General Considerations

 General Considerations

In late 2019, a novel coronavirus emerged, spreading quickly from its origin in China across the globe. The CDCrecommended terminology for the virus is SARS-CoV-2, and the illness caused by this virus is called “Coronavirus Disease 2019” or COVID-19 (https://www.cdc.gov/coronavirus/2019-ncov/summary.html). COVID-19 was declared a pandemic by the WHO on March 11, 2020. The earliest known case in the United States was documented on January 21, 2020, in a man who had recently returned to the state of Washington from China. The first US case that was not associated with travel or contact with infected travelers was identified in February 2020 in Solano, California. As of May 22, 2020, the confirmed number of global cases is over 5.1 million, including more than 333,000 deaths. The United States reported the largest number of cases at almost 1.6 million cases (and over 95,000 deaths). Early in the outbreak, most fatalities were from the Chinese province of Hubei and its capital, Wuhan. By early March 2020, case numbers outside of China were growing faster than inside China; particular foci of exponential growth were from nations in Europe, Asia, and the Americas (see the Johns Hopkins Coronavirus Resource Center website for specifics at a given time https://coronavirus.jhu.edu/). Some COVID-19 strains from Western Europe have enhanced transmissibility as a function of a modified spike protein S. A pattern of mutations is being described as phylodynamic and three main groups comprise current global strains, with ongoing efforts underway to identify new variants as they emerge. Since April 2020, the CDC has recommended that travelers avoid nonessential international travel, restrict domestic travel, and stay at home as much as possible. The CDC website provides a complex set of guidelines and suggestions regarding travel (www.cdc.gov). All travelers should be aware of the likelihood of quarantine both abroad and on return based on origin and destination of travel. A case tally and other current information are available through the WHO website (https://www.who.int/emergencies/diseases/novel-coronavirus-2019) and, with an interactive map, through The Johns Hopkins University Wuhan Coronavirus website (https://coronavirus.jhu.edu/map.html). Highly informative weekly UCSF Medical Grand Rounds focused entirely on COVID-19 since March 19, 2020 to at least June 2020 can be found on YouTube. Severe COVID-19 disease is hypothesized to occur due to development of an intense and/or prolonged inflammatory reaction, often called a “cytokine storm,” in the later phase of illness. Specifically, persistent immune activation in predisposed patients can lead to uncontrolled amplification of cytokine production (including interleukin-6 [IL-6]), leading to multiorgan failure and death.

MEDICAL SOURCES 29/12/2020