Tuberculosis (TB) is a serious infectious disease that usually attacks the lungs but can spread to other organ systems, including the skeletal system and the central nervous system, where it can cause meningitis, brain abscesses and other major infections. Once a leading cause of death worldwide, tuberculosis was almost wiped out in the United States in the 1950's, thanks to improved sanitation, mandatory pasteurization of commercial milk (since one form of the disease is transmitted by cows) and the advent of antituberculosis drugs.
Unfortunately, a serious resurgence of tuberculosis began in this country in the 1980's. At first limited to high-risk groups (such as immigrants from Southeast Asia, the urban homeless, drug abusers, and people with compromised immune systems, such as people with AIDS), tuberculosis has made steady inroads into low-risk populations in recent years. Therefore, screening for the disease, which is done through a simple skin test, is more important than ever.
WHAT CAUSES TB?
The organism responsible for the disease is called Mycobacterium tuberculosis. This bacterium is spread almost exclusively by infected adolescents, adults and older children. As a rule, small children with the infection are not highly contagious.
TB bacteria pass from person to person via moisture droplets expelled when an infected person coughs or sneezes. Inhalation of these droplets can lead to infection in a previously healthy person.
If all people infected with TB developed symptoms of the disease, its control would be much more straightforward. In reality, however, most people with TB infections do not have symptoms. For that reason, screening tests to detect these latent infections in apparently healthy people are vital to preventing widespread TB. These tests are generally performed as part of routine well-child care at 12 to 15 months of age, before school entry and during adolescence. Early detection and treatment of latent infections can prevent their progression to serious illness.
WHEN SHOULD I SUSPECT TB?
Usually, the only indication is a positive screening test. Signs and symptoms of respiratory illness are the most common manifestations of active infection. These signs include a persistent cough with mucus production, shortness of breath, chest pain, fever (which appears early in the course of the infection and then subsides), and swollen lymph nodes, usually in the chest and underarms. Active infection is most likely to develop if TB exposure occurs in early infancy. Other factors associated with development of active infection include other illnesses and poor nutrition.
IS MEDICAL ATTENTION NECESSARY?
Yes. A child who develops a positive TB test needs additional testing and, in most cases, medication. In addition, all the child's close contacts need to be tested. It is vitally important to identify the adult or older child who is the source of infection, as well as to treat any other members of the family who may have been exposed. In general, even family members who have negative TB tests should undergo antibiotic treatment to prevent infection from taking hold.
HOW CAN THE PEDIATRICIAN TELL IF MY CHILD HAS TB?
After a positive screening test, the pediatrician performs another, more precise skin test to confirm the result. He also evaluates the child's overall health, with special attention to growth and nutritional status and asks questions about recent or ongoing respiratory illnesses in the child and other members of the household. Chest X rays usually are performed as well. Based on the degree of involvement, hospitalization may be needed.
WHAT TREATMENTS ARE AVAILABLE?
Children with positive skin tests who have no signs of active infection need to receive antibiotic treatment. A single drug (usually isoniazid) is prescribed to be taken daily for about a year.
Various combinations of anitbiotics are used to treat active tuberculosis. If the child has symptoms, a brief period of bed rest may be needed. Long-term treatment usually has to continue for 12 to 18 months, even though symptoms subside much sooner. In addition, since small children rarely spread the disease, full participation in school and other activities is usually possible.
SCREENING TESTS FOR TB
In the past, routine annual screening using a multiprong skin patch was recommended for all children beginning at one year of age. Although these tests are still available, their widespread use for children with little risk of contracting TB is discouraged because they are highly unreliable, with a large percentage of both false positive and false negative results. Also, parents do not always comply with instructions or fail to interpret results properly. Thus, annual screening is recommended only for high-risk children, such as those Native Amercicans or minority children who live in impoverished inner city neighborhoods where TB is prevalent. Children of recent immigrants from Asia, Africa, the Middle East, Latin America, or the Caribbean, as well as those living in a household with a TB patient, should also be screened annually. Otherwise, screening at three stages of childhood—12 to 15 months, 4 to 6 years, and 14 to 16 years—is considered sufficient for low-risk children.
The preferred method of testing uses an intradermal, or Mantoux, technique in which a purfied antigen is injected under the skin, and then observed 48 to 72 hours later. Development of a large wheal at the site of injection indicates a need for further diagnostic tests to rule out or confirm TB. If further tests are positive, other household members should be tested, and appropriate treatment or preventative measures undertaken.
GETTING HELP
Call your pediatrician if:
• Your child (or an adult in the child's household) has a positive skin test for TB
• Your child develops a persistent cough, shortness of breath or chest pain
• TB has been diagnosed in any of the child's contacts, including family members, playmates, classmates or babysitters
