Which of the following is not a disadvantage of using the PCR testing in equine medicine?

• A. False positive reaction
• B. Lack of viable virus isolates
• C. Inability to detect new viruses
• D. Sensitivity of the test

Answer: (D)

PCR testing in equine medicine is valued for its ability to detect viral genetic material with high sensitivity and specificity. This means it can identify infections even when only tiny amounts of viral nucleic acid are present, providing rapid and informative results. However, the method does have limitations: false positive reactions can occur due to contamination or the presence of nonviable viral nucleic acid, you cannot obtain viable virus isolates from a positive PCR result, and standard PCR is designed to detect only known or anticipated sequences, so it may miss new or highly divergent viruses unless assays are updated or broader techniques are used. The idea that high sensitivity is a disadvantage isn’t accurate; it’s a strength that increases the chance of detecting true infections, as long as proper laboratory controls are in place.