(P173) INVESTIGATION OF A CLUSTER OF CEFTRIAXONE RESISTANT GONORRHEA: THE COLORADO SURRG PROJECT

Background:
In 2016, the CDC initiated the Strengthening the United States Response to Resistant Gonorrhea (SURRG) project to explore rapid, integrated strategies to identify and respond to antibiotic-resistant gonorrhea. The Colorado Department of Public Health and Environment (CDPHE) and Denver Sexual Health Clinic (DSHC) are participating sites. In 2023, Colorado’s SURRG partnership investigated a cluster of gonorrhea cases with reduced susceptibility to ceftriaxone.

Methods:
The DSHC identified a cluster of five cases in June 2023, with initial encounters all occurring in a one-month period. The cases were all Hispanic males who received ceftriaxone on their initial presentation. Etest revealed that the cases had reduced susceptibility to ceftriaxone (MIC = 0.125 ug/mL). At test-of-cure, a CDPHE Disease Intervention Specialist (DIS) conducted an interview. Agar dilution was used to confirm antimicrobial susceptibilities. Whole genome sequencing (WGS) was also conducted.

Results:
The cluster included a total of five cases, with infection sites of urethral (2), rectal (1), and pharyngeal (2). The cases reported meeting their partners at similar local venues and nightclubs. Two of the five cases were linked through the DIS interview. Four of the five cases received a negative test of cure. One pharyngeal case had a positive test of cure, received a repeated, higher dose of ceftriaxone, and subsequently cleared the infection. Follow-up with clients required close coordination between CDPHE DIS and DSHC staff. WGS revealed high relatedness between the samples.

Conclusion:
Investigation of this cluster of cases revealed several strengths of the SURRG partnership, including the ability to rapidly identify and respond to clusters of ceftriaxone resistance and conduct a coordinated public health response. Local capacity to perform Etest was vital in rapidly identifying reduced antibiotic susceptibility. The high relatedness identified via WGS suggests that there may be more widespread transmission of ceftriaxone-resistant gonorrhea in Colorado.