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| LETTER TO EDITOR |
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| Year : 2017 | Volume
: 15
| Issue : 3 | Page : 258-259 |
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Author's Reply
Valsan Philip Verghese
Pediatric Infectious Diseases Unit, Department of Child Health, Christian Medical College, Vellore - 632 004, Tamil Nadu, India
| Date of Web Publication | 7-Aug-2017 |
Correspondence Address:
Valsan Philip Verghese
Pediatric Infectious Diseases Unit, Department of Child Health, Christian Medical College, Vellore - 632 004, Tamil Nadu
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0973-4651.212385
How to cite this article:
Verghese VP. Author's Reply. Curr Med Issues 2017;15:258-9 |
Dr. Ramasamy raises a very valid question about prevention of TB in asymptomatic child contacts of sputum positive pulmonary TB, a situation faced by many of our practicing colleagues and me as well during 7 years spent in small mission hospitals and the base hospital of Christian Medical College's Community Health Department. These children are often not thought of as potential TB patients, and till some years ago the Revised National Tuberculosis Control Programme did not even have a protocol to deal with these children at very real risk of developing TB.
There are two issues that Dr. Ramasamy raises here:
- What is the simplest protocol to prevent TB in such children?
- How does one assess for TB in such children whose parents, due to either illness or potential loss of earnings, have limited access to care?
The answers to these questions are as follows:
The simplest protocol to prevent tuberculosis in such children is as given in the 2012 Indian Academy of Pediatrics' guidelines, [1] below TB preventive therapy
The current recommended dose of Isoniazid (INH) for chemoprophylaxis is 10 mg/kg (instead of currently recommended dosage of 5 mg/kg) administered daily for 6 months. TB preventive therapy should be provided to:
- All asymptomatic contacts (under 6 years of age) of a smear positive case, after ruling out active disease and irrespective of their BCG, tuberculin skin test (TST), or nutritional status
- Chemoprophylaxis is also recommended for all HIV-infected children who either had a known exposure to an infectious TB case or are TST positive (≥5 mm induration) but have no active TB disease
- All TST positive children who are receiving immunosuppressive therapy (e.g., children with nephrotic syndrome, and acute leukemia)
- A child born to a mother who was diagnosed to have TB in pregnancy should receive prophylaxis for 6 months, provided congenital TB has been ruled out. BCG vaccination can be given at birth even if INH chemoprophylaxis is planned.”
As mentioned above, all children younger than 6 years of age in contact with an adult with open pulmonary TB should receive INH prophylaxis, even if their Mantoux test is negative or not done.
In an asymptomatic child older than 6 years of age, doing a Mantoux to look for evidence of latent Tb (TB infection) before starting prophylaxis should not really be considered an unattainable ideal. When one has health workers who do home visits to the adult patient, a Mantoux can easily be administered at one visit and read at a second visit 48–72 h later. A positive Mantoux would be an indication to do a chest X-ray to rule out signs of pulmonary TB. In such a child, a positive Mantoux and a normal chest X-ray would indicate the presence of latent TB infection and necessitate prophylaxis with INH for 6 months. A positive Mantoux and chest X-ray findings compatible with TB, as mentioned in the author's article,[2] would indicate the need to send tests for bacteriological confirmation and start the child on empiric antituberculous therapy.[3]
Assessment for the presence of TB disease in this situation
As shown in '[Figure 10]: Algorithm for initiating antituberculous Therapy for pulmonary TB in children' in the author's article,[2] the presence of symptoms suggestive of TB such as persistent fever or cough, or failure to gain weight should raise the suspicion of TB. The Mantoux does not add to the decision-making process in the WHO algorithm for the very reason that a negative Mantoux does not rule out active TB due to various factors, of which the most common is malnutrition among our children.{Figure 10}
The algorithm also makes it clear that when a child is symptomatic, the presence of any two of the following three: (1) signs suggestive of TB (that would include growth faltering), (2) the presence of a known close TB contact, or (3) X-ray or other imaging findings suggestive of TB, is sufficient for the care provider to start empiric antituberculous therapy.
In this light, I would like to comment on the management of child contacts as mentioned by Dr. Ramasamy in his letter:
- Asymptomatic children up to the age of 6 years should be offered INH prophylaxis irrespective of Mantoux test results, whether positive or negative
- Children of any age with unexplained weight loss or documented growth faltering (failure to gain weight) over time should be considered as symptomatic for the purpose of starting empiric antituberculous therapy, especially if they have other symptoms suggestive of TB such as persistent fever or cough even in the absence of a chest X-ray or other investigations for bacteriological confirmation. However, all efforts to do these investigations should be pursued, as a wrong diagnosis would result in exposing the child to the potential side-effects of antituberculous medication
- Empiric antituberculous therapy with 4 drugs should not be started for asymptomatic child contacts of adults with pulmonary TB. In India, where one in five children are poorly nourished due to inadequate nutritional intake, anti-TB treatment should not be started based only on a single recording of weight-for-height of <80% of expected, in the absence of any other evidence of TB. If the child has weight faltering or weight loss over an adequate period of observation (3–6 months) and other symptoms suggestive of TB such as persistent fever or cough, then he/she may be considered to be symptomatic and empiric anti-TB treatment started.
About a third of children in contact with adults with TB have been documented to have latent TB infection.[4] INH prophylaxis provides excellent protection against TB disease, with a 65%–70% reduced risk of developing TB in those receiving prophylaxis.[5],[6]
There is no evidence that starting antituberculous therapy for all child contacts of open pulmonary TB is better than offering prophylaxis alone, because standard protocols differentiate between latent TB infection and active TB disease based on the presence or absence of symptoms and X-ray findings, and the treatment for each of these differs.[5] While it is true that primary INH resistance exists in India, and that malnutrition or measles can predispose a child to develop TB, indiscriminate use of antituberculous therapy will only foster the rise of multi-drug-resistant TB due to issues with availability of and adherence to medication.[7]
Antituberculous drugs are not exactly harmless. The most common side-effect, hepatotoxicity, has been documented in 0.36%–0.5% of patients receiving INH monotherapy as prophylaxis. Hepatotoxicity is higher with combinations of anti-TB drugs, being 2.55% in those receiving INH and Rifgamicin and between 15% and 40% in those receiving 4-drug antituberculous therapy.[8] Other side-effects of antituberculous drugs including rash, peripheral neuropathy, and gouty arthritis have all been documented by us in children, which leads us to believe that empiric antituberculous therapy should not be started unless one is very definite that a child's symptoms are most likely due to TB and not due to other diagnoses.
To paraphrase Marais and Schaaf, “whereas ultimate epidemic control requires factors to be addressed at a population level, much can be done to alleviate the TB disease burden in children by offering adequate prevention, considering TB in the differential diagnosis, and providing appropriate treatment.”[5]
| References | |  |
| 1. | Kumar A, Gupta D, Nagaraja SB, Singh V, Sethi GR, Prasad J; Indian Academy of Pediatric. Updated national guidelines for pediatric tuberculosis in India, 2012. Indian Pediatr 2013;50:301-6.  |
| 2. | Verghese VP. Diagnosing pulmonary tuberculosis in children. Curr Med Issues 2017;15:106-13. [Full text] |
| 3. | Lancella L, Vecchio AL, Chiappini E, Tadolini M, Cirillo D, Tortoli E, et al. How to manage children who have come into contact with patients affected by tuberculosis. J Clin Tuberc Other Mycobact Dis 2015;1:1-12. |
| 4. | Nguyen TH, Odermatt P, Slesak G, Barennes H. Risk of latent tuberculosis infection in children living in households with tuberculosis patients: A cross sectional survey in remote northern Lao People's Democratic Republic. BMC Infect Dis 2009;9:96. |
| 5. | Marais BJ, Schaaf HS. Tuberculosis in children. Cold Spring Harb Perspect Med 2014;4:a017855. |
| 6. | Zar HJ, Cotton MF, Strauss S, Karpakis J, Hussey G, Schaaf HS, et al. Effect of isoniazid prophylaxis on mortality and incidence of tuberculosis in children with HIV: Randomised controlled trial. BMJ 2007;334:136. |
| 7. | John TJ. Tuberculosis control in India: Why are we failing? Indian Pediatr 2014;51:523-7. |
| 8. | Saukkonen JJ, Cohn DL, Jasmer RM, Schenker S, Jereb JA, Nolan CM, et al. An official ATS statement: Hepatotoxicity of antituberculosis therapy. Am J Respir Crit Care Med 2006;174:935-52. |
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