Data about COVID-19 in the infant population is scarce. Less than 1% of patients in a review of over 72,000 cases from China were younger than 10 years of age, and less than 20% of a pediatric subset were younger than 1 year of age [6, 7]. There is contradictory evidence regarding vertical transmission of COVID-19 between infected mothers and newborns, though the current consensus is that vertical transmission is unlikely to occur [8, 9]. Symptoms in this age group vary as with older age groups. A case series of nine hospitalized patients under the age of one noted that most hospitalized patients were symptomatic with fever and upper respiratory symptoms [10]. Another reported case described a 55-day-old infant who developed more severe symptoms, including pneumonia, and demonstrated evidence of liver and cardiac injury [11].
In younger populations, viral load may persist for weeks regardless of symptoms, as case reports have noted persistently positive PCR tests even in asymptomatic patients, including in a well 6-month-old who tested positive for 16 days [12]. As our patient’s immediate family members were sick one week prior to the onset of his symptoms, his family was the likely source from which he contracted the virus. He tested positive on admission for both hospitalizations via PCR testing, with 21 days between the two tests.
Our patient’s presentation, initially for an isolated episode of perioral cyanosis and apnea, was at first attributed to a BRUE. A BRUE is defined as an event lasting less than one minute without an identifiable explanation and with full resolution of symptoms, in an infant less than one year of age, and symptoms can include cyanosis [13]. Past research has found a strong correlation between apparent life-threatening events, a less-specific diagnosis that has been replaced by the term “BRUE,” and a positive respiratory viral infection test [13]. However, given his recurrence of symptoms and new onset of stridor in the setting of a persistently positive COVID-19 PCR, his symptoms are more likely to be directly due to his infection by SARS-CoV-2. Furthermore, the recurrence of symptoms after a prolonged asymptomatic period indicates this patient’s infection appears to have followed an atypical course.
Despite increasing evidence demonstrating children have more mild presentations and better outcomes in COVID-19 infections, there is limited documentation of individual cases, especially infants, in the medical literature. Since children appear to most commonly present asymptomatically or mildly symptomatic, they have the potential to serve as undetected vectors of the disease as cities and countries start to loosen restrictions on commerce and socialization. Given the lack of universal testing infrastructure worldwide, the implication therefore may be to focus on opportunities to test these patients whenever possible. With disease modeling estimating continued COVID-19 infection in the years ahead, our case highlights the need for clinicians to consider more subtle presentations in infants such as brief episodes of apnea, cyanosis, and stridor as potential catalysts to prompt testing for SARS-CoV-2 infection, caregiver testing, and/or recommending quarantine protocol.