Rapid Syphilis Screening Useful in Community-based Clinics and Organizations

Rapid syphilis screening tests can be useful in community-based facilities, according to the results of five studies presented in a mini-plenary on September 22 at the Centers for Disease Control and Prevention 2016 STD Prevention Conference in Atlanta, Georgia.

Rocky Block, MPH, training coordinator, STD/HIV Program, Louisiana Office of Public Health (OPH), New Orleans, LA, and colleagues screened people who might not otherwise be tested for syphilis in a pilot study of rapid testing and they identified 20 new syphilis cases.

In 2014, Louisiana had the second-highest rate of primary and secondary syphilis cases in the United States. The OPH aimed to reduce these rates and provide rapid syphilis testing for people who might not take part in traditional lab-based screening,

The agency’s pilot study of Syphilis Health Check (Diagnostics Direct, Cape May Court House, New Jersey) rapid syphilis test (RST) was carried out in community-based organizations (CBOs) that had clinical wellness centers providing HIV and STD screening services for men who have sex with (MSM) and people who are transgender; and the CBOs began to offer rapid syphilis testing at their main office. To increase the number of tests the agency could provide, the program trained clinical and non-clinical staff on how to screen.

Of the 1,234 rapid tests carried out between October 2015 and February 2016, 54 results were positive and 30 were confirmed positive. Overall, 20 of the confirmed cases were new syphilis diagnoses and 10 cases had previously been diagnosed and treated.

Beth Butler, BA, division director, Division of TB/STD, Pennsylvania Department of Health, Harrisburg PA, and colleagues found that, in order to expedite treatment, an RST is the best choice in some settings, such as in outreach and other venues where syphilis tests are being offered to people at high risk and where following up with those who test positive will be difficult.

Between 2014 and 2015, the Pennsylvania STD Program reported a 52% increase of primary and secondary syphilis from 223 (205 male) to 337 (313 male) cases, the highest number of reported cases in Pennsylvania outside of Philadelphia. Younger people were increasingly becoming infected, with those under age 30 accounting for 58% of reported cases. Due to the fact that males were predominantly infected, the researchers rolled out the Syphilis Health Check RST in phases among male test participants at gay campgrounds, STD clinics targeted to MSM patients, and high-yield chlamydia and gonorrhea screening sites.

Of the 698 tests performed between May and December 2015, 4.1% (29 people) tested positive by RST. Of those, 52% were confirmed positive through RSA and 48% tested negative through RSA.

Of the 824 tests performed between January and August 2016, 2.54% (21 people) tested positive by RST. Of those, 48% were confirmed positive through RSA, and 43% tested negative through RSA.

The authors found no false negatives, but due to the high false positive rate, they advise that RST should not be the only tool used to diagnose syphilis, and everyone in the study whose RST was positive had their results confirmed through a reverse syphilis algorithm (RSA).

The Department of Health plans to modify the agency’s online reporting system to allow providers to report RST results to its database.

Michele-Corinne Ako, BS, research program coordinator, School of Medicine, Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD, and colleagues explored the potential clinical impact of rapid testing for Chlamydia trachomatis (CT) and Neisseria Gonorrhea (NG), which disproportionately affect women, as well as on antibiotic treatment for STIs in an academic Emergency Department (ED).

"Patients without CT/NG were less likely to receive unnecessary antibiotics in the rapid testing group compared to standard of care [SOC]. Patients with confirmed CT were more likely to receive appropriate antibiotic treatment in the rapid testing group compared to the standard-of care-group," Ako told the audience.

In 2015, the researchers randomized 221 women between the ages of 18 and 50 in the ED who were having pelvic exams and STI testing to either the control group or the rapid-testing group in roughly even numbers.

The control group received SOC nucleic acid amplification tests (NAATs) consisting of polymerase chain reaction CT/NG testing with 2-to-3-day turnaround time. Patients in the rapid-testing group received the SOC test along with a vaginal swab for rapid testing using Xpert CT/NG instrumentation (Cepheid, Sunnyvale California) with 90-minute turnaround.

On chi-square analysis of preliminary results, antibiotic treatment rates for positive CT/NG patients in the rapid-test group improved. From the rapid-test group, 100% of both the 7 CT-positive patients (p<0.017) and the 5 NG-positive patients (p<0.061) received antibiotic treatment.

By contrast, in the control group, only 41.7% of CT-positive patients and 33.3% of NG-positive patients received antibiotics; and 28 (28.6%) of CT and 32 (30.8%) of NG-negative patients in the control group were overtreated.

"The availability of a rapid diagnostic test in such an episodic care setting as an Emergency Department could have significant impact on not just the individual patient, but on antibiotic stewardship," Ako explained.

Charlotte A. Gayos, MS, MPH, DrPH, professor, Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, and her colleagues investigated the clinical performance of a new point-of-care trichomonas assay from vaginal swabs and urine specimens of symptomatic and asymptomatic women and recommend the test as a potentially valuable point-of-care (POC) test in the clinic.

The Solana Point-of-Care Trichomonas Assay (Quidel, San Diego, California) rapid test detects Trichomonas vaginalis (TV) DNA in less than 40 minutes by preparing the specimen and amplifying and detecting trichomonas-target sequence by isothermal helicase-dependent amplification (HDA) and target-specific fluorescence.

For each patient, 4 vaginal swab specimens were clinician-collected and used for reference: wet mount, InPouch TV Culture (BioMed Diagnostics, White City, Oregon), Solana TV assay, and Aptima TV assay (Hologic, Marlborough, Massachusetts). The third swab was used for the Solana assay and the fourth was used for the Aptima assay. A first-catch urine was collected from each woman and tested by all four methods. Sensitivity/specificity calculations were based on an FDA-composite reference method (wet mount and InPouch TV culture), and a specimen was considered positive if either test was positive.

From the clinician-collected vaginal swabs and urine samples of 501 asymptomatic and 543 symptomatic women, the prevalence of TV by vaginal swabs and/or urine samples was 11.5%. The Solana assay showed high sensitivity/specificity in the swabs from asymptomatic (100%/98.9%, respectively) and symptomatic (98.6%/98.5%) patients as well as from the urine samples of asymptomatic (98.0%/98.4%) and symptomatic (92.9%/97.9%) patients, compared to the FDA-composite reference method. The sensitivity/specificity was 89.7%/99.0% for swabs and 100%/98.9% for urine samples, compared to the Aptima assay.

The combined sensitivities/specificities were 99.2%/98.7% for swabs and 95.0%/98.2% for urine specimens, and were similar for asymptomatic and symptomatic women. The researchers recommend the Solana assay as a potentially valuable POC test in the clinic.

Brandy Maddox, MPH, MCHES, health scientist, Division of STD Prevention, CDC, Atlanta, GA, talked about her group's study of a national scale-up of a novel dual HIV/Syphilis Rapid Diagnostic Test in Malawi.

The World Health Organization recommends that at least 95% of pregnant women receive syphilis testing at their first antenatal care visit to prevent possible severely adverse pregnancy outcomes.

Pregnant women in Malawi are routinely tested for HIV, but only 10% are tested for syphilis, Maddox told the audience.

Her research team assessed potential barriers to national scale-up of a novel dual-platform rapid diagnostic test (RDT) that integrates syphilis with HIV testing on one device.

Between June and July, 2015, the authors interviewed 25 healthcare providers, lab workers, Ministry of Health leaders, and agency representatives working to prevent mother-to-child syphilis transmission in Malawi. They asked the participants about the importance of RDT, their concerns about obtaining and using RDT, and their recommendations for national expansion.

Overall, the stakeholders acknowledged the importance of dual RDTs for increasing syphilis testing, diagnosis, and treatment, to improve infant outcomes. Most stated that pregnant women would be unwilling to pay for dual RDT so Ministry funding would be necessary, and that a national scale-up would require cost-savings, training of testers, understanding of the populations to be tested, testing guideline and algorithm revision, and a reliable supply chain.

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.

SOURCES: 2016 CDC STD Prevention Conference Program, pp 73-74: Point-of-Care Tests Are Here, But Are They Useful?

(https://www.cdc.gov/stdconference/2016/STD_Conference_2016_Program_Book.pdf )

(Sources for studies: abstracts, slides, audio recordings, interviews)

Presentations:

Rocky Block, MPH, training coordinator, STD/HIV Program, Louisiana Office of Public Health, New Orleans, LA, Using Rapid Syphilis Testing to Increase Screening in Community Based Clinics and Organizations

Beth Butler, BA, division director, Division of TB/STD, Pennsylvania Department of Health, Harrisburg, PA, Rapid Syphilis Testing in the Real World

Michele-Corrine Ako, BS, research program coordinator, School of Medicine, Department of Emergency Medicine, John Hopkins University, Baltimore MD, The Clinical Impact of Rapid Diagnostics on Improving Appropriate Treatment of STIs in Women in the Emergency Department

Charlotte A. Gayos, MS, MPH, DrPH, professor, Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, Clinical Performance of the Solana Point-of-Care Trichomonas Assay from Clinician-Collected Vaginal Swabs and Female Urine Specimens from Symptomatic or Asymptomatic Women

Brandy Maddox, MPH, MCHES, health scientist, Health Services Research and Evaluation Branch/Program Evaulation Team, Division of STD Prevention, CDC, Atlanta, GA, National Scale-up of a Novel Dual HIV/Syphilis Rapid Diagnostic Test: Perspectives of Key Stakeholders in Malawi