Which method is considered the most sensitive for diagnosing CMV infection in clinical specimens?

Which method is considered the most sensitive for diagnosing CMV infection in clinical specimens?

• A. Serology
• B. Virus culture
• C. PCR
• D. Antigen detection

Answer: (C)

PCR detection of CMV DNA is the most sensitive way to diagnose CMV infection in clinical specimens. By amplifying viral genetic material, PCR can identify very small amounts of virus that other methods might miss, making it effective across various sample types such as blood, CSF, and tissues. It also enables quantification, which helps monitor viral load and treatment response. Serology mainly shows whether someone has ever been exposed to CMV and cannot reliably distinguish active infection from past immunity, especially in immunocompromised patients or newborns. Virus culture is accurate but slow and often less practical for timely diagnosis, since it requires viable virus and longer turnaround. Antigen detection detects a CMV protein in leukocytes and depends on leukocyte counts and sample quality, so its sensitivity can be limited.

PCR detection of CMV DNA is the most sensitive way to diagnose CMV infection in clinical specimens. By amplifying viral genetic material, PCR can identify very small amounts of virus that other methods might miss, making it effective across various sample types such as blood, CSF, and tissues. It also enables quantification, which helps monitor viral load and treatment response.

Serology mainly shows whether someone has ever been exposed to CMV and cannot reliably distinguish active infection from past immunity, especially in immunocompromised patients or newborns. Virus culture is accurate but slow and often less practical for timely diagnosis, since it requires viable virus and longer turnaround. Antigen detection detects a CMV protein in leukocytes and depends on leukocyte counts and sample quality, so its sensitivity can be limited.