It was a potentially lethal form of strep A.
“We were very surprised,” said Myers. “We just don’t see that many together in such a short time.”
Infection with Streptococcus pyogenes — or group A streptococci for short — usually causes mild symptoms, such as a rash, fever, or swollen tonsils leading to the eponymous strep throat. But in recent months, cases have been emerging in the United States and Europe linked to a rare invasive form of the common bacteria, often associated with sometimes confusing symptoms, including rash, fever, palpitations and unexplained swelling.
The first confirmed pediatric deaths in this country, in two young children in the Denver area, were reported last week. At least 16 children have died from it in the United Kingdom, seven in the Netherlands and two in France.
The emergence of invasive Streptococcus A is one of the unusual ways that pathogens interact with us – and with each other – amid the end of the coronavirus era of social distancing and masking this year. Both the World Health Organization and the US Centers for Disease Control and Prevention said they are investigating the cases, including whether the viral storm that has left many people sick could be at least partially to blame.
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Viral infections tend to create disorder in a person’s immune system, making it easier for a secondary bacterial infection to take hold and, in some cases, amplifying its effects.
Minnesota health officials said they had seen 46 cases of invasive strep A across all ages in November, more than double the average 20 cases in previous months. Colorado reported that it was investigating not only an increase in invasive Streptococcal A cases, but also a possible increase in other serious or invasive bacterial infections in children.
The Texas Children’s Hospital said it saw more than 60 patients with invasive strep A in October and November — a fourfold increase from the same period last year. James Versalovic, the medical center’s chief pathologist, said many of the affected children had current or recent viral infections. But, he said, it’s too early to rule out other factors that may contribute to the severity of their illness.
“It may be that due to the pandemic we have different immunity patterns that have increased our vulnerability. But it could also be… different varieties of strep, he said. “It could be a combination of factors. Nobody knows.”
Unlike SARS-CoV-2, Strep A is something humans have been battling for centuries.
Throughout history, it has been variously described, erroneously, as associated with phenomena such as comets and eclipses, or the introduction of non-living matter into humans. It wasn’t until 1874 that Austrian surgeon Theodor Billroth described an organism he saw under a microscope that appeared to be grouped into chains of four or more that would later be classified as bacteria. Bacteria can live inside or outside a patient’s body, unlike viruses, which are a collection of molecules that can only replicate inside a host. Both are transmitted in similar ways – through air, water, food and living things.
Several million people in the United States become infected with strep A each year, and in our modern world, with its ample supply of antibiotics, it is usually a nuisance. It usually translates to a sore throat and perhaps a missed school or work day during the 24 hours it takes to stop being contagious after taking antibiotics such as penicillin and amoxicillin.
“The good news is we know how to treat it and how to test for it,” says Kristin Moffitt, an infectious disease expert at Boston Children’s Hospital who studies bacterial infections. “Normally, it’s not a source of serious concern that I would be hyper-concerned about.”
But in a small number of cases, Streptococcus A can become dangerous when it invades parts of the body where bacteria are not normally found. When it invades such areas, including the blood, cerebrospinal fluid, bone marrow, and organs such as the brain and heart, it can spread rapidly and be fatal.
The first reports of unusual activity due to invasive streptococci A, especially in children aged 5 years and younger, came from the Netherlands between March and July. It wasn’t just the number and severity of cases, doctors said in a preprint research paper posted Dec. 13, but also the fact that many of the patients were co-infected with viruses such as the flu or chickenpox. (Unlike in the United States, vaccinations for chickenpox, which causes chickenpox, are not part of the childhood immunization program in the Netherlands.)
In 2018 and 2019, most children seen in Dutch hospitals with invasive strep A developed sepsis, a systemic infection or pneumonia. But this year, many were diagnosed with necrotizing fasciitis, a flesh-eating disease involving bacteria that destroy tissue under the skin. Doctors Evelien B. van Kempen, Patricia CJ Bruijning-Verhagen and their co-authors urged the public to be aware that early recognition and prompt treatment can save lives.
“Clinicians and parents should be vigilant and aware of unusual pediatric presentations,” they wrote.
Severe illness in children has also been reported in the UK, the Netherlands, France, Ireland and Sweden, but the patterns are not always the same. In the UK, doctors reported an increase in scarlet fever – which is also caused by streptococcal A bacteria – around the same time as the invasive cases. But that was not seen in the Netherlands.
Several hospitals in the United States said they were unaware of any unusual scarlet fever activity in their area.
Figuring out what is going on in the United States is trickier than in some other countries due to the lack of a national health care system that facilitates case tracking. CDC spokeswoman Kate Grusich said in an email that it’s too early to say if the number of cases is “just returning to pre-pandemic levels, or if they’re rising beyond what we would normally expect.”
The “CDC is closely monitoring this data and talking to surveillance sites and hospitals in multiple states to learn more about any trends,” she said.
The email list for pediatricians and infectious disease specialists in this country started blowing up in October with a question from a midwestern physician: Did anyone else see an increase in invasive strep A?
Reactions were, as expected, mixed, given that such cases tend to cluster. Boston Children’s had seen nothing alarming. But doctors in Kansas City, Houston and Denver did.
At Texas Children’s, Versalovic said some children have come in with low blood pressure and septic shock, some with bacterial pneumonia and still others with skin infections. Several were so ill that they required intensive care. He is afraid that some things will be missed. To diagnose invasive strep A, doctors must take samples of a patient’s blood, skin, or fluid in the lungs or other areas. But if a child needs emergency care, there may not be time to think about the cause of the illness.
Invasive strep A “does not follow a simple linear progression,” he said.
In Denver, Samuel Dominguez, an infectious disease specialist at Children’s Hospital Colorado and a professor at the University of Colorado School of Medicine, said the cases he had seen were “across the age spectrum” in children, noting that they may be more susceptible because bacteria tend to colonize their throat and skin more aggressively than adults.
Dominguez tried to balance reassurance that this is a relatively rare infection with calls to watch for warning signs.
Versalovic agreed. “We don’t want to sound too much alarm, but these infections can evolve very quickly,” he said.
Myers said all patients seen at Children’s Mercy in Missouri have recovered with treatment, but she urged parents to make sure their children’s vaccinations are up to date to avoid a viral infection which can open the door to a more serious bacterial infection. “I think there are a lot of things at play that we don’t quite know yet,” she said.
One of the tricky things about the disease is that it can look so different in different kids, she said. The child who had trouble moving his eyeball had an infection of the soft tissues of the eye socket; the one with the lump behind the ear, an infection of the bone in that area; and the third patient, a collection of pus in the back of the throat.
Myers urged parents to exercise caution.
“If a child looks sicker than they should be after developing a fever, it’s always a good idea to take them to a doctor if they’re having trouble breathing, or if you notice anything else – even a swollen eye” , she said.