Conducted by researchers at Children’s Hospital Los Angeles, the study suggests that a longer infection time increased the chance of viral mutation and made these immunocompromised youth contagious for a longer period. This is the first pediatric report of its kind and could inform future hospital strategies for immunocompromised youth.

The Study

This study examined three patients, ages 2, 3, and 21, with acute lymphoblastic leukemia. Each of the patients tested positive for SARS-CoV-2, the virus that causes COVID 19. These individuals, all of whom are considered immunocompromised, were followed for six months. The findings provided fresh insight into the virus’s behavior. “This virus is capable of mutating much faster and more often to become more efficient. This could result in the virus being more transmissible and more virulent,” notes Jennifer Dien Bard, PhD, D(ABMM), director of the clinical microbiology and virology laboratory in the department of pathology and laboratory medicine at Children’s Hospital Los Angeles. “Their testing revealed that these patients were probably contagious for months after their initial symptoms,” explains Chad R. Sanborn, MD, pediatric infectious disease specialist at KIDZ Medical Services. The study is small in size but significant in its outcome. “While we cannot draw any generalizable conclusions for all or even most children with immune compromise from the three cases in this report, it certainly raises some important questions,” notes Dr. Sanborn. The study carries additional significance. “This is the first study reporting prolonged infection in children and young adults,” adds Dr. Dien Bard, who is one of the authors of this study. “Why our study and other similar studies are important is that it helps guide policy changes to ensure containment of the virus. For example, the CDC currently recommends that additional testing may be warranted in patients that are severely immunocompromised,” she concludes.

What Does Prolonged Mean?

“In general, similar to adults, children seem to be contagious for about 10 days from the time of their symptom onset. The longer duration of infection…is quite significant for infection-control purposes in a hospital or community setting,” notes Dr. Sanborn. The longer time frame provides opportunities for the virus to change. “All viruses make ‘mistakes’ from time to time when making copies of their genetic material. These are known as mutations. The idea is that we want the immune system to defeat and clear up the virus before these mutations can come about,” explains Dr. Sanborn. In this situation, a challenged immune system lacks the ability to fight a virus the way it needs to. A child may then remain sicker for longer. Dr. Dien Bard says that one patient in the study remained infected for up to 162 days. She gives three main reasons that prolonged infection is critical:

Who Is Immunocompromised?

In this study, the youth who were observed were being treated for a type of cancer. Other conditions can also lead to a compromised immune system. “In addition to patients undergoing chemotherapy for cancer, other examples of immune compromise are children with recent organ transplant, receiving high doses of steroids and [who] have severe immune deficiency disease,” states Dr. Dien Bard.

Precautions and Management

Centers for Disease Control and Prevention (CDC) guidelines recommend handwashing, social distancing, and wearing masks as general practices to avoid COVID transmission. For immunocompromised children, additional safety measures can help keep them healthy. “We typically should be extra careful to try and prevent infection in immunocompromised children. We can do this by making sure they… or people around them [if the children are younger than 12 years of age] are fully vaccinated, and having those who have not [been] vaccinated wear masks around them because of the potential for more severe disease,” notes Dr. Sanborn. Precautions taken to help just one immunocompromised child can be beneficial to all of us. The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.