BACKGROUND
SARS-CoV-19, the virus that causes COVID-19, is a global pandemic that has placed unprecedented stress on national economies, food systems and healthcare resources in Latin America and the Caribbean (LAC). This region has become an epicenter for the coronavirus, with Brazil and Mexico leading the globe in deaths following the U.S. in death count. Existing surveillance provides a proxy on COVID-19 caseload and deaths; however, these measures make it difficult to identify shifts to the pandemic and changes in the speed and acceleration in COVID-19. Accordingly, we provide an enhanced surveillance system to complement static metrics with dynamic ones that inform hen there are shifts and where explosive growth is likely to occur in LAC.
OBJECTIVE
This study aims to provide additional surveillance metrics for SARS-Cov-2 transmission that more accurately tracks shifts in the pandemic, speed, acceleration, jerk, and persistence in transmission than existing metrics. Enhanced surveillance will inform policy and COVID-19 outbreaks for leaders in LAC.
METHODS
Using a longitudinal trend analysis study design, we extracted 45 days of COVID data from public health registries. We use an empirical difference equation to measure the daily number of cases in the Latin America and Caribbean region as a function of the prior number of cases, the level of testing, and weekly shift variables based on a dynamic panel model that was estimated using the generalized method of moments (GMM) approach by implementing the Arellano-Bond estimator in R.
RESULTS
COVID transmission rates were tracked for Latin America and the Caribbean during the weeks of 9/30-10/06 and 10/07-10/13. New cases in the region totaled 79,053 on 10/06 and 42,837 on 10/13. The 7-day moving average of new cases for the week of 10/6 was 56,106 and for the week of 10/13 was 47,276. Total infection rate decreased from 12.42 to 6.73 accompanied by a death rate decrease from 0.33 to 0.24. Within the region, on 9/30, Brazil had the largest number of new cases at 41,906 followed by Argentina at 14,740, Colombia at 7,650, and Mexico at 4,828. On 10/07, Argentina had the largest number of new cases in the region at 13,305, followed by Brazil at 10,220, Colombia at 5,014, and Mexico at 4,295. For both weeks, Brazil had the highest 7-day moving average, followed by Argentina. The region as a whole saw a decrease in speed, acceleration, and jerk for the week of 10/13 compared to the week of 10/6, accompanied by a decrease in new cases and 7-day moving average. For the week of 10/6, Belize had the highest acceleration and jerk in the region, at 1.7 and 1.8 respectively, which is particularly concerning given the high death rate in the country. The Bahamas also had a high acceleration at 1.5. 11 countries had a positive acceleration during the week of 10/6 whereas only six countries had a positive acceleration for the week of 10/13. The region overall is trending positively, with a speed of 10.40, an acceleration of 0.27, and a jerk of -0.31 all decreasing the subsequent week to 9.04, -0.81 and -0.03 respectively.
CONCLUSIONS
1) Metrics such as new cases, cumulative cases, deaths, and 7-day moving averages provide a static view of the pandemic but fail to identify where and the speed at which SARS-CoV-19 is infecting new persons, the rate at which the speed is accelerating or decelerating and comparing this week to last week, how the rate of acceleration is increasing or decreasing indicate pending explosive growth or control of the pandemic; and 2) Although Latin America and the Caribbean saw an overall decrease in speed, acceleration, and jerk for the week of 10/13 compared to the week of 10/6, accompanied by a decrease in new cases and 7-day moving average, this is largely due to decreases in infections in Brazil and Mexico, the two countries containing over 50% of the population in the region. However, Brazil continues to have the highest 7-day moving average in the region, more than two times that of Argentina, the next highest in the region.
CLINICALTRIAL
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Latin America and the Caribbean SARS-Cov-2 Surveillance: Longitudinal Trend Analysis (Preprint)
