TUESDAY, June 2, 2020 (HealthDay News) -- Sustained, community transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) possibly resulted from importation of a single lineage of virus from China between Jan. 18 and Feb. 9, 2020, according to research published in the May 29 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Michelle A. Jorden, M.D., from the County of Santa Clara Office of the Medical Examiner-Coroner in San Jose, California, and colleagues present evidence for limited early spread of COVID-19 within the United States.
The first and second non-travel-related cases in the United States were confirmed on Feb. 26 and Feb. 28, 2020. The researchers found that based on syndromic surveillance from emergency department records from counties affected early by the pandemic, there was no increase in visits for COVID-19-like illness before Feb. 28, 2020. No positive results were identified before Feb. 20, 2020, in retrospective SARS-CoV-2 testing of about 11,000 respiratory specimens from several U.S. locations beginning Jan. 1, 2020. Based on viral RNA analysis, a single lineage of virus imported directly or indirectly from China began circulating in the United States between Jan. 18 and Feb. 9, 2020, followed by several importations from Europe. Cryptic circulation of the virus was confirmed by early February based on the occurrence of three cases, two in California who died on Feb. 6 and 17, 2020, and one on a Pacific cruise ship on Feb. 11, 2020.
"Enhanced syndromic and virus surveillance will be needed to monitor COVID-19 trends for the duration of the pandemic," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.