ABSTRACT
Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter ("miasmata"). Notable Roman and medieval schol-ars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century micro-biology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious his-torical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid -20th century work of Wells, Riley and Mills who proved how expiratory aerosols (their "droplet nuclei") could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th cen-tury "Great Acceleration" of an increasingly hypermobile human population repeatedly infected by dif-ferent strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chem-istry are accelerating human awareness of current environmental challenges. As such, the "anthropause" lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be pre-served in the Anthropocene stratal record.(c) 2021 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
ABSTRACT
Background: To evaluate whether the ongoing coronavirus disease 2019 (COVID-19) pandemic has had an impact on assisted reproductive technology (ART) outcomes and assess the possible role of geographic differences in the pandemic's trajectory on these outcomes. Methods: Multi-center retrospective cohort study involving patients who underwent oocyte cryopreservation, in vitro fertilization (IVF), embryo cryopreservation, or frozen euploid embryo transfer in 2019 and 2020 at two academic fertility centers located in regionally distinct areas of the US with high coronavirus infection rates. Patients were screened for infectious symptoms, exposure to sick contacts, and fevers, and tested with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction testing within 5 days of oocyte retrieval. The primary outcomes were the number of oocytes retrieved, embryos fertilized, blastocyst or euploid embryos produced in oocyte retrieval and IVF cycles, and rates of embryo implantation, biochemical pregnancy or no pregnancy following frozen embryo transfer (FET). Results: We found no consistent significant differences in the number of oocytes retrieved, embryos fertilized, blastocysts or euploid embryos produced at either institution over the study period. Furthermore, we did not detect any differences in FET outcomes, including rates of embryo implantation, biochemical pregnancy, or no pregnancy, at either institution during the study time period. Conclusions: There were no significant differences in ART outcomes in patients who received fertility treatment during the pandemic at our centers. Patients and providers can be reassured that with proper testing, sanitizing, and distancing measures, treatments can continue safely during the pandemic without compromising outcomes. © 2022 S.O.G. CANADA Inc.. All rights reserved.