The burden of childhood tuberculosis and the accuracy of community-based surveillance data

Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Stellenbosch, Cape Town, South Africa.
The International Journal of Tuberculosis and Lung Disease (Impact Factor: 2.76). 03/2006; 10(3):259-63.
Source: PubMed

ABSTRACT Inadequate surveillance and diagnostic difficulties compromise the quality of epidemiological data on childhood tuberculosis (TB).
To document the incidence of childhood TB and to evaluate the accuracy of community-based surveillance data in a high-burden setting.
This prospective observational study was conducted from February 2003 to October 2004 at five primary health care clinics in Cape Town, South Africa. Comprehensive surveillance was done to ensure that all children <13 years of age treated for TB were included.
During the study period, 443 children (<13 years of age) received anti-tuberculosis treatment, of whom 389 (87.8%) were recorded in the TB treatment register. The TB incidence calculated from the TB treatment register was 441/100,000/year amongst children and 845/100,000/year amongst adults. Fifty-four children treated for TB were not recorded in the TB treatment register, including 21/28 (75%) children with severe disease.
Children <13 years of age contributed 13.7% of the total TB burden, but experienced more than half (52.2%) the TB incidence recorded in adults. Community-based surveillance data excluded the majority of children with severe disease. The accuracy of surveillance data is an important consideration when describing the epidemiology of childhood TB or measuring the success of public health interventions.

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Available from: Ben Marais, Oct 02, 2014
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    • "However, because the majority of children are sputum microscopy smear negative, these data underestimate the true burden of childhood TB. It is estimated that childhood TB constitutes 10–20% of all TB in highburden countries [4], accounting for 8–20% of TB-related deaths [5] [6] [7]. The epidemiology of TB in young children (<5 years old), a vulnerable population where diagnosis and treatment are most challenging, is not well understood, "
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    ABSTRACT: Background. India has one of the highest tuberculosis (TB) burdens globally. However, few studies have focused on TB in young children, a vulnerable population, where lack of early diagnosis results in poor outcomes. Methods. Young children (≤5 years) with suspected TB were prospectively enrolled at a tertiary hospital in Pune, India. Detailed clinical evaluation, HIV testing, mycobacterial cultures, and drug susceptibility testing were performed. Results. 223 children with suspected TB were enrolled. The median age was 31 months, 46% were female, 86% had received BCG, 57% were malnourished, and 10% were HIV positive. 12% had TB disease (definite or probable), 35% did not have TB, while TB could not be ruled out in 53%. Extrapulmonary disease was noted in 46%, which was predominantly meningeal. Tuberculin skin test (TST) was positive in 20% of children with TB. Four of 7 (57%) children with culture-confirmed TB harbored drug-resistant (DR) strains of whom 2 (50%) were multi-DR (MDR). In adjusted analyses, HIV infection, positive TST, and exposure to household smoke were found to be significantly associated with children with TB (P ≤ 0.04). Mortality (at 1 year) was 3 of 26 (12%) and 1 of 79 (1%), respectively, in children with TB and those without TB (P < 0.05). Conclusions. Diagnosis of TB is challenging in young children, with high rates of extra-pulmonary and meningeal disease. While the data on DR-TB are limited by the small sample size, they are however concerning, and additional studies are needed to more accurately define the prevalence of DR strains in this vulnerable population.
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    • "The adult tuberculosis incidence in the province was 678/100,000 in 2003, the incidence of tuberculosis in children <13 years of age was 407/100,000 and the HIV prevalence among women attending public antenatal care facilities was 15.4% (95% CI: 12.5–18.2%) in 2004 [12] [13] [14]. Current South African BCG vaccination policy recommends universal intradermal vaccination at birth with Danish Strain BCG (1331, Statens Serum Institute, Copenhagen , Denmark) in the right deltoid region. "
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    ABSTRACT: Document prepared for a 3-day International Workshop "Exploring Development of a birth cohort to understand and prevent diseases of children in the developing world" 1 Childhood mortality and respiratory disease Globally, respiratory illness is the major cause of childhood mortality. The World Health Organisation (WHO) estimates that approximately 10.6 million children under 5 years of age die each year; of which almost 2 million or 19% are due to acute respiratory infection (ARI), mainly pneumonia. 1 . In addition a further 10% of all childhood deaths are due to neonatal pneumonia or sepsis. The main burden of childhood respiratory disease and associated deaths occur in developing countries. 1-3 More than 90% of deaths from childhood ARI occur in developing countries, especially in Africa where almost half of pneumonia-associated deaths occur. 1,3 Other respiratory illnesses contributing to the global under-5 mortality include measles and HIV/AIDS, responsible for approximately 4% and 3% of deaths respectively. 1 A number of differences between developed and developing countries impact on the global burden of pediatric respiratory illness. Firstly, children account for a relatively higher proportion of the population in developing compared with developed countries. In 2005, children under 15 years of age comprised approximately 31% of the total population in developing countries, compared to 17% in developed nations. 4 Secondly the prevalence of some infectious agents may differ as a result of socioeconomic, medical or geographic factors. For example measles occurs almost exclusively in developing countries. 1,5 Similarly the incidence of severe pneumococcal disease including pneumonia has declined substantially in developed countries with routine immunization of young children with the conjugate vaccine. 6,7 While the burden of childhood tuberculosis (TB) is difficult to quantify, estimates are that it accounts for 15 to 20% of the TB caseload in developing countries, where the major global TB burden exists. 8 Thirdly, the paediatric HIV epidemic is now largely confined to developing countries especially those in sub-Saharan Africa, where almost 2 million HIV-infected children live. 9 Prenatal screening and effective preventative perinatal interventions have virtually eliminated pediatric HIV in developed countries. The impact of the HIV epidemic on childhood respiratory illness has been compounded by poor access and unavailability of preventative strategies and limited availability of highly active antiretroviral therapy (HAART) in developing countries. As a result, HIV-associated lung disease is a major cause of childhood morbidity, hospitalisation and mortality in sub-Saharan Africa with 90% of HIV-infected children developing a respiratory illness during the course of their HIV disease. 10 Fourthly, socio-economic factors including nutrition impact on child lung health, influencing the epidemiology and severity of illness. Co-morbid malnutrition occurs in almost half of all children dying from pneumonia. 1 Fifthly, environmental determinants of child lung health may play an important role in developing countries. For example overcrowded living conditions, exposure to biomass fuel or passive smoke exposure may be risk factors that are more prevalent in developing country settings. 11 Finally, lack of attention to the social determinants of child lung health and global inequities with large differences in access, affordability and quality of healthcare for children in developing and developed countries are important factors.
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