An overview of CDC's Tuberculosis Technical Instructions for Panel Physicians. Panel physicians must follow the full instructions; this page is not a substitute for them.
What these instructions are
Panel physicians examine people applying abroad for U.S. immigrant or refugee status, and certain non-immigrants who need an overseas medical exam. CDC's Division of Global Migration Health (DGMH) wrote these instructions with U.S. tuberculosis experts and panel physicians. They set out the physicians' duties in testing for and treating infectious tuberculosis disease — TB of the lung tissue, pleura, larynx or chest lymph nodes — and apply only to the immigration exam, not to other settings. Treatment of drug-susceptible TB must follow CDC's Treatment for TB Disease.
They replace all earlier TB instructions. Most parts took effect on January 24, 2024; the requirements for molecular testing, interferon-gamma release assay (IGRA) testing of adults, and the changes to drug susceptibility testing (DST) took effect no later than October 1, 2024.
Who gets which tests
What an applicant needs depends on age and on the WHO-estimated TB incidence in the country of the exam — low burden (under 20 cases per 100,000) or high burden (20 or more).
- Everyone gets a medical history and physical exam.
- Chest x-ray: all applicants 15 and older, in every country.
- IGRA: all applicants 2 and older in high-burden countries.
- Three sputum specimens — for smears, cultures, and a molecular test on the first — for anyone with signs or symptoms of TB, a suggestive chest x-ray, or known HIV infection; positive cultures get DST.
| Low-burden countries | High-burden countries | |
|---|---|---|
| Younger children (under 15 in low-burden; under 2 in high-burden) | history and exam; IGRA (a tuberculin skin test, TST, under age 2) and chest x-ray only if they have signs or symptoms or known HIV | same: history and exam; IGRA or TST and chest x-ray only with signs, symptoms or known HIV |
| Children 2–14 (high-burden) | — | IGRA; chest x-ray if the IGRA is positive, or with signs, symptoms or known HIV |
| Applicants 15 and older | history, exam and chest x-ray | IGRA and chest x-ray, whatever the IGRA result |
TB screening in low-burden countries. CDC.
TB screening in high-burden countries. CDC.
- HIV: HIV testing is not part of U.S. medical screening, but panel physicians may advise it when clinically indicated, with consent that makes clear it is voluntary and that results go on the paperwork. People with HIV are less likely to show an abnormal x-ray or positive IGRA even with TB, so anyone with known HIV must give three sputum specimens whatever the IGRA and x-ray show.
- Extrapulmonary TB only (TB outside the lungs, pleura, larynx and chest lymph nodes): a chest x-ray and three sputum specimens are required regardless.
The exam, step by step
- History: past TB, cough of 3 weeks or more, shortness of breath, weight loss, fever, coughing blood, and past TB treatment or evaluation — and any household contact with TB.
- Physical exam: vital signs, a thorough lung exam, lymph nodes, and scars of scrofula or chest surgery.
- IGRA: tests approved by the FDA or WHO, following the manufacturer's instructions; a documented past positive IGRA can stand in. A TST may be used only under age 2, or with DGMH approval where no IGRA is available.
- Chest x-ray: a posteroanterior view from age 10; under 10, a front view plus a lateral view. Images must be digital (DICOM), read by a board-certified radiologist on a medical-grade monitor. Common bacterial chest infections may be treated with antibiotics, but not fluoroquinolones, which are central to TB treatment. Pregnant applicants may postpone the x-ray until after pregnancy but must have one to immigrate.
Sputum testing
- Three early-morning, fasting specimens of 5–10 mL, collected at least 24 hours apart under direct observation; saliva is not acceptable. People who can't produce sputum may have it induced with hypertonic saline (from age 3); failing that, with DGMH approval, molecular testing of three stool specimens, then gastric aspirates, then bronchoscopy.
- Specimens must reach the lab within 24 hours, refrigerated if not sent within an hour.
- Each specimen gets a smear and three cultures (two solid, one liquid), with species confirmed at least to the M. tuberculosis complex. The first specimen also gets a molecular test (NAAT): a positive result allows treatment to start, but a negative one cannot rule out TB.
- Positive cultures get DST for isoniazid, rifampin, ethambutol, pyrazinamide and a fluoroquinolone, with results within 10 weeks; rifampin-resistant strains are tested against second-line drugs and reported to DGMH within 1 week.
TB classifications
| Classification | Meaning | Travel clearance |
|---|---|---|
| No TB classification | no findings of TB, no known HIV, and normal tests where required | 6 months |
| Class A | infectious TB disease — any positive culture, or a clinical diagnosis | not cleared until treatment is complete |
| Class B0, pulmonary | TB diagnosed and treated with DGMH-defined directly observed therapy (DOT) before immigrating | 3 months from negative end-of-treatment cultures |
| Class B1, pulmonary | signs, symptoms, suggestive x-ray or known HIV, but negative cultures | — |
| Class B1, extrapulmonary | extrapulmonary TB with a normal x-ray and negative cultures | 3 months |
| Class B2, LTBI evaluation | positive IGRA or TST, otherwise no TB disease | — |
| Class B3, contact evaluation | recent contact of someone with infectious TB | — |
A dash means the full instructions set the time.
- Children 10 and under may travel while cultures are pending, if smears and molecular tests are negative and they have no cavities or extensive disease, forceful productive cough, or known contact with multidrug-resistant (MDR) TB — and can see a U.S. provider within days of arrival, as with international adoptees.
- People with a well-documented history of completed TB treatment a year or more earlier, a normal x-ray, no symptoms and no known HIV get no TB classification. Old, dead TB bacteria can make molecular tests falsely positive.
Latent TB and other findings
- Latent TB infection (LTBI) — typically a positive IGRA with a normal x-ray and no symptoms — is not infectious and need not be treated for immigration, but applicants must be told about their diagnosis, treatment options and their local U.S. health department.
- Nontuberculous mycobacteria (NTM) can cause positive smears; physicians use clinical judgment and document them.
- Contacts must get an IGRA within 2 weeks, and further tests as needed. Presumptive LTBI treatment, though not required, should be started overseas for high-risk contacts such as children under 5 and people with weakened immunity.
Treatment by directly observed therapy
- TB disease must be treated by DOT: a health worker watches each dose being swallowed, in person, and records it. Virtual or electronic DOT (watching by phone or another device) and self-administered doses (including over weekends and holidays) do not count.
- Panel physicians must provide DOT, or supervise in-country programs that meet the standard, and use quality-assured drugs. Expert advice is available from the TB Centers of Excellence.
- During treatment, sputum is tested monthly (how many specimens depends on the DST result) and at the end, with an end-of-treatment chest x-ray.
- Applicants who refuse DOT must show detailed treatment records; a doctor's letter is not enough. In exceptional cases, applicants still under treatment may apply for a Class A waiver, with a U.S. physician and health departments accepting responsibility for their care.
- Panel physicians report annually on TB indicators so DGMH can monitor how well the instructions work.
Sources
Based on "Tuberculosis: Technical Instructions for Panel Physicians," Immigrant and Refugee Health, Centers for Disease Control and Prevention; a work of the United States government in the public domain. This page summarizes the instructions and leaves out many operational details.
Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
1
0
0
0
Comments
