COVID-19 Trends in the Phoenix Metropolitan Area from a Mobile Testing Program: Last Quarter of 2020

The coronavirus (COVID-19) pandemic continues to be a public health concern, and Arizona has once again been a COVID-19 hotspot, peaking at 118.3 cases per 100,000. Understanding the trends in COVID-19 positivity rates over time is crucial in planning and mitigation of the virus. This current study analyzes the trends in COVID-19 testing, and COVID-19 antigen and antibody positivity rates over a 3-month time-span from October to December 2020. A retrospective study was conducted collecting data from a mobile testing program during October to December 2020 in the Phoenix metropolitan area. COVID-19 antigen and antibody positivity rates were analyzed. A total of 6710 patients were included in the study. As the months progressed, more patients were tested (October: 1635; November: 2037; December: 3038). The COVID-19 antigen positivity rate was significantly higher in December, compared to October and November (13.43% vs. 11.43 and 10.86%, p = 0.021). COVID-19 IgG rates were also significantly higher in November and December, compared to October (16.65 and 16.50% vs. 8.74%, p < 0.001). There was a progressive increase in COVID-19 positivity cases towards the end of 2020, likely attributed to factors including social gatherings during the holidays and the relaxing of the closure restrictions. Continued public health measures is crucial in preventing the spread of COVID-19.