Minimal influenza virus transmission from touching contaminated face masks: a laboratory study.

The risk of virus transmission via the touching of contaminated masks has long been assumed by infection control teams. Yet, robust evidence to support this belief has been lacking. This risk was investigated in a laboratory setting by measuring the amount of viable influenza virus successfully transferred from artificially contaminated medical (surgical) mask surfaces to a human finger used to swipe their outer surface under various experimental conditions.

Development of positive/negative pressure booth generating airflow for protection of medical staff from contagious respiratory pathogens.

Background: The pandemic of COVID-19 caused confusion in medical settings because of increased patient load, and caused many infections among medical staff which occurred through exposure to bio-particles discharged from patients. The risk of exposure became maximum at the examination of patients, particularly in the collection of respiratory specimens. Effective interventions to reduce the risk are needed.

Development of a lightweight, 'on-bed', portable isolation hood to limit the spread of aerosolized influenza and other pathogens.

Background: The annual seasonal influenza epidemics in the winter season lead to many hospital admissions, increasing risks of nosocomial infections. Infectious diseases caused by contagious respiratory pathogens also pose a great risk to hospitals as has been seen in the current epidemic by a novel coronavirus infection. Such risk occurs in high density patient settings with few or no partitions, since the pathogens are transmitted by aerosols discharged from the patients.

New applications of a portable isolation hood for use in several settings and as a clean hood.

Background: We previously reported that we developed a compact and portable isolation hood that covers the top half of a patient sitting or lying in bed. The negative pressure inside the hood is generated by a fan-filter-unit (FFU) through which infectious aerosols from a patient are filtered. The outside area is kept clean which decreases the risk of nosocomial infections in hospital wards.

Establishment and clinical applications of a portable system for capturing influenza viruses released through coughing.

Coughing plays an important role in influenza transmission; however, there is insufficient information regarding the viral load in cough because of the lack of convenient and reliable collection methods. We developed a portable airborne particle-collection system to measure the viral load; it is equipped with an air sampler to draw air and pass it through a gelatin membrane filter connected to a cone-shaped, megaphone-like device to guide the cough airflow to the membrane. The membrane was dissolved in a medium, and the viral load was measured using quantitative real-time reverse transcriptase-polymerase chain reaction and a plaque assay.

A new methodology for studying dynamics of aerosol particles in sneeze and cough using a digital high-vision, high-speed video system and vector analyses.

Microbial pathogens of respiratory infectious diseases are often transmitted through particles in sneeze and cough. Therefore, understanding the particle movement is important for infection control. Images of a sneeze induced by nasal cavity stimulation by healthy adult volunteers, were taken by a digital high-vision, high-speed video system equipped with a computer system and treated as a research model.