Medical Xpress (12.12.2013)
Aids Weekly Plus
An article in Medical Xpress reported on a new rapid and sensitive test of Chlamydia trachomatis, the most common sexually transmitted infection. Chlamydia affects approximately 5–10 percent of the population, particularly young adults under 25. In many cases, individual have few or no symptoms and are unaware of the infection. It can cause urethritis in men and inflammation of the reproductive organs—uterine, cervical, and pelvic inflammation—in women. The disease also can cause ectopic pregnancy and infertility in women.
The test uses recombinase polymerase amplification, a nucleic acid amplification technique, to find the infection in urine samples. It does not require purification of total DNA from the urine sample; therefore, it does not require specialized equipment. Heating the sample for five minutes at 90 degrees Celsius releases sufficient amplification target to make a diagnosis of chlamydia. The test takes fewer than 20 minutes and can be performed at point-of-care (POC) during the patient’s visit. According to Ülo Langel, PhD, professor of molecular biotechnology at the University of Tartu in Estonia and professor of neurochemistry at Stockholm University in Sweden, the assay’s sensitivity levels are significantly higher than those of current assays.
Current polymerase chain reaction-based tests are suitable for use in medical facilities with trained staff and expensive machinery. Also, existing rapid diagnosis POC tests are less sensitive than hospital-based tests, with a sensitivity of 10–40 percent. The new assay indicated a specificity of 100 percent and sensitivity of 83 percent in recent tests.
The full report, “Sensitive and Rapid Detection of Chlamydia Trachomatis by Recombinase Polymerase Amplification Directly from Urine Samples," was published online in the Journal of Molecular Diagnostics (2014; doi: 10.1016/j.jmoldx.2013.08.003).