324 - Hospitalizations for Pediatric COVID-19 and MIS-C: Comparing the Delta Variant to Previous Waves

Poster Number: 324
Publication Number: 324.214

Hannah Wilson, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; Leigh Anne DiCicco, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Kristina Gaietto, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; Megan C. Freeman, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; Sherry Rauenswinter, children's community pediatrics, Baden, PA, United States; Zachary Aldewereld, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, United States; Jennifer S. Iagnemma, UPMC Children's Community Pediatrics, Wexford, PA, United States; David Wolfson, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Traci M. Kazmerski, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Erick Forno, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

Background: Pediatric hospitalizations for COVID19 and MISC have markedly increased since the delta variant of SARS-CoV-2 became prevalent in the US. Beyond this higher incidence, little is known about how delta affects pediatric populations compared to prior variants.

Objective: To evaluate the differences in COVID19 hospitalizations during the Delta variant, compared to prior waves.

Design/Methods: The Western Pennsylvania COVID19 Registry (WPACR), established in March 2020, includes all cases of SARS-CoV-2 infection admitted to Children’s Hospital of Pittsburgh (CHP), the region’s largest pediatric referral center. We analyzed characteristics of patients hospitalized at CHP with COVID19 or MISC before (3/01/20-2/28/21) and after (8/01/21-) the emergence of the delta variant.

Results: We analyzed 78 pre-delta and 155 delta-wave hospitalizations (25 and 27 with MISC, respectively) (Figure).
 
Non-MISC hospitalizations: There were no differences in age, sex, race, zipcode median income, PICU admission, or length of stay (LOS) between pre-delta and delta waves (Table). Delta hospitalizations had fewer pre-existing conditions (52% vs 76%) and a trend towards lower BMI, and presented more frequently with cough (67% vs 42%), abnormal CXR (66% vs 39%), and hypoxia (33% vs 17%). During delta, hospitalized patients were more likely to receive systemic steroids (31% vs 13%) and remdesivir (21% vs 6%).
 
MISC: There were no differences in age, sex, race, BMI, income, or inflammatory markers between waves. All patients received systemic steroids. During delta, LOS was markedly shorter (mean 5.4 [4.3-6.5] days vs 10.6 [5.2-15.9] pre-delta) and there was a trend towards fewer PICU admissions (59.3% vs 80%).
 
Overall: Compared to non-MISC cases, those with MISC had more systemic and GI symptoms but fewer respiratory symptoms; fewer CXR abnormalities; higher inflammatory markers; and longer LOS. They were more likely to receive steroids, IVIg, and pressors.
 
In our adjusted models, factors associated with PICU admission were chronic conditions, hypoxia, and MISC. Factors associated with longer LOS included pre-delta case, PICU stay, MISC, chronic conditions, and lower income. Viral testing during the delta wave showed 20% co-infection with RSV, which was associated with hypoxia (39% vs 6% in cases without RSV).Conclusion(s): Delta has led to a large increase in pediatric COVID19 cases, who were more likely to present with respiratory symptoms and hypoxia than in previous waves. LOS for MISC was markedly shorter during delta than in prior months, perhaps due to improvements in management. RSV co-infection was linked to hypoxia.
Figure – Hospitalizations before and during Delta variant
Table – Characteristics of study cohort