Covid-19: Study Reveals How Long It Takes Omicron Symptoms To Surface

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A survey following an outbreak of 111 confirmed or probable Omicron cases among mostly fully vaccinated guests at a Christmas party at a closed location in a restaurant in Oslo, Norway found symptoms surfaced at a relatively fast rate.

The party was held on Friday, Nov. 26, two days after one of the attendees returned from South Africa, where the Omicron strain was first detected in mid-November.

Detection of the outbreak came on Tuesday, Nov. 30, and the study showed that on average, most symptoms surfaced in a three-day window after exposure.

"Of the 111 respondents, 66 (59 percent) were confirmed cases (26 based on WGS and 40 based on PCR VOC screening) and 15 (14 percent) were probable cases (PCR-positive only)," according to survey findings. "One PCR-positive attendee was confirmed to be infected with SARS-CoV-2 Delta variant."

According to the World Health Organization (WHO), it takes five to six days, on average, from when someone is infected with the original COVID-19 virus for symptoms to show, and it could take up to 14 days.

The apparent accelerated rate for Omicron symptoms to show up after exposure would appear to provide another reason the new variant is able to spread so quickly.

• COVID-19: Study Of Omicron Outbreak At Christmas Party Reveals Three New Symptom

Omicron "replicates, multiples very well in the upper airway (above the neck), but less well in the lung," Top Infectious Disease Specialist Dr. William Schaffner of Vanderbilt University Medical Center told NBC News.

People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. 

Symptoms may appear two to 14 days after exposure to the virus, according to the Centers for Disease Control and Prevention (CDC). 

Anyone can have mild to severe symptoms, said the CDC, which currently lists these 11 symptoms for COVID-19:

• Fever or chills,
• Cough,
• Shortness of breath or difficulty breathing,
• Fatigue,
• Muscle or body aches,
• Headache,
• New loss of taste or smell.
• Sore throat,
• Congestion or runny nose.
• Nausea or vomiting,
• Diarrhea.

The list does not include all possible symptoms, the CDC said. 

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