Between May 1, 2021–July 31, 2022, four health departments [San Francisco Department of Public Health (San Francisco, California); Maricopa County Department of Public Health (Phoenix, Arizona); Public Health Institute at Denver Health (Denver, Colorado); and DC Health (Washington D.C.)] implemented pharyngeal GC TOC into routine clinical practice at public STD clinics. We conducted a cross-sectional analysis of all pharyngeal GC cases treated at the participating clinics during the study period. Pharyngeal GC episodes, including TOC and all associated follow up data, were included in the analysis if the initial treatment date occurred during the project period.

All patients treated for pharyngeal GC were advised to return in 10–14 days for TOC with a nucleic acid amplification test (NAAT). Strategies for TOC activities such as scheduling TOC visits, tracking patients, follow-up communications to encourage TOC completion, and TOC specimen collection varied by site; all sites employed additional dedicated TOC staff/navigator(s) to perform them (Table 1).¹¹ All sites offered in-clinic TOC by clinician specimen collection or self-collection; two sites also offered TOC via self-collected NAAT outside of the clinic (i.e., home specimen collection kit). Patients with a positive pharyngeal GC TOC were managed per CDC STI Treatment Guidelines and local protocols.^9,11 Patients with positive TOC were asked to return to clinic for further evaluation including consideration for re-treatment (depending on clinical suspicion of false-positive test, re-infection, or treatment failure) and specimen collection for gonococcal culture; initial TOC culture was typically performed at time of repeat TOC NAAT and re-treatment. Antimicrobial susceptibility (AST) by Etest and/or agar dilution was performed by participating sites’ local laboratories if N. gonorrhoeae was isolated from TOC culture; AST results were reported as minimum inhibitory concentrations (MIC) for anti-gonococcal antimicrobials.¹²

Although implementation strategies varied, all sites collected line-listed, de-identified demographic and clinical data for treated pharyngeal GC cases using a standardized data-collection form. Sites assigned a unique identifier to the patient, allowing for longitudinal tracking of patients, and linked the patient’s epidemiologic and clinical data to lab results. For TOC positive cases, additional data were collected including reported sexual activity (i.e., oral, genital, anal sex) between most recent treatment for pharyngeal gonorrhea and TOC, follow-up testing and treatment, and the final case disposition (i.e., the suspected reason for the positive TOC). The final case disposition for the positive pharyngeal GC TOC was determined by the site project staff based on chart reviews and often involved consultation with the clinic medical director.

For male patients, we defined men who have sex with men (MSM) as males that reported only having male sex partners within the past 3 months; men who have sex with men and women (MSMW) were defined as males that reported having male and female sex partners within the past 3 months; and men who have sex with women only (MSW) were defined as males that reported only having female partners in the past 3 months. The TOC response rate was defined as the number of patients that had TOC performed within 1–6 weeks of GC treatment over the total number of patients treated for pharyngeal GC at the participating clinical site. For this analysis, TOC response rate was based on the first TOC performed for a case (initial TOC); data on subsequent TOC visits (follow-up TOC) for patients who tested positive at initial TOC visit were not included. The final case dispositions for cases with positive TOC were classified as 1) reinfection, 2) false-positive due to residual genetic material, 3) treatment failure due to non-recommended regimen, 4) treatment failure to ceftriaxone without resistance (MIC ≤0.25 μg/mL) and 5) treatment failure to ceftriaxone with resistance (MIC >0.25 μg/mL; see Table 2 for final case disposition definitions). Cases with a positive TOC that did not return to clinic for further testing, treatment, or additional evaluation that could inform the suspected reason for the positive test were classified as “insufficient data to disposition.” If cases were dispositioned as “unknown” or “missing” by participating sites, additional review and consultation with CDC clinical project staff were conducted to determine the most likely final case disposition.

To assess perceived feasibility of routine pharyngeal GC TOC implementation, a qualitative project evaluation was conducted with site representatives, including 1–2 staff per site (site project leads for all sites, clinical lead for two sites), that participated in two virtual one-hour qualitative interviews: a mid-project interview in December 2021 and an end-of-project interview in August 2022. A semi-structured interview guide was developed to explore the strengths and limitations of each site’s TOC implementation. Interviews were recorded and sent to a contractor for verbatim transcription. Qualitative data were also collected in final implementation progress reports that were submitted by each of the participating sites. The progress report included free response questions about sustainability of TOC implementation.

We calculated the frequencies of demographic, behavioral, and clinical characteristics of pharyngeal GC cases overall and stratified by pharyngeal GC TOC performed. Key outcomes included the TOC response rate calculated overall and by sites, the median [interquartile range (IQR)] time to TOC from GC treatment date, type of TOC diagnostic test performed, number/proportion of cases with positive pharyngeal GC TOC, and the final case disposition. These analyses were performed using SAS version 9.4 (SAS Institute, Cary, North Carolina).

Qualitative data from interview transcripts and progress reports were analyzed using inductive coding in NVivo (released in March 2020). Codes were generated for each interview or progress report question. Relationships among codes were examined to develop themes related to perceived feasibility of pharyngeal GC TOC implementation, drivers, and limitations to TOC implementation (including considerations among other STD clinics), and perceived sustainability of implementation.

Data were collected as public health program evaluation activities and were determined to be exempt from CDC Institutional Review Board review.

During the study period, 1,968 pharyngeal GC cases were diagnosed at the four clinical sites. Among those diagnosed, 1,829 cases (93%) were treated among 1,654 individual patients. Most patients had one episode of pharyngeal GC (n=1514; 92%); 7.3% (n=120) had 2 episodes and 1.2% (n=20) had ≥3 episodes during the study period.

Pharyngeal GC cases treated varied by site with almost half of treated cases (49%, n=888) reported by Maricopa County (Table 3). Across sites, the median age was 30 years (IQR: 25–36). Most cases were among men (84%) and, among men, 68% were among MSM. Approximately one-third of treated cases were reported as Non-Hispanic White and 39% as Hispanic. Overall, 8% of cases were among persons with HIV.

Almost half of treated pharyngeal GC cases had a prior history of GC (ever); among these, over half (57%, n=443) had ≥1 GC infections within the past 12 months. At the time of the first clinical evaluation for the present pharyngeal GC episode, 9.1% reported experiencing a symptom of pharyngeal GC (i.e., sore throat) and almost half of all treated cases (48.7%) had GC diagnosed at other anatomic sites at the same time. Most cases (n=1,777; 97.2%) received CDC recommended treatment (ceftriaxone 500mg IM or 1g IM once).*

In over half of treated pharyngeal GC cases (58%; n=1,061), staff made or attempted follow-up communication/contact to encourage TOC; 64.2% (n=681) of cases had a TOC reminder card provided and/or sent, 26.8% (n=284) received telephone call(s) from staff, and 8.2% (n=87) received both reminder telephone call(s) and text messages. Among those cases that had follow-up communication (n=1061), 39.7% had one contact, 23.6% had two contacts, and 36.8% had three or more contacts.

Among 1,829 treated pharyngeal GC cases, 836 (45.7%) had TOC completed. Completion rate varied by project site – from 35.5% in Maricopa County to 70.8% in Washington DC (Table 3). The median time to TOC from treatment date was 14 days (IQR 14–18). Just over half of asymptomatic patients returned for TOC while about 40% patients reporting any urogenital or extragenital gonococcal symptoms had TOC performed. Similarly, patients without concurrent GC infection(s) at other anatomic sites were more likely to return for pharyngeal GC TOC (47.2% vs. 38.4%). Among the 356 patients at the two sites that opted for self-collected NAAT outside of the clinic, approximately half completed TOC (n=199; 55.9%). Among cases with TOC performed (n=836), 95.6% had initial TOC performed using only NAAT and 4.2% had both NAAT and culture performed (Table 4). The NAAT type used most for TOC was Aptima Combo 2 assay (n=737; 88.2%; Hologic Inc., San Diego, CA, USA), followed by Roche cobas 8800 CT/NG assay (n=67; 7.9%; Roche Diagnostics, Indianapolis, IN, USA), and Cepheid Xpert^® CT/NG assay (n=31; 3.7%; Cepheid, Sunnyvale, CA, USA). TOC positivity varied by NAAT type with Roche being the highest at 7.5% (5/67), 4.3% (32/737) for Aptima, and 3.2% (1/31) for Cepheid. The five TOC positive cases using the Roche assay were dispositioned as false-positive results (making up 38.5% of all false-positive TOCs).

Among cases with TOC performed, 4.7% (n=39) had a positive TOC; all were positive by NAAT and 3 cases had both positive NAAT and culture at the initial TOC visit. Culture was performed at the re-treatment visit to further investigate 16 NAAT positive TOC cases that did not have culture performed at initial TOC; of these, thirteen (81.3%) were culture negative, and three (18.8%) were culture positive. Overall, among all TOC positive cases, six (15.4%) were both NAAT positive and culture positive. Among the 39 positive TOC cases, one-third (33.3%, n=13) were considered likely re-infection, one-third (33.3%, n=13) likely false-positive tests, 15.4% (n=6) were dispositioned as clinical treatment failures, and 17.9% (n=7) had insufficient data to disposition mostly due to loss-to-follow-up (Table 2). Among the six cases dispositioned as treatment failures, two were treated with a non-ceftriaxone regimen. Among the four ceftriaxone-receiving treatment failure cases, all had received ceftriaxone 500 mg intramuscular once as initial treatment, all had TOC performed ≥12 days from treatment and had culture performed, all of which were positive (Table 5). AST was performed for two cases, both of which were susceptible to ceftriaxone and cefixime. All four cases were re-treated with different anti-gonococcal regimens and were cured as evidenced by repeat TOC NAAT with negative results.