© Smith Collection/Gado Streptococcus pyogenes, also known as group A strep, a common bacteria that can produce strep throat.
Even as the burden of COVID-19 has eased this winter, other infectious diseases continue to display unusual, and in some cases lethal, new patterns. The latest example: Massachusetts doctors are watching out for signs of a rare but serious infection in children driven by group A Streptococcus, the same bacteria that cause strep throat.
Several states, including Colorado and Minnesota, have seen significant spikes in cases of severe pediatric illness, including at least two deaths, prompting the Centers for Disease Control and Prevention to issue a warning to health care providers earlier this month.
The condition, known as invasive group A strep, occurs when bacteria move beyond the throat or skin, where they are likely to cause mild infection, and enter the bloodstream, lungs, spinal fluid, or other places inside the body they would not typically live.
Invasive group A strep can lead to pneumonia, sepsis, toxic shock syndrome, and a serious skin and tissue infection called necrotizing fasciitis, also known as the “flesh-eating disease.”
Last week, the World Health Organization issued an alert noting an increase in invasive strep infections mostly in children under age 10 in five countries — France, Ireland, the Netherlands, Sweden, and the United Kingdom. The UK has reported deaths in at least 16 children under age 18, and the Netherlands has reported six cases of flesh-eating disease.
Several million cases of mild group A strep infection, including strep throat, are reported each year in the United States and approximately 14,000 to 25,000 of the cases are invasive group A strep disease, the CDC says.
In Massachusetts, about 200 to 400 invasive strep cases annually have been reported by hospitals to the state health department between 2015 and this year. But the department said in a statement that it has, to date, not seen “any noticeable trends” toward an increase in invasive strep.
Nationally in the past five years, the CDC said, between 1,500 and 2,300 people die annually from this form of the infection. But health officials are concerned now because the recent spike in invasive infections in several states is predominantly among children.
“I can understand why parents and guardians and caretakers could be nervous about this after all the infections we have seen in the last couple of years,” said Dr. Nicolas Nguyen, associate chief medical officer at Beth Israel Lahey Health Primary Care, who practices family medicine.
Doctors stress that invasive strep is rare, but that parents should call their health care provider if their child is short of breath or lethargic, or has a cough that sounds more like pneumonia, with mucus or phlegm, than a minor upper respiratory infection. The CDC said early symptoms can include fever, severe pain and a red, warm, or swollen area of skin that spreads quickly in the case of flesh-eating disease, and fever, chills, muscle aches, nausea, and vomiting with streptococcal toxic shock syndrome.
“Often parents, guardians, and caretakers can tell when their kiddos are not quite right,” said Nguyen.
A European study posted online last week, but not yet peer reviewed found a sharp increase in cases among children under age 5 in the Netherlands. The researchers said they were uncertain what is fueling the surge, but said the recent increase in viral infections, such as the flu, may be linked to the spike. They said that influenza infections were confirmed in 18 percent of the invasive strep cases and that an increased prevalence of viral infections is known to predispose people to secondary bacterial infections.
Or as Dr. Rick Malley a pediatric infectious disease specialist at Boston Children’s Hospital, puts it: “Viruses and bacteria are co-conspirators in an effort to cause disease in humans.”
He said the spike in Massachusetts and many other states of flu and respiratory syncytial virus, or RSV, a common respiratory infection in children, raises the risk that bacteria, such as group A strep, may invade and cause high rates of the super infections.
“The virus causes damage that lets the bacteria get through the mucus membrane and invade the tissues,” he said.
“That’s something we worry about when we have a typically bad influenza season, or a really early flu season, when some people have not yet been vaccinated,” Malley added.
The Netherlands study also found that in a third of invasive strep cases they studied, the children recently had chickenpox. In the Netherlands, chickenpox vaccine is not part of the required childhood immunizations, and the country’s chickenpox epidemic this year had been exceptionally high.
The Varicella, or chickenpox, vaccine is among the childhood shots required in Massachusetts. The flu shot is not required but is recommended.
Malley urged parents to get their children the flu shot if they haven’t yet been vaccinated.
If doctors suspect a typical case of strep throat, they will swab a patient’s throat area. But testing for invasive strep is more involved, with doctors drawing blood if a bloodstream infection is suspected, or doing a biopsy if they believe the bacteria has spread to other tissue.
Quick treatment with very common antibiotics works well, doctors said.
“The good news, so far, is we have a lot of options for group A strep,” Malley said.
Amoxicillin, a decades-old antibiotic, has been hard to find lately in its liquid formulation, the type typically prescribed for young children. But other common antibiotics also can be used to treat strep, Malley said.
Another piece of advice from physicians: think prevention.
“Group A strep is spread by respiratory droplets and sometimes contact, so good hand hygiene is important,” said Nguyen, the Beth Israel Lahey physician.
“Make sure, if your children have symptoms,” he said, “don’t bring them to school.”
