|Tuberculosis (Tb) is a serious infection caused by the bacteria Mycobacterium tuberculosis. Unfortunately, the incidence of tuberculosis has been increasing in recent years and there are an increasing number of cases of multi-drug resistance tuberculosis.
Routine testing for Tb with a tuberculin skin test is now only recommended in children who are at high risk for having the illness. Risk factors include being exposed to an infected adult, contact with someone who has been in prison, contact with the homeless, and travel to countries with a high rate of tuberculosis, including Mexico, India, Vietnam, China, Philippines, and many countries in Latin America, Asia, the Middle East and Africa. Adopted children from any high risk area should also be tested, including Romania and Russia.
Also, all contacts of a person with a positive tuberculin skin test should also be tested. Even with a negative test, some younger children may need a chest x-ray and treatment if they were recently exposed to someone with tuberculosis and that person was thought to be contagious. Negative skin tests may need to be repeated in three months.
Testing for tuberculosis is by the tuberculin skin test, which is usually a Mantoux test with 5 units of purified protein derivative (PPD). Other forms of testing are not recommended. After being placed on a child's forearm, the tuberculin skin test should be read 48-72 hours later by experienced personal. Interpretation depends not only on the type of reaction after the test, but also the child's risk of having tuberculosis. A child over 4 years of age with no risk factors may have a small reaction (5-14mm of induration) and not have a tuberculosis infection, while a child who have had close contact with someone with tuberculosis will be considered infected even with a very small reaction (greater than or equal to 5mm induration). Even children who have received the BCG vaccine can have skin testing done.
Children exposed to someone with tuberculosis will likely develop a positive tuberculin skin test about 2-12 weeks later. Some children, especially with immune system problems, can have a negative tuberculin skin test and still be infected with tuberculosis.
Most children with tuberculosis do not have symptoms. They have a positive PPD, a normal chest x-ray and no signs or symptoms of tuberculosis and are said to have a tuberculosis infection or a latent tuberculosis infection. Even though they do not have symptoms, people with a positive PPD need treatment, which usually consists of 9 months of isoniazid (INH). If the infection is thought to be resistant to isonizid, then rifampin may be used for 6 months.
Children with symptoms of tuberculosis, a positive tuberculin skin test and/or a positive chest x-ray are said to have tuberculosis disease. This is more serious than just have a tuberculosis infection. If untreated, children with a tuberculosis infection can develop tuberculosis disease (usually within six months to two years), with symptoms including a cough, fever, night sweats, swollen glands, descreased appetite and activity, weight loss and difficulty breathing.
In addition to the tuberculin skin test, children with tuberculosis disease should have additional testing to try and culture the tuberculosis bacteria so that it can be determined what drugs the infection is sensitive to. Because tuberculosis is a slow growing bacteria, culture can take as long as ten weeks for a final result. To obtain a culture, unless the child has a productive cough and can produce a sputum sample, cultures may need to be obtained from a gastric aspirate in the early morning. Children with tuberculosis disease should also be tested for HIV.
In the lungs, tuberculosis causes the formation of cavitary lesions, pleural effusions and enlarged lymph nodes. These can usually be seen on a chest x-ray. In addition to the pulmonary symptoms described above, tuberculosis disease can also cause meningitis and infections of the ear, kidney, bones and joints.
Treatment for tuberculosis disease is with a long-term use of a combinations of antibiotics, depending on whether or not it is resistant to commonly used drugs. Treatment should be coordinated with your local health department and/or a pediatric infectious disease specialist.
Treatments for tuberculosis disease involving the lungs consists of 6 or 9 months regimens including isoniazid, rifampin and pyrazinamide. Another drug, either ethambutol or streptomycin may be needed for multi-drug resistant Tb. Extrapulmonary tuberculosis disease (either meningitis or infections of the bones or joints) usually includes a 9-12 month regimen of three or four drugs, depending on resistance.
Most people with tuberculosis disease need to undergo directly observed therapy (DOT) in which treatment is observed by a health care worker, either in person or sometimes by video.
Adults with tuberculosis disease are contagious for at least a few weeks after beginning proper treatment. Children with tuberculosis disease are not as contagious, because they usually have smaller lung lesions and do not cough as much.
All cases of tuberculosis infection and disease should be reported to your local health department.
Tuberculosis Internet Resources:
- Tuberculosis Fact Sheet: Tuberculosis information and answers to common questions, including the difference between tuberculosis infection and disease, how it is spread, symptoms, and treatments.
- Chemotherapy for Tuberculosis in Infants and Children : From the American Academy of Pediatrics, treatment guidelines for infants and children with tuberculosis.
- Tuberculosis Overview: An overview of tuberculosis from the NIAID, a component of the National Institutes of Health, supports research on AIDS, tuberculosis and other infectious diseases as well as allergies and immunology. NIH is an agency of the U.S. Department of Health and Human Services.
- Clinical Trials - Tuberculosis: ClinicalTrials.gov - Linking Patients to Medical Research about Tuberculosis.
- Tuberculosis - The Meaning of a Positive Test: "The most commonly used skin test to check for tuberculosis is the PPD. If you have a positive PPD, it means you have been exposed to a person who has tuberculosis and you are now infected with the bacteria that causes the disease."
- Tuberculosis Resources: "CDC's mission includes providing leadership in preventing, controlling, and eventually eliminating tuberculosis (TB) from the United States in collaboration with partners at the community, state, and international levels. The Division of TB Elimination is part of CDC's National Center for HIV, STD and TB Prevention and coordinates CDC's effort in Tuberculosis prevention, control and eventual elimination."
- Pediatric Tuberculosis Fact Sheet: information about tuberculosis in children from the American Lung Association.
- Tuberculosis: This article will provide you with some basic information about tuberculosis.