QuantiFERON-TB Gold Test in San Leandro: Blood Test for TB

Need a TB blood test for work, school, or immigration? Specifically, this blood test detects TB infection with just one visit. Unlike the skin test, you do not need to come back for a reading. At CityHealth San Leandro, you can walk in and get your QFT the same day.

What Is the QuantiFERON TB Gold Test?

The QuantiFERON TB Gold test (also called QFT-Plus) is a blood test that checks for tuberculosis infection. In short, it works by measuring how your immune system responds to TB bacteria proteins. Specifically, the lab looks for a chemical called interferon-gamma in your blood sample.

Importantly, this test detects both latent TB infection and helps evaluate active TB. Also, QIAGEN manufactures the test, and the FDA has approved it as an alternative to the TB skin test. Because of its accuracy, many employers, schools, and immigration offices now prefer this blood test over the skin test. According to the CDC’s TB testing guidelines, both IGRA blood tests and skin tests are acceptable methods for TB screening.

QFT Blood Test vs. TB Skin Test

If you got the BCG vaccine in your home country, the QFT blood test is your best option. The skin test often gives false positives in BCG-vaccinated people. However, the blood test avoids this problem entirely.

Who Needs a QuantiFERON TB Gold Test?

In fact, many people need TB testing for work, school, or legal reasons. This blood test works in all of these situations:

• Healthcare workers: Most hospitals and health systems require the QFT blood test for new hires and annual screening.
• People vaccinated with BCG: If you got the BCG vaccine abroad, the skin test may give a false positive. The QFT avoids this issue.
• Students: Similarly, some California schools and nursing programs accept QFT results for enrollment.
• Immigration applicants: For the I-693 medical exam, the CDC now requires an IGRA blood test (like the QFT) instead of the skin test for adults.
• Annual employee screening: As a result, one visit is more convenient than two visits for the skin test.
• People with a past positive skin test: Therefore, the QFT can confirm or rule out TB infection.

What to Expect at Your QuantiFERON TB Gold Test Visit

The process is quick and straightforward. Here is what happens step by step:

1. Blood draw: First, a technician collects 3 tubes of blood from your arm. The draw takes about 5 minutes.
2. Lab processing: Next, the lab incubates your blood with TB proteins. This process takes 1 to 3 business days.
3. Results: Finally, CityHealth contacts you with your results. We also provide paperwork for your employer, school, or immigration officer.

Consequently, you do not need a follow-up visit. This is the biggest advantage of the QFT over the skin test.

Understanding Your QFT Results

Your results will fall into one of three categories. Each one means something different.

Negative Result

First, a negative result means the test found no evidence of TB infection. Specifically, you will receive a written negative result for your employer, school, or immigration paperwork. Typically, this is the expected outcome.

Positive Result

Second, a positive result means your body has been exposed to TB bacteria. However, it does not tell you if the TB is latent (dormant) or active. As a result, you will need more testing. Specifically, this usually includes a chest X-ray and a symptom check. In that case, your doctor may recommend treatment to keep it from becoming active.

Indeterminate Result

Third, an indeterminate result means the lab could not read the test clearly. This sometimes happens if your immune system is weak. As a result, your provider will therefore recommend retesting.

How Long Do QFT Results Take?

Results from the QFT typically arrive in 1 to 3 business days. Because the lab needs time to incubate your blood sample and run the analysis. After that, CityHealth will call or message you when your results are ready.

However, if you need results fast, let the front desk know. In some cases, labs can prioritize the sample. However, nevertheless, the standard turnaround is 1 to 3 days.

How Much Does the QFT Cost?

Naturally, the cost depends on your insurance. Most insurance plans cover this test when ordered for work, preventive screening, or medical reasons. CityHealth accepts:

• Blue Shield of California, Aetna, United Healthcare, Cigna
• Medi-Cal (coverage varies by plan; call to verify)
• Self-pay at a flat rate (ask at check-in for pricing)

Without insurance, the QFT at CityHealth costs less than at most hospitals. In addition, you save money because you only need one visit instead of two.

Preparing for Your QFT Visit

First, you do not need to prepare for this test. In other words, there is no fasting required. Also, you do not need to stop any medications. Simply walk into CityHealth during business hours.

However, bring the following if you have them:

• Your insurance card
• Any forms from your employer or school that need to be filled out
• Your photo ID

If you had a positive TB skin test in the past, let the staff know. Because of this, the provider can interpret your results more accurately. In addition, tell them if you take medications that weaken your immune system, since this can affect the test results.

Frequently Asked Questions

How is this test different from a TB skin test?
Essentially, this test needs only one visit. The TB skin test requires an injection plus a return visit 48 to 72 hours later. In addition, the blood test is not affected by prior BCG vaccination, which makes it more accurate for people vaccinated abroad.

Is the QFT accepted for immigration?
Yes. For U.S. immigration medical exams (Form I-693), the CDC now requires IGRA testing (such as the QFT) for adults. However, a USCIS-authorized civil surgeon must perform the exam. Ask CityHealth about our immigration physical services.

Do I need to fast before this test?
No. You do not need to fast or prepare in any way. Just walk in during business hours.