Transmission risk of respiratory viruses in natural and mechanical ventilation environments: implications for SARS-CoV-2 transmission in Africa.

• Authors: Anuoluwapo Sopeyin, Yale University; Emilio Hornsey, Public Health England; Tochi Okwor, Nigeria Centre for Disease Control; Yewande Alimi, Africa Centres for Disease Control and Prevention; Tajudeen Raji, Africa Centres for Disease Control and Prevention; Abdulaziz Mohammed, Africa Centres for Disease Control and Prevention; Hiwot Moges, Africa Centres for Disease Control and Prevention; Ezinne V. C. Onwuekwe, Africa Centres for Disease Control and Prevention; Frank Minja, Emory University; Giorgia Gon, London School of Hygiene & Tropical Medicine; Onyema Ogbuagu, Yale University; Folasade Ogunsola, University of Lagos; Elijah Paintsil, Yale University
• Journal Title: BMJ Global Health
• Volume: Volume 5, Number 8
• Publisher: BMJ Public Health | 2020-08
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1136/bmjgh-2020-003522
• Subjects: Health Sciences, Immunology; Biology, Virology
• Keywords: prevention strategies; respiratory infections; Africa; Air Microbiology; Betacoronavirus; Coronavirus Infections; Environment, Controlled; Humans; Pandemics; Patient Isolation; Patients' Rooms; Pneumonia, Viral; Respiration, Artificial

Abstract

Respiratory viruses can be transmitted through contact, droplet and airborne routes. Viruses that are not naturally airborne may be aerosolised during medical procedures and transmitted to healthcare workers. Most resource-limited healthcare settings lack complex air handling systems to filter air and create pressure gradients that are necessary for minimising viral transmission. This review explores the association between ventilation and the transmission of respiratory viruses like SAR-CoV-2. When used appropriately, both natural and mechanical ventilation can decrease the concentration of viral aerosols, thereby reducing transmission. Although mechanical ventilation systems are more efficient, installation and maintenance costs limit their use in resource-limited settings, whereas the prevailing climate conditions make natural ventilation less desirable. Cost-effective hybrid systems of natural and mechanical ventilation may overcome these limitations.