Coronavirus Disease-2019 Case, Death, and Testing Rates in the United States and Worldwide: Primary Data and Review

Schaefer, E. J.; Geller, A. S.; Diffenderfer, M. R.; Dulipsingh, L.; Wisotzkey, J.; Kleiboeker, S. B.

ABSTRACT Coronavirus disease-2019 (COVID-19), due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has been associated with a world-wide pandemic, with the United States (US) having the largest total number of cases and deaths (>7 million and >200,000, respectively) at this time. We assessed data as of September 1, 2020 from our combined laboratories and as reported for selected states and countries for case, death, and testing rates per 1 million in the population. Our goal was to elucidate potential causes for the large rate differences observed. SARS-CoV-2 naso-pharyngeal (NP) RNA swab testing in 985,219 US subjects referred to our laboratories by healthcare providers revealed an overall 10.1% positive rate, comparable to the 7.3% rate reported nationwide. In a small subset of 91 subjects, all of whom had been positive for SARS-CoV-2 RNA in NP swabs 2-4 weeks earlier, NP swab testing was twice as likely to be positive (58.6%) as saliva samples (21.5%), based on paired sampling. Our positive rates per state agreed reasonably well with reported Centers for Disease Control and Prevention (CDC) data (r=0.609, P<0.0001) based on 19,898 cases, 593 deaths, and 271,637 tests, all per 1 million in the US population. Louisiana had the highest case rate; New Jersey had the highest death rate; and Rhode Island had the highest testing rate. Of 47 countries, including all countries with populations >50 million, Qatar had the highest case rate; Peru had the highest death rate; and Israel had the highest testing rate for SARS-CoV-2 infection. Correlations between case rates and death rates as well as testing rates were 0.473 and 0.398 for US states and 0.473 and 0.476 for the various countries, respectively (all P<0.0001). In conclusion, outpatient saliva testing is not as sensitive as NP testing for SARS-CoV-2 RNA detection. While testing is important, without adequate public health measures, it is unlikely that we will get this pandemic under adequate control until vaccines become available.