Molecular epidemiology

Coronavirus Disease 2019 (COVID-19) Pandemic and Pregnancy

American journal of obstetrics and gynecology

Dashraath, P.; Jing Lin Jeslyn, W.; Mei Xian Karen, L.; Li Min, L.; Sarah, L.; Biswas, A.; Arjandas Choolani, M.; Mattar, C.; Lin, S. L.

Abstract

The current coronavirus disease 2019 (COVID-19) pneumonia pandemic, caused by the severe acute respiratory syndrome 2 (SARS-CoV-2) virus, is spreading globally at an accelerated rate, with a basic reproduction number (R0) of 2 - 2.5, indicating that 2 - 3 persons will be infected from an index patient. A serious public health emergency, it is particularly deadly in vulnerable populations and communities in which healthcare providers are insufficiently prepared to manage the infection. As of March 16, 2020, there are more than 180,000 confirmed cases of COVID-19 worldwide, with over 7,000 related deaths. The SARS-CoV-2 virus has been isolated from asymptomatic individuals, and affected patients continue to be infectious two weeks after cessation of symptoms. The substantial morbidity and socioeconomic impact have necessitated drastic measures across all continents, including nationwide lockdowns and border closures. Pregnant women and their fetuses represent a high-risk population during infectious disease outbreaks. To date, the outcomes of 55 pregnant women infected with COVID-19 and 46 neonates have been reported in the literature, with no definite evidence of vertical transmission. Physiological and mechanical changes in pregnancy increase susceptibility to infections in general, particularly when the cardiorespiratory system is affected, and encourage rapid progression to respiratory failure in the gravida. Furthermore, the pregnancy bias towards T-helper 2 (Th2) system dominance which protects the fetus, leaves the mother vulnerable to viral infections, which are more effectively contained by the Th1 system. These unique challenges mandate an integrated approach to pregnancies affected by SARS-CoV-2. Here we present a review of COVID-19 in pregnancy, bringing together the various factors integral to the understanding of pathophysiology and susceptibility, diagnostic challenges with real-time reverse transcriptase polymerase chain reaction (RT-PCR) assays, therapeutic controversies, intrauterine transmission and maternal-fetal complications. We discuss the latest options in antiviral therapy and vaccine development, including the novel use of chloroquine in the management of COVID-19. Fetal surveillance, in view of the predisposition to growth restriction and special considerations during labor and delivery are addressed. Additionally, we focus on keeping frontline obstetric care providers safe while continuing to provide essential services. Our clinical service model is built around the principles of workplace segregation, responsible social distancing, containment of cross-infection to healthcare providers, judicious use of personal protective equipment and telemedicine. Our aim is to share a framework which can be adopted by tertiary maternity units managing pregnant women in the flux of a pandemic while maintaining the safety of the patient and healthcare provider at its core.

Keywords

Normative guidance; Epidemiology

Towards our understanding of SARS-CoV, an emerging and devastating but quickly conquered virus

Comparative Immunology, Microbiology and Infectious Diseases
Volume 30, Issues 5–6, September 2007, Pages 309-327

Youjun Feng, George F. Gao.

Abstract

Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease caused by a novel coronavirus (SARS-CoV), which has overwhelmed more than 30 countries claiming nearly 8400 cases with over 800 fatalities. Thanks to the unprecedented international collaboration, the whole-genomes of SARS-CoVs were successfully deciphered shortly after the identification of the causative pathogen for outbreak of SARS in southern China, in 2003. Hitherto, the SARS-CoV, as a viral paradigm of emerging infectious entities, has been extensively studied that has ranged from epidemiology, molecular virology/immunology to structural genomics. Also, several lines of breakthroughs have been record-brokenly obtained, that included the finding of ACE2, a functional receptor for the SARS-CoV, solution of the 3CLpro structure, a first crystal structure of SARS-related macromolecules, revealing of bats as natural reservoirs for SARS-like viruses and the possible involvement of civet cats in the SARS emergence. This review intends to outline the major progress in the journey of SARS-related exploration, by emphasizing those inaugurated studies with milestone-like significance contributed by Chinese research groups.

Keywords

Severe acute respiratory syndrome (SARS), Coronavirus (CoV), SARS-CoV, Molecular epidemiology, Natural reservoir, Receptor, T cell immunity, CTL epitopes, Structural genomics