUND

Chemokine (C-C motif) ligand 2 CCL2/MCP-1 is among the key signaling molecules of innate immunity; in particular, it is involved in recruitment of mononuclear and other cells in response to infection, including tuberculosis (TB) and is essential for granuloma formation.

METHODOLOGY/PRINCIPAL FINDINGS

We identified a tag SNP for the CCL2/MCP-1 gene (rs4586 C/T). In order to understand whether this SNP may serve to evaluate the contribution of the CCL2 gene to the expression of TB disease, we further analysed distribution of its alleles and genotypes in 301 TB cases versus 338 non-infected controls (all BCG vaccinated) representing a high-risk pediatric population of North China. In the male TB subgroup, the C allele was identified in a higher rate (P = 0.045), and, acting dominantly, was found to be a risk factor for clinical TB (P = 0.029). Homozygous TT genotype was significantly associated with lower CSF mononuclear leukocyte (ML) counts in patients with tuberculous meningitis (TBM) (P = 0.001).

CONCLUSIONS/SIGNIFICANCE

The present study found an association of the CCL2 tag SNP rs4586 C allele and pediatric TB disease in males, suggesting that gender may affect the susceptibility to TB even in children. The association of homozygous TT genotype with decreased CSF mononuclear leukocyte (ML) count not only suggests a clinical significance of this SNP, but indicates its potential to assist in the clinical assessment of suspected TBM, where delay is critical and diagnosis is difficult.

Polymorphic variation in TIRAP is not associated with susceptibility to childhood TB but may determine susceptibility to TBM in some ethnic groups

Host recognition of mycobacterial surface molecules occurs through toll like receptors (TLR) 2 and 6. The adaptor protein TIRAP mediates down stream signalling of TLR2 and 4, and polymorphisms in the TIRAP gene (TIRAP) have been associated with susceptibility and resistance to tuberculosis (TB) in adults. In order to investigate the role of polymorphic variation in TIRAP in childhood TB in South Africa, which has one of the highest TB incidence rates in the world, we screened the entire open reading frame of TIRAP for sequence variation in two cohorts of childhood TB from different ethnic groups (Xhosa and mixed ancestry). We identified 13 SNPs, including seven previously unreported, in the two cohorts, and found significant differences in frequency of the variants between the two ethnic groups. No differences in frequency between individual SNPs or combinations were found between TB cases and controls in either cohort. However the 558C→T SNP previously associated with TB meningitis (TBM) in a Vietnamese population was found to be associated with TBM in the mixed ancestry group. Polymorphisms in TIRAP do not appear to be involved in childhood TB susceptibility in South Africa, but may play a role in determining occurrence of TBM.

Trends in Mycobacterium tuberculosis resistance, Pakistan, 1990-2007

OBJECTIVE

To determine resistance trends including the emergence of extensive drug resistance (XDR) in Mycobacterium tuberculosis (MTB) isolates from Pakistan.

METHODS

This was a retrospective analysis of MTB isolates (January 1990-June 2007) collected from the four provinces of Pakistan. Standard methods were used to isolate MTB. Susceptibility against rifampin, isoniazid, streptomycin, ethambutol, ethionamide, capreomycin, cycloserine, and ciprofloxacin was tested using the agar proportion method, while susceptibility to pyrazinamide was determined using BACTEC. Resistance over the study period was assessed using Chi-square for trend analysis.

RESULTS

Resistance in 15343 MTB isolates showed a steady increase over the study period; a significant trend of increasing resistance was noted in three of the four provinces included in the study. XDR-tuberculosis was first seen in 1998; to date 22 XDR cases have been documented. MTB resistance was significantly lower (p<0.001) in patients under 5 and over 60 years of age, and significantly higher in males than females (p<0.001). MTB resistance was also higher in pulmonary than extrapulmonary isolates (p<0.001).

CONCLUSION

This study documenting a steady increase in resistance among MTB isolates and the emergence of XDR strains is concerning. The data highlight the need to ensure adequate treatment of cases in order to prevent a further increase in multidrug resistance within the country. The importance of developing systems for monitoring drug resistance through nationwide surveillance is emphasized.

An unusual case of craniovertebral junction tuberculosis in an infant

STUDY DESIGN

We present, to the best of our knowledge, the first reported case of craniovertebral junction tuberculosis with complete quadriplegia in an infant.

OBJECTIVE

To describe report of an unusual case and discuss the difficulties and peculiarities of diagnosis, management, and follow-up of craniovertebral tuberculosis in an infant.

SUMMARY OF BACKGROUND DATA

Spinal tuberculosis is prevalent in areas where tuberculosis is endemic, and its incidence is on the rise in developed nations with the rising incidence of HIV/AIDS. Although common in children and young adults, spinal tuberculosis is rare in infants. Again, craniovertebral tuberculosis is one of the rarest forms of spinal tuberculosis.

METHODS

The infant presented to us at the age of 9 months with Grade IV quadriplegia. Among many of the clinical differential diagnoses, craniovertebral tuberculosis was suspected only on MRI and proved after fine needle aspiration cytology demonstrated granulomas. The patient was subjected to transoral debridement, immobilized with help of a pair of pillows by either side of the head and multidrug antitubercular treatment was started, which continued for duration of 12 months.

RESULTS

At the last follow-up of 1 year, the patient had recovered fully and caught up with the milestones suitable for her age.

CONCLUSION

Craniovertebral tuberculosis is difficult to diagnose and treat in infants. A high index of suspicion is essential for a prompt diagnosis and treatment, which is all the more crucial in this age group.

Increasing rate of childhood tuberculosis in a region of east Croatia

BACKGROUND

The incidence of childhood tuberculosis as well as the number of children being in contact with persons having tuberculosis has increased in the region of Slavonski Brod during the past decade (1993-2003). The region is located in east Croatia along the border with Bosnia and close to the besieged and destroyed town of Vukovar. The region was heavily involved in recent military activities and migrations in Croatia and Bosnia (1991-1995). Before the war, the population was reasonably well situated, educated and provided with health services.

METHODS

Routine clinical and epidemiological methods for the diagnosis of tuberculosis were used.

RESULTS

A total of 225 cases of tuberculosis were discovered among 271 suspected cases in a total number of 19 623 children below 18 years of age admitted during the last decade to the county hospital (1.38%). The number increased from three patients with tuberculosis in 1993 to 59 in 2003. Discharge diagnoses were: latent infection 40.1%, specific hilar lymphadenopathy 22.1%, primary lung tuberculosis 18.0%, postprimary tuberculosis 3.0%, and contact with infected person but otherwise normal findings 16.9%. The infection was usualy (53.1%) acquired within the family, more often so in younger patients. Bacteriological cultures were positive in 19 of 117 patients with tuberculosis (16.4%). Antituberculosis drug treatment was carried out to completion in all children. Resistance was not encountered.

CONCLUSION

The authors attribute high incidence of childhood tuberculosis in the region of Slavonski Brod, the second highest incidence in Croatia, to the sequellae of migrations during military activities in Croatia and Bosnia (1991-1995) and to the post-war recession.

Contact investigation and genotyping to identify tuberculosis transmission to children

BACKGROUND

Tuberculosis (TB) in young children is an indicator of ongoing community transmission. We examined contact investigations related to pediatric TB, yield for source case identifications and genotypes for relevant Mycobacterium tuberculosis isolates in a low-incidence setting.

METHODS

We reviewed public health data for all patients with TB aged <18 years reported to Montreal authorities during 1996 to 2000. M. tuberculosis isolates from patients of all ages were subjected to IS6110-based genotyping, supplemented by spoligotyping, to compare isolates from children and adults during the same years.

RESULTS

Sixty-six patients aged <18 years were diagnosed with active TB from 1996 to 2000. Mean age was 11.1 years (standard deviation 6.7 years). Twenty-five children (38%) were Canadian-born, all with at least one foreign-born parent. Nineteen children were diagnosed after contact investigations of known adult cases; 8 underwent no contact investigation. For the remaining 39 children, a total of 616 contacts were identified. The median number of contacts per child was 9 (interquartile range, 6-10). Four hundred eighty-one contacts (78%) underwent tuberculin testing; 188 (39%) were reactors and 186 (39%) began treatment of latent TB. Investigations uncovered 4 probable source cases, all involving parents or other relatives. M. tuberculosis genotyping for 38 children identified up to 14 additional possible source cases; in only one was a possible epidemiologic link evident from public health records.

CONCLUSIONS

Among largely foreign-born children with active TB, contact investigations were extensive and often identified latent tuberculosis infection--but rarely source cases. However, genotyping suggested substantial, previously unrecognized transmission to children despite low overall incidence.

Effect of BCG vaccination on childhood tuberculous meningitis and miliary tuberculosis worldwide: a meta-analysis and assessment of cost-effectiveness

BACKGROUND

BCG vaccine has shown consistently high efficacy against childhood tuberculous meningitis and miliary tuberculosis, but variable efficacy against adult pulmonary tuberculosis and other mycobacterial diseases. We assess and compare the costs and effects of BCG as an intervention against severe childhood tuberculosis in different regions of the world.

METHODS

We calculated the number of tuberculous meningitis and miliary tuberculosis cases that have been and will be prevented in all children born in 2002, by combining estimates of the annual risk of tuberculosis infection, the proportion of infections that lead to either of these diseases in unvaccinated children, the number of children vaccinated, and BCG efficacy.

FINDINGS

We estimated that the 100.5 million BCG vaccinations given to infants in 2002 will have prevented 29,729 cases of tuberculous meningitis (5th-95th centiles, 24,063-36,192) in children during their first 5 years of life, or one case for every 3435 vaccinations (2771-4177), and 11,486 cases of miliary tuberculosis (7304-16,280), or one case for every 9314 vaccinations (6172-13,729). The numbers of cases prevented would be highest in South East Asia (46%), sub-Saharan Africa (27%), the western Pacific region (15%), and where the risk of tuberculosis infection and vaccine coverage are also highest. At US2-3 dollars per dose, BCG vaccination costs US206 dollars (150-272) per year of healthy life gained.

INTERPRETATION

BCG vaccination is a highly cost-effective intervention against severe childhood tuberculosis; it should be retained in high-incidence countries as a strategy to supplement the chemotherapy of active tuberculosis.

The benefits and risks of bacille Calmette-Guérin vaccination among infants at high risk for both tuberculosis and severe combined immunodeficiency: assessment by Markov model

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccine is given to Canadian Aboriginal neonates in selected communities. Severe reactions and deaths associated with BCG have been reported among infants born with immunodeficiency syndromes. The main objective of this study was to estimate threshold values for severe combined immunodeficiency (SCID) incidence, above which BCG is associated with greater risk than benefit.

METHODS

A Markov model was developed to simulate the natural histories of tuberculosis (TB) and SCID in children from birth to 14 years. The annual risk of tuberculous infection (ARI) and SCID incidence were varied in analyses. The model compared a scenario of no vaccination to intervention with BCG. Appropriate variability and uncertainty analyses were conducted. Outcomes included TB incidence and quality-adjusted life years (QALYs).

RESULTS

In sensitivity analyses, QALYs were lower among vaccinated infants if the ARI was 0.1% and the rate of SCID was higher than 4.2 per 100,000. Assuming an ARI of 1%, this threshold increased to 41 per 100,000. In uncertainty analyses (Monte Carlo simulations) which assumed an ARI of 0.1%, QALYs were not significantly increased by BCG unless SCID incidence is 0. With this ARI, QALYs were significantly decreased among vaccinated children if SCID incidence exceeds 23 per 100,000. BCG is associated with a significant increase in QALYs if the ARI is 1%, and SCID incidence is below 5 per 100,000.

CONCLUSION

The possibility that Canadian Aboriginal children are at increased risk for SCID has serious implications for continued BCG use in this population. In this context, enhanced TB Control--including early detection and treatment of infection--may be a safer, more effective alternative.

Increased reported cases of tuberculosis among children younger than 5 years of age, Maricopa County, Arizona, 2002-2003

OBJECTIVES

Although tuberculosis (TB) rates in the United States among children younger than 5 years old (2.8/100,000 in 2003) have been declining, Maricopa County, Arizona, reported an increase from 4.1/100,000 in 2002 to 9.0/100,000 in 2003. We investigated factors associated with this increase.

METHODS

We reviewed county TB clinic records of pediatric patients (younger than 5 years old) and their probable adult sources, interviewed parents or guardians of pediatric TB patients and examined changes in clinic procedures.

RESULTS

We verified 11 pediatric TB cases in 2002 and 25 in 2003 (n = 36). A total of 31 (86%) patients were born in the United States, and 28 (78%) had at least 1 foreign-born parent. There were 19 children (53%) identified from an adult TB contact investigation. Of children with identified sources (n = 24, 67%), 23 (96%) had probable household transmission; 20 (83%) had a foreign-born relative from a TB-endemic country as the probable source. Seven (50%) of 14 adult sources investigated had a delayed TB diagnosis. In 2003, increased TB clinic staffing, more frequent pediatric TB clinics and on-site gastric aspirates for TB diagnosis contributed to 55% more children being evaluated for TB.

CONCLUSIONS

Close interaction with family members and delayed diagnoses were the primary means of TB transmission to children. The increase in pediatric TB likely reflects improved clinic diagnostic capacity and may indicate a more accurate baseline rate for Maricopa County. Programmatic improvements in TB control and targeted outreach to high-risk immigrant populations may increase pediatric and adult source case detection and reduce Mycobacterium tuberculosis transmission.

Tuberculosis in children: considerations for children from developing countries

Although accurate data are scarce for children, tuberculosis (TB) represents one of the most common infectious causes of morbidity and mortality worldwide. TB case rates have declined among children in the United States in the last decade, but they remain high among children from low-income countries and racial or ethnic minorities. Establishing the definitive diagnosis of TB in a child remains difficult and frequently relies on a constellation of history, clinical findings, and bacteriology. Recently, updated national and international treatment recommendations have been published. Contact investigation and treatment using directly observed therapy are important components of the optimal case detection and management of TB in children.

Epidemiology of childhood tuberculosis in the United States, 1993-2001: the need for continued vigilance

OBJECTIVE

To describe trends and highlight epidemiologic and clinical characteristics of childhood tuberculosis (TB) in the United States.

METHODS

All verified TB cases reported to the national TB surveillance system from 1993 to 2001 were included. A child was defined as a person younger than 15 years.

RESULTS

A total of 11,480 childhood TB cases were reported. Case rates (TB cases/100,000 population) in all children declined from 2.9 (n = 1663) in 1993 to 1.5 (n = 931) in 2001. Among children, those who were younger than 5 years had the highest rate. California, Texas, and New York accounted for 48% of all childhood TB cases. In 2001, TB case rates were higher for foreign-born (12.2) than US-born children (1.1). Hispanic and non-Hispanic black children accounted for nearly three quarters of all cases. Twenty-four percent of children with TB were foreign-born children, with the largest number originating from Mexico (39.8%), the Philippines (8.6%), and Vietnam (5.7%). Most children had evidence of pulmonary TB disease (78.9%). Among culture-positive cases without previous TB, drug resistance to at least isoniazid was 7.3% and to isoniazid and rifampin was 1.6%. In 1999, 82.9% of children received directly observed therapy for at least part of their treatment and 94.8% completed treatment.

CONCLUSIONS

Although the overall TB case number among children is declining in the United States, certain groups of children (eg, younger children, racial and ethnic minorities, foreign-born) are at higher risk for TB. As the United States moves toward the elimination of TB, future efforts should endeavor to prevent all cases of childhood TB.

Global epidemiology of paediatric tuberculosis

Tuberculosis is one of the major infections affecting children worldwide. It causes significant morbidity and mortality, especially in infants and young children. Factors such as overcrowding, poverty and the HIV epidemic have all contributed to the resurgence of tuberculosis globally. The highest rates of tuberculosis occur in resource-poor countries and over the last decade case notifications in children have been increasing steadily, particularly in Sub-Saharan Africa. Mycobacterium tuberculosis infects millions of children worldwide every year, yet accurate information on the extent and distribution of disease in children is not available for most of the world. We describe some of the unique aspects of tuberculosis infection in children and review the epidemiology of disease in children worldwide.

Global aspects of tuberculosis in children

Tuberculosis (TB) in children reflects the prevalence of the disease in adults as well as current transmission rates. Africa and South-east Asia have the largest number of tuberculosis cases and the situation there has been worsened by the HIV epidemic. Children born to HIV-infected parents, whether infected or not, are at high risk of developing tuberculosis because of the increased risk of exposure to the disease. Tuberculosis is more common among the disadvantaged and vulnerable groups in each society and the impact of overcrowding, under-nutrition and poverty is particularly severe on children. Recent studies have documented the increase in the occurrence of tuberculosis in children, both in developed and developing countries. The peak age of notification of tuberculosis decreases as the incidence of the disease increases in the region. Tuberculosis infection can progress rapidly to disease, particularly in infancy and early childhood. Most of the morbidity occurs in the first few years after infection. Recently infected children and those with large tuberculin reaction (>18 mm) are at increased risk for progression and should be followed closely. Mortality from tuberculosis is also highest in early childhood, mainly due to disseminated forms like meningeal and miliary tuberculosis. Tuberculosis can be controlled either by preventing the infection from occurring or by treating early infection after it has occurred. An efficient tuberculosis control program with early detection of infectious adults and their cure is the best long-term approach to the reduction of TB disease in children. The DOTS strategy advocated by the WHO has the potential to have a significant impact on the epidemiology of tuberculosis by achieving high cure rates and thereby decreasing community transmission. BCG vaccination, through effective against disseminated forms of the disease in childhood, has very little impact on adult forms of the disease. Chemoprophylaxis or preventive therapy is effective, but difficult to implement on a mass scale and is only recommended for special high-risk groups in developing countries.

Targeted testing of children for tuberculosis: validation of a risk assessment questionnaire

OBJECTIVE

Given the directive of the American Academy of Pediatrics to test children for tuberculosis (TB) only if they are at high risk for the disease, we sought to determine how well a risk assessment questionnaire can predict a positive tuberculin skin test (TST) result among children seen in a medical office setting.

METHODS

In a prospective observational study, we identified 31 926 children who received well-child care in 18 pediatric offices of the Kaiser Permanente Northern California Region from August 1996 through November 1998 and who were due to receive a routine TST (Mantoux method) as part of universal screening. Parents were asked to complete a questionnaire about risk factors for TB infection that included demographic information. The TST result at 48 to 72 hours was compared with questionnaire responses to identify responses that were most highly associated with a positive TST result at both the 10-mm and 15-mm cutoffs. A concurrent study was conducted to determine whether parents can recognize induration.

RESULTS

This population was diverse in age (range: 0-18 years), race/ethnicity (white: 37%; Hispanic: 26.4%; Asian: 15.0%; black: 11.8%; other: 8.4%; not stated by parent: 1.6%), and household annual income (range: $10 524-$175 282). Overall incidence of positive TST results was 1.0% at the 10-mm cutoff and 0.5% at the 15-mm cutoff. Positive predictive value of selected individual risk factors at the 10-mm cutoff were: child born outside the United States, 10.4%; history of receiving bacille Calmette-Guérin vaccine, 5.5%; and child having lived outside the United States, 5.3%. Using multivariate analysis, we selected a subset of risk factors that were independently and significantly associated with a positive TST result >/=10 mm: history of receiving bacille Calmette-Guérin vaccine (odds ratio [OR]: 2.31; 95% confidence interval [CI]: 1.70-3.13); household member with history of positive TST result or TB disease (OR: 1.53; 95% CI: 1.14-2.04); child born outside the United States (OR: 8.63; 95% CI: 6.16-12.09); child having lived outside the United States (OR: 2.06; 95% CI: 1.49-2.85); and race/ethnicity reported by parent as Asian (OR: 2.28; 95% CI: 1.59-3.27) or Hispanic (OR: 1.57; 95% CI: 1.09-2.26). Several factors were not statistically significant predictors of a positive TST result: age, sex, household annual income, household member infected with human immunodeficiency virus or who had stayed in a homeless shelter, and being an adopted or foster child. Overall sensitivity of the 9 main items on the questionnaire was 80.9%; when a subset of 4 of these questions plus the race/ethnicity questions were used, sensitivity of responses was 83.5%. Parents failed to recognize positive TST results at a rate of 9.9% (for the 10-mm cutoff) and 5.9% (at the 15-mm cutoff).

CONCLUSION

A 5-question risk assessment questionnaire completed by parents can be used to accurately identify risk factors associated with TB infection in children. In our population, some risk factors suggested by the American Academy of Pediatrics could not be validated. Parents cannot be relied on to read TST results accurately. Screening for TB can be enabled by using a standardized, validated questionnaire to identify children who should be given tuberculin skin testing.

Missed opportunities for preventing tuberculosis among children younger than five years of age

OBJECTIVES

Childhood tuberculosis (TB) is an important indicator of public health success in interrupting and preventing TB transmission. To determine the frequency and types of missed opportunities for preventing TB among children <5 years of age.

METHODS

We collected data from the public health records of child TB cases and their adult source cases. These children were from health jurisdictions where TB case rates in children were higher than the California average for this age group.

RESULTS

We reviewed the records for 165 children reported with TB (20% confirmed by culture). These children were evaluated for TB because of signs or symptoms of illness (32%), a contact investigation (26%), screening (22%), a source case investigation (4%), and unknown reasons (16%). Excluding 4 children infected by Mycobacterium bovis, only 59 of 161 children (37%) had a source case found. Children found in a contact investigation, born in the United States, <1 year of age, or who were black were more likely to have a source case found than children who did not have one of these characteristics. Of 43 children found in a contact investigation, improvements in contact investigations may have prevented TB in 17 of these children (40%). Among the 43 adult source cases, factors that may have facilitated transmission include delayed reporting in 23%, a delayed contact investigation in 21%, and delayed or nondocumented bacteriologic sputum conversion in 42% of culture-positive cases.

CONCLUSIONS

Important missed opportunities to prevent TB in children include the failure to find and appropriately manage adult source cases and failure to completely evaluate and properly treat children exposed to TB. Improvements in case detection, case management, and contact investigations are necessary to eliminate TB in children.

A population-based study of children with cerebral tuberculosis in New South Wales

OBJECTIVE

To determine the incidence of childhood cerebral tuberculosis (tuberculous meningitis [TBM] and tuberculoma) in a defined population.

DESIGN

Retrospective, population-based study.

SETTING AND PARTICIPANTS

All resident children aged up to 14 years in New South Wales diagnosed with cerebral tuberculosis, from 1982 to 1996.

MAIN OUTCOME MEASURE

Population-based incidence of childhood TBM.

RESULTS

10 children with TBM and one with tuberculoma were identified in the 15 years. The incidence of TBM was 0.053 (95% CI, 0.025-0.097) per 100,000. Eight of the 10 TBM patients were born in Australia and five were of white European origin. Only one had been vaccinated with BCG vaccine. Three of the children died.

CONCLUSIONS

The incidence of childhood TBM in New South Wales is low, and comparable with that in other First World countries.

Costs associated with tuberculosis control programs at hospitals caring for children

OBJECTIVE

No data are available on the costs of implementing infection control measures for the control of Mycobacterium tuberculosis (MTB) in pediatric settings. In this study we determined the cost of MTB control measures at three hospitals caring for children.

DESIGN

Infection control and tuberculosis (TB) coordinators obtained cost data retrospectively for the years 1994 to 1995 for tuberculin skin test programs, respiratory protection programs and the retrofit or new construction of environmental controls in pediatric settings.

SETTING

Two pediatric hospitals and one pediatric ward in a large tertiary care hospital.

RESULTS

Total expenditures for TB controls ranged from $15270 to $28158 for the 2-year study period. Engineering controls involved the largest capital outlay at two of three facilities. Average yearly tuberculin skin test costs ranged from $949 to $12504/hospital. Respiratory protection programs cost from $480 to $1680 during the 2-year study period.

CONCLUSIONS

Costs associated with implementing control measures varied slightly by hospital but were less than those incurred by hospitals caring for adults. These costs represent improvements made to upgrade selected aspects of hospital TB control programs, not the cost of an optimal TB control program. Optimal TB control programs in pediatric settings have yet to be described.

Detection of Mycobacterium tuberculosis in gastric aspirates collected from children: hospitalization is not necessary

OBJECTIVE

To compare the yields of gastric aspirates collected for culture of Mycobacterium tuberculosis from children evaluated as outpatients versus inpatients and to determine factors associated with a positive culture.

METHODS

Retrospective study of 100 children <12 years of age with tuberculosis diagnosed at a pediatric referral hospital or in one of two tuberculosis control programs in California.

RESULTS

Of the 100 children who had tuberculosis, 80 had at least one gastric aspirate collected. M tuberculosis was isolated from 33 (41%) of the 80 children who had a gastric aspirate; 4 children had a positive culture from an aspirate subsequent to the first. Inpatients had a higher proportion of positive gastric aspirates than that of children who had aspirates collected as outpatients (48% vs 37%); however, this difference was not statistically significant. Resistance to isoniazid was found in three isolates (9%) of children all of whose presumptive source case had a susceptible strain of M tuberculosis. Characteristics that were associated with an approximately 50% yield from gastric aspirates were identification of a source case, age <2 years, birth in the United States, symptomatic tuberculosis, and pulmonary disease.

CONCLUSIONS

The culture of M tuberculosis from gastric aspirates of children in the outpatient setting has a yield comparable to aspirates collected from hospitalized children. Collection of gastric aspirates in the outpatient setting will reduce both the cost and the inconvenience of the procedure. Although the yield from gastric aspirates is relatively low, important information including drug susceptibility patterns may be obtained. tuberculosis, gastric aspirate, children.