Chapter 2 Empirical Background
This is a study of variation in the COVID-19 pandemic. Coronavirus disease 19 (COVID-19) is the disease resulting from infection by the Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) (Gorbalenya et al. 2020). The very first identified and genetically sequenced case of COVID-19 was on 26 December 2019 of a patient who was a worker at a seafood market in Wuhan China ((“A Novel Coronavirus from Patients with Pneumonia in China, 2019 | NEJM,” n.d.)). The designation of pandemic was assigned by the World Health Organization on March 11, 2020 on the criteria that the disease is both new and has cases observed worldwide (“WHO | What Is a Pandemic?” n.d.).
Occupation, Income, Race Hospitlization COVID-19 Symptoms -> COVID-19 Tested Occupation -> COVID-19 Positive -> COVID-19 Symptoms
Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019 — COVID-NET, 14 States, March 1–30, 2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e3.htm (Garg 2020)
Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization Surveillance Network (COVID-NET) https://www.cdc.gov/coronavirus/2019-ncov/covid-data/covid-net/purpose-methods.html COVID-NET differs from hospitalizations reported in national and state case counts in two ways. First, state and national COVID-19 case reporting are based on all people who test positive for COVID-19 in the United States. COVID-NET is limited to COVID-19-associated hospitalizations captured in the COVID-NET surveillance area. Second, COVID-NET reports rates and not just counts. These rates show how many people are hospitalized with COVID-19 in the surveillance area, compared to the entire number of people residing in that area. COVID-NET comprises 99 counties in the 14 states participating in the Emerging Infections Program (EIP) and the Influenza Hospitalization Surveillance Project (IHSP). Participating states include: California, Colorado, Connecticut, Georgia, Iowa, Maryland, Michigan, Minnesota, New Mexico, New York, Ohio, Oregon, Tennessee, and Utah. COVID-NET covers approximately 10 percent of the U.S. population. The counties covered are located in all 10 Health and Human Services (HHS) regionsexternal icon. The designated COVID-NET surveillance area is generally similar to the U.S. population by demographics; however, the information might not be generalizable to the entire country. So it’s 14 states, 99 counties, sampled-ish maybe from the 10 HHS regions.
Non-random samples (Griffith et al. 2020)
Who get’s tested? Polymerase chain reaction (PCR) antigen tests are used to confirm a suspected (currently active) COVID-19 infection. Studies that aim to determine the risk factors for confirmed current COVID-19 infection therefore rely on participants having received a COVID-19 antigen test (hereafter for simplicity: COVID-19 test or test).
Timeline On December 31 2019, China notified the World Health Organisation (WHO) about a cluster of pneumonia cases of unknown aetiology in Wuhan, the capital of the Hubei Province. The initial evidence was suggestive of the outbreak being associated with a seafood market in Wuhan, which was closed on January 1 2020. The aetiological agent was characterised as a SARS-like betacoronavirus, later named SARS-CoV-2, and the first whole genome sequence (Wuhan-HU-1) was deposited on NCBI Genbank on January 5 2020 (Wu et al., 2020).
References
Garg, Shikha. 2020. “Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019 COVID-NET, 14 States, March 130, 2020.” MMWR. Morbidity and Mortality Weekly Report 69. https://doi.org/10.15585/mmwr.mm6915e3.
Gorbalenya, Alexander E., Susan C. Baker, Ralph S. Baric, Raoul J. de Groot, Christian Drosten, Anastasia A. Gulyaeva, Bart L. Haagmans, et al. 2020. “The Species Severe Acute Respiratory Syndrome-Related Coronavirus : Classifying 2019-nCoV and Naming It SARS-CoV-2.” Nature Microbiology 5 (4): 536–44. https://doi.org/10.1038/s41564-020-0695-z.
Griffith, Gareth, Tim T Morris, Matt Tudball, Annie Herbert, Giulia Mancano, Lindsey Pike, Gemma C Sharp, et al. 2020. “Collider Bias Undermines Our Understanding of COVID-19 Disease Risk and Severity.” medRxiv, January, 2020.05.04.20090506. https://doi.org/10.1101/2020.05.04.20090506.
“WHO | What Is a Pandemic?” n.d. WHO. http://www.who.int/csr/disease/swineflu/frequently_asked_questions/pandemic/en/; World Health Organization.