Observations on the interaction of older age and diabetes on COVID-19 mortality, and of non-pharmaceutical interventions on daily reported cases in El Paso, Texas, 2020

Introduction. In El Paso, Texas, a largely Hispanic population, a large surge of COVID-19 occurred in October 2020. Using public health surveillance data and a field survey we report on the epidemiology and control of this pandemic in 2020. Population and methods. We used reported COVID-19 cases to the notifiable disease reporting system to: 1) calculate morbidity and mortality rate ratios by age, gender, race/ethnicity, and poverty; and 2) to assess temporal trends using joinpoint regression. A door-to-door cluster sampling serologic survey assessed prevalence of SARS-CoV-2 infection. We calculated the relative excess risk due to interaction (RERI) of older age and diabetes on mortality from COVID-19. Results. By the end of 2020, the reported morbidity and mortality were 0.8% and 216.8 per 100,000 population, respectively. The overall prevalence of infection reached 18.5%. Compared to those under 20 years of age, the reported morbidity was nearly twice among 65+ years of age (RR=1.6 [95% CI=1.6, 1.7]), but the mortality in this group was disproportionately large (RR=1,026 [95% CI=329.0, 3,171.0]). Hispanics had twice the morbidity and mortality than non-Hispanics. Essential workers had an increased prevalence of SARS-CoV-2 infection compared to other occupations. Social distancing measures appeared to have contributed to decrease the morbidity by the end of 2020. Diabetes and older age jointly increased the risk of COVID-19 mortality (RERI=27.9 [95% CI = 24.0, 32.2]). Conclusions. US Hispanics experienced excess COVID-19 morbidity and mortality. Older age and diabetes mellitus synergistically increased the risk of COVID-19 mortality.