Confirmatory test for Lyme disease?

Confirmatory test for Lyme disease?

• A. ELISA
• B. Western blot
• C. PCR
• D. Immunofluorescence

Answer: (B)

Lyme disease serology relies on a two-tier testing approach to balance sensitivity and specificity. A screening test that detects antibodies is good at catching most infections but can yield false positives from other conditions. The confirmatory test is used to verify true infection with a highly specific pattern of antibody responses to multiple Borrelia burgdorferi antigens. The Western blot fits this role because it screens for antibodies against several Borrelia proteins, and a positive pattern of bands provides strong evidence of true Lyme disease, reducing the chance of false positives that can arise with screening alone. PCR detects bacterial DNA and is not routinely used as a general confirmatory test because it may be insensitive in blood and isn’t as reliable for confirming infection across most clinical scenarios; it has limited utility in certain specimens like joint fluid. Immunofluorescence is also not the standard confirmatory method due to variable specificity.

Lyme disease serology relies on a two-tier testing approach to balance sensitivity and specificity. A screening test that detects antibodies is good at catching most infections but can yield false positives from other conditions. The confirmatory test is used to verify true infection with a highly specific pattern of antibody responses to multiple Borrelia burgdorferi antigens. The Western blot fits this role because it screens for antibodies against several Borrelia proteins, and a positive pattern of bands provides strong evidence of true Lyme disease, reducing the chance of false positives that can arise with screening alone.

PCR detects bacterial DNA and is not routinely used as a general confirmatory test because it may be insensitive in blood and isn’t as reliable for confirming infection across most clinical scenarios; it has limited utility in certain specimens like joint fluid. Immunofluorescence is also not the standard confirmatory method due to variable specificity.