The number of cases of tuberculosis in children of age younger than five years in cities has increased 94.3% in the last four years.
Normally, the inhalation of organisms into the lung initiates tuberculosis. During an incubation period, that lasts 2 to 10 weeks, the organisms spread to the hilar lymph nodes. This condition is considered primary tuberculosis. During the incubation period, the purified protein derivative (PPD) test usually becomes positive.
Primary tuberculosis is often completely asymptomatic, and the chest radiograph may be only minimally abnormal, with hilar adenopathy, and/or small parenchymal infiltrates.
Healed primary tuberculosis may leave calcified deposits in the lung parenchyma and/or hilum.
Extrapulmonary disease is more common in children than in adults. In children, 25% of tuberculosis disease is extrapulmonary. Children and young adolescents are more likely than adults to have tuberculous meningitis, miliary tuberculosis, adenitis,and bone and joint infections.
Reactivation is most likely to occur during adolescence, during an episode of immunosuppression, in the presence of chronic disease, or in the elderly.
Diagnosis of tuberculosis in children
1. Children exposed to tuberculosis
All household contacts of adults with active disease should be tested by PPD (purified protein derivative). Thirty to 50% of all household contacts of infectious adults will have a positive PPD.
The PPD is repeated in 3 months to check for conversion to a positive PPD test, which would indicate infection. If the repeat PPD test remains negative, the child is assumed not to be infected, and prophylactic therapy can be discontinued. If the repeat PPD test is positive, the child should be treated for 9 months.
Any child with a positive PPD test should be evaluated for active pulmonary and extrapulmonary tuberculosis with a historyand physical examination and postero anterior and lateral chest radiographs.
The source of the child's infection should be determined. Also, contact with the person with contagious tuberculosis who infected the child must be prevented until the source case is no longer infectious.
2. Children at risk for infection
A purified protein derivative (PPD) test is recommended for children in high-risk groups.
The size of the PPD reaction determined to be positive varies with the risk of tuberculous infection. The diameter of the induration is measured 48 to 72 hours after PPD placement. A positive PPD test requires an evaluation for tuberculous disease.
Previous vaccination with bacille Calmette-Guerin (BCG) vaccine does not change the interpretation of the PPD test.
High tuberculous infection rates occur in Southeast Asia, Africa, Eastern Mediterranean countries, Western Pacific countries, Mexico, the Caribbean, and South and Central America.
Clinical evidence suggestive of tuberculosis
Tuberculosis must be considered when a child presents with pneumonia that is unresponsive to antibiotic treatment, aseptic meningitis, joint or bone infection, hilar or cervical adenopathy, or pleural effusion.
Evaluation of tuberculosis in children
The work-up for a child with a positive PPD test or suspected tuberculosis includes the following:
: Risk factors for exposure to tuberculosis; symptoms of tuberculosis; adult source case.
2. Physical examination
: Adenopathy, positive respiratory system findings, bone or joint disease, meningitis.
3. Diagnostic tests
Treatment of active tuberculosis
- a. Chest x-ray (posteroanterior and lateral).
- b. Gastric aspirates in children who are too young to produce a deep sputum sample
- c. Sputum collection or induction in children who are able to produce a deep sputum sample.
- d. Cultures and smears of appropriate body fluidsinchildrenwithsuspected extrapulmonary
Treatments should be directly observed to ensure compliance. If possible, the susceptibility results of the adult source case should guide the medication choice.
Children with a positive PPD test, but no signs of active disease should receive isoniazid for 9 months if they are younger than 18 years and for at least 6 months if they are 18 years of age or older. Exposure to drug-resistant tuberculosis requires more specific therapy.
The child with tuberculous infection or disease may return to school or child care after drug therapy has been initiated and clinical symptoms have resolved. HIV testing should be completed for any older child or adult with tuberculosis.