USCIS Quality Control & Assurance 2

Question 1

What is the primary purpose of running a control serum alongside patient samples in a USCIS civil surgeon laboratory test?

Accepted Answer

To verify that the assay is performing within acceptable limits

Answer

Control sera are run to confirm the assay is functioning correctly before patient results are reported.

Question 2

A civil surgeon's lab uses a commercial TB IGRA kit. The kit insert states results are invalid if the positive control OD is below 0.8. The run shows a positive control OD of 0.6. What is the correct action?

Accepted Answer

Repeat the entire run with a new kit lot or after troubleshooting

Answer

A failed positive control invalidates the entire run; the test must be repeated after identifying the cause.

Question 3

Which document typically defines the acceptable range for a laboratory's quality control results?

Accepted Answer

The laboratory's standard operating procedure (SOP)

Answer

SOPs specify control ranges, corrective actions, and documentation requirements for each test.

Question 4

When reviewing syphilis screening results for I-693 purposes, a civil surgeon notices the RPR titer has doubled from the previous visit. What does this suggest?

Accepted Answer

There may be active or reinfection with syphilis

Answer

A fourfold (two-dilution) rise in RPR titer generally indicates active infection or reinfection.

Question 5

A clinic performing I-693 examinations discovers that refrigerated vaccine vials were stored at 10°C instead of the required 2–8°C. What quality assurance step must occur?

Accepted Answer

Document the excursion and contact the manufacturer or public health authority for guidance

Answer

Temperature excursions must be documented and the manufacturer or health authority consulted to determine vaccine viability.

USCIS - Medical Exam Practice Test

USCIS - Medical Exam Practice Test

USCIS Quality Control & Assurance 2