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

Missed opportunities in the prevention and diagnosis of pediatric tuberculosis: a scoping review

OBJECTIVES

Identify potential barriers, delays, and missed opportunities in the prevention and diagnosis of childhood TB.

METHODS

Scoping review according to the PRISMA extension. The definitions considered for the selection followed the acronym PCC where the population (P) is children under 18 years of age with TB disease, the concept (C) refers to missed opportunities for prevention and diagnosis, and context (C) is defined as a diagnosis of TB disease. The authors searched systematically in the databases; VHL/Lilacs, Medline via PubMed, Cochrane, Scopus, and Web of Science, without date or language limitation.

RESULTS

Seven studies were included. In developed countries, with low disease burden, the main shortcoming is the delay in diagnosing bacilliferous adults in contact with young children. This problem is concentrated in the portion of the population with socioeconomic vulnerability. In underdeveloped countries, with a high burden of disease, the biggest challenge is tracking children who come into contact with bacilliferous patients.

CONCLUSIONS

There are still many missed opportunities in the prevention and diagnosis of childhood TB. The positive legacy of the COVID-19 pandemic should be taken advantage of and the encouragement of scientific development in the management of infectious diseases should be taken.

Tuberculous meningitis during infancy: 26 cases in South Turkey among 20 years

BACKGROUND

Due to the lack of a standard case definifion and the diffuculty in estabilishing a definitive diagnsos, TB in children needs increasing attention by physicians caring for pediatric patients. Tuberculous meningitis (TBM) is the most serious form of extrapulmonary tuberculosis that is associated with significant morbidity and mortality rate in the pediatric age group, especially in infants. This descriptive study was conducted in an University hospital, at the South of Turkey, from May 1999 to May 2019.

METHODS

The hospital records of 26 TBM infant that was diagnosed at our hospital were retrospectively evaluated. The epidemiological findings (age, gender, family history of TB, tuberculin skin test results, status of BCG scaring), stage of TBM at admission and clinical, laboratory and radiological features were collected.

RESULTS

Of the 26 infants, 61.5% were male and mean age of the patients was 7,65±2,6 (range, 3-12 months). The history of close contact with an infected adult was encountered in 73.1% (19 infant) of the cases. Only 69.2% of the patients (18 case) had a BCG scar. The prodromal stage (period between the onset of symptoms to hospital admission) ranged from 4 days to 180 days (39±51.3). 2 cases were defined as stage I, 10 cases as stage II and 14 cases as stage III TBM. Only two patients were initially positive for PPD test. While no neurological findings were found in 2 patients (diagnosed as stage I), neurologic findings at the time of admission included increased intracranial pressure; alteration in consciousness (92.3%), seizures (88.4%), vomiting (61.5%) cranial nerve palsy (23%), irritability 19.2%, hemiplegia 15.3% and meningeal signs (7%, only 2 patients). The presence of hepatomegaly 26.9 % and/or splenomegaly 11.5 % and/or extrapulmonary lymphadenopathy 3.8 % in nearly half of the cases suggested that totally 42,2% of cases had disseminated of tuberculosis. On admission, 46.1% of the patients were noted to have hyponatremia. Microbiologic confirmation was established in eleven (42.3%) of the 26 infant. A positive CSF culture for Mtb and/or smear for AFB and/or PCR was obtained in only 5 (19.2%) patients, whereas 3 of the cases had accompaining gastric aspirate examination positivity. Pulmonary consolidation in 14 (53.8%) patients, miliary patern in 10 (41.6%) and pulmonary hilar lymphadenopathy in only 5 (20.8%) patients. 23 (88.4 %) had hydrocephalus, 15 (57.6 %) infarction, 10 (38.4 %) basilar meningitis and 9 (34.6%) tuberculomas. Empiric anti-tuberculosis treatment was instituted in all, at a median of 3 days (range 1-15 days) following admission. 8 (30.7%) died, 3 (11.5%) recovered completely, and 15 (57.6%) recovered with sequelae. 12 case (2 died) of the infants had required ventriculoperitoneal shunting.

CONCLUSION

As early diagnosis and specific treatment appears to prevent serious complications and reduce mortality, a high index of suspicion among pediatricians is especially required in an infant with an atypical picture suggestive of tuberculosis infection.

Pilot study to identify missed opportunities for prevention of childhood tuberculosis

Tuberculosis (TB) in exposed children can be prevented with timely contact tracing and preventive treatment. This study aimed to identify potential barriers and delays in the prevention of childhood TB in a low-incidence country by assessing the management of children subsequently diagnosed with TB. A pilot retrospective cohort study included children (< 15 years) treated for TB between 2009 and 2016 at a tertiary care hospital in Berlin, Germany. Clinical data on cases and source cases, information on time points of the diagnostic work up, and preventive measures were collected and analyzed. Forty-eight children (median age 3 years [range 0.25-14]) were included; 36 had been identified through contact tracing, the majority (26; 72.2%) being < 5 years. TB source cases were mostly family members, often with advanced disease. Thirty children (83.3%) did not receive prophylactic or preventive treatment, as TB was already prevalent when first presented. Three cases developed TB despite preventive or prophylactic treatment; in three cases (all < 5 years), recommendations had not been followed. Once TB was diagnosed in source cases, referral, assessment, TB diagnosis, and treatment were initiated in most children in a timely manner with a median duration of 18 days (interquartile range 6-60, range 0-252) between diagnosis of source case and child contact (information available for 35/36; 97.2%). In some cases, notable delays in follow-up occurred.

CONCLUSION

Prompt diagnosis of adult source cases appears to be the most important challenge for childhood TB prevention. However, improvement is also needed in the management of exposed children.

WHAT IS KNOWN

• Following infection with Mycobacterium tuberculosis, young children have a high risk of progression to active and severe forms of tuberculosis (TB). • The risk of infection and disease progression can be minimized by prompt identification of TB-exposed individuals and initiation of prophylactic or preventive treatment.

WHAT IS NEW

• We could show that there are avoidable time lags in diagnosis in a relevant proportion of children with known TB exposure. • Delayed diagnosis of adult source cases, losses in follow-up examinations, and delay in referral to a specialized TB clinic of TB-exposed children, especially among foreign-born children, appear to be the main issue in this German pediatric study cohort.

Immunologic-based Diagnosis of Latent Tuberculosis Among Children Younger Than 5 Years of Age Exposed and Unexposed to Tuberculosis in Tanzania

BACKGROUND

Childhood tuberculosis (TB) is acquired after exposure to an infectious TB case, often within the household. We prospectively screened children 6-59 months of age, exposed and unexposed to an infectious TB case within the same household, for latent tuberculosis infection (LTBI), in Dar es Salaam, Tanzania.

METHODS

We collected medical data and clinical specimens (to evaluate for helminths, TB and HIV coinfections) and performed physical examinations at enrollment and at 3-month and 6-month follow-up surveys. LTBI was assessed using QuantiFERON-TB Gold (QFT) at enrollment and at 3 months.

RESULTS

In total, 301 children had complete data records (186 with TB exposure and 115 without known TB exposure). The median age of children was 26 months (range: 6-58); 52% were females, and 4 were HIV positive. Eight children (3%) developed TB during the 6-month follow-up. We found equal proportions of children with LTBI among those with and without exposure: 20% (38/186) versus 20% (23/115) QFT-positive, and 2% (4/186) versus 4% (5/115) indeterminate QFT. QFT conversion rate was 7% (22 children) and reversion 8% (25 children). Of the TB-exposed children, 72% initiated isoniazid preventive therapy, but 61% of parents/caregivers of children with unknown TB exposure and positive QFT refused isoniazid preventive therapy.

CONCLUSIONS

In this high burden TB setting, TB exposure from sources other than the household was equally important as household exposure. Nearly one third of eligible children did not receive isoniazid preventive therapy. Evaluation for LTBI in children remains an important strategy for controlling TB but should not be limited to children with documented TB exposure.

Treatment of tuberculosis infection in children

INTRODUCTION

Identifying and treating children with tuberculosis (TB) infection in both low and high-TB burden settings will decrease the incidence of TB disease worldwide. Areas covered: This review covers each of the available TB infection treatment options for children based on effectiveness, safety, tolerability and treatment completion rates. Six to 9 months of daily administered isoniazid is no longer the treatment of choice for many children with TB infection. Shorter, rifamycin based, TB infection treatment regimens are effective, safe and easier for children to complete. Fluroquinolone-based regimens are recommended for the treatment of children infected by a source case with drug-resistant TB. Directly observed therapy (DOT) programs improve childhood TB infection treatment completion rates. Expert commentary: As shorter, rifamycin-based, TB infection treatment regimens offer superior treatment success rate in both adults and children; the widespread use of these regimens has huge potential to decrease the burden of TB disease worldwide. The implementation of these programs will involve improving patient access to the medications, decreasing their cost to the patient, and the use of novel electronic methods to document patient treatment completion.

Diagnosis of Tuberculosis in an Asymptomatic Child, Sibling, and Symptomatic Pregnant Mother in New York City by Tuberculin Skin Testing and the Importance of Screening High-Risk Urban Populations for Tuberculosis

BACKGROUND In 2017, in New York City (NYC), 86% of the cases of tuberculosis (TB) occurred in patients who were born outside the United States (US). This case report illustrates the importance of the use of the tuberculin skin test (TST), and other tests for TB infection (TTBI), in screening high-risk groups, the challenges of diagnosing TB in young children, and highlights the importance of preventing a delay in the diagnosis of TB in family members. CASE REPORT Following a routine TST in an asymptomatic 10-year-old girl, a diagnosis of TB was made, which was confirmed on chest X-ray (CXR) and by the presence of acid-fast bacilli (AFB) in the sputum. Her family had emigrated from China to NYC ten years previously. All the family was screened using the TST, which was positive in her 2-year-old sister and her 37-year-old pregnant mother, and pulmonary TB was confirmed on CXR and by AFBs in the sputum. All three family members and the newborn baby were treated according to current guidelines, with a good clinical outcome. CONCLUSIONS This case report raises awareness about the lack of symptoms in childhood TB and the importance of screening high-risk patients in an urban immigrant population. In children under 5 years of age, a diagnosis of TB can indicate a sentinel event, suggesting a potential undiagnosed or untreated source case, which is usually an adult family member. This report highlights the challenges of diagnosing TB in children, who may be asymptomatic with negative laboratory findings.

Genotyping and Whole-Genome Sequencing to Identify Tuberculosis Transmission to Pediatric Patients in British Columbia, Canada, 2005-2014

Background

Tuberculosis (TB) in children is often an indicator of recent transmission. Genotyping and whole-genome sequencing (WGS) can enhance pediatric TB investigations by confirming or refuting transmission events.

Methods

Mycobacterium tuberculosis isolates from all pediatric patients <18 years with culture-confirmed TB in British Columbia (BC) from 2005 to 2014 (n = 49) were genotyped by Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat (MIRU-VNTR) and compared with adult isolates. Genotypically clustered cases underwent WGS. Clinical, demographic, and contact data were reviewed for each case.

Results

Twenty-three children were Canadian-born, 7 to Canadian-born parents (CBP) and 16 to foreign-born parents (FBP). Of the 26 foreign-born children, all were born in Asia (81%) or Africa (19%). Using molecular and epidemiological data, we determined that 15 children had acquired their infection within BC, and household transmission explained all 7 Canadian-born (FBP) children that acquired TB locally. In contrast, 6 of 7 Canadian-born (CBP) children were exposed via a non-household community source. Eight Canadian-born (FBP) children acquired their infections through travel to their parents' place of birth. All but 1 of the foreign-born children acquired their infection outside of BC.

Conclusions

Genotyping and genomic data reveal that drivers of pediatric transmission vary according to a child's age, birthplace, and their parents' place of birth.

Towards the elimination of paediatric tuberculosis in high-income, immigrant-receiving countries: a 25-year conventional and molecular epidemiological case study

The epidemiology of tuberculosis (TB) in high-income countries is increasingly dictated by immigration. The influence of this trend on paediatric TB and TB elimination are not well defined.

We undertook a 25-year conventional and molecular epidemiologic study of paediatric TB in Alberta, one of four major immigrant-receiving provinces in Canada. All isolates of Mycobacterium tuberculosis were DNA fingerprinted using standard methodology.

Between 1990 and 2014, 176 children aged 0–14 years were diagnosed with TB. Foreign-born children or Canadian-born children of foreign-born parents accounted for an increasingly large proportion of total cases during the study period (from 32.1% to 89.5%). Of the 78 culture-positive cases, 35 (44.9%) had a putative source case identified by conventional epidemiology, with 34 (97.1%) having a concordant molecular profile. Of the remaining 43 culture-positive cases, molecular profiling identified spatially and temporally related sources in six cases (14.0%). These six children, along with four other children whose source cases were discovered through reverse-contact tracing, had a high morbidity and mortality.

The increasing burden of paediatric TB in both foreign-born children and Canadian-born children of foreign-born parents calls for more timely diagnosis of source cases and more targeted screening for latent TB infection.

Conventional and molecular epidemiology can inform paediatric TB elimination strategy in high-income countrieshttp://ow.ly/mwbn30iY1WF

Tuberculosis in Infants and Children

One million children develop tuberculosis disease each year, and 210,000 die from complications of tuberculosis. Childhood tuberculosis is very different from adult tuberculosis in epidemiology, clinical and radiographic presentation, and treatment. This review highlights the many unique features of childhood tuberculosis, with special emphasis on very young children and adolescents, who are most likely to develop disease after infection has occurred.

Cross Sectional Study Evaluating Routine Contact Investigation in Addis Ababa, Ethiopia: A Missed Opportunity to Prevent Tuberculosis in Children

The 2013 global roadmap for childhood tuberculosis calls for countries to implement contact screening and provide preventive therapy to children younger than 5 years. Therefore, this study designed to evaluate the implementation status of child contact screening and management in the health facilities of Addis Ababa, Ethiopia. Smear positive TB patients living with children attending daily observed treatment at the TB clinic and health care workers providing service were approached to address the study objective. Structured questionnaires were administered to smear positive index cases living with children whether they were requested to bring children age five year and below for TB screening and to health care providers in HIV, TB and child health clinics to assess their knowledge and practice on contact screening and management. Double data entry and analysis was done using EpiData software 3.1. In 27 health centres, 688 smear-positive index tuberculosis patients were approached of whom 203 (29.5%) reported to have children five years and below in their household. A total of 48 (23.6%) index cases had been requested by the health care workers to bring their children for tuberculosis screening and 45 (93.8%) had complied with this request. Of 230 children living with index smear positive tuberculosis patient, 152 (66.1%) were not screened for tuberculosis, 78 (33.9%) children screened, 2 had tuberculosis, 76 screened negative of which 3 (3.8%) received preventive treatment. None of the health care workers indicated to routinely record and report on child contact management. Household child contact screening and preventive intervention was sub-optimal in Addis Ababa. An important opportunity lost to prevent tuberculosis in young children. Training of health care workers, availing simple symptom based screening tool, and proper documentation could improve implementation.

Are TB control programmes in South Asia ignoring children with disease? A situational analysis

Paediatric tuberculosis (TB) has long been an evasive entity for public health practitioners striving to control the disease. Owing to difficulty in diagnosis of paediatric TB, incidence estimates based on current case detection fall short of actual rates. The four high-burden countries in South Asia (SA-HBC)-Afghanistan, Pakistan, India and Bangladesh-alone account for >75% of missed TB cases worldwide. It follows that these countries are also responsible for a large although unmeasured proportion of missed paediatric cases. In view of current Millennium Development Goals recommending a scale-up of paediatric TB detection and management globally, there is a dire need to improve paediatric TB programmes in these high-burden countries. Inherent problems with diagnosis of paediatric TB are compounded by programmatic and social barriers in SA-HBC. We have reviewed the current situation of TB control programmes in SA-HBC countries based on published statistics and performed a strengths, weaknesses, opportunities and threats situational analysis with a view towards identifying critical issues operant in the region posing barriers to improving paediatric TB control.

Outbreak of pyrazinamide-monoresistant tuberculosis identified using genotype cluster and social media analysis

SETTING

Monoresistance to pyrazinamide (PZA) has infrequently been associated with Mycobacterium tuberculosis.

OBJECTIVE

To report an outbreak of PZA-monoresistant M. tuberculosis in Virginia involving two genotype clusters from December 2004 to August 2010.

RESULTS

Thirty cases were identified involving a predominantly young, US-born population with histories of substance use and incarceration and a large proportion of children aged <15 years (n= 6, 20%); of these, 23 cases (77%) were culture-confirmed as M. tuberculosis complex. DNA fingerprinting and molecular analysis of the PZA resistance gene, pncA, demonstrated a clonal strain that was not M. bovis. Genotypic data provided the initial link between seemingly unrelated cases, and helped reveal a historic genotype cluster of cases from 2004. Further genotype cluster and contact investigation procedures, including the novel use of the social networking website Facebook.com, revealed additional links between the 2004 and 2009 genotype clusters and described an ongoing, extensive outbreak necessitating an enhanced screening and treatment protocol for contacts.

CONCLUSIONS

This outbreak demonstrates how tuberculosis can spread through a young, vulnerable population. The use of genotypic data and the novel incorporation of social media investigations were critical to understanding the settings and context of infectivity.

Source Case Investigation for Children with TB Disease in Pune, India

Setting. Contact tracing is broadly encouraged for tuberculosis (TB) control. In many high-burden countries, however, little effort is made to identify contacts of newly diagnosed TB patients. This failure puts children, many of whom live in poor crowded communities, at special risk. Objectives. To perform source-case investigations for 50 pediatric TB cases in Pune, India. Design. A descriptive cross-sectional observational study of pediatric TB cases < 5 years of age. Information was collected about the index case and household contacts. Results. In 15 (30%) of the 50 pediatric index cases, the household contained known TB contacts, 14 (86%) of whom were adults. Prior to their own diagnosis of TB, only one of the 15 pediatric index cases who met criteria for isoniazid preventive therapy received it. The index cases with known household TB contacts had a longer delay in initiating TB treatment than those without TB contacts (17.5 versus 2 days; P = 0.03). Use of contact tracing identified 14 additional household TB suspects, 8 (57%) of whom were children. Conclusions. This study identified missed opportunities for TB prevention, as contact tracing is poorly implemented in resource-limited countries, like India. Further strategies to improve the implementation of TB prevention, especially in young children, are urgently needed.

The epidemiology of childhood tuberculosis in the Netherlands: still room for prevention

Background

The occurrence of tuberculosis (TB) among children has long been neglected as a public health concern. However, any child with TB is a sentinel event indicating recent transmission. Vaccination, early case finding and treatment of those latently infected with TB can prevent cases, severe morbidity and unnecessary death.

Method

The objective of the study was to describe the occurrence of TB events among children in the Netherlands which may be avoided through preventive measures. For this purpose we performed a trend analysis of routine Dutch TB and LTBI (surveillance data in 1993–2012 and a descriptive analysis of children with TB and with LTBI diagnosed in 2005–2012).

Results

Overall childhood TB incidence has declined over the last two decades from 3.6 in 1993 to 1.9 per 100,000 children in 2012. The decline was stronger among Dutch-born children compared to foreign-born children. In 2005–2012 64% of childhood TB cases were detected through active case finding. Foreign-born children with TB were less likely to be detected through active case finding, when not detected through post-entry TB screening. Childhood TB diagnosis was culture confirmed in 68% of passively detected cases and 12% of actively detected cases. Of 1,049 children with LTBI started on preventive treatment in 2005–2012, 90% completed treatment. In 37% of all childhood TB cases there was at least one ‘missed opportunity’ for prevention. Thirty nine percent of child TB patients eligible for BCG were not vaccinated.

Conclusion

Children with TB in the Netherlands are generally detected at an early stage and treatment completion rates are high. However, more TB cases among children can be prevented through enhancing TB case finding and screening and preventive treatment of latent TB infection among migrant children, and improving the coverage of BCG vaccination among eligible risk groups.

Epidemiology of tuberculosis in young children in the United States

OBJECTIVES

To estimate tuberculosis (TB) rates among young children in the United States by children's and parents' birth origins and describe the epidemiology of TB among young children who are foreign-born or have at least 1 foreign-born parent.

METHODS

Study subjects were children <5 years old diagnosed with TB in 20 US jurisdictions during 2005-2006. TB rates were calculated from jurisdictions' TB case counts and American Community Survey population estimates. An observational study collected demographics, immigration and travel histories, and clinical and source case details from parental interviews and health department and TB surveillance records.

RESULTS

Compared with TB rates among US-born children with US-born parents, rates were 32 times higher in foreign-born children and 6 times higher in US-born children with foreign-born parents. Most TB cases (53%) were among the 29% of children who were US born with foreign-born parents. In the observational study, US-born children with foreign-born parents were more likely than foreign-born children to be infants (30% vs. 7%), Hispanic (73% vs. 37%), diagnosed through contact tracing (40% vs. 7%), and have an identified source case (61% vs. 19%); two-thirds of children were exposed in the United States.

CONCLUSIONS

Young children who are US born of foreign-born parents have relatively high rates of TB and account for most cases in this age group. Prompt diagnosis and treatment of adult source cases, effective contact investigations prioritizing young contacts, and targeted testing and treatment of latent TB infection are necessary to reduce TB morbidity in this population.

Drug-resistant tuberculosis: controversies and challenges in pediatrics

Tuberculosis remains one of the top two causes of death caused by a single infectious disease worldwide, despite curative therapy. Children with tuberculosis are especially difficult to detect, since acid fast bacilli smears and cultures are usually negative and clinical signs are nonspecific or lacking. Multidrug-resistant tuberculosis, or tuberculosis resistant to at least isoniazid and rifampin, has emerged in most areas of the world over the past 20 years. Treatment of multidrug-resistant tuberculosis is more expensive and difficult. The second-line tuberculosis medications required for treatment are more toxic and less efficacious than standard treatment. These medications are not readily available in many areas of the world where drug resistance is most common. Fluoroquinolones are one of the most promising classes of second-line medications, but are not generally recommended for use in children. Ethambutol is recommended in the initial treatment of tuberculosis in children treated in areas where there is a risk of drug-resistant disease and the susceptibility of the source case is not known. Some experts have been hesitant to use ethambutol due to the risk of visual impairment associated with the drug and the difficulties in monitoring vision in young children. Pediatric drug formulations are not available for most antituberculosis medications, even the first-line tuberculosis drugs. Treatment of children exposed, infected or ill with multidrug-resistant tuberculosis is reviewed with special emphasis on second-line drugs, including recommended dosage, available formulations and necessary monitoring. While new cases of multidrug-resistant tuberculosis have decreased in most developed countries over the past 10 years, cases continue to increase in many developing countries and among immigrants from high-risk areas. Tuberculosis and multidrug-resistant tuberculosis are serious threats requiring worldwide strategies to control and treat. Better diagnostic tests, medications, public health strategies and vaccines will all be needed to eliminate tuberculosis.

Improved outcomes found after implementing a systematic evaluation and program improvement process for tuberculosis

California's state and local tuberculosis (TB) programs collaborated to develop the Tuberculosis Indicators Project (TIP), a program evaluation and improvement process. In TIP, local and state staff review data, identify program gaps, implement plans to improve local TB program performance, and evaluate outcomes. After 10 years of project implementation, indicator performance changes and patient outcomes were measured. Eighty-seven percent of participating programs showed a performance increase in targeted indicators after three years compared with 57% of comparison groups. Statistically significant performance change was more common in the intervention local health departments (LHDs) than in comparison groups. The most notable performance changes were in the contact investigation and case management indicators. These results indicate that this systematic evaluation and program improvement project was associated with improved LHD TB control performance and may be useful to inform improvement projects in other public health programs.

Management of Infants and Children who are Contacts of Contagious Tuberculous Patients

Contact investigation and management form the key for tuberculosis (TB) control in countries with a low tuberculosis incidence. Oman, with a low TB incidence, has implemented contact investigation and management as one important strategy to control TB. However there is a lack of clear guidelines for the investigation and treatment of contacts, especially with regard to children who are contacts of TB cases. The failure to manage children in contact with infectious TB cases indicates a missed opportunity to prevent TB disease in a population which is prone to progress rapidly to severe and complicated illness. This article attempts to provide a concise and practical approach for managing infants and children who are in contact with TB patients. Essential steps in a variety of possible scenarios are briefly discussed.

Treatment of Latent Tuberculosis Infection in Children

Treatment of latent tuberculosis infection (LTBI) is an effective way of preventing future cases of tuberculosis disease. We review pediatric and adult studies of LTBI treatment (isoniazid and rifampin monotherapy, isoniazid plus rifampin, isoniazid plus rifapentine, and rifampin plus pyrazinamide). Based upon this review and our pediatric experience, we can offer recommendations for routine (isoniazid) and alternative courses of therapy.

The impact of monitoring tuberculosis reporting delays in New York City

Public health departments rely on the timely receipt of tuberculosis (TB) reports to promptly initiate patient management and contact investigations. In 2003, 43% of persons in New York City with confirmed or suspected TB were reported 4 or more days late. An intervention to increase the timeliness of TB reporting was initiated in 2004. A list of patients who were reported late and had a smear positive for acid-fast bacilli, a pathology finding consistent with TB, or who initiated 2 or more anti-TB medications was generated quarterly. Health care providers and laboratories were contacted to determine the reasons for reporting late and were educated on TB reporting requirements. To assess the effectiveness of the intervention, we evaluated the trend in delayed reports between 2003 and 2006, using the Jonckheere-Terpstra test for trend. The proportion of patients who were reported late decreased from 43% (942/2183) in 2003 to 20% (386/1930) in 2006 (Ptrend < .0001). There were improvements in reporting timeliness for all 3 reporting criteria included in the evaluation and all provider types (all Ptrend < .0001); however, private providers consistently had a higher proportion of delayed reporting (22% reported late in 2006). This relatively simple intervention was very effective in improving the timeliness of TB reporting and could be utilized for other reportable diseases where prompt reporting is critical.

Childhood tuberculosis deskguide and monitoring: an intervention to improve case management in Pakistan

Background

Childhood tuberculosis (TB) has been a neglected area in national TB control programme (NTCP) in high burden countries. The NTP Pakistan adapted the global approaches by developing and piloting its policy guideline on childhood TB in ten districts of the country. We developed an intervention package including a deskguide and a monitoring tool and tested with the ongoing childhood TB care in a district. The objective of our study was to measure effectiveness of intervention package with deskguide and monitoring tool by comparing TB case finding and treatment outcomes among districts in 2008, and performance assessment in intervention district.

Method

An intervention study with cohort design within a routine TB control programme comparing case findings and treatment outcomes before and after the intervention, and in districts with and without intervention. We enrolled all children below 15 years registered at all nine public sector hospitals in three districts of Pakistan. The data was collected from hospital TB records.

Results

In eight months during 2007 there were 164 childhood TB cases notified, and after intervention in 2008 a total of 194 cases were notified. In intervention district case finding doubled (110% increase) and correct treatment practice significantly increased in eight months. Successful outcomes were significantly higher in intervention district (37,100%) compared to control district A (18, 18%, p < 0.05) and control district B (41, 72%, p < 0.05).

Conclusion

Childhood TB deskguide and structured monitoring was associated with improved case management and it augmented NTP policy. More development and implementation in all health services of the district are indicated.

[Specific features of tuberculosis in childhood]

Primary infection with Mycobacterium tuberculosis usually occurs during childhood. The source of infection is most often an adult. The risk of infection in exposed children is modulated by various factors related to the infectiousness of the index case, exposure conditions, and the child himself. This review aims to describe the specific diagnostic and therapeutic features of latent TB infection and TB disease in childhood.

Enhancement of human antigen-specific memory T-cell responses by interleukin-7 may improve accuracy in diagnosing tuberculosis

Children and immunocompromised adults are at an increased risk of tuberculosis (TB), but diagnosis is more challenging. Recently developed gamma interferon (IFN-gamma) release assays provide increased sensitivity and specificity for diagnosis of latent TB, but their use is not FDA approved in immunocompromised or pediatric populations. Both populations have reduced numbers of T cells, which are major producers of IFN-gamma. Interleukin 7 (IL-7), a survival cytokine, stabilizes IFN-gamma message and increases protein production. IL-7 was added to antigen-stimulated lymphocytes to improve IFN-gamma responses as measured by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Antigens used were tetanus toxoid (n = 10), p24 (from human immunodeficiency virus [HIV], n = 9), and TB peptides (n = 15). Keyhole limpet hemocyanin was used as a negative control, and phytohemagglutinin was the positive control. IL-7 improved antigen-specific responses to all antigens tested including tetanus toxoid, HIV type 1 p24, and TB peptides (ESAT-6 and CFP-10) with up to a 14-fold increase (mean = 3.8), as measured by ELISA. Increased IFN-gamma responses from controls, HIV-positive patients, and TB patients were statistically significant, with P values of <0.05, 0.01, and 0.05, respectively. ELISPOT assay results confirmed ELISA findings (P values of <0.01, 0.02, and 0.03, respectively), with a strong correlation between the two tests (R(2) = 0.82 to 0.99). Based on average background levels, IL-7 increased detection of IFN-gamma by 39% compared to the level with antigen alone. Increased production of IFN-gamma induced by IL-7 improves sensitivity of ELISA and ELISPOT assays for all antigens tested. Further enhancement of IFN-gamma-based assays might improve TB diagnosis in those populations at highest risk for TB.

[Microepidemics of tuberculosis in schools. How should we select contacts?]

BACKGROUND

Outbreaks of microepidemics of tuberculosis indicate the existence of Mycobacterium tuberculosis transmission. We describe a microepidemic in a school in which an index case with low infective capacity gave rise to a high percentage of tuberculosis infection and disease in the center.

METHODS

Contact investigation was performed in 423 pupils of a school after a recently arrived teacher with few symptoms was diagnosed with tuberculosis. A cross-sectional study was carried out to calculate the prevalence of tuberculosis infection and disease in the school center.

RESULTS

Statistically significant differences were found in the distribution of positive results in the first tuberculosis skin test for primary and secondary students, with more positive results in secondary school pupils (18.4%) than in primary school pupils (6.1%). The incidence of skin tuberculosis test converters was 5.7%. The prevalence of infection by educational level was 10% in primary education and 23.4% in secondary education. The risk of infection in secondary school pupils was more than twice that in primary school pupils (OR = 2.4; 95% CI, 1.5-3.5). There were 6 new cases of tuberculosis in pupils.

CONCLUSION

The high percentage of conversions in the second tuberculosis skin test indicated the existence of transmission in the school. The results of this study support contact investigation in schools where there is exposure to a case of tuberculosis, whether highly infective or nort.

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.

Active surveillance for tuberculosis in Wales: 1996-2003

AIMS

To estimate the incidence of active tuberculosis (TB) and study the use of chemoprophylaxis for latent TB in children in Wales, and to identify potential areas for improving prevention and management.

METHODS

Active surveillance for TB in children aged 0-15 years from July 1996 to December 2003, using the Welsh Paediatric Surveillance Scheme.

RESULTS

A total of 232 children, 102 with active TB (2.3 per 100 000) and 130 with latent TB (2.9 per 100 000), were identified. Nearly half (45%) belonged to ethnic minorities (19% were of black African origin), a much higher proportion than the base population. Pulmonary disease was the most common presentation (47%), including six (9%) children who were sputum smear positive. There were 10 cases of disseminated TB, nearly all in white children under 10 years of age. Less than two thirds of eligible children (27/46, 59%) were known to have received BCG immunisation. The source of infection was an adult household contact in most cases, but was not known in 44 cases, particularly among teenagers. Four community outbreaks occurred during the surveillance period, including three in high schools.

CONCLUSION

TB incidence in children in Wales remains low, but the epidemiology is changing with an increasing proportion of cases in black African children. The high proportion of patients with disseminated TB is of particular concern. TB in teenagers was often associated with school outbreaks. Many eligible children do not receive BCG immunisation, indicating further scope for prevention.

Tuberculose de l'enfant après contage familial : une expérience en pédiatrie générale

The heterogeneity of clinical presentations of children in contact with a tuberculous adult do not allow simple guidelines for treatment and exams. Indications of thoracic computed tomography (CT) in young children and the risk of a follow-up without antituberculous treatment are always discussed.

PATIENTS

Sixty-nine children, belonging to 50 families, living in close contact with an adult treated for tuberculosis were explored during 7 years in a General Pediatric Unit. A CT was performed in 51 patients.

RESULTS

Mantoux test was negative in 3/17 children with typical tuberculous disease on X-ray. When results of CT were compared with those of standard thoracic X-ray, a difference for the diagnosis of mediastinal adenopathies was found only in children younger than 5 years. Fifty-eight patients were given usual treatment of latent or patent tuberculosis if indicated, or a chemoprophylaxis. All of them had normal clinical and X-ray exam 2 to 4 years later. Eleven children, initially checked in an other unit, were given no treatment, but a follow-up was set up. However, after 6 to 24 months, 4/11 had a patent tuberculosis and 5/11 a latent tuberculosis, 6/9 being aged more than 3 years.

CONCLUSION

This study shows that risk of tuberculosis after familial contamination is high, and that the choice of absence of treatment with following re-evaluation, is sometimes questionable because families or doctors do not perform the prescribed follow-up. To perform systematically a thoracic CT, searching for mediastinal adenopathies, is useful only before the age of 5 years.

Improved program activities are associated with decreasing tuberculosis incidence in the United States

OBJECTIVE

This study was conducted to determine whether improvements in tuberculosis (TB) program activities correlate with incident TB cases.

METHODS

National TB surveillance data and program data from patients with pulmonary and laryngeal TB and their contacts were collected. These data were analyzed using regression models to assess the association between changes in incident TB cases and indicators of program performance (a time series of percent changes in program indices).

RESULTS

A total of 1,361,113 contacts exposed to 150,668 TB patients were identified through contact investigations. From 1987 to 1992 (the period of TB resurgence and antedating increased funding), there was a decline in several measures used by TB programs for outcomes of contact investigations. From 1993 to 1998 (the period after increases in TB funds), there was an observable improvement in the program indices. Four program indices for contacts and two for TB cases (directly observed therapy and completion of therapy) were statistically associated (p < or = .01) with the decline in TB incident cases.

CONCLUSIONS

These analyses suggest that expanded TB program activities resulted in the reduction in national TB cases and underscore the importance of treatment completion for TB disease and latent TB infection. Based on these results, we propose that further improvements in these activities will accelerate the decline of TB in the United States.

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.

Facteurs de risque de tuberculose chez l'enfant

In order to better target children who should be screened for tuberculosis and to tailor treatment according to risk a good knowledge of the risk factors for latent tuberculosis infection and progression to disease is needed. Risk of infection is strongly related to number and duration of exposure and is particularly high when contact happens at home. Host factors like a young age or chronic underlying disease seem to favor progression to disease but do not increase infection rate. Some M. tuberculosis strains seem to be more easily transmissible. An adaptation of the criteria for a positive tuberculin skin test according to risk may help to increase the positive and negative predictive values of the test. When the risk of progression to disease is high a prophylactic treatment may be considered.

BCG scar and positive tuberculin reaction associated with reduced child mortality in West Africa. A non-specific beneficial effect of BCG?

Previous studies have suggested that the bacille Calmette-Guérin (BCG) vaccine may have a non-specific beneficial effect on childhood survival in areas with high mortality. We examined whether BCG-vaccinated children with a BCG scar or a positive tuberculin reaction had better survival than children without such reactions. As part of an ongoing two-dose measles vaccine trial for which children were recruited at 6 months of age, we examined 1813 children for BCG scar at 6 months of age and 813 BCG-vaccinated children were skin-tested for delayed hypersensitivity to tuberculin, tetanus and diphtheria. We found that BCG-vaccinated children with a BCG scar had significantly lower mortality compared with BCG scar-negative children, the mortality ratio in the first 12 months of follow-up being 0.41 (0.25-0.67). BCG-vaccinated children with a positive tuberculin test had a mortality ratio of 0.45 (0.24-0.85) compared with tuberculin negative children. These results were unchanged by control for potential confounders or using different cut-off points for a tuberculin-positive response. Exclusion of dead children who had HIV antibodies did not modify the estimate (mortality rate (MR)=0.46 (0.23-0.94)). After censoring for tuberculosis (TB) exposure at home, the mortality ratios for having a scar and being tuberculin-positive were 0.46 (0.27-0.79) or 0.42 (0.21-0.84), respectively. Children positive to tetanus or diphtheria in the skin test had the same mortality as children not responding to these vaccine-related antigens. Thus, BCG scar and a positive tuberculin reaction were associated with better survival in early childhood in an area with high mortality. Since nothing similar was found for responders to diphtheria-tetanus-pertussis (DTP) vaccine, and the effect could not be explained by protection against tuberculosis, the effect of BCG vaccination could be due to non-specific immune-stimulation protecting against other infections.

Tuberculosis

Tuberculosis is an infectious disease caused by bacteria in the Mycobacterium tuberculosis complex. Of these, the most common species to infect humans is M. tuberculosis. The TB bacillus is an extremely successful human pathogen, infecting two billion persons worldwide; an estimated 2 to 3 million people die from tuberculosis each year. In the United States, TB rates decreased steadily at the rate of 5% per year from 1953 until 1985 when the trend reversed, with the number of TB cases peaking in 1992. Outbreaks of multidrug-resistant TB (MDR TB) were reported, and these cases were documented to be transmitted in nosocomial and congregate settings, including hospitals and prisons. AIDS patients infected with M. tb developed disease rapidly, and case-fatality rates of >80% were noted in those infected with multidrug-resistant M. tb. Intensive intervention, at enormous cost, caused the number of TB cases to decline. This article discusses factors that led to the increase in TB cases, their subsequent decline, and measures needed in the future if TB is to be eliminated in the United States.

Identifying the sources of tuberculosis in young children: a multistate investigation

To better understand the molecular epidemiology of tuberculosis (TB) transmission for culture-confirmed patients <5 years of age, data were analyzed from a population-based study conducted in seven U.S. sites from 1996 to 2000. Mycobacterium tuberculosis isolates were genotyped with IS6110-based restriction fragment length polymorphism analysis and spoligotyping. Case-patient data were obtained from the Centers for Disease Control and Prevention s national tuberculosis registry and health department records. Routine public health investigations conducted by local health departments identified suspected source patients for 57 (51%) of 111 culture-confirmed patients <5 years of age. For 8 (15%) of 52 culture-confirmed patients <5 years of age and their suspected source patients with complete genotyping results, genotypes suggested infection with different TB strains. Potential differences between sources for patients <5 years of age and source patients that transmitted TB to adolescent and adult patients were identified.

Transmission of tuberculosis from adults to children in a Paris suburb

Tuberculosis in children is often acquired by contact with a family or household member. The aim of our study was to evaluate risk factors for latent infection and active disease in exposed children in a suburb of Paris. We examined medical records for the period 1997-2000 at six departmental centers for medical prevention in Val de Marne. Thirty-nine patients aged 18 years or more with M. tuberculosis-positive sputum samples, and living with children or adolescents, were identified. Ninety-one children, aged 3 months-17 years, were exposed to these index cases. All the children initially underwent a tuberculin skin test and chest radiography, and children with no criteria for latent infection or active disease at time of initial evaluation were asked to attend a second evaluation 3 months later. Overall, 20 of the 91 (22%) children were infected, including 4 children identified only at the second evaluation. Eight (40%) of the 20 infected children had active disease, including 2 of the 4 children identified at the second evaluation. The risk of infection was not influenced by the children's age, but was significantly associated with three characteristics of the adult cases, i.e., age younger than 40 years, presence of cavitary lesions, and smears with more than 100 bacilli per microscopic field. In conclusion, our results call for early examination of all exposed children, in order to prevent infection and progression to active disease, and for a routine second evaluation after the adult contact has ended.

Congenital tuberculosis: a rare manifestation of a common infection

The epidemiology of tuberculosis has changed dramatically over the past 5 years with significant shifts in at-risk populations, resulting in increased disease among young adults and children, especially among those from developing countries. Congenital tuberculosis is rare, and the clinical presentation of tuberculosis during pregnancy and infancy is often non-specific, making recognition difficult. Advances have been made with diagnostic tools, in public health practices, and with treatment recommendations. Controversy and debate continue regarding the safety and use of isoniazid for latent tuberculosis infection during pregnancy. New vaccine development may be promising for the future, but much work is needed to understand the complicated immune response to tuberculosis.