Telling the Story of COVID-19 Through Natural History Study at CHOP

Susan Coffin is researching the natural history of COVID-19 in children.

shafere1 [at] email.chop.edu (By Emily Shafer)

One of the first things infectious disease researchers do when faced with a novel virus is to study its natural history. This includes answering questions such as how and when it is passed from person to person, where the virus is present in the body, and how its presence leads to disease.

Researchers at Children’s Hospital of Philadelphia are acting quickly to study the natural history of COVID-19 in children and hope to understand why they seem to fare better than adults when infected.

“This coronavirus is new to us and everyone else in the world, and there are a number of questions that need to be answered,” said Susan Coffin, MD, MPH, attending physician in the Division of Infectious Diseases at CHOP and professor of Pediatrics at the Perelman School of Medicine at University of Pennsylvania. “Linking some of those pieces of information together and understanding the course of the disease, are all part of the work to define a disease’s natural history. You are discovering the story of something you never knew existed.”

Researchers at CHOP are studying how COVID-19 affects children, and why they seem to be largely spared from severe illness.

Most natural history studies are observational. Dr. Coffin and colleagues are taking advantage of information being collected as part of clinical care within CHOP’s pediatric care network, which provides care for more than 200,000 children. The study team is asking for additional samples to be collected to study and having patients and caregivers fill out questionnaires.

The researchers chose a starting point of January 2020 for the study, since prior to that time, nobody in the United States was known to have COVID-19. They are studying how many diagnoses are being made, how frequently diagnoses are being made, and how children are presenting with the disease. As of May 14, 5,678 CHOP patients were tested for COVID-19, and among those, there were 325 positive results.

The study team is characterizing patients using four categories: Children who are not exposed to the virus; children who are exposed to the virus, but not infected; children who are infected and then become symptomatic; and children who are infected, but don’t present with symptoms.

“Each of those permutations is a fascinating story,” Dr. Coffin said. “Why does a child end up on one trajectory and not the other? Our study will give us the opportunity to help define children’s role in this pandemic. We know this virus preferentially affects adults, and that the risk of a child becoming seriously ill with this disease is very low. However, there are no respiratory illnesses that exempt children.”

The study team will analyze data on a rolling basis, Dr. Coffin said. Although this study is primarily being conducted at CHOP, the researchers are partnering with other children’s hospitals in the U.S. to help build the picture of pediatric COVID-19 across diverse settings.