Getting a QuantiFERON Gold test is straightforward: you can order one through your doctor, a walk-in clinic, or directly from a consumer lab service like Quest Health without a physician visit. The test requires a single blood draw at a lab or clinic, with results typically available within a few business days.
The QuantiFERON-TB Gold Plus (often called QFT-Plus) is a blood test that detects tuberculosis infection. It’s used as an alternative to the traditional TB skin test (the PPD or Mantoux test) and is the preferred option for many people, especially those who’ve received the BCG vaccine common in countries outside the United States.
Who Needs This Test
Most people searching for a QuantiFERON Gold test need it for employment screening, school enrollment, immigration requirements, or because a healthcare provider identified them as higher risk for TB exposure. Healthcare workers, people who’ve recently traveled to countries where TB is common, and anyone with a weakened immune system are frequently asked to get tested.
The U.S. Preventive Services Task Force recommends TB testing for people at increased risk of infection. Joint guidelines from the American Thoracic Society, the Infectious Diseases Society of America, and the CDC specifically recommend the blood test over the traditional skin test for anyone five years or older who has a history of BCG vaccination or is at low to intermediate risk of progressing to active TB.
Where to Get the Test
You have several options depending on your situation, timeline, and budget.
Your primary care doctor or a walk-in clinic: Any physician or nurse practitioner can order the test. They’ll write a lab order, and you’ll go to a nearby lab for the blood draw. This is the most common route if you have insurance, since the office visit and lab work may be covered.
Urgent care centers: Many urgent care locations can order and collect the blood draw on-site or send you to a partner lab. This works well if you need the test quickly and don’t have a regular doctor.
Direct-to-consumer lab orders: Quest Health sells the TB blood test online without requiring a doctor’s visit. You purchase the test, visit a nearby Quest Diagnostics location for the blood draw, and get your results. An independent healthcare provider is still involved in reviewing the order behind the scenes, but you don’t need to schedule a separate appointment with your own doctor. Quest is the only national reference lab offering both the QuantiFERON Gold Plus and the T-SPOT TB test.
Public health departments: Local and county health departments often provide TB testing at low or no cost, particularly for people without insurance. Availability varies by location, so call ahead to confirm they offer the blood test rather than only the skin test.
What the Blood Draw Involves
The test itself is a simple blood draw from a vein in your arm, similar to any routine lab work. What makes it slightly different is the collection tubes. The lab technician draws blood into up to four specialized tubes, each containing different substances that stimulate your immune cells in specific ways. Each tube collects about 1 mL of blood, so the total amount drawn is small.
After filling each tube, the technician shakes it to coat the inner surface with blood. This mixing step is important for accurate results. If the draw is done using a butterfly needle (common for people with smaller veins), the technician will fill a separate empty tube first to prime the tubing before collecting the specialized QFT tubes.
The entire process takes just a few minutes. You only need one visit, unlike the TB skin test, which requires you to return 48 to 72 hours later for a reading.
No Special Preparation Needed
You don’t need to fast, stop any medications, or do anything special before the test. There are no dietary or medication restrictions. Just show up for your appointment and get the blood draw done.
How Long Results Take
Expect results within about four business days after the lab receives your blood sample. Depending on where you had the draw done, add a day or two for shipping to the reference lab. Your ordering provider or the consumer lab portal will notify you when results are ready.
Understanding Your Results
Results come back as one of three categories: negative, positive, or indeterminate.
- Negative means your immune cells did not react to TB-specific proteins, indicating you most likely do not have a TB infection.
- Positive means your immune cells recognized TB proteins, which indicates you’ve been infected with TB bacteria at some point. A positive result does not tell you whether the infection is latent (dormant and not contagious) or active (causing symptoms and potentially contagious). Your provider will order a chest X-ray and possibly other tests to figure that out.
- Indeterminate means the test couldn’t produce a reliable result, often due to a weakened immune system or a problem with the blood sample. You’ll likely need to repeat the test.
Why Choose the Blood Test Over the Skin Test
The traditional TB skin test (TST) injects a small amount of protein under your skin and measures the reaction two to three days later. The problem is that many of those proteins also exist in the BCG vaccine and in harmless environmental bacteria, leading to false-positive results. If you grew up in a country where BCG vaccination is routine (most of Latin America, Asia, Africa, and parts of Europe), a skin test may flag you as positive even though you don’t have TB.
The QuantiFERON Gold test uses antigens unique to the actual TB bacterium, which makes it far more specific. It won’t react to a prior BCG vaccination. It also eliminates the subjectivity of reading a skin bump and removes the need for a second visit. For most adults, it’s the more practical and more accurate option.
Cost Without Insurance
If you’re paying out of pocket, the QuantiFERON Gold test typically costs between $75 and $200 depending on the lab and whether you’re ordering through a direct-to-consumer service or going through a clinic. Public health departments may offer it free or on a sliding scale. If your employer or school requires the test, check whether they’ll cover or reimburse the cost before paying out of pocket.