SARS-CoV-2 Transmission Channels: A Review of the Literature.

BACKGROUND The novel coronavirus SARS-CoV-2 is responsible for the current global pandemic. There is a concerted effort within the global scientifi c community to identify (and thereby potentially mitigate) the possible modes of transmission through which the virus spreads throughout populations. OBJECTIVE Summarize the ways in which SARS-CoV-2 is transmitted and provide scientifi c support for the prevention and control of COVID-19. EVIDENCE AQUISITION We conducted an extensive literature search using electronic databases for scientifi c articles addressing SARSCoV-2 transmission published from December 28, 2019 through July 31, 2020. We retrieved 805 articles, but only 302 were included and discussed in this review. The report captured relevant studies investigating three main areas: 1) viral survival, 2) transmission period and transmissibility, and 3) routes of viral spread. DEVELOPMENT Currently available evidence indicates that SARSCoV-2 seems to have variable stability in different environments and is very sensitive to oxidants, such as chlorine. Temperature and humidity are important factors infl uencing viral survival and transmission. SARSCoV-2 may be transmitted from person to person through several different routes. The basic mechanisms of SARS-CoV-2 transmission person-to-person contact through respiratory droplets, or via indirect contact. Aerosolized transmission is likely the dominant route for the spread of SARS-CoV-2, particularly in healthcare facilities. Although SARS-CoV-2 has been detected in non-respiratory specimens, including stool, blood and breast milk, their role in transmission remains uncertain. A complicating factor in disease control is viral transmission by asymptomatic individuals and through what would otherwise be understood as innocuous human activities. CONCLUSIONS This article provides a review of the published research regarding human-to-human transmission of SARS-CoV-2 and insights into developing effective control strategies to stop viral propagation. KEYWORDS COVID-19, SARS-CoV-2, transmission, pandemics, microbial viability.

A novel influenza A (H1N1) outbreak experience among residents of a long term-care facility in Saudi Arabia during 2010 seasonal flu circulation.

The aim of this work was to describe and analyze an outbreak of novel 2009 influenza A (H1N1) among residents of a long-term care facility (LTCF) in Prince Mansour Military Hospital (PMMH), Taif, Saudi Arabia. These patients had been admitted to the LTCF months or years before the outbreak for several reasons, e.g. cerebral palsy, neurological deficits due to road traffic accidents with resultant handicap, chronic diseases associated with old age. An observational study was carried out to demonstrate and analyze the epidemiological characteristics (demographic factors, risk factors, and outcomes) associated with the outbreak in order to clarify which prevention and control measures had been taken and which recommendations were followed. During the period October 28 to November 11 2010, 21 LTCF residents were suspected to be clinically involved: fever ≥38°C with influenza-like illness (ILI). Age ranged from 9-91 years (mean 46±24.13); 62% were males. Among them, 12 (57%) were influenza A (H1N1) positive by reverse transcription polymerase chain reaction (RT-PCR). Mortality involved 2 (17%) of the A (H1N1) laboratory confirmed individuals. Implementation of the recommended infection control measures mitigated the transmission of infection to new individuals. The fulfillment of strict infection control measures could limit H1N1 infection among LTCF-PMMH patients. Routine influenza, including specific H1N1 immunization of all LTCF residents together with their healthcare staff, should be mandatory in those settings serving immunocompromised patients.