Ongoing Syphilis Outbreak Among Drug Users in a Small County in Minnesota 2016-2017

BACKGROUND:   Over the past five years, Minnesota has seen a 160% increase in early syphilis (ES) cases. Historically, men have been ninety percent of all ES cases. In the past two years, Minnesota has seen a 114% increase in the number of female ES cases. At the Minnesota Department of Health (MDH) all ES cases are assigned to a Disease Intervention Specialist (DIS) for interview. In June 2016, the MDH received two syphilis reports in residents of a small Minnesota county. This county had no syphilis cases reported in the previous year. One of the reported cases had indicated they used methamphetamine (meth). The STD Surveillance Coordinator and DIS monitored for cases with possible links and/or drug use that were residents of this county.

METHODS:  The MDH recently revised their outbreak response plan utilizing the CSTE Syphilis Outbreak Detection Guidance. As part of the plan, the STD Surveillance Coordinator meets weekly with the DIS staff. Syphilis cases from the small county were sporadically reported to the MDH from June 2016 to late January 2017. By late January 2017, seven of the interviewed cases had reported drug use. On February 6, 2017 the STD Surveillance Coordinator triggered the notification process declaring an outbreak. The case definition is: any reported syphilis case diagnosed in 2016 or 2017 that resides in the small county or a syphilis case that is linked to a case that is part of the outbreak. On February 27, 2017 a health advisory went out alerting health care providers statewide of a syphilis outbreak among drug users.

RESULTS:  As of April 7, 2017 there are thirty-three syphilis cases related to the outbreak. Fifty-two percent of the cases are female, with six reported as pregnant at the time of their diagnosis. One congenital syphilis case has been identified. Cases range from 16 to 51 years of age. Twenty-seven, reside in the small county. Thirteen of the cases admit to drug use, with interviews ongoing. One recently conducted event identified four new syphilis cases and one partner that needed treatment. Response activities are ongoing.

CONCLUSIONS:  This is the first declared syphilis outbreak in Minnesota since 2002. Increasing drug use and multiple sex partners appear to be large factors in the ongoing outbreak. At a minimum weekly case reviews and timeline communication between the DIS and STD Surveillance Coordinator are critical for quick identification of additional cases and identified risk factors.