The Role of PCR in the Diagnosis of Infectious Disease

Infectious agents such as HIV1, hepatitis B virus2, Chlamydia trachomatis3, Mycobacterium tuberculosis4, Plasmodium falciparum5, and anthrax6—just to name a few—can all be detected thanks to the use of polymerase chain reaction (PCR) in analyzing clinical specimens.

In addition to diagnostic applications, PCR has been used for the quantitative measure of viral load in order to monitor response to therapy for patients with HIV.

In other infectious disease such as malaria, PCR-based methods are used to complement microscopic analysis of blood, which is the standard for malaria detection. PCR technology allows rapid identification of malaria species, which is important in case of mixed infection and determining the type of drug treatment to use.

When detecting for anthrax, PCR has replaced the conventional culture method of using a specimen to grow the bacteria in the lab. What used to take weeks can now provide accurate same-day results with PCR-based assays.

Employing appropriate primers, PCR can be applied to test for a range of organisms in a routine diagnostic laboratory. Currently, 63% of invasive meningococcal disease and about 70% of cases of meningitis are diagnosed using PCR alone7. As PCR technology continues to evolve, its role in diagnosing and managing patients with infectious disease will become even more important.

Citations:

  1. Nolte FS et al. (1998) Clinical comparison of an enhanced-sensitivity branched-DNA assay and reverse transcription-PCR for quantitation of human immunodeficiency virus type 1 RNA in plasma. J. Clin Microbiol 36:716-20.
  2. Pawlotsky JM et al. (1997) What technique should be used for routine detection and quantification of HBV DNA in clinical samples? J Virol Methods 65:245-53.
  3. Vincelette J et al. (1999) Multicenter evaluation of the fully automated COBAS AMPLICOR PCR test for detection of Chlamydia trachomatis in urogenital specimens. J Clin Microbiol 35:402-5.
  4. Piersimoni C et al. (1997) Comparative evaluation of two commercial amplification assays for direct detection of Mycobacterium tuberculosis complex in respiratory specimens. J. Clin Microbiol 35:193-6.
  5. Zhong KJY et al. (1999) Evaluation of a colorimetric PCR-based assay to diagnose Plasmodium falciparum malaria in travelers. J Clin Microbiol 37:339-41.
  6. Bell CA et al. (2002) Detection of Bacillus anthracis DNA by LightCycler PCR. J Clin Microbiol 2002 40:2897-2902.
  7. Read SJ et al. (1997) Aseptic meningitis and encephalitis: the role of PCR in the diagnostic laboratory. J Clin Microbiol 35:691-695.