Related Experiment Video
Updated: Dec 3, 2025

Infection of Primary Nasal Epithelial Cells Grown at an Air-Liquid Interface to Characterize Human Coronavirus-Host Interactions
Published on: September 22, 2023
Asymptomatic COVID-19 in hospital visitors: The underestimated potential of viral shedding
Victor C Passarelli1, Klinger Faico-Filho1, Luiz Vinicius Leão Moreira1
1Universidade Federal de São Paulo, Laboratório de Virologia, Division of Infectious Diseases, Department of Medicine, Escola Paulista de Medicina, São Paulo, Brazil.
Abstract:
In a single day, six of 150 (4%) asymptomatic visitors were diagnosed with COVID-19 at a hospital with a universal masking policy. Two inpatients (contacts) subsequently developed symptoms. More rigorous protective measures during visitation periods may need to be included in infection control practices to reduce nosocomial transmissions.
More Related Videos
Related Concept Videos
Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
Transmission-based Precautions I: Contact, Enteric, and Droplets
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
Infection
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
Standard Precaution
Hand hygiene is the most crucial means to prevent the transmission of disease. Employers are legally required to provide their workers with personal protective equipment (PPE) to minimize exposure or contact with...
Viral Recombination
Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...

