Over Memorial Day weekend 2025, Connecticut public health and safety partners launched a rapid, coordinated response to a spike in overdoses in New Haven County. In late May to early June 2025, the Connecticut Overdose Response Strategy (ORS) team identified a surge in overdose activity through the Overdose Detection Mapping Application Program (ODMAP) and consequently, Connecticut public health and safety partners launched a rapid, coordinated response to a spike in overdoses in New Haven County. They quickly mobilized a network of partners, including the Drug Enforcement (DEA)-New Haven, New Haven Police Department, city and state health departments and the New Haven Syringe Services Community Drug Checking Program (NHSSPDCP).

Shortly after recognizing a spike in overdoses, the NHSSPDCP tested a community submitted sample suspected to be linked to the surge in overdoses. The FTIR results suggested a combination of fentanyl, procaine and medetomidine (a veterinary anesthetic with potent sedative effects). This real-time data, along with harm reduction messaging, was immediately shared with local public health partners, and community members.

The following day, DEA officials requested support for field testing at the scene of a fatal overdose in Hamden, CT. The NHSSPDCP agreed to utilize FTIR testing capacity on scene to support urgent, tangible data distribution back to the community and partners. An additional sample tied to a separate fatal overdose was provided by the New Haven Police Department for testing and rapid distribution of community results. Both samples showed consistent results of fentanyl, medetomidine and procaine, which continued to emerge as potential contributors to the fatalities. The NHSSPDCP’s role is not to identify “evidence,” but to generate real-time, community-centered intelligence that helps people make safer decisions and allows service providers to adapt outreach and care strategies.

Although a direct source or distribution pattern had not yet been identified, investigators continued to analyze seized phones and pursue leads. Meanwhile, the CT ORS team and NHSSPDCP disseminated alerts to local overdose prevention organizations and the broader community. On June 3, 2025, as fatal overdoses continued to occur, the team conducted additional testing with DEA-New Haven and found a slightly higher concentration of fentanyl than what had been observed in the previous six to eight months—an alarming shift in local supply potency. That same day, the New Haven Health Department convened EMS and local and state partners to coordinate next steps. Simultaneously, the ORS team worked with the Department of Mental Health and Addiction Services to ensure local EMS agencies were prepared to receive naloxone kits from the Alliance for Prevention and Wellness (APW) for distribution at nonfatal overdose scenes. APW provided 50 naloxone leave-behind kits to EMS in New Haven. To support these outreach efforts, NHSSPDCP developed drug-checking info cards for community distribution.

On June 4, 2025, the ORS team shared updated ODMAP data with cross-sector partners during their monthly drug sync meeting. The data revealed ongoing overdose clusters along the I-91 and I-95 corridors, extending into Massachusetts. Following the meeting, the Connecticut Public Health Analyst alerted Regional Behavioral Health Action Organizations (RBHAOs) and, in partnership with NHSSPDCP, encouraged expanded naloxone distribution and harm reduction education efforts.

As the surge continued and new data emerged, the Connecticut Department of Public Health, CT ORS team and state partners moved swiftly to develop and distribute a situational alert bulletin. Public health agencies quickly mobilized, providing the CT ORS team with data from multiple surveillance sources, including EMS overdose reports from ODMAP and EMS data, as well as emergency department data from the state’s syndromic surveillance system. This deep dive into available data revealed that the spike in overdose activity had started earlier than initially realized. Between May 16 and June 6, 2025, Connecticut recorded 61 suspected overdose deaths—44 of them in New Haven and Hartford counties—with significant clusters along the I-91 and I-95 corridors. The findings confirmed that a highly adulterated drug supply was moving rapidly across the state, requiring urgent and coordinated action. Real-time insights from ODMAP, EMS, hospital surveillance systems and the Office of the Chief Medical Examiner confirmed the observations reported by partners on the ground. The alert bulletin was quickly finalized and disseminated; the CT ORS team continues to monitor trends and support response efforts statewide.

Connecticut’s response to the May 16–June 6, 2025, overdose spike demonstrates the power of strong cross-sector collaboration. The ability to share real-time data, conduct field testing, equip EMS with naloxone leave-behind kits and engage overdose prevention partners was the result of years of trust-building and coordination led by the CT ORS team. Public health, public safety, overdose prevention and law enforcement worked side by side—communicating clearly, aligning strategies and supporting one another without institutional barriers. This response reflects the core mission of the ORS: fostering collaboration to reduce fatal and nonfatal overdoses. The strong relationships built before the crisis made it possible to act quickly and protect lives during a rapidly evolving emergency.