Frequently Asked Questions (FAQs) about Tuberculosis (TB) Screening for International Adoptees
- #7: What does each TB test involve?
- #9: To bring my child to the United States, which TB tests are required?
- #10: How long do the results of the TB tests typically take?
- #17: I have heard of children with TB being granted a waiver to travel to the United States before their TB treatment is complete. What does this waiver process involve, and who qualifies for this waiver?
As a parent adopting a child from a country outside the United States, screening for tuberculosis (TB) is important to protect both the health of your child and people with whom your child interacts. The process can be confusing, so we hope answers to these Frequently Asked Questions (FAQs) are helpful to you and your family.
Tuberculosis (TB) is a disease caused by germs that are spread from person to person through the air. TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. People with TB can die if they do not get treatment.
TB germs get into the air when a person with TB disease in the lungs or throat coughs, sneezes, speaks, or sings. These germs can stay in the air for several hours, depending on the environment. People who breathe in the air containing these TB germs can become infected.
Children can spread TB to others, though the chance of that happening is much less likely than it is for adults who have TB. There have been several cases in which a child was found to be infectious and spread TB to others. These cases highlight the need to use caution when assuming that children with TB cannot spread the disease.
TB is among the top 10 causes of death in the world. Although, the number of TB cases is still declining in the United States, the speed of decline has slowed since 2000. Multidrug-resistant TB (MDR TB) caused by TB germs resistant to the best first-line drugs (isoniazid and rifampin) used for TB treatment remains a concern. This type of TB is both difficult and expensive to treat. Extensively drug-resistant TB (XDR TB) is caused by TB germs resistant to the most effective first- and second-line drugs used to treat TB. Thus, it is much more difficult to treat than MDR TB. Although XDR TB is very rare in the United States, it is much more common in certain parts of the world and the number of cases appears to be rising worldwide.
As required by U.S. law (please see FAQ 15), any child or adult who is becoming a permanent U.S. resident needs an overseas medical exam, which includes testing for TB. This medical exam must be conducted by a specific physician, known as a panel physician.
Several factors that affect the choice of TB tests for children include:
- their age,
- whether they have a known HIV infection, and
- if they have signs or symptoms of TB.
You can visit CDC’s Basic TB Facts to find information about:
- the differences between latent Mycobacterium tuberculosis infection (latent or inactive TB) and TB (also called active TB),
- the signs and symptoms of TB, and
- how TB is spread.
The current TB screening requirements, called the Technical Instructions for Tuberculosis (TB) Screening and Treatment using Cultures and Directly Observed Therapy (DOT) were most recently updated in 2009. However, these requirements were first created in 1991 and have been updated throughout the years. These Technical Instructions have been implemented on a country-by-country basis since 2007. As of October 1, 2013 the Technical Instructions are being used by all countries that screen immigrants and refugees coming to the United States. These Technical Instructions include tests and procedures for diagnosing TB sooner and more accurately.
Tuberculin Skin Test (TST)
- This test is performed by a health care worker, who injects a small amount of fluid (called tuberculin) into the skin of your child’s lower arm.
- After 48-72 hours, your child returns to the health care worker, who looks for a raised, hard area or swelling and if present, measures its size with a ruler. A raised area measuring 10 millimeters or more is a positive TST test result.
Interferon Gamma Release Assay (IGRA)
- This is a blood test that can be conducted instead of a TST to detect and measure your child’s immune response to TB bacteria.
- Under the direct observation of a health care provider, three samples of your child’s sputum (mucus that is coughed up) are collected and tested for TB bacteria.
- Children who are unable to cough up enough sputum for testing have the options of sputum induction or an early morning gastric aspirate.
- In sputum induction, your child is given an inhaler with saline solution (a mixture of salt and water) to help him or her cough up sputum.
- In an early morning gastric aspirate, a tube is passed through your child’s nose and used to collect mucus from your child’s stomach. This method can be very helpful if your child is young and has difficulty following directions to cough. While your child will be awake for this procedure, the panel physician will take care to ensure your child is as comfortable as possible.
- To confirm whether your child has TB, the sputum sample is examined for TB bacteria under a microscope.
- The combination of the sputum smears and sputum cultures tests is the most accurate way for doctors to determine whether your child has TB.
- To confirm whether your child has TB, the sputum sample is stored in a lab for 8 weeks, where medical professionals watch for the growth of TB bacteria.
- If your child has TB, the bacteria should grow and be visible within 2-8 weeks which means a positive diagnosis. Because TB bacteria often grow slowly, a full 8 weeks must pass to allow the bacteria to grow.
- If your child does not have TB, no growth of the bacteria will be present by the end of 8 weeks which means a negative diagnosis.
Drug Susceptibility Test
- If your child has a positive sputum culture, this laboratory test determines which medications can kill the TB bacteria. Based on the results of this test, your child will be given the TB medications that are most effective against their TB.
TB is treated with a combination of antibiotics determined by your child’s strain of TB. If your child is receiving medication to treat TB, a health care worker or other trained person will watch your child swallow each dose of medication. This treatment is called Directly Observed Therapy (DOT) and is the standard care. DOT typically takes at least 6 months to complete.
For children WITHOUT known HIV infection:
- <2 years old: No tests unless child has signs or symptoms of TB or has been in contact with a person with TB.
- 2-14 years old: TST or IGRA* (if positive) → Chest X-ray* (if positive) → sputum smear and cultures (if positive) → DST → DOT
- 15 years old & up: Chest X-ray* (if positive) → sputum smear and cultures (if positive) → DST → DOT
For children WITH known HIV infection:
- <15 years old: TST or IGRA → chest X-ray✝ → sputum smear and cultures (if positive) → DST → DOT
- 15 years old & up: Chest X-ray✝ →sputum smear and cultures ✝ (if positive) → DST → DOT
|TB Test||Time typically required|
|Tuberculin Skin Test (TST)||2-3 days|
|Interferon Gamma Release Assay (IGRA)||less than a week|
|Chest X-ray||same day|
|Sputum smears||3 days after last sputum collection|
|Sputum culture||8 weeks|
|Drug Susceptibility Test (DST)||2-4 weeks|
TB is the leading cause of death among people with known HIV infection and one of the most common infections for people with weakened immune systems. Additionally, HIV infection is the most common risk factor that can cause latent (inactive) TB infection to become (active) TB. Without treatment, TB can be fatal. Therefore, it is especially important for people with known HIV infection to be tested for TB.
Because HIV infection weakens a person’s immune system, and some of the TB tests measure a person’s immune response to the TB bacteria, people with known HIV infection and TB may
- test negative on the tuberculin skin test (TST), the interferon gamma release assay (IGRA), and the chest X-ray, BUT
- test positive on the sputum smear and sputum culture.
Therefore, to accurately determine whether people with known HIV infection have TB and receive the appropriate medical care as quickly as possible, they are required to receive multiple tests (please see FAQ 9).
12. My child with known HIV infection is required to have a sputum test even if his or her chest X-ray is normal. Why can’t the chest X-ray be skipped?
If your child has a known HIV infection, he or she must have 1. a TST or IGRA (if younger than 15 years) and 2. a chest X-ray before the sputum tests. Your child must have a chest X-ray because the chest X-ray helps the panel physician determine if your child currently has TB or has had TB in the past. Children who are diagnosed with TB and receive treatment often have a second chest X-ray. Comparing the chest X-rays taken before and after treatment can help the panel physician determine whether the medication your child is taking is effectively curing the TB infection.
13. I understand other faster tests are approved for diagnosing TB that can significantly reduce the time it takes to get results back. Why are these tests not being used by panel physicians for clearing my child to travel to the United States?
In recent years, molecular tests for TB (such as the GeneXpert MTB/RIF® and the Hain GenoType® MTBDR plus assay) have been developed to help diagnose patients more quickly. While the results of these rapid tests are available more quickly than the results of the sputum culture test, studies have shown that they are less accurate than sputum culture tests. Panel physicians conducting the TB testing for your child may use a rapid test to determine presence of a TB infection in order to begin treatment as quickly as possible. However, because the molecular tests cannot detect TB as well as the sputum culture, a negative molecular test result does not completely rule out that your child has TB. Therefore, sputum culture testing must still be completed before your child can be cleared for travel to the United States.
The panel physician will conduct several tests to see if your child has TB. If your child’s sputum cultures and sputum smears test positive for TB or if your child has signs or symptoms of TB (regardless of laboratory tests), the panel physician may determine that having your child start treatment (Directly Observed Therapy, or DOT – please see FAQ 8) is the best course of action. In these situations, TB treatment must begin overseas.
15. Prior to adoption, my child visited my family in the United States with a hosting program and was not required to have TB testing. Why must my child now undergo testing before being cleared for travel to the United States?
Children participating in hosting programs usually visit the United States on tourist visas. Under the Immigration and Nationality Act, people applying for a tourist visa are not required to have a medical examination. However, also under this Act, people becoming permanent U.S. residents, such as your child, are required to have an immigrant visa. To apply for an immigrant visa, your child is required to have a medical exam, which includes testing for TB.
16. After arriving in the country of adoption, do I have to wait until after the adoption paperwork is finalized to begin the TB testing process?
You may not have to wait. In many countries, CDC has worked with the adoption agencies, U.S. Consular Sections, and panel physicians to have children evaluated by a panel physician before the adoption process is complete. The adoption agency, orphanage, or the Consular Section of the U.S. Embassy with whom you are working in the home country of your child will be able to help with having the required medical exam performed before you arrive in the United States.
17. I have heard of children with TB being granted a waiver to travel to the United States before their TB treatment is complete. What does this waiver process involve, and who qualifies for this waiver?
People who have TB and who are applying to come to the United States as immigrants must complete their medical treatment (please see FAQ 8) before traveling to the United States. However, for people with TB whose medical situations suggest that they would benefit from receiving their TB treatment in the United States, the U.S. Citizenship and Immigration Services (USCIS) of the Department of Homeland Security may grant a waiver (also called a Class A waiver) allowing them to travel to the United States before the end of their TB treatment.
For additional information about the waiver process for your child, please visit: International Adoption: Health Guidance and the Immigration Process.
- Centers for Disease Control and Prevention. Tuberculosis Screening and Treatment (TB TIs) Using Cultures and Directly Observed Therapy (DOT) Frequently Asked Questions (FAQ). Centers for Disease Control and Prevention Home. https://www.cdc.gov/immigrantrefugeehealth/exams/ti/panel/tuberculosis-panel-technical-instructions-faq.html. 2010. Cited July 5, 2013.
- Centers for Disease Control and Prevention. Tuberculosis (TB). Centers for Disease Control and Prevention Home. https://www.cdc.gov/tb/topic/basics/default.htm. 2013. Cited July 5, 2013.
- U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention Annual Report Fiscal Year 2012. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. https://www.cdc.gov/nchhstp/publications/docs/NCHHSTP-AnnualReport-2012-508.pdf. 2012. Cited July 8, 2013.
- Centers for Disease Control and Prevention. Test for Tuberculosis (TB). Centers for Disease Control and Prevention Home. https://www.cdc.gov/tb/publications/factsheets/testing/TB_testing.htm. 2012. Cited July 8, 2013.
- Centers for Disease Control and Prevention. Technical Instructions. Centers for Disease Control and Prevention Home. https://www.cdc.gov/immigrantrefugeehealth/exams/ti/panel/technical-instructions/panel-physicians/introduction-background.html. 2012. Cited July 8, 2013.
- Page last reviewed: April 24, 2015
- Page last updated: April 28, 2015
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