With nine suspected cases of a newly identified pediatric condition in Massachusetts that may be connected to the COVID-19 pandemic, Public Health Commissioner Monica Bharel on Thursday alerted health care providers to be on the lookout and ordered them to report any additional cases immediately.

More than 100 cases of the condition, referred to as pediatric multi-system inflammatory syndrome, have been confirmed in New York, including three deaths.

Bharel said in a Thursday memo that nine children in Massachusetts hospitals are suspected to have PMIS, flagging it as a key issue for those on the front lines to watch. She called for mandatory reporting of any confirmed or suspected cases in patients younger than 21 to the Department of Public Health, effective immediately, "to reduce morbidity and mortality."

"The reason this order's important is to put out what the symptoms are that primary care and hospitals should be looking for to report this condition," Health and Human Services Secretary Marylou Sudders said at a Thursday press conference on COVID-19 response. "We don't know what the prevalence is of the condition in Massachusetts yet. That's why the public health order was so important."

Health experts have long said that children are less vulnerable to the COVID-19 respiratory illness than adults, but evidence is growing in Europe and in New York state that they may be susceptible to an inflammatory condition that appears linked to the same novel coronavirus.

In her advisory, Bharel wrote that the majority of PMIS patients tested positive for SARS-COV-2, the virus that causes COVID-19.

Bharel instructed providers to investigate whether pediatric patients who may be presenting symptoms of the syndrome have had any recent illness with COVID-19 or close contact with someone else who caught the highly infectious virus.

The symptoms do not mirror COVID-19, however. Fever, inflammation and other severe issues such as organ failure could be signs of the syndrome, Bharel wrote, when there is no evidence of a plausible alternative diagnosis.

"This syndrome has features which overlap with Kawasaki disease and toxic shock syndrome," Bharel wrote. "Inflammatory markers may be elevated, and fever and abdominal symptoms may be prominent. Other reported findings have included rash, myocarditis and other cardiovascular changes, coagulopathies, and acute kidney injury. Additionally, some patients have developed cardiogenic or vasogenic shock and required intensive care. Respiratory symptoms may not be a prominent feature."

She stressed the importance of "early recognition" by pediatricians and added that it is "essential" for providers to collaborate with specialists in infectious diseases, rheumatology, cardiology and critical care.

Public health officials have confirmed 80,497 COVID-19 cases in Massachusetts since the outbreak began and a cumulative death toll of 5,315. Less than 4 percent of all confirmed cases were observed in residents 19 and younger, and the rate of confirmed cases per 100,000 was also the lowest in that age group by a wide margin.

In a Wednesday statement, before Bharel issued new guidance and while state officials were still compiling data about the prevalence of the syndrome in the state, American Academy of Pediatrics Massachusetts Chapter President Dr. Elizabeth Goodman said the growing concerns highlight "why it's important that parents stay connected to their pediatrician."

"If a pediatrician thinks a child should be seen in the office, we urge parents to follow through so that we can catch things early, before they become emergent," she said. "Any family with a known COVID-19 case -- any family member -- should be on the lookout for fever, rash, red eyes, cracked lips, abdominal pain, swollen or red hands or feet in their children, even if the child was never sick."