Abstract
Background
Respiratory syncytial virus (RSV) and SARS-CoV-2 can cause acute respiratory failure in children. We compared characteristics and outcomes of children aged <2 years with respiratory failure from infection with RSV, SARS-CoV-2, or both viruses.
Methods
We used data from a US pediatric respiratory virus hospitalization surveillance network including children with ICU admission for acute respiratory failure (receiving high-flow oxygen or mechanical ventilation) with RSV and/or SARS-CoV-2 during November 2023–March 2024. Demographic, clinical characteristics, and hospitalization outcomes were stratified by a positive test for RSV, SARS-CoV-2, or both viruses, and compared using chi-squared or Kruskal–Wallis tests. Multivariable analyses assessed independent associations between outcomes and infection.
Results
Overall, 1406 children were included: 1253 (89.1%) for RSV, 105 (7.5%) for COVID-19, and 48 (3.4%) with RSV + SARS-CoV-2 detected. Children with RSV or RSV + SARS-CoV-2 had lower median ages (3.9 and 5.4 months, respectively) compared with those with SARS-CoV-2 (8.8 months; P < .001). Twenty percent of children with RSV and 43.8% with COVID-19 had an underlying medical condition. Among infants aged <1 year for whom preterm status was available, 31.5% with RSV and 50% with COVID-19 had either prematurity or a comorbidity. Children with SARS-CoV-2 were more likely to require invasive mechanical ventilation, receive vasoactive infusions, and die compared with RSV with and without SARS-CoV-2.
Conclusions
Critically ill children <2 years of age infected with SARS-CoV-2 had more severe illness presentation and outcomes and were older compared with those with RSV and RSV + SARS-CoV-2 codetection. Most children were previously healthy, highlighting the need for prevention measures.
Keywords: COVID-19, pediatric, respiratory failure, respiratory syncytial virus
Children <2 years of age hospitalized for respiratory failure with COVID-19 were older and more likely to require intubation than those with respiratory syncytial virus (RSV) infection. Most children did not have an underlying condition before hospitalization.
Respiratory syncytial virus (RSV) and SARS-CoV-2 can cause critical illness in infants and young children. During the 2023–2024 United States (US) respiratory season, the cumulative hospitalization rates of infants <1 year of age with RSV and COVID-19 were 1359.8 and 249.5 per 100 000 [1]. Hospitalization incidence is highest among infants <6 months of age [2–4]. Most RSV infections do not cause critical illness, but RSV is the leading cause of acute lower respiratory tract infections in infants and young children, and can present with pneumonia or bronchiolitis [5]. While children with COVID-19 generally experience mild illness, some develop life-threatening illness, requiring intensive care and occasionally leading to death [6].
The COVID-19 pandemic impacted seasonal patterns of RSV [7]. Respiratory syncytial virus circulation was almost absent from 2020 to 2021, followed by a re-emergence of off-season RSV in 2022, with increased positive RSV tests and hospitalizations compared with earlier seasons [1, 7, 8]. This re-emergence brought a surge of RSV-related hospitalizations and ICU admissions in 2022 [9]. Respiratory syncytial virus now appears to be returning to pre-pandemic seasonality [1], with co-circulation of SARS-CoV-2. Co-circulation of RSV and SARS-CoV-2 may impact clinical testing, decision making, treatment, and illness course. Recent studies have compared the clinical characteristics and outcomes of hospitalized children infected with SARS-CoV-2, RSV, or both [10–17], but critical illness among young patients has not been well characterized.
In this study, we compared sociodemographic and clinical characteristics, and hospital outcomes of infants and toddlers hospitalized in the intensive care unit (ICU) for acute respiratory failure with RSV and/or COVID-19.
METHODS
Study Population
This study included children <2 years of age enrolled in the Overcoming COVID-19 Network, a pediatric respiratory virus hospitalization surveillance network conducted across 33 hospitals in 28 states (Supplementary Table 1). Patients were included if they were <2 years of age, were admitted to the ICU for ≥24 hours, had either RSV or COVID-19 respiratory failure, and had laboratory testing results for RSV and SARS-CoV-2. Data from 2 different data sources within the surveillance network were leveraged. Potentially eligible patients were first considered for inclusion in a case-control investigation of pediatric COVID-19 hospitalization (“COVID-19 hospitalization investigation”); patients with laboratory confirmed SARS-CoV-2 with acute COVID-19 or COVID-19-like illness without positive SARS-CoV-2 testing were included. Those not included in the COVID-19 hospitalization investigation were considered for inclusion in a critical care registry of infants and children admitted to the ICU with laboratory-confirmed RSV for RSV-related complications (“RSV critical care registry”). All viral testing was clinician driven; for this analysis viral testing for COVID-19 and RSV were required. Analytic inclusion criteria for the current analysis were: (1) hospitalization 1 November 2023–31 March 2024; (2) age at hospitalization <2 years; (3) ICU stay ≥24 hours; (4) acute respiratory failure requiring support of high flow nasal cannula oxygen, or invasive or noninvasive mechanical ventilation; and (5) testing results for both SARS-CoV-2 and RSV.
Children were classified as having RSV disease (RSV) if they were admitted with RSV and did not also have a SARS-CoV-2 codetection; having COVID-19 (COVID-19) if they were admitted for COVID-19 with a positive test for SARS-CoV-2 and did not also have an RSV codetection; or having RSV and SARS-CoV-2 codetection (RSV + SARS-CoV-2). Patients with detection of other respiratory viruses were not excluded. Children diagnosed with multisystem inflammatory syndrome were excluded. This activity was reviewed by CDC, deemed not research and exempt from patient informed consent, and was conducted consistent with applicable federal law and CDC policy (see eg, 45 C.F.R. part 46.102(l)(2), 21 C.F.R. part 56; 42 U.S.C. §241(d); 5 U.S.C. §552a; 44 U.S.C. §3501 et seq.).
Data Collection
Data were collected through medical record abstraction (for both investigations) and parent interview (COVID-19 hospitalization investigation only). Patient information included demographics, symptoms at hospitalization, comorbidities, and any additional clinical viral testing results. Gestational age at delivery was collected for infants <1 year of age at hospitalization. Preterm birth was defined as being born before 37 weeks gestation. Preterm birth was considered separately from other underlying comorbidities. Prespecified hospitalization outcome information included patient length of stay (LOS), maximum level of respiratory support (high flow nasal cannula, noninvasive mechanical ventilation [bilevel positive airway pressure or continuous positive airway pressure], or invasive mechanical ventilation [tracheal intubation]), and critical illness indicators (receipt of vasopressors, extracorporeal membrane oxygenation [ECMO], or death). Bacterial cultures collected during the first 72 hours of hospitalization were evaluated. Two physician investigators with expertise in pediatric infectious diseases (N. B. H. and J. E. S.) adjudicated bacterial coinfections.
Vaccine Verification
Maternal COVID-19 vaccination for infants <6 months or child (patients 6 months–<2 years) receipt of COVID-19 vaccination were collected in the COVID-19 hospitalization investigation. Vaccine receipt was verified by searching electronic medical records, COVID-19 vaccine cards, and state immunization information systems. COVID-19 vaccination was classified as (1) vaccinated: infants <6 months of age whose mother received a maternal COVID-19 vaccine in the year before date of birth or children 6 months to <2 years of age who received at least 1 COVID-19 vaccine within 1 year before their hospitalization; (2) unvaccinated: infants <6 months of age whose mother did not receive a maternal COVID-19 vaccine in the year before date of birth or children 6 months to <2 years of age who did not receive a COVID-19 vaccine within 1 year before their hospitalization.
Receipt of maternal RSV vaccination or infant/child receipt of a short- or long-acting monoclonal antibody against RSV was also collected in the COVID-19 hospitalization investigation. Those classified as receiving a prevention product were infants 0–7 months of age with parental report of receipt of a maternal RSV vaccine during pregnancy or children <2 years of age with parent report of either a dose of nirsevimab or palivizumab within 1–5 months before hospitalization. RSV preventive product receipt was verified from electronic medical records and state immunization systems. The RSV critical care registry did not collect information about COVID-19 or RSV vaccination or immunization.
Analysis
Descriptive statistics included frequencies (percent) for categorical variables and medians (interquartile range) for continuous variables. χ2 or Fisher’s exact and Kruskal–Wallis tests were used to assess statistical significance for 3-level comparisons (RSV, COVID-19, and RSV + SARS-CoV-2) at the alpha <0.05 level. We compared differences in patient characteristics and hospitalization outcomes stratified by presence of a positive test for RSV, SARS-CoV-2, or both. We estimated prevalence ratios for the independent effects of RSV and RSV + SARS-CoV-2 on receipt of invasive mechanical ventilation using multivariable log-binomial regression. Due to small sample size, multivariable associations for receipt of vasoactive infusions, ECMO, and death were not assessed. Differences in hospital and ICU lengths of stay were estimated using multivariable negative binomial models with a log link. Models were adjusted for age group (<6 months, 6 months to <1 year, 12 months to <2 years), and presence of respiratory, cardiac, or other underlying conditions. To assess the impact of the presence of underlying conditions and prematurity on our results, we performed a sensitivity analysis redefining underlying comorbidities to include prematurity and restricting the analysis to those <1 year of age.
RESULTS
A total of 1406 children were included (Supplementary Figure 1): 272 (19.3%) from the COVID-19 hospitalization investigation (124 with RSV, 43 with RSV + SARS-CoV-2, and 105 with COVID-19) and 1134 from the RSV critical care registry (1129 with RSV, 5 with RSV + SARS-CoV-2). The final cohort included: 1253 (89.1%) children with RSV, 48 (3.4%) with RSV + SARS-CoV-2, and 105 (7.5%) with COVID-19 (Supplementary Figure 1, Table 1). Children with RSV were younger than those with COVID-19 and RSV + SARS-CoV-2 (Table 1) (P < .001). Children were similar across viral groups by gestational age, sex, and race and ethnicity (Table 1) (P ≥ .05 for all comparisons). Among children from the COVID-19 hospitalization investigation with information on maternal (n = 162) and child (n = 110) COVID-19 vaccination, no significant differences were observed in receipt of COVID-19 vaccination (Table 1). Few children from the COVID-19 hospitalization investigation had information about RSV preventive products (n = 149); no children admitted with RSV had received short- or long-acting monoclonal antibodies, and only 1 had been exposed to maternal vaccination (Supplementary Table 2).
Table 1.
Demographic and Clinical Characteristics of Young Children (<2 Years) Hospitalized with Acute Respiratory Failure with Respiratory Syncytial Virus (RSV), COVID-19, or RSV and SARS-CoV-2: United States, 1 November 2023–31 March 2024
| … | RSVa N = 1253 (%) |
RSV and SARS-CoV-2b N = 48 (%) |
COVID-19c N = 105 (%) |
P Valued |
|---|---|---|---|---|
| Age in months, median (p25, p75) | 3.9 (1.7, 10.2) | 5.4 (3.4, 9.3) | 8.8 (4.2, 13.4) | <.001 |
| Age categories | ||||
| <6 m | 768 (61.3) | 26 (54.2) | 39 (37.1) | <.001 |
| 6 m to <1 y | 231 (18.4) | 13 (27.1) | 27 (25.7) | |
| 1 y to <2 y | 254 (20.3) | 9 (18.8) | 39 (37.1) | |
| Social vulnerability indexe, median (p25, p75) | 0.52 (0.25, 0.71) | 0.46 (0.27, 0.66) | 0.53 (0.31, 0.69) | .63 |
| Gestational age (n = 1097)f | ||||
| Term (≥ 37 wk gestation) | 769 (77.0) | 29 (74.4) | 47 (71.2) | .53 |
| Preterm (<37 wk gestation) | 230 (23.0) | 10 (25.6) | 19 (28.8) | |
| Sex | ||||
| Male | 711 (56.7) | 31 (64.6) | 67 (63.8) | .22 |
| Female | 542 (43.3) | 17 (35.4) | 38 (36.2) | |
| Census region | ||||
| Northeast | 221 (17.6) | 4 (8.3) | 16 (15.2) | .01 |
| Midwest | 272 (21.7) | 7 (14.6) | 27 (25.7) | |
| South | 374 (29.8) | 18 (37.5) | 44 (41.9) | |
| West | 386 (30.8) | 19 (39.6) | 18 (17.1) | |
| Transferred from outside hospital | ||||
| Yes | 239 (19.1) | 8 (16.7) | 27 (25.7) | .23 |
| No | 1014 (80.9) | 40 (83.3) | 78 (74.3) | |
| Race and ethnicityg,h | ||||
| American Indian/Alaska native | 23 (1.8) | 2 (4.2) | 1 (1.0) | |
| Hispanic, any race | 275 (21.9) | 12 (25.0) | 27 (25.7) | |
| Non-Hispanic White | 588 (46.9) | 28 (58.3) | 39 (37.1) | .12 |
| Non-Hispanic Black | 209 (16.7) | 3 (6.3) | 24 (22.9) | |
| Non-Hispanic Asian | 31 (2.5) | 0 | 4 (3.8) | |
| Multiple/other | 41 (3.3) | 1 (2.1) | 6 (5.7) | |
| Unknown | 86 (6.9) | 2 (4.2) | 4 (3.8) | |
| COVID-19 vaccination | ||||
| Maternal vaccination (n = 162)g,i | 15/101 (14.9) | 1/22 (4.5) | 1/39 (2.6) | .06 |
| Child vaccination (n = 110)g,j | 2/23 (8.7) | 0/21 | 3/66 (4.4) | .56 |
| Symptoms | ||||
| Respiratory symptoms | 1235 (98.6) | 46 (95.8) | 95 (90.5) | <.001 |
| Difficulty or fast breathing | 1151 (91.9) | 44 (91.7) | 84 (80.0) | <.001 |
| Cough | 1139 (90.9) | 43 (89.6) | 72 (68.6) | <.001 |
| Fever | 620 (49.5) | 29 (60.4) | 57 (54.3) | .23 |
| Gastrointestinal symptoms | 333 (26.6) | 14 (29.2) | 32 (30.5) | .65 |
| Underlying conditions | ||||
| Any underlying medical condition | 251 (20.0) | 12 (25.0) | 46 (43.8) | <.001 |
| Underlying respiratory system disorderk | 125 (10.0) | 5 (10.4) | 25 (23.8) | <.001 |
| Needs assistance with clearance of secretionsf | 17 (1.4) | 1 (2.1) | 10 (9.5) | <.001 |
| Disorder of the cardiovascular systeml | 83 (6.6) | 4 (8.3) | 23 (21.9) | <.001 |
| Neurologic and/or neuromuscular disorderg,m | 35 (2.8) | 2 (4.2) | 14 (13.3) | <.001 |
| Immunosuppressive or oncologic disorderg,n | 8 (0.6) | 0 | 1 (1.0) | .65 |
| Endocrine disorderg,o | 10 (0.8) | 1 (2.1) | 5 (4.8) | .01 |
| Metabolic or genetic disorderg,p | 44 (3.5) | 3 (6.3) | 14 (13.3) | <.001 |
| Other conditionq | 117 (9.3) | 4 (8.3) | 19 (18.1) | .02 |
| Codetection or coinfection/number tested | ||||
| Influenzag codetection/coinfection (n = 1321) | 10/1177 (0.8) | 1/47 (2.1) | 3/97 (3.1) | .06 |
| Positive bacterial cultures/Number testedg,r,s(n = 652) | 36/547 (6.6) | 0/19 | 3/59 (7.7) | .83 |
aOne hundred twenty-four (10%) came from the COVID-19 hospitalization investigation; 1129 (90%) came from the RSV critical care registry.
bForty-three (90%) came from the COVID-19 hospitalization investigation; 5 (10%) came from the RSV critical care registry.
cAll observations from the COVID-19 hospitalization investigation.
dχ2 test used for categorical variables; Kruskal–Wallis test used for continuous variables; Fisher's exact test used for comparison of categorical variables with >20% of expected cell counts <5.
eBased on 2022 US SVI data. The SVI ranges from 0–1.0, with higher scores indicating greater social vulnerability. https://www.atsdr.cdc.gov/place-health/php/svi/svi-data-documentation-download.html.
fGestational age was assessed among those <1 y of age at hospital admission.
gFisher's exact test used.
hDue to large sample size, a Monte Carlo estimate for the Fisher's exact test was used.
iMaternal COVID-19 vaccination was assessed among infants <6 m of age at admission; vaccination was defined as receiving at least 1 dose of a COVID-19 vaccine within 1 y of date of birth (data available only from the from the COVID-19 hospitalization investigation).
jChild vaccination was assessed among infants and children aged ≥6 m to <2 y at admission; vaccination was defined as receiving at least 1 dose of a COVID-19 vaccine within 1 y of hospital admission (data available only from the from the COVID-19 hospitalization investigation).
kRespiratory system disorders, including: asthma, chronic restrictive lung disease, tracheomalacia/bronchomalacia, bronchopulmonary dysplasia, cystic fibrosis, obstructive sleep apnea, recurrent aspiration into lungs, pulmonary hypertension, requiring assistance with clearance of secretions, other.
lCardiovascular system disorders, including: congenital heart disease, acquired heart disease, cardiac repair (surgery or interventional catheterization), systemic hypertension, other.
mNeurologic or neuromuscular disorders, including: muscular dystrophy, static encephalopathy, spastic quadriplegia (eg, cerebral palsy), seizure disorder (excluding simple febrile seizures), neuromuscular weakness, other.
nNononcologic immunosuppressive disorder, including: primary immune deficiency, HIV, acquired immune deficiency, including from steroid or other immune suppressive treatments, solid organ transplant or bone marrow transplant for non-oncologic disease, other non-oncologic immunosuppressive disorder; or active or prior oncologic disorder.
oEndocrine disorder, including: diabetes mellitus, adrenal insufficiency, hypothyroidism, other.
pMetabolic or suspected or confirmed genetic disorder, including: trisomy 21, other chromosomal disorder, mitochondrial disorder, fatty acid oxidation defect, other.
qAny other chronic condition not reported above (e.g., rheumatologic/autoimmune disorder, hematologic disorder, renal or urologic dysfunction, gastrointestinal/hepatic disorder, or atopic or allergic condition).
rChildren could have multiple specimens tested.
sStatistical testing done between those with COVID-19 and RSV; those with RSV + SARS-CoV-2 excluded from statistical testing.
Respiratory symptoms were common among all children. Approximately 90% of children with RSV and RSV + SARS-CoV-2 presented with cough and difficulty or fast breathing, respectively, whereas 68.6% and 80.0% of those with COVID-19 had cough or difficulty or fast breathing (P < .001 for both comparisons). Presence of fever and GI symptoms were similar by virus group. Having an underlying condition was more common among those with COVID-19 (43.8%) compared with those with RSV (20.0%) or RSV + SARS-CoV-2 (25.0%) (P < .001). This was consistent for infants <6 months of age, but not for older age groups (Supplementary Table 3). Among children with COVID-19, the most common underlying conditions were respiratory system disorders (23.8%), cardiovascular system disorders (21.9%), neurologic/neuromuscular disorders (13.3%), and metabolic or genetic disorders (13.3%) (Table 1). Underlying conditions were less common among infants <6 months with RSV or RSV + SARS-CoV-2 than among those with COVID-19; however, this was not true in older age groups (Supplementary Table 3). Among infants <6 months of age, underlying respiratory conditions were more common in those with COVID-19 compared with those with RSV or RSV + SARS-CoV-2 (P = .03), but not in older age groups (Supplementary Table 3).
Nearly all patients (93.9%) were tested for influenza; however, the frequency of codetection was low (3.1% at the highest, in children with COVID-19) (Table 1). The most common additional pathogen identified in all groups was rhinovirus/enterovirus (21.3%–24.4%) (Supplementary table 4). Six hundred fifty-two children had bacterial testing conducted: 574 (45.8%) of those with RSV, 19 (39.6%) of those with RSV + SARS-CoV-2, and 59 (56.2%) of those with COVID-19. (Table 1). Overall, 36 children with RSV and 3 children with COVID-19 were diagnosed with a confirmed bacterial coinfection (2.9% each of their respective total populations). Of 142 children with a lower respiratory tract culture performed, 20.5% of those with RSV and 10.0% of those with COVID-19 had a bacterial coinfection (Supplementary Table 4). Among children with RSV, the most common endotracheal bacterial coinfections were Moraxella catarrhalis, Streptococcus pneumoniae, and nontypeable Haemophilus influenzae (Supplementary Table 5).
Of children admitted for COVID-19, 39% (n = 41/105) required invasive mechanical ventilation (Figure 1), most of whom were 1 year to <2 years of age (Figure 1, Supplementary Table 6). In contrast, 16% of children with RSV (n = 206/1253) required invasive mechanical ventilation, most of whom were <6 months of age, and 13% with both viruses. Non-invasive mechanical ventilation was more common for children with RSV and with both viruses. Of children in all 3 groups, 35%–40% required high flow nasal cannula (Figure 1; Supplementary Table 6). In a multivariable model, children with RSV infection with acute respiratory failure were 54% less likely to receive invasive mechanical ventilation (vs non-invasive or high flow nasal cannula) compared with children with COVID-19 (Table 3).
Figure 1.
Maximum level of respiratory support of children <2 y hospitalized with acute respiratory failure with respiratory syncytial virus (RSV), COVID-19, or RSV and SARS-CoV-2, 1 November 2023–31 March 2024, United States. Bars represent proportion of children with invasive mechanical ventilation (n = 253), noninvasive ventilation (n = 620), and high flow nasal cannula (n = 533), by virus and age. Numbers above bars represent the total number of children requiring respiratory support within each group (RSV, COVID-19, or RSV and SARS-CoV-2); within bars represent proportion of children by age and group.
Table 3.
Associations Between Virus Group and Hospitalization Outcomes Among Young Children (<2 Years) Hospitalized With Acute Respiratory FailureWith Respiratory Syncytial Virus (RSV), COVID-19, or RSV and SARS-CoV-2: United States, 1 November 2023–31 March 2024
| Invasive Mechanical Ventilationa,b | Number/Total (%) | Adjusted Prevalence Ratio (95% Confidence Interval) | |
|---|---|---|---|
| RSV | 206/1253 (16.4) | .46 (.25, .61) | |
| RSV and SARS-CoV-2 | 6/48 (12.5) | .36 (.16, .78) | |
| COVID-19 | 41/105 (39.0) | 1 (Ref) |
| Hospital length of stay (d)c | Median (25th–75th percentile) | Min–Max d | Negative binomial ratio coefficient (95% CI) |
|---|---|---|---|
| RSV | 6.0 (4.0, 9.0) | 2–157 | .75 (.65, .86) |
| RSV and SARS-CoV-2 | 6.0 (4.0, 8.0) | 3–30 | .71 (.56, .89) |
| COVID-19 | 6.0 (4.0, 10.0) | 2–156 | 1 (Ref) |
| Intensive care unit (ICU) length of stay (d) | Median (25th–75th percentile) | Min–Max d | Negative binomial ratio coefficient (95% CI) |
|---|---|---|---|
| RSV | 4.0 (3.0, 6.0) | 1–63 | .94 (.82, 1.08) |
| RSV and SARS-CoV-2 | 4.0 (3.0, 6.5) | 1–27 | .89 (.69, 1.13) |
| COVID-19 | 4.0 (3.0, 6.0) | 1–143 | 1 (Ref) |
aReceipt of invasive mechanical ventilation versus non-invasive ventilation or high flow nasal cannula.
bMultivariable log-binomial model; model controlled for age group (<6 m, 6 m to <1 y, 12 m to <2 y), presence of a respiratory underlying condition, presence of a cardiac underlying condition, and presence of another type of underlying condition.
cNegative binomial regression; model controlled for age group (<6 m, 6 m to <1 y, 12 m to <2 y), presence of a respiratory underlying condition, presence of a cardiac underlying condition, and presence of another type of underlying condition.
In bivariate analyses, median hospital LOS (6 days) and ICU LOS (4 days) did not differ across the 3 groups (Table 2). However, the multivariable analysis suggests that patients with RSV had reduced hospital LOS compared with patients with COVID-19 (Table 3). The percentage of children receiving life supportive interventions (invasive mechanical ventilation, vasoactive infusions, ECMO) or who died was highest among children with COVID-19 compared with RSV (P < .05 for all comparisons) (Table 2). Eight children died: 3 (2.9%) with COVID-19 and 5 (0.4%) with RSV (P = .03). Of the 8 children who died, 5 were <6 months of age (3 with COVID-19 [2.9%] and 2 [0.2%] with RSV) (Supplementary Table 7).
Table 2.
Hospitalization Outcomes Among Young Children (<2 Years) Hospitalized With Acute Respiratory Failure With Respiratory Syncytial Virus (RSV), COVID-19, or RSV and SARS-CoV-2: United States, 1 November 2023–31 March 2024
| RSV N = 1253 (%)a |
RSV And SARS-CoV-2 N = 48 (%)a |
COVID-19 N = 105 (%)a |
P Valueb | |
|---|---|---|---|---|
| Hospital length of stay | ||||
| Median length of hospital stay (p25, p75)c in d | 6.0 (4.0, 9.0) | 6.0 (4.0, 8.0) | 6.0 (4.0, 10.0) | .92 |
| Categorical hospital length of stay | ||||
| 2–4 d | 394 (31.4) | 14 (29.2) | 39 (37.1) | .41 |
| 5–7 d | 449 (35.8) | 15 (31.3) | 29 (27.6) | |
| 8 or more d | 410 (32.7) | 19 (39.6) | 37 (35.2) | |
| Intensive care unit (ICU) length of stay | ||||
| Median length of ICU stay (p25, p75)c in d |
4.0 (3.0, 6.0) | 4.0 (3.0, 6.5) | 4.0 (3.0, 6.0) | .93 |
| Categorical ICU length of stay | ||||
| 2–4 d | 772 (61.6) | 29 (60.4) | 60 (57.1) | .87 |
| 5–7 d | 275 (21.9) | 12 (25.0) | 27 (25.7) | … |
| 8 or more d | 206 (16.4) | 7 (14.6) | 18 (17.1) | … |
| Critical Illness | ||||
| Invasive mechanical ventilation | 206 (16.4) | 6 (12.5) | 41 (39.0) | <.001 |
| Vasoactive infusionsd,e | 77 (6.1) | 1 (2.1) | 18 (17.1) | <.001 |
| Extracorporeal membrane oxygenationf | 3 (0.2) | 0 | 3 (2.9) | .01 |
| Diede | 5 (0.4) | 0 | 3 (2.9) | .03 |
aColumn percents; Hospital and ICU length of stay are median and interquartile range.
bKruskal–Wallis test used to compare length of stay; χ2 test used to compare maximum respiratory support; Fisher's exact test used to compare severe outcomes.
c25th–75th percentile.
dAmong children with vasoactive infusions, 12/77 (15.6%) of those with RSV and 8/18 (44.4%) of those with COVID-19 had underlying cardiovascular disease.
eAmong children with vasoactive infusions, 30 (39.0%) of those with RSV were tested for, and 11 (36.7%) had bacterial coinfection; 4 (22.2%) of those with COVID-19 were tested for, and 3 (75%) had bacterial coinfection.
fFisher's exact test.
The results of the supplemental analysis among infants <1 year in which prematurity was categorized as an underlying condition was similar to the main analysis. In this younger sample, fewer infants had nonprematurity underlying comorbidities, and a nonstatistically significant increase in the prevalence of difficulty or fast breathing (Supplementary Table 8). Unadjusted analyses of hospitalization outcomes were similar (Supplementary Table 9), and multivariable analyses of hospitalization outcomes were similar or attenuated (Supplementary Table 10). Patterns of respiratory support requirements were also similar (Supplementary Figure 2).
DISCUSSION
This study included children under 2 years of age hospitalized in the ICU at least 24 hours with acute respiratory failure with RSV infection, COVID-19, or RSV + SARS-CoV-2 during the 2023–2024 US RSV season. We found that infants and children with RSV were more likely to be younger compared with those with COVID-19, and those with COVID-19 were more likely to require invasive mechanical ventilation compared with those with RSV. The clinical presentation, severity, and age distribution of the children testing positive for RSV + SARS-CoV-2 were more similar to those with RSV compared with those with COVID-19. Underlying conditions were uncommon among all children but occurred in a larger proportion of those with COVID-19. Proportionally, children with COVID-19 were more likely to experience critical illness.
In our study, more than 90% of all children presented with respiratory symptoms, although a slightly higher proportion with RSV presented with cough and difficulty breathing than children with COVID-19. Most children with RSV in the present study did not have an underlying medical condition, similar to findings of other studies of pediatric RSV hospitalizations, both within and outside of the ICU [18–20]. Among infants <1 year in this analysis, approximately 75% were born at term. More children with COVID-19 had an underlying condition than children with RSV, aligning with other studies describing children with underlying conditions at increased risk of experiencing a COVID-19 hospitalization requiring ICU admission than the general pediatric population [21, 22]. However, severe COVID-19 disease also occurred in children without underlying conditions.
Results of recent studies examining outcomes of infants and young children with COVID-19 and RSV have varied, likely due to differences in baseline study characteristics, such as age, underlying conditions, and illness severity. Infants and children admitted to the hospital for RSV often experience more frequent ICU admissions, longer hospital stays and require oxygen supplementation more frequently than children with COVID-19 [12, 16, 23]. Other studies have observed that coinfection with RSV and SARS-CoV-2 resulted in more severe clinical outcomes [10, 14, 24].
Effective preventive products exist for both RSV and COVID-19. In the US, an RSV maternal vaccine was approved in August 2023 for administration during 32 and 36 weeks of gestation to protect infants through passive antibody transfer [25, 26]. In the same month, a long-acting monoclonal antibody was approved for use in US infants 0–7 months entering their first RSV season, and in older infants and toddlers with specific underlying health conditions entering their second RSV season [27, 28]. Although these products were first available for the 2023–2024 RSV season, product uptake was hampered by product availability and limited awareness [28]. COVID-19 vaccinations were approved for adults in late 2020; vaccination during pregnancy can help prevent severe outcomes in infants caused by SARS-CoV-2 through placental antibody transfer [29, 30]. Although an updated 2023–2024 COVID-19 vaccination for young children aged 6 months through 11 years was approved on 12 September 2023 in the United States [31], cumulative updated vaccination coverage was only 5.5% for infants and children aged 6–23 months [32]. This analysis indicates that some previously healthy children can become critically ill with COVID-19 and RSV, underscoring the need for broad use of available preventive products.
Strengths of this study include using information from a national surveillance network that verified that admission to the ICU was for RSV or COVID-19. Further, these data reflect hospitalizations of children occurring during circulation of more recent Omicron SARS-CoV-2 subvariants, rather than the earlier and more severe Delta variant, and in the context of RSV seasonality returning to pre-pandemic patterns [1, 8]. Finally, we were able to include ICU-admitted children with RSV + SARS-CoV-2 codetections. These findings are important to understand the clinical differences and clinical course of these virus-infected groups, and also have implications for design of evaluations of prevention products for RSV and COVID-19 in infants and young children. Our findings suggest that RSV and SARS-CoV-2 coinfected children should be excluded from studies when evaluating COVID-19 hospitalizations, or that sensitivity analyses should be performed in which coinfections are excluded. Further characterization of this population can aid in understanding clinical course and designing preventive product evaluations.
There are limitations to the current analysis. First, these data represent data collection from 33 hospitals with pediatric ICUs throughout the US and may not be representative of other settings. Second, data included in the analysis were combined from 2 data sources within the same surveillance network, although methods for case identification and data collection were similar, likely minimizing issues with misclassification of symptoms and outcomes. Of note, only data from the COVID-19 hospitalization investigation included information about COVID-19 vaccination and RSV preventive products. Data from the COVID-19 hospitalization investigation indicate that product receipt was low during this first season of availability. While we could not assess illness severity among those who did and did not receive preventive products the impact in this population is likely minimal due to low overall uptake. Third, since viral testing was clinician driven, and pan-respiratory viral testing was not required for enrollment, infection with other pathogens was possible and could not be fully evaluated. Additionally, patients with RSV and/or COVID-19 who were not tested for these infections would not be included in the network. However, clinical testing for COVID-19 and RSV has increased since the end of the COVID-19 pandemic [33], and the use of multi-pathogen testing panels reduces the potential for patients being tested for RSV and not SARS-CoV-2 (or vice versa) [34]. Fourth, entrance into both investigations relied on clinical testing, which by default tends to select patients with higher severity or risk factors.
CONCLUSIONS
Respiratory syncytial virus and COVID-19 can both result in severe illness in infants and young children, but symptoms and clinical outcomes may differ. In this study among children <2 years of age hospitalized in the ICU with acute respiratory failure, children with RSV + SARS-CoV-2 codetection had an age distribution, illness presentation, and clinical severity more similar to children with RSV than those with COVID-19. Proportionally, severe outcomes, including invasive mechanical ventilation, receipt of vasopressors, and death occurred more frequently in children who were older and hospitalized for COVID-19 versus RSV. Preventive measures against RSV and COVID-19 are critical among very young children.
Supplementary Material
Notes
Author Contributions . Conception and Design: R. M. S., A. P. C., A. G. R. Data acquisition: A. B. M., A. B. P., A. G. R., A. O., A. P. P., B. M. C., D. M. Z., H. C., J. A. G., J. C. C., J. E. S., J. M. C., J. R. H., K. C., K. I., K. L., K. W., L. D. Z., L. M. M., M. A. C., M. A. S., M. K., M. M., M. M. N., M. S. Z., N. B. H., R. A. N., R. M. S., S. J. G., S. K., S. L. S., S. S. B., T. J. C., and T. T. B. Analysis and interpretation: A. G. R., A. P. C., J. M. C., L. D. Z., M. M. N., R. M. S. Drafting manuscript: R. M. S. Revision of manuscript: A. B. M., A. B. P., A. G. R., A. O., A. P. P., B. M. C., D. M. Z., H. C., J. A. G., J. C. C., J. E. S., J. M. C., J. R. H., K. C., K. I., K. L., K. W., L. D. Z., L. M. M., M. A. C., M. A. S., M. K., M. M., M. M. N., M. S. Z., N. B. H., R. A. N., R. M. S., S. J. G., S. K., S. L. S., S. S. B., T. J. C., and T. T. B.
Acknowledgments. Overcoming COVID-19 Investigators: Michele Kong, Children's of Alabama, Birmingham, Alabama; Meghan Murdock, Children's of Alabama, Birmingham, Alabama; Heather Kelley, Children's of Alabama, Birmingham, Alabama; Candice Colston, Children's of Alabama, Birmingham, Alabama; Neelima Marupudi, Banner Children's Hospital, Mesa, Arizona; Katherine Irby, MD, Arkansas Children's Hospital, Little Rock, Arkansas; Ronald C. Sanders, Arkansas Children's Hospital, Little Rock, Arkansas; Masson Yates, Arkansas Children's Hospital, Little Rock, Arkansas; Ashlyn Madding, Arkansas Children's Hospital, Little Rock, Arkansas; Shahwar Yousuf, Arkansas Children's Hospital, Little Rock, Arkansas; Melissa A. Cameron, Rady Children's Hospital, San Diego, California; Matt S. Zinter, UCSF Benioff Children's Hospital, San Francisco, California; Kanokporn Mongkolrattanothai, Children's Hospital Los Angeles, Los Angeles, California; Aline B. Maddux, Children's Hospital Colorado, Aurora, Colorado; Ariana Valenzuela, Children's Hospital Colorado, Aurora, Colorado; Natasha Baig, Children's Hospital Colorado, Aurora, Colorado; Lexi Petruccelli, Children's Hospital Colorado, Aurora, Colorado; Rachel Greer, Children's Hospital Colorado, Aurora, Colorado; Heidi Sauceda, Children's Hospital Colorado, Aurora, Colorado; Frances Zorensky, Children's Hospital Colorado, Aurora, Colorado; Alexander H. Hogan, Connecticut Children's Medical Center, Hartford, Connecticut; Katherine Herbst, Connecticut Children's Medical Center, Hartford, Connecticut; Carlie Defelice, Connecticut Children's Medical Center, Hartford, Connecticut; Jigar C. Chauhan, Nemours Children's Hospital, Wilmington, Delaware; Scott L. Weiss, Nemours Children's Hospital, Wilmington, Delaware; Rebecca Clifford, Nemours Children's Hospital, Wilmington, Delaware; Jenna Lapira, Nemours Children's Hospital, Wilmington, Delaware; Satoshi Kamidani, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Mark D. Gonzalez, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Caroline R. Ciric, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Jong-Ha C. Choi, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Gabriella Ess, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Anna K. Mitchell, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Luis W. Salazar, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta; Sarah Jae Wershil, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; Kelly N. Michelson, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; Bria M. Coates, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; Samina S. Bhumbra, Riley Hospital for Children, Indianapolis, Indiana; Mary Stumpf, Riley Hospital for Children, Indianapolis, Indiana; Kari Wellnitz, Stead Family Children's Hospital, Iowa City, Iowa; Tamara T. Bradford, Children's Hospital of New Orleans, New Orleans, Louisiana; Adrienne G. Randolph, Boston Children's Hospital, Boston, Massachusetts; Margaret M. Newhams, Boston Children's Hospital, Boston, Massachusetts; Amber O. Orzel-Lockwood, Boston Children's Hospital, Boston, Massachusetts; Jemima M. Calixte, Boston Children's Hospital, Boston, Massachusetts; Benjamin Schattman, Boston Children's Hospital, Boston, Massachusetts; Allison Zaff, Boston Children's Hospital, Boston, Massachusetts; Amira Toivonen, Boston Children's Hospital, Boston, Massachusetts; Janet R. Hume, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota; Lora Martin, Children's Hospital of Mississippi, Jackson, Mississippi; Joseph M. Majure, Children's Hospital of Mississippi, Jackson, Mississippi; Lacy Malloch, Children's Hospital of Mississippi, Jackson, Mississippi; Maygan Martin, Children's Hospital of Mississippi, Jackson, Mississippi; Jennifer E. Schuster, Children's Mercy Kansas City, Kansas City, Missouri; Berenice Marrufo, Children's Mercy Kansas City, Kansas City, Missouri; Abigail Kietzman, Children's Mercy Kansas City, Kansas City, Missouri; Shira J. Gertz, Cooperman Barnabas Medical Center, Livingston, New Jersey; Elizabeth Ricciardi, Cooperman Barnabas Medical Center, Livingston, New Jersey; Thomas J. Connors, Columbia University Irving Medical Center, New York City, New York; Melissa S. Stockwell, Columbia University Irving Medical Center, New York City, New York; Celibell Y. Vargas, Columbia University Irving Medical Center, New York City, New York; Raul A. Silverio Francisco, Columbia University Irving Medical Center, New York City, New York; Saul R. Hymes, Bernard & Millie Duker Children's Hospital, Albany, New York; Ilana Harwayne-Gidansky, Bernard & Millie Duker Children's Hospital, Albany, New York; Stephanie P. Schwartz, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Tracie C. Walker, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Alison Mathers, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Miriam Davis, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Ryan A. Nofziger, Akron Children's Hospital, Akron, Ohio; Nicole Twinem, Akron Children's Hospital, Akron, Ohio; Olivia Kennedy, Akron Children's Hospital, Akron, Ohio; Mary Allen Staat, Cincinnati Children's Hospital, Cincinnati, Ohio; Chelsea C. Rohlfs, Cincinnati Children's Hospital, Cincinnati, Ohio; Steven Shein, UH Rainbow Babies and Children's Hospital, Cleveland, Ohio; Rajashri Rasal, UH Rainbow Babies and Children's Hospital, Cleveland, Ohio; Judith A. Guzman-Cottrill, Oregon Health and Science University, Portland, Oregon; Chelsea Heisler, Health and Science University, Portland, Oregon; Kathleen Chiotos, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Alanah Mckelvey, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Jenny Bush, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Rebecca Douglas, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Mickael Boustany, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Austin Biggs, MUSC Children's Health, Charleston, South Carolina; Zach Rusler, MUSC Children's Health, Charleston, South Carolina; Natasha B. Halasa, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee; Laura S. Stewart, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee; Kristina Betters, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee; Julie A. Boom, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas; Leila C. Sahni, Texas Children's Hospital and Baylor College of Medicine, Houston, Texas; Mia Maamari, University of Texas Southwestern, Children's Medical Center Dallas, Dallas, Texas; Cindy Bowens, University of Texas Southwestern, Children's Medical Center Dallas, Dallas, Texas; Hillary Crandall, University of Utah and Primary Children's Hospital, Salt Lake City, Utah; Danielle Zerr, Seattle Children's Hospital, Seattle, Washington; Amanda Adler. Seattle Children's Hospital, Seattle, Washington.
Disclaimer The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.
Financial support. This work was funded by the Centers for Disease Control and Prevention (CDC) under a contract (75D30122C13330) with Boston Children's Hospital.
Data availability . Data are not publicly available. Deidentified participant data in a limited dataset may be made available upon formal request for a specified purpose for researchers whose proposed use of the data has been approved.
Contributor Information
Regina M Simeone, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Margaret M Newhams, Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.
Laura D Zambrano, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Jemima M Calixte, Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.
Katherine Lindsey, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 4ES Corporation, Atlanta, Georgia, USA.
Amber Orzel-Lockwood, Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.
Amanda B Payne, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Natasha B Halasa, Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee,USA.
Satoshi Kamidani, The Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA.
Aline B Maddux, Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA.
Kathleen Chiotos, Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
Hillary Crandall, Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA.
Jennifer E Schuster, Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri, USA.
Danielle M Zerr, Division of Infectious Diseases, Department of Pediatrics, University of Washingtonand Seattle Children's Research Institute, Seattle, Washington, USA.
Lora M Martin, Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi, USA.
Melissa A Cameron, Division of Pediatric Hospital Medicine, UC San Diego–Rady Children's Hospital, San Diego, California, USA.
Katherine Irby, Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas, USA.
Shira J Gertz, Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, New Jersey, USA.
Steven L Shein, Department of Pediatrics, Rainbow Babies and Children's Hospital, Cleveland, Ohio, USA.
Ryan A Nofziger, Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio, USA.
Samina S Bhumbra, Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Janet R Hume, Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA.
Michele Kong, Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
Mia Maamari, Department of Pediatrics, Division of Critical Care Medicine, Children's Medical Center Dallas, University of Texas Southwestern, Dallas, Texas, USA.
Bria M Coates, Division of Pediatric Critical Care Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA.
Judith A Guzman-Cottrill, Department of Pediatrics, Oregon Health and Science University, Portland, Oregon, USA.
Mary Allen Staat, Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
Thomas J Connors, Division of Child and Adolescent Health, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, NewYork, New York, USA.
Matt S Zinter, Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California SanFrancisco, San Francisco, California, USA.
Jigar C Chauhan, Division of Pediatric Critical Care, Nemours Children's Hospital, Wilmington, Delaware, USA.
Tamara T Bradford, Division of Cardiology, Department of Pediatrics, Louisiana State University Health Sciences Center and Children’s Hospital of New Orleans, New Orleans, Louisiana, USA.
Kari Wellnitz, Division of Pediatric Critical Care, Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
Angela P Campbell, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Adrienne G Randolph, Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA; Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA; Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.
Overcoming COVID-19 Investigators:
Michele Kong, Meghan Murdock, Heather Kelley, Candice Colston, Neelima Marupudi, Katherine Irby, Ronald C Sanders, Masson Yates, Ashlyn Madding, Shahwar Yousuf, Melissa A Cameron, Matt S Zinter, Kanokporn Mongkolrattanothai, Aline B Maddux, Ariana Valenzuela, Natasha Baig, Lexi Petruccelli, Rachel Greer, Heidi Sauceda, Frances Zorensky, Alexander H Hogan, Katherine Herbst, Carlie Defelice, Jigar C Chauhan, Scott L Weiss, Rebecca Clifford, Jenna Lapira, Satoshi Kamidani, Mark D Gonzalez, Caroline R Ciric, Jong-Ha C Choi, Gabriella Ess, Anna K Mitchell, Luis W Salazar, Sarah Jae Wershil, Kelly N Michelson, Bria M Coates, Samina S Bhumbra, Mary Stumpf, Kari Wellnitz, Tamara T Bradford, Adrienne G Randolph, Margaret M Newhams, Amber O Orzel-Lockwood, Jemima M Calixte, Benjamin Schattman, Allison Zaff, Amira Toivonen, Janet R Hume, Lora Martin, Joseph M Majure, Lacy Malloch, Maygan Martin, Jennifer E Schuster, Berenice Marrufo, Abigail Kietzman, Shira J Gertz, Elizabeth Ricciardi, Thomas J Connors, Melissa S Stockwell, Celibell Y Vargas, Raul A Silverio Francisco, Saul R Hymes, Ilana Harwayne-Gidansky, Stephanie P Schwartz, Tracie C Walker, Alison Mathers, Miriam Davis, Ryan A Nofziger, Nicole Twinem, Olivia Kennedy, Mary Allen Staat, Chelsea C Rohlfs, Steven Shein, Rajashri Rasal, Judith A Guzman-Cottrill, Chelsea Heisler, Kathleen Chiotos, Alanah Mckelvey, Jenny Bush, Rebecca Douglas, Mickael Boustany, Austin Biggs, Zach Rusler, Natasha B Halasa, Laura S Stewart, Kristina Betters, Julie A Boom, Leila C Sahni, Mia Maamari, Cindy Bowens, Hillary Crandall, Danielle Zerr, and Amanda Adler
Supplementary Data
Supplementary materials are available at Open Forum Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author.
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