Accuracy of Screening Tests

Nucleic acid amplification tests (NAATs), such as polymerase chain reaction (PCR) and transcription-mediated amplification (TMA), can identify chlamydial infection in asymptomatic women (nonpregnant and pregnant) and asymptomatic men. NAATs have high sensitivity (>80%) and specificity (>99%) and can be used with urine, vaginal, and cervical swabs (Meyers et al., 2007). It is important to remember that even with a test with high sensitivity, in a low-prevalence population, a positive screening result is more likely to be a false positive than an actual case. When screening a 20-year-old woman with no other risk factors other than her young age, given a prevalence rate of 1%, the positive predictive value for a positive chlamydial screen with an NAAT is only 47%. Point-of-care tests are becoming available that can be conducted in the office setting in about 30 minutes. Their sensitivity remains substantially lower than for laboratory-conducted NAATs, although their specificity is high (Mahi-lum-Tapay et al., 2007).

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How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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