BOSTON (WPRI) — The Massachusetts Department of Public Health is warning of an alarming strain of gonorrhea that’s resistant to numerous antibiotic treatments.

The health department said the “concerning” strain has been detected in two Massachusetts residents — both of which showed reduced response to five different courses of antibiotics.

The residents were eventually successfully cured with ceftriaxone, which is an antibiotic that’s currently recommended to treat gonorrhea.

The infections appear to be unrelated to one another, and the health department said contact tracing is being conducted.

“This is the first time that resistance or reduced response to five classes of antibiotics has been identified in gonorrhea in the United States,” the health department said.

The health department said the strain was previously detected in Asia-Pacific countries and in the United Kingdom.

The health department is working with the Centers for Disease Control and Prevention (CDC) to expand gonorrhea testing to determine whether this strain has infected any other residents.

Laboratories and clinicians across the state have been notified of the novel strain and directed to treat all infections with high doses of ceftriaxone.

“Overall, these cases are an important reminder that strains of gonorrhea in the United States are becoming less responsive to a limited arsenal of antibiotics,” the health department said.

Massachusetts Public Health Commissioner Margret Cooke said described the strain as “a serious public health concern.”

“We urge all sexually active people to be regularly tested for sexually transmitted infections and to consider reducing the number of their sexual partners and increasing their use of condoms when having sex,” Cooke said.

Gonorrhea is a bacterial sexually transmitted infection, according to the CDC. If left untreated, gonorrhea can cause serious health problems such as pelvic inflammatory disease and infertility.

Massachusetts has seen a significant increase in gonorrhea infections over the last decade, according to the health department, with confirmed cases having increased by 312% between 2009 and 2021.