The recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use. The data were compatible with lesser degrees of self-protection.
Our random-sample study estimated 187 802 cumulative infections, to which 180 hospitalizations were added. The average age among all COVID-19 decedents was 76.9 years (SD, 13.1). The overall noninstitutionalized IFR was 0.26%. In order of magnitude, the demographic-stratified IFR varied most by age, race, ethnicity, and sex. Persons younger than 40 years had an IFR of 0.01%; those aged 60 or older had an IFR of 1.71%. Whites had an IFR of 0.18%; non-Whites had an IFR of 0.59%.
By using SARS-CoV-2 population prevalence data, we found that the risk for death among infected persons increased with age. Indiana’s IFR for noninstitutionalized persons older than 60 years is just below 2% (1 in 50). In comparison, the ratio is approximately 2.5 times greater than the estimated IFR for seasonal influenza, 0.8% (1 in 125), among those aged 65 years and older. Of note, the IFR for non-Whites is more than 3 times that for Whites, despite COVID-19 decedents in that group being 5.6 years younger on average.
However, new research from Johns Hopkins University (MD, USA) has found that the chance of these tests giving a false negative – stating no infection when the individual actually is infected – is greater than 1 in 5, at times being far higher. The study, which analyzed seven previously published studies that evaluated RT-PCR performance, calls into question the accuracy of the predictive value of such tests.Biotechniques, 29 May 2020