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Coronavirus%20disease%202019%20(covid-19) Signs and Symptoms
Definition
- A respiratory tract infection caused by a newly emergent coronavirus, SARS-CoV-2, that was first recognized in Wuhan, China in December 2019
Etiology
- SARS-CoV-2 is classified within the genus Betacoronavirus (subgenus Sarbecovirus) of the family Coronaviridae
- An enveloped, positive-sense, single-stranded ribonucleic acid (RNA) virus with a 30-kb genome
- SARS-CoV-2 is most genetically similar to SARS-CoV-1 and both belong to the subgenus Sarbecovirus within the genus Betacoronavirus
- However, SARS-CoV-1 is currently not known to circulate in the human population
- Infection is caused by binding of the viral surface spike protein to the human angiotensin-converting enzyme 2 (ACE2) receptor after activation of the spike protein by transmembrane protease serine 2
- Variants of concern (VOC) are mutations in SARS-CoV-2 genome that have rapid emergence within populations and evidence for transmission or clinical implications
| Variants of Concern as of 4 October 2022 | ||
| WHO Label | Pango Lineage* | Earliest Documented Samples |
| Omicron# | B.1.1.529 | Multiple countries; November 2021 |
| WHO = World Health Organization *Resource that compiles reported SARS-CoV-2 genome sequences and assigns them to a most likely phylogenetic lineage #Includes BA.1, BA.2, BA.3, BA.4, BA.5 and descendent lineages. It also includes BA.1/BA.2 circulating recombinant forms such as XE. |
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- VOC lineages under monitoring are variants that belong to currently circulating VOC that shows signals of transmission advantage compared to other circulating VOC lineages and has additional changes in the amino acids that are known or confer the observed change in epidemiology and fitness advantage as compared to other circulating variants
| Omicron Subvariants under Monitoring as of 4 October 2022 | ||
| Pango Lineage* (+ mutation) |
Relationship to Circulating VOC Lineages | Earliest Documented Samples |
| BA.51 (+R346X or +K444x or +V445X or +N450D or +N460X) |
BA.5 sublineages (eg BF.7, BF.14, BQ.1) |
2 February 2022 |
| BA.2.752 | BA.2 sublineage | 31 December 2021 |
| BJ.13 | BA.2 sublineage (B.1.1.529.2.10.1.1) |
6 September 2022 |
| BA.4.6 | BA.4 sublineage | 20 July 2022 |
| *Resource that compiles reported SARS-CoV-2 genome sequences and assigns them to a most likely
phylogenetic lineage. Includes descendant lineages. 1Includes additional mutations outside of the spike protein: N:G30-, N:S33F, ORF1a:Q556K,ORF1a:L3829F, ORF1b:Y264H, ORF1b:M1156I, ORF9b:P10F, ORF9b:D16G, ORF9b:M26-, ORF9b:A29I,ORF9b:V30L 2Includes additional mutation outside the spike protein: ORF1a:S1221L, ORF1a:P1640S, ORF1a:N4060S;ORF1b:G662S; E:T11A 3Includes additional mutations outside of the spike protein: Mutations: M:D3Y, N:T282I, ORF1a:K47R,ORF1b:G662S, ORF1b:S959P, ORF7a:I110T |
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- Variants of interest (VOI) are SARS-CoV-2 isolates that when compared to a reference isolate, its genome has mutations with established or suspected phenotypic implications
- As of 4 October 2022, there is no currently circulating VOI
Initial Signs and Symptoms
- Fever or chills
- Cough
- Dyspnea
- Chest imaging showing bilateral infiltrates
- Fatigue
- Muscle or body aches
- Headache
- New loss of smell or taste
- Sore throat
- Diarrhea
Epidemiology
- Globally as of 6 October 2022, there have been 616,951,418 confirmed cases of COVID-19, including 6,530,281deaths, reported to WHO
- Per region, confirmed cases based on WHO data as of 6 October 2022 are as follows:
- Americas: 178,580,482
- Europe: 255,176,621
- South-East Asia: 60,320,240
- Eastern Mediterranean: 23,099,945
- Africa: 9,334,291
- Western Pacific: 90,439,075
Modes of Transmission
- Contact and droplet transmission through direct, indirect, or close contact with infected individuals through secretions ie saliva and respiratory secretions
- Airborne transmission occurs during medical procedures that generate aerosols (aerosol-generating procedures)
- Fomite transmission is through contaminated surfaces and objects
- Viable SARS-CoV-2 virus and/or RNA detected by RT-PCR can be found on those surfaces for periods ranging from hours to days, depending on the ambient environment (including temperature and humidity) and the type of surface
- Others like urine, feces, plasma or serum
Factors that Determine Transmission Risk
- Whether the virus is still replication-competent
- Presence of symptoms eg cough
- Behavior and environmental factors associated with the infected person
- COVID-19 patient starts to gradually produce neutralizing antibodies that reduces the risk of virus transmission, usually 5-10 days after infection with SARS-CoV-2
Incubation Period
- Generally after exposure to the virus, the mean time to develop symptoms is 4-6 days, with a range of between 1 and 14 days
