COVID-19 surveillance in Southeastern Virginia using wastewater-based epidemiology.

Wastewater-based epidemiology (WBE) has been used to analyze markers in wastewater treatment plant (WWTP) influent to characterize emerging chemicals, drug use patterns, or disease spread within communities. This approach can be particularly helpful in understanding outbreaks of disease like the novel Coronavirus disease-19 (COVID-19) when combined with clinical datasets. In this study, three RT-ddPCR assays (N1, N2, N3) were used to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in weekly samples from nine WWTPs in southeastern Virginia. In the first several weeks of sampling, SARS-CoV-2 detections were sporadic. Frequency of detections and overall concentrations of RNA within samples increased from mid March into late July. During the twenty-one week study, SARS-CoV-2 concentrations ranged from 101 to 104 copies 100 mL-1 in samples where viral RNA was detected. Fluctuations in population normalized loading rates in several of the WWTP service areas agreed with known outbreaks during the study. Here we propose several ways that data can be presented spatially and temporally to be of greatest use to public health officials. As the COVID-19 pandemic wanes, it is likely that communities will see increased incidence of small, localized outbreaks. In these instances, WBE could be used as a pre-screening tool to better target clinical testing needs in communities with limited resources.

Restructuring Argentina's airline networks: Successes and challenges

Argentina's aviation networks underwent significant restructuring after the 2015 election of President Mauricio Macri. Historically constrained by poor aviation infrastructure, economic uncertainty, currency devaluations, labor unrest, comparatively weak passenger demand, and operational barriers to low-cost carriers (LCCs), Argentina's airline networks have experienced deep restructuring in both providers and network interactions. With less than 0.3 trips per capita in Argentina, compared to 3.0 in the mature U.S. aviation market, analysts argue that there is significant potential for moving bus and automobile travelers to airlines, and to expanding Argentina's airline connectivity profitably throughout the region. LCCs such as Flybondi, Norwegian, Air Europa, Sky, JetSmart, and others are challenging long-standing transportation relationships in the region and developing new routes for consumers. A set of interlinked questions aims to understand Argentina's changing aviation geography. Comparing O-D data from 1972, 1982, 1996, and 2019, the results indicate a significant reorganization of Argentinas domestic and regional network interactions, with modest adjustments to its global north-south connections. Challenges include outcomes of a recent change in Argentina's government and the long-term impact of the global COVID19 pandemic on the aviation system.