Section 1: Introduction (from DOI: 10.1016/j.jcv.2020.104372)
From publication: "SARS-CoV-2: Is it the newest spark in the TORCH?" published as J. Clin. Virol.; 2020 Apr 14 ; 127 104372. DOI: https://doi.org/10.1016/j.jcv.2020.104372
Section 1: Introduction
Since the World Health Organization (WHO) declaration of a COVID-19 pandemic, infections with SARS-CoV-2 have exacted a profound impact on public health. As of this writing, nearly 2.5 million cases of SARS-CoV-2 infection have been identified globally, with over 165,000 deaths reported to date. It is generally believed that these are under-estimates, given continuing resource restrictions that preclude wide-spread testing in many countries. The range of manifestations of illness is expanding, with recent evidence of transmission by aerosol route in addition to droplet spread. Infections during pregnancy are increasingly being described, but the frequency and severity of infections in the newborn are incompletely defined. A critical and as yet unanswered question is whether SARS-CoV-2 can be transmitted in utero. The possibility of maternal-fetal transmission has been suggested by several observational studies, including the documentation of neonatal disease in some cases, reviewed below. Still, it remains uncertain whether these are post-natally acquired infections or represent vertically transmitted infections.
In this review, we summarize the state of knowledge acquired to date about potential risks of transmission of SARS-CoV-2 to the fetus and newborn. By analogy with animal models of coronavirus disease, congenital transmission of SARS-CoV-2 is feasible, and this literature is reviewed. The possibility of analogous congenital transmission of coronaviruses in humans requires continued study. Perinatal and post-natal environmental routes of transmission appear to be clear risks to the newborn infant, and measures to prevent the acquisition of SARS-CoV-2 in this setting are warranted. Reassuring information has been reported that suggests a lack of breast milk-mediated transmission, although this needs to be confirmed by more extensive studies. Of considerable interest is the question of whether SARS-CoV-2 should be considered as a "TORCH" infection. The TORCH acronym, first coined by Nahmias, was initially defined as a group of infections (toxoplasmosis, "other" infections, rubella, CMV, and herpes simplex virus [HSV]) that were commonly encountered in the newborn and acquired from a maternal source. Numerous variants of this acronym have evolved over the past four decades, and the definition of TORCH infection is today more broadly recognized as a heterologous collection of infections that can cause neonatal disease following acquisition by either trans-placental or perinatal routes. We submit that SARS-CoV-2 should be included in the grouping of TORCH infections and that efforts should be made both to more fully define the mechanisms of transmission and the scope of disease in the fetus and neonate. Strategies to prevent transmission, including virologic monitoring of pregnant women, are likely to be of great value. Therapeutic interventions to prevent transmission in the newborn period, including vaccines and immunotherapies, also warrant investigation.