One study of health care workers in South Africa, which has not yet been peer-reviewed, found the rate of people carrying the disease without symptoms had climbed from 2.6% during the Beta and Delta variant outbreaks to 16% with Omicron. Scientists caution that Omicron's rapid ascent may be fueled in large part by more people spreading the virus with no symptoms at all. is on track to exceed the Delta variant's worst days of hospitalizations and deaths due to the sheer numbers of people who may catch the fast-spreading strain. A consortium of disease forecasters warned Tuesday that the U.S. The incubation period in both outbreaks also averaged around three days, shorter than the four to five days seen with the Delta variant.ĭespite signs that Omicron leads to a lower individual risk of severe illness, it's so contagious that hospitals are struggling to handle the growing caseload. One additional unvaccinated person, who had not been previously diagnosed with COVID-19, reported "cough, joint pain, congestion, fever, and chills."
In an Omicron outbreak between five reinfected people in a Nebraska household, a recent report published by the Centers for Disease Control and Prevention found none had reported loss of taste or smell - compared to four during their first bout of COVID-19 in 2020. Only 12% reported reduced smell and 23% reported reduced taste. One analysis of data compiled from reports of positive cases in London, where Omicron cases surged last month, tallied the top five symptoms as runny nose, headache, fatigue, sneezing, and sore throat.Īmong mostly vaccinated people infected at a Christmas party in Norway, cough and runny nose showed up in more than three-quarters of the 81 cases.
Investigations of outbreaks outside of South Africa have turned up similar trends.
South Africa's National Institute for Communicable Diseases warned residents late last month to watch for those kinds of upper respiratory symptoms, and noted that one distinctive symptom seen in cases of earlier COVID variants - loss of taste and smell - "seems to be uncommon" with Omicron.