Book excerpt: The overarching goal of the work described herein is to investigate strategies for improving the detection and surveillance of multidrug-resistant Neisseria gonorrhoeae (MDRNG) and syphilis, two important sexually transmitted infections. First, we conducted a critical review of the literature to ascertain whether improvements could be made in the way that Neisseria gonorrhoeae is screened and treated. We reviewed the existing literature on the global distribution of MDRNG, current public health surveillance practices, and new methods for detection and molecular characterization of N. gonorrhoeae. Based on a synthesis of this information, we recommended that clinical samples should be screened using rapid molecular testing for known antimicrobial susceptibility markers to enable the treatment paradigm for N. gonorrhoeae to be shifted towards individualized treatment. Next, we conducted studies to provide guidance to public health laboratories to enable them to choose Syphilis screening assays and algorithms that are both cost effective and meet public health goals. First, we compared the performance, cost, and ease of use for three automated treponemal assays: Phoenix Biotech Trep-Sure Syphilis Total Antibody EIA, Siemens Advia Centaur Syphilis, and the DiaSorin Liaison Treponema assay. We found that each of the automated assays performed comparably to the current standard treponemal assay, Treponema pallidum particle agglutination (TP-PA). We also investigated the economic impact of the Los Angeles County Public Health Laboratories (LACPHL) switching from the traditional syphilis-screening algorithm that they currently use to a reverse screening algorithm using laboratory and surveillance data collected during 2015. We found that the reverse algorithm would cost less to implement than the traditional algorithm and could potentially identify more cases of syphilis. Further, modest cost increases for follow-up investigations would be offset by laboratory cost savings. Our modeling methods could be used to determine whether the reverse algorithm is cost-effective for other laboratories. Together, these studies underscore the importance of using evidence-based approaches to determine when public health laboratories should implement new technological advances