GESTIÓN EN SALUD PÚBLICA: CDC | TB | Tuberculosis in Children in the United States

jueves, 2 de agosto de 2012

CDC | TB | Tuberculosis in Children in the United States

Children

TB in Children in the United States

TB disease in children under 15 years of age (also called pediatric tuberculosis) is a public health problem of special significance because it is a marker for recent transmission of TB. Also of special significance, infants and young children are more likely than older children and adults to develop life-threatening forms of TB disease (e.g., disseminated TB, TB meningitis). Among children, the greatest numbers of TB cases are seen in children less than 5 years of age, and in adolescents older than 10 years of age.

Basic TB Facts

TB is caused by a bacterium called Mycobacterium tuberculosis. TB bacteria are spread from person to person through the air. The TB bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.

People with TB disease of the lungs or throat can spread bacteria to others with whom they spend time every day. However, children are less likely to spread TB bacteria to others. This is because the forms of TB disease most commonly seen in children are usually less infectious than the forms seen in adults.
Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection and TB disease.
More: Basic TB Facts

Latent TB Infection

Persons with latent TB infection:

Usually have a skin test or blood test indicating TB infection;
Have TB bacteria in their bodies, but the bacteria are not active;
Are not sick and do not have symptoms;
Cannot spread bacteria to others; and
Are often given medicine to prevent them from developing TB disease.

TB Disease

If TB bacteria become active in the body and multiply, the person will get sick with TB disease.
Persons with TB disease:

Usually have a skin test or blood test indicating TB infection;
Are sick from TB bacteria that are active (meaning that they are multiplying and destroying tissue in their body);
Usually have symptoms of TB disease; and
Must be given medicine to treat TB disease.

Once infected with TB bacteria, children are more likely to get sick with TB disease and to get sick more quickly than adults. In comparison to children, TB disease in adults is usually due to past TB infection that becomes active years later, when a person’s immune system becomes weak for some reason (e.g., HIV infection, diabetes).
Confirming the diagnosis of TB disease in children with a laboratory test can be challenging. This is because:

It is difficult to collect sputum specimens from infants and young children; and
The laboratory tests used to find TB in sputum are less likely to have a positive result in children; this is due to the fact that children are more likely to have TB disease caused by a smaller number of bacteria (paucibacillary disease).

For these reasons, the diagnosis of TB disease in children is often made without laboratory confirmation and instead based on combination of the following factors:

Clinical signs and symptoms typically associated with TB disease,
Positive tuberculin skin test (TST) or positive TB blood test (IGRA),
Chest x-ray that has patterns typically associated with TB disease, and
History of contact with a person with infectious TB disease.

Testing for TB in Children

In the absence of symptoms, usually the only sign of TB infection is a positive reaction to the TB skin test or TB blood test. TB skin testing is considered safe in children, and is preferred over TB blood tests for children less than 5 years of age.
More: Testing for TB
All children with a positive test for TB infection, symptoms of TB, or a history of contact with a person with infectious TB disease should undergo a medical evaluation. Medical evaluations for TB disease include a chest x-ray and physical examination to exclude TB disease, and must be done before beginning treatment for latent TB infection.
For more information on where to get a TB test, contact your State TB Control Program.

Signs and Symptoms of TB Disease in Children

Signs and symptoms of TB disease in children include:

Cough;
Feelings of sickness or weakness, lethargy, and/or reduced playfulness;
Weight loss or failure to thrive;
Fever; and/or
Night sweats.

The most common form of TB disease occurs in the lungs, but TB disease can affect other parts of the body as well. Symptoms of TB disease in other parts of the body depend on the area affected. Infants, young children, and immunocompromised children (e.g., children with HIV) are at the highest risk of developing the most severe forms of TB such as TB meningitis or disseminated TB disease.

Treatment

A pediatric TB expert should be involved in the treatment of TB in children and in the management of infants, young children, and immunocompromised children who have been exposed to someone with infectious TB disease. It is very important that children or anyone being treated for latent TB infection or TB disease finish the medicine and take the drugs exactly as instructed.

Latent TB Infection

Treatment is recommended for children with latent TB infection to prevent them from developing TB disease. Infants, young children, and immunocompromised children with latent TB infection or children in close contact with someone with infectious TB disease, require special consideration because they are at increased risk for getting TB disease. Consultation with a pediatric TB expert is recommended before treatment begins. Isoniazid is the anti-TB medicine that is most commonly used for treatment of latent TB infection. In children, the recommended length of treatment with isoniazid is 9 months.

TB Disease

TB disease is treated by taking several anti-TB medicines for 6 to 9 months. It is important to note that if a child stops taking the drugs before completion, the child can become sick again. If drugs are not taken correctly, the bacteria that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat, and treatment lasts much longer (up to 18 to 24 months).
More: Treatment

Vaccines

BCG, or bacille Calmette-Guerin, is a vaccine to prevent TB disease. BCG is used in many countries to prevent childhood TB disease. However, the BCG vaccine is not generally used in the United States, because of the low risk of infection with TB bacteria and the variable effectiveness of the vaccine. The BCG vaccine should only be considered for very select persons who meet specific criteria and in consultation with a TB doctor.
More: TB Vaccine (BCG)

Statistics

In the United States, a total of 11,182 cases of TB were reported in 2010, of which 670 (6%) cases were among children less than 15 years of age. Worldwide, it is estimated that there are at least 1 million cases of TB among children less than 15 years of age each year. In high TB burden settings outside of the United States, children account for an estimated 15–20% of TB cases.