Abstract
This cross-sectional study assesses the risk associated with Coronavirus Disease 2019 for pediatric patients with cancer.
Data on the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children, and in children with cancer specifically have been limited. Less than 1% of cases reported from China were in children younger than 10 years. The MSK Kids pediatric program at Memorial Sloan Kettering Cancer Center (MSK) is one of the largest pediatric cancer programs in the US. Starting in mid-March, 2020, we instituted a screening and testing plan to mitigate risk associated with coronavirus disease 2019 (COVID-19).
Methods
On presentation for outpatient or inpatient care, patients were screened for the presence of symptoms of COVID-19 or exposure to contacts with known SARS-CoV-2 infection. We also instituted testing for SARS-CoV-2 using a RT-PCR assay for 3 cohorts of individuals: (1) patients exposed to COVID-19 (screen positive) or with symptoms of infection (symptom positive); (2) asymptomatic patients (symptom negative) prior to deep sedation, myelosuppressive chemotherapy, or admission to the hospital; and (3) caregivers accompanying patients for admission or multiday outpatient chemotherapy. Data for this report were gathered a retrospective research protocol approved by the MSK institutional review board with waiver of informed consent owing to the retrospective and deidentified nature of the data used. Groups were compared using a 2-tailed Fisher exact test.
Results
Between March 10 and April 12, 2020, a total of 335 tests for SARS-CoV-2 were performed on pediatric patients and their caregivers (Table 1). Of the 178 unique pediatric patients (107 male and 71 female) tested (mean [SD] age 11.1 [8.5] years), 20 (11.2%) had positive test results (mean [SD] age 15.9 [6.6] years). Of patients specifically tested for positive screening or symptoms (screen positive or symptom positive), the rate of positivity for SARS-CoV-2 was 29.3%. By comparison, in the 120 asymptomatic patients without known exposure (screen negative and symptom negative) the rate of SARS-CoV-2 positivity was only 2.5% (29.3%; 95% CI, 18.1%-42.7% versus 2.5%; 95% CI, 0.5%-7.1%; P < .001) (Table 1). Of the 20 patients who tested positive for SARS-CoV-2, only 3 were female (Table 2), a significant sex skewing when compared with pediatric patients who tested negative (15%; 95% CI, 3%-38% vs 43%; 95% CI, 35%-51%; P = .02).
Table 1. Results of COVID-19 Testing at Memorial Sloan Kettering (MSK).
| Variable | No. | SARS-CoV-2 positive, No. (%) |
|---|---|---|
| March 10-April 12, 2020 | ||
| Total pediatric outpatient visits | 1267 | |
| Total unique patients | 505 | |
| Total pediatric patients swabs | 244 | 25 (10.2) |
| Total pediatric unique patients | 178 | 20 (11.2) |
| Total unique patients screen positive or symptom positive | 58 | 17 (29.3)a |
| Total unique patients screen negative and symptom negative | 120 | 3 (2.5)a |
| Total adult caregiver swabs | 91 | 15 (16.5) |
| Total unique adult caregivers | 74 | 13 (17.6) |
| Total unique caregivers screen positive or symptom positive | 6 | 3 (50.0) |
| Total adult caregivers screen negative and symptom negative | 68 | 10 (14.7) |
| Total patients tested at MSK, April 12, 2020 | 2932 | 608 (20.7) |
Abbreviation: COVID-19, coronavirus disease 2019.
P<.001, Fisher exact test comparing [screen positive or symptom positive] to [screen negative and symptom negative].
Table 2. Sex Distribution in Pediatric Cohort.
| Variable | Male | Female | P value |
|---|---|---|---|
| All pediatric patients tested | 107 | 71 | |
| Pediatric patients screen positive or symptom positive | 34 | 24 | .87 |
| Pediatric patients screen negative and symptom negative | 73 | 47 | |
| SARS-CoV-2 positive | 17 | 3 | .02a |
Fisher exact test comparing SARS-CoV-2–positive with SARS-CoV-2–negative groups.
Only 1 patient with COVID-19 illness required noncritical care hospitalization for COVID-19 symptoms. Three other patients without significant COVID-19 symptoms were admitted for concomitant fever and neutropenia, cancer morbidity, or planned chemotherapy. All other pediatric patients had mild symptoms and were managed at home.
We also instituted testing of adult caregivers of patients (Table 1). Of the 74 individuals tested, 13 caregivers (17.6%) of 10 patients tested positive for SARS-CoV-2. Notably among 68 asymptomatic and unexposed caregivers (screen negative and symptom negative), 10 tested positive for SARS-CoV-2 (14.7%). Simultaneous detection of virus in patient and caregiver was found in 5 patient/caregiver dyads, whereas 5 patients were negative for virus despite close exposure to caregivers with COVID-19.
Discussion
Although this report is limited by small numbers, the data show that (1) the overall morbidity of COVID-19 in pediatric patients with cancer is low with only 5% requiring hospitalization for symptoms of COVID-19; (2) that the rate of SARS-CoV-2 infection among asymptomatic pediatric patients is very low; (3) that unrecognized SARS-CoV-2 infection in asymptomatic caregivers is a major infection control consideration; and (4) that consistent with the sex difference previously seen in adults with critical disease, there is a male bias in SARS-CoV-2 infections in children, suggesting a biological basis in skewed infectivity.
This report suggests that pediatric patients with cancer may not be more vulnerable than other children to infection or morbidity resulting from SARS-CoV-2. Although the asymptomatic SARS-CoV carrier rate in children in the general population is not known, our testing of 120 asymptomatic pediatric patients with cancer revealed only a 2.5% rate of SARS-CoV-2 positivity. By comparison, we observed a 14.7% rate of SARS-CoV-2 positivity in their asymptomatic caregivers (2.5%; 95% CI, 0.5%-7.1% vs 14.7%; 95% CI, 7.3%-25.4%; P = .002), which closely matches the asymptomatic carrier rate in pregnant women in New York (13.5%). Together, our results do not support the conjecture that children are a reservoir of unrecognized SARS-CoV-2 infection.
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