Researchers are Improving Chlamydia and Gonorrhea Testing and Treatment

Researchers find that rapid diagnostic testing may be the key to improving testing and treatment for chlamydia and gonorrhea.

Researchers are working to improve the testing and treatment of patients for chlamydia and gonorrhea, and the results of recent studies highlight some areas of progress.

The introduction of rapid diagnostic testing (RDT) can help Emergency Department (ED) providers notify their patients of an infection more quickly and help to treat them appropriately, while avoiding unnecessary antimicrobial use and costs, a new study suggests.

"RDT for NG/CT [Neisseria gonorrhoeae/Chlamydia trachomatis] in the ED significantly improved initial treatment appropriateness by sparing unnecessary antimicrobial use, decreased time to patient notification, and resulted in cost savings," the authors, led by Kaitlyn R. Rivard, PharmD, of the Department of Pharmaceutical Services of Mercy Health Saint Mary's in Grand Rapids, Michigan, wrote in the February 2017 issue of Diagnostic Microbiology & Infectious Disease.

Dr. Rivard and her colleagues assessed the impact of RDT for NG/CT in an urban ED. They used electronic medical records to retrospectively identify all patients 15 years of age and above who were tested for NG/CT during the study period and collected data about the patients and their testing and treatment details.

Overall, 200 consecutive patients in the "RDT" group were tested for NG/CT by RDT in December 2014 and January 2015. These patients were then compared with 200 consecutive patients in the "traditional" historical control group who had been tested between December 2013 and January 2014 using traditional nucleic acid amplification tests (NAAT).

The patients in the RDT group had significantly more appropriate treatment, 72.5% vs 60% (P = .008) and significantly faster test time to results notification (median 17.4 versus 51.5 hours, P = .010).

Patients who received their test results before they were discharged also received more appropriate treatment (odds ratio 22.65 [95% confidence interval, 2.86 to 179.68]), and thus RDT could save approximately $37,000 annually. These results support the use of NG/CT RDT to expand antimicrobial stewardship efforts within the ED.

For the RDT group, testing was performed on male and female urine and endocervical and vaginal swabs. For the traditional group, NAAT testing was performed on male urine or urethral samples and female endocervical samples.

The median time to test results dropped significantly in the RDT group compared with the traditional group: (2.4vs 31.7 hours, P<0.001), as did time to patient notification of positive results (17.4 vs 53.7 hours, P=0.010).

The mean time to appropriate treatment for test-positive patients in the traditional group was 23.0 hours. The mean time to appropriate treatment in the RDT group was 4.9 hours.

Testing via RDT saved $4,891 ($24.46 per patient) over NAAT testing over the course of the study ($343,566 vs $348,457).

Nonculture methods, including NAAT, are widely available for the detection of genital NG/CT and are the preferred diagnostic tests recommended by the Centers for Disease Control and Prevention (CDC). With traditional NAAT, many health care facilities have a turnaround time between 1 and 4 days for results of NG/CT.

However, this prolonged time to results impacts time to patient and partner notification as well as treatment for test-positive patients who do not receive empiric therapy. Meanwhile, excessive empiric antimicrobial use in test-negative patients may contribute to increasing rates of antimicrobial resistance.

Antimicrobial stewardship programs have been developed within hospitals to promote optimal prescribing of antimicrobial agents in an effort to increase efficacy, improve patient safety, and reduce antimicrobial resistance.

The development of RDTs can help to achieve these goals by providing timely detection of infectious organisms and allowing for targeted antibiotic therapy. The Infectious Diseases Society of America and Society for Healthcare Epidemiology of America advocate for the use of RDT to improve detection capabilities and to guide appropriate treatment as part of an antimicrobial stewardship program.

Lorraine L. Janeczko, MPH, is a medical science writer who creates news, continuing medical education and feature content in a wide range of specialties for clinicians, researchers and other readers. She has completed a Master of Public Health degree through the Department of Epidemiology of the Johns Hopkins Bloomberg School of Public Health and a Dana Postdoctoral Fellowship in Preventive Public Health Ophthalmology from the Wilmer Eye Institute, the Johns Hopkins University School of Medicine and the Bloomberg School.