If you oversee Tuberculosis (TB) testing for current employees and candidates, you know how important it is to keep the process running smoothly and keep everything on track. While ordering and tracking TB tests can involve tight timelines and careful coordination, employers are finding opportunities to streamline the process and improve the experience for both internal HR teams and candidates. With the right approach, TB testing can be managed efficiently and with greater confidence for everyone involved.
There are two types of TB testing, blood testing and skin testing. Either type can detect both active and latent (currently inactive) TB. However, skin and blood testing are not interchangeable in all cases, making it important to know when to use one or the other.
When testing a current employee or job candidate for tuberculosis, a small protein solution injection is placed just under the skin of the individual’s forearm. If a raised bump appears, it may be a sign that the individual has tuberculosis.
In the United States, TB is relatively uncommon, so for most healthy individuals, a bump larger than 15 millimeters typically suggests an infection. For others, like those vaccinated, exposed to TB, or in a country where TB infection is more common, a smaller bump might be significant. Simple enough, but the details for the follow-up for skin testing are where the process often becomes frustrating and time-consuming for employers.
After the injection, the employee or candidate must return to the lab so a technician can inspect the site. The timing is strict, and the test must be read between 48 and 72 hours after the injection. This means that at least two visits are required, and if the employee or candidate misses the window, the entire process must be restarted.
The advantages of TB skin testing:
The cons of TB skin testing:
TB blood testing approaches the process from a different angle. Instead of relying on a visible skin reaction like TB skin testing, blood is drawn and then analyzed in a laboratory setting to measure how the employee or job candidate’s immune system responds to TB-specific antigens. If an immune response is present when exposed to TB antigens, it may indicate a TB infection.
Blood testing is typically a simpler and quicker process for employers. Blood samples only need to be collected once and sent to a lab. The result is then reported without requiring the employee or candidate to return for a second appointment. There is no injection site to monitor, no narrow return window to manage, and most notably, no need to entirely restart the process if someone misses a follow-up visit.
This testing method is also unaffected by prior BCG vaccination, which removes one of the most common sources of false positives seen with skin testing. Because the results are generated by a laboratory rather than visual interpretation, they tend to be more consistent and less subjective.
The advantages of TB blood testing:
• Only one visit is usually required
• Results are not affected by a previous BCG vaccination
• Lab-based analysis (as opposed to a visual observation) often gives a more reliable reading
The cons of TB blood testing:
• Higher cost per test
• Requires lab processing and access to blood draw services that may not be as widely available as TB skin testing
• Blood testing may not explicitly be accepted for some site-specific or compliance requirements
While positive results for either type of test mean that TB is likely in the body, neither testing type can differentiate whether TB is active or latent. Confirming whether TB is active or latent can be done through a chest X-ray. Unusual nodules, lesions, or inflammation indicate that TB is active and might require further testing and caution to avoid spreading, while a clear X-ray indicates latent TB that may require further treatment but is not contagious.
Whether a role requires TB skin tests or allows for TB blood testing, having a system in place to simplify the process can help avoid delayed start dates and reclaim time in your day. Understanding the timeframe and requirements from the start can help your team avoid wasted time and potentially delayed job placements, as well as delays for candidates and employees.
At Verified Credentials, we offer both a la carte and custom packages that allow you to deploy TB skin testing, TB blood testing, or chest X-rays with just a few clicks to initiate the process.
Keeping candidates and employees on track helps your team stay efficient and avoids having to restart the process. Candidates get clear, step-by-step guidance, and with our Employment Screening platform, you can view results in real-time to support on-time job placements.
Ready to start reclaiming your time with more efficient TB testing? Connect with our team to see how it works.