UK study suggests that Omicron BA.2 is tied to more symptoms and greater disruption in daily activities than BA.1, and Taiwanese researchers describe fatal cerebral edema in six children hospitalized for BA.2.
Imperial College London researchers tracked SARS-CoV-2 transmission and symptoms among 1,542,510 randomly selected English adults, including 17,448 COVID-19 patients, from May 1, 2020, to Mar 31, 2022.
A greater proportion of BA.2 patients (75.9%) reported at least one of 26 symptoms, compared with 70.0% of those with BA.1, 63.8% with Delta, 54.7% with Alpha, and 45.0% with the wild-type virus.
Patients with wild-type, Alpha, or Delta infections were at highest risk for loss of sense of smell (odds ratios [ORs], 49.7, 37.8, and 73.4, respectively) and taste (ORs, 35.9, 38.9, and 68.1, respectively), while those with BA.1 or BA.2 had higher odds of flu- and cold-like symptoms.
A total of 17.6% of BA.2-infected people said their symptoms had affected their ability to complete daily activities "a lot," compared with 10.7% with BA.1 and 10.5% with Delta infections.
"With restrictions lifted and routine testing limited in many countries, monitoring the changing symptom profiles associated with SARS-CoV-2 infection and effects on daily activities will become increasingly important," the authors wrote.
In Taiwan, researchers examined clinical records from six BA.2-infected children diagnosed as having acute fulminant cerebral edema (usually fatal, rapid-onset brain swelling) from Apr 13 to Jun 30, 2022.
All six initially had shock and significantly elevated inflammatory biomarkers, with five rapidly progressing to multi-organ failure and diffuse blood-vessel clotting and three developing acute respiratory distress.
The researchers said that fever above 41oC (105.8oF) and atypical complex fever-related seizures are early signs of cerebral edema in pediatric patients. "The rapid and fulminant course highlights a need for close monitoring of cardiopulmonary and hematological functions in such patients, especially during the first day after the onset of neurological signs," they wrote.