Investigation of a SARS-CoV-2 B.1.1.529 (Omicron) Variants Cluster — Nebraska, November–December 2021

Details

• Personal Author:
  Jansen, Lauren ; Tegomoh, Bryan ; Lange, Kate ; Showalter, Kimberly ; Figliomeni, Jon ; Abdalhamid, Baha ; Iwen, Peter C. ; Fauver, Joseph ; Buss, Bryan ; Donahue, Matthew
• Corporate Authors:
  Nebraska. Department of Health and Human Services. ; Centers for Disease Control and Prevention (U.S.)Epidemic Intelligence Service. ; CDC Foundation. ; Public Health Solutions District Health Department. ; Nebraska Public Health Laboratory. ; University of Nebraska Medical Center. College of Public Health. ; Center for Preparedness and Response (U.S.)Division of State and Local Readiness.
• Description:
  The B.1.1.529 (Omicron) Variants of SARS-CoV-2 (the Virus that causes COVID-19) was first detected in specimens collected on November 11, 2021, in Botswana and on November 14 in South Africa;* the first confirmed case of Omicron in the United States was identified in California on December 1, 2021 (1). On November 29, the Nebraska Department of Health and Human Services was notified of six probable cases† of COVID-19 in one household, including one case in a man aged 48 years (the index patient) who had recently returned from Nigeria. Given the patient’s travel History, Omicron infection was suspected. Specimens from all six persons in the household tested positive for SARS-CoV-2 by reverse transcription–polymerase chain reaction (RT-PCR) tTesting on December 1, and the following day genomic sequencing by the Nebraska Public Health Laboratory identified an identical Omicron genotype from each specimen (Figure). Phylogenetic Analysis was conducted to determine if this cluster represented an independent introduction of Omicron into the United States, and a detailed epidemiologic investigation was conducted. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.
  
  The index patient, who was unvaccinated, had a History of domestically acquired symptomatic SARS-CoV-2 infection confirmed by RT-PCR a year prior in November 2020. He reported unmasked close contact with a masked, coughing person on November 20, 2021, during an international conference in Nigeria, which included attendees from multiple African countries. Before his return trip to the United States, he completed required pretravel tTesting with receipt of a negative antigen test result on November 21. Upon his return on November 23, while still asymptomatic, he had unmasked close contact with five household contacts. One household contact was fully vaccinated (second Pfizer-BioNTech vaccine dose received in August 2021) and had previous symptomatic COVID-19 (RT-PCR confirmed in November 2020), three were unvaccinated and had previous symptomatic COVID-19 (RT-PCR confirmed in November 2020), and one was unvaccinated and had mild upper respiratory symptoms in November 2020, just before illness onset in the other household members, but received a negative SARS-CoV-2 RT-PCR test result at that time. No household members reported underlying medical conditions or immunocompromising conditions known to increase the risk for severe COVID-19 or diminish response to vaccination.
  
  Suggested citation for this article: Jansen L, Tegomoh B, Lange K, et al. Investigation of a SARS-CoV-2 B.1.1.529 (Omicron) Variant Cluster — Nebraska, November–December 2021. MMWR Morb Mortal Wkly Rep. ePub: 28 December 2021.
  
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  mm705152e3-H.pdf
  
  
• Subjects:
  CoronaVirus Infections COVID-19/Epidemiology Disease Outbreaks SARS-CoV-2
• Source:
  MMWR: Morbidity and Mortality Weekly Report 2021; v. 70 Early Release
• Series:
  Weekly Report: Morbidity and Mortality Weekly Report (MMWR)
• ISSN:
  0149-2195 (print) ; 1545-861X (digital)
• Document Type:
  Journal Article
• Name as Subject:
  "Test to Stay"
• Pages in Document:
  3 pdf pages
• Volume:
  70
• Collection(s):
  Morbidity and Mortality Weekly Report (MMWR)
• Main Document Checksum:
  urn:sha-512:8b57b1b1015654dd7ceaaabcf37ffa2bcac30621c5e99571db75463dc9bc55909bd404e6a20ecf097bd7639d0ae89063cc7d67f2fc7aacca1a9491fbb3e54b55
• Download URL:
  https://stacks.cdc.gov/view/cdc/112952/cdc_112952_DS1.pdf
• File Type:
  [PDF - 233.81 KB ]