RECENT ADVANCES IN DIAGNOSIS OF SEXUALLY-TRANSMITTED DISEASES

In an effort to better diagnose, treat, and control sexually transmitt ed diseases (STD), a number of new diagnostic assays using molecular t echniques have been developed. By incorporating molecular amplificatio n, the sensitivity for detecting sexually transmitted infections has b ecome markedly enhanced, and organisms that were difficult or impossib le to cultivate, such as human papillomavirus (HPV) or Treponema palli dum can now be detected and monitored. By using polymerase chain react ion (PCR) or ligase chain reaction (LCR), the sensitivity of detecting some pathogens is comparable to, or in some cases better than, direct in vitro cultivation of the agent. DNA fingerprint analysis of amplif ied microbial DNA also has been effectively used for detailed study of the epidemiology and pathophysiology of sexually transmitted infectio ns. In addition to direct detection, molecular techniques have been us ed to enhance serologic techniques by use of cloned proteins and recom binant antigens. These techniques have enabled investigators to differ entiate infection caused by closely related pathogens, such as human i mmunodeficiency virus type 1 (HIV-1) and HIV-2 and human T-cell lympho trophic virus type 1 (HTLV-1) and HTLV-2. As a consequence of these mo lecular tools, the diagnostic repertoire of the clinical laboratory fo r the diagnosis of STD will expand significantly, allowing investigato rs to better diagnose and more effectively control the spread of STD. However, with such new technology, new problems and challenges have ar isen, such as the risk of sample contamination resulting in false-posi tive results, and the presence of inhibitors resulting in false-negati ve results. To effectively use these molecular diagnostic assays, a co ncerted international effort will be required to help evaluate these n ew assays and to define their place in the clinical arena.