Author: Sharma Sharan
Institution: Medicine
Date: February 2005
In Sanskrit, tuberculosis (TB) is known as Rajyachhyama, or "the king of diseases." It is one of the world's most serious infectious threats. Globally it has been estimated that 1.7 billion people are infected with tuberculosis, a third of them in Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. TB infection is very common, and it continues to be the major public health problem in Nepal. About 60% of the economically active population has been infected. Published data about the epidemiology of TB in children is scarce in Nepal, though it is considered one of the most common causes of childhood morbidity in the country. One study has shown that in a developing country such as Nepal, the annual risk of getting TB infection in children is 2-5%, but 8-20% of the deaths are children.
Scenario in Nepal
In Nepal, tuberculosis in children represents 5-15% of all TB cases. Gender-wise, no significant difference has been found in the number of reported TB cases in children. The reports of the World Health Organization (WHO) did not show any differences between reported cases of tuberculosis between males and females from 1997 to 2000.
Tuberculosis in children differs from tuberculosis in adults. Unlike adults, children are rarely infectious. Instead, the source of transmission of TB to children is usually an adult, often a family member, with smear-positive pulmonary tuberculosis (PTB). Untreated adults pass the disease on to 43% of children under one and to 16% of children from 11-15 years old. Only 5-10% of adults in similar contact would contract the disease.
In Nepal, tubercular lymphadenopathy, tubercular meningitis, tuberculoma, TB nephritis, TB abdomen and TB bone are the most common extrapulmonary TB that occur in children. It is often said that tubercular infection is so common in Nepal that almost every child would be exposed to tuberculosis during his childhood, though all children who are exposed do not necessarily develop this disease.
Unhealthy and malnourished children are more likely to get tuberculosis. Malnutrition is a widespread problem that affects the health of many children, and it is one of the triggers of tubercular infection. Co-infection of HIV and M. tuberculosis (microbacterium TB) has often been described as a diabolical duet' and has intensified the problem associated with tuberculosis control. No study has been done to determine the exact number of HIV-positive children living with tuberculosis in Nepal, but compared to an HIV-negative child, one who is infected with HIV has a 10-fold increased risk of developing TB.
Diagnosis of tuberculosis in children is very difficult. "If you find the diagnosis of TB in children easy, you are probably over-diagnosing TB. If you find the diagnosis of TB in children difficult, you are not alone." Unlike diagnosing adults, there is no such "gold standard" test such as sputum smear microscopy for diagnosing children. TB in children is a general disease which may appear in any part of the body. Also, children under 10 years old with PTB rarely cough up sputum because they usually swallow their sputum. Gastric suction and laryngeal swabs are generally not useful unless facilities are available for M. tuberculosis culture. Due to poor health care services in many parts of Nepal, helpful special diagnostic investigations such as specialized X-rays, biopsy and histology, and TB culture are not always available. To make the diagnosis of childhood TB easy and available in every part of the country, Nepal Pediatric Society (NEPAS) recommends the use of a score chart adapted from Crofton, Horne and Miller for the diagnosis of TB in children. The basis of the score system is the careful and systematic collection of features that a child with suspected TB shows. The presence of each symptom is given a certain score according to the chart and a total score is calculated. A score of seven or more indicates a high likelihood of TB.
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Nepal is a mostly rural country, and the majority of its citizens are illiterate. There is widespread belief in these rural communities that TB is a disease sent from God, and only cursed or bad people get it. This causes many people who are infected with tuberculosis to hide the disease and to deny immediate, if any, treatment. Taking such things into consideration, the National Tuberculosis Centre (NTC) of Nepal has envisaged the concept of community control of tuberculosis. Under this program, the community is educated about symptoms of TB patients, and parents are made aware of when their child needs to receive medical help. Additionally, active contact tracing of children who are members of a household with infectious adults is especially important under this program. With the help of many international organizations, NTC has been working strongly to raise the BCG vaccination coverage in children. On the other hand, NTC recommends the use of Directly Observed Treatment Short Course (DOTS) therapy for the management of every diagnosed case. Now DOTS has been started all over the country, and the present treatment success rate of DOTS in Nepal is nearly 90%.
The future
Childhood tuberculosis has been likened to a canary in a coal mine, which is used as a diagnostic tool to alert miners when the atmosphere in the mines is too toxic. Similarly, when there is an increase in the number of cases of childhood tuberculosis, it implies a failure to cure adult infectious cases. Therefore, to control of tuberculosis in children, health care programs should focus on treating infectious adults. To achieve this, the public and private sectors need to concert their efforts towards eliminating TB.
Tuberculosis is one of the most common infectious diseases in children, especially in the developing world. The high incidence of childhood tuberculosis reflects the prevalence of this disease in adults, as well as influencing current transmission rates. In Nepal, 6 out of every 10 people are infected with tuberculosis, so it is not surprising to find such statistics of childhood TB. Though there is a lack of major epidemiological studies about childhood tuberculosis in Nepal, the National Tuberculosis Centre estimates it to be one of the highest among the member countries of the South Asian Association for Regional Cooperation (SAARC).
Diagnosis of childhood tuberculosis is always a difficult task. One study has shown that in developed countries, newer techniques such as the liquid based culture detection system and nucleic acid amplification are widely used for the diagnosis of childhood tuberculosis. However, these techniques are not perceived to offer enough benefits to justify their routine use in developing countries. Thus the predominant use of the score chart system for the diagnosis of childhood TB is well-justified in a country like Nepal where even simple X-rays are not always available.
To reduce the morbidity and mortality from tuberculosis, the NTC of Nepal has been working relentlessly through the coordination of private and public treatment centers. Now DOTS has been started all over Nepal, and treatment for TB is available free of cost in most government hospitals. Due to the availability of DOTS throughout the country and the high treatment success rate of DOTS, the prevalence of childhood TB has decreased over the last decade.
What has been accomplished in the control of childhood tuberculosis in Nepal is still a fraction of what needs to be done. Failure in early detection and the emergence of new problems such as drug resistance and the co-infection of AIDS and TB are important problems encountered in the treatment and cure of TB. The road that lies ahead will be even harder as we face these challenges.
References and Suggested Reading
National Tuberculosis center (NTC). Tuberculosis in Nepal, June 2001.
National tuberculosis programme. A clinical manual for Nepal, Feb 2002.
Kabra SK, Lodha R, Seth V. (2004). Some current concepts on childhood tuberculosis. J Med Res. 120:387-9.
World Health Organization. Global tuberculosis control: surveillance, planning, financing. WHO Report. 1999, 2000, 2001, and 2002.
Starke JR, Jacobs RF, Jeres J. (1992). Resurgence of tuberculosis in children. J Paediatrics. 20:839-55.
Ejaz AK, Hassad M. (2002). Recognition and management of TB in children. Current Paediatrics. 12(7):545-50.
Datta M, Swaminathan. (2001). Global aspects of tuberculosis in children. Paediatric Respiratory Review. 2(2):91-6.
Bhatta BK, Thapaliya A, Ramachandran U, Sharma KK. (2003). Can directly observed treatment short course (DOTS) be modified for childhood tuberculosis? Journal of Nepal Paediatric Society. 21:15-20.
Gray JW. (2004). Childhood tuberculosis and its early diagnosis. Clinical Biochemistry. 37(6):450-5.