Invasive strep A cases on the rise in Colorado

The number of invasive strep A cases in Colorado has nearly doubled this year compared to previous years, state public health officials said in a news conference Wednesday. 

So far this year there have been 672 cases, and in 2021 there were 351 cases, said Dr. Rachel Herlihy, state epidemiologist with the Colorado Department of Public Health and Environment.

Between 2017 and 2021, fewer than 390 cases were reported annually, so this year’s increase is “significant,” Herlihy said.

“Group A strep can at times cause more severe infection and invasive infections,” she said. “The bacteria that causes these infections gets beyond places where bacteria normally lives.”

In rare cases, bacteria can get into the blood, lungs, fat or deep muscle tissue; in severe cases, the infection can cause organ failure and even death. 

Around 32 cases of strep A this year have been among children and teenagers under age 18, Herlihy said.

“Two cases here in Colorado have been among children who have died — we know that those are still preliminary determinations — we’re waiting for the official cause of death determination for those children,” Herlihy explained.

Similar increases in invasive strep A have been reported in Europe and other U.S. states, she noted.

“I think we have lots of questions — trying to understand what might be driving these increases,” Herlihy said.

Dr. Sam Dominguez, an infectious disease expert with Children’s Hospital Colorado, said he’s seen an “unusual” increase in the number of patients with strep A admitted to the hospital since mid-November.

“These type of infections present in several different ways that we’re seeing here at the hospital, including kids presenting with very severe pneumonia; sepsis — and this is when bacteria gets into the bloodstream; toxic shock; bone, joint and muscle infections; several kids with severe sinus disease; and then necrotizing fasciitis, which is a very severe type of skin infection,” Dominguez said.

He said parents should seek care if their child:

• Has difficulty breathing.
• Is lethargic or difficult to wake up.
• Is unable to eat and drink.
• Refuses to walk.
• Has a rapidly spreading rash.
• Has mild symptoms of a respiratory infection that suddenly gets worse.

While invasive strep A cases are on the rise, cases of COVID-19 declined over the past few weeks, Herlihy said. Respiratory syncytial virus and flu cases have also decreased in Colorado.