The new crown pneumonia has been raging around the world for nearly three years. So far, many Chinese and foreign experts, and even the World Health Organization believe that the epidemic has come to an end, and even some countries or regions have returned to normal exchanges in terms of entry and exit.
Although the author is not a medical staff, I have also contributed to the fight against the epidemic in the past two years. In particular, I have accumulated a lot of experience through research when dealing with isolation or ventilation design projects in the past. Construction and other work is more handy.
Looking back on the most profound lessons from the anti-epidemic work in the past few years, I have to mention the "SARS" (SARS) battle nearly 20 years ago. The sudden epidemic that year taught many people a valuable lesson.
Written by: Yuan Bailiang, senior engineer and former president of the Institution of Engineers
I remember that in 2003, there were not many isolation wards in Hong Kong hospitals, and there were no high or uniform requirements for ventilation systems.
However, with the outbreak of the outbreak in the general ward 8A of the Prince of Wales Hospital, it was later discovered that the virus was caused by a new type of virus, which finally opened the prelude to the epidemic of infectious diseases in Hong Kong.
On March 15, 2003, the World Health Organization (WHO) named the new virus "Severe Acute Respiratory Syndrome" or "SARS".
At that time, the impact of SARS on Weiyuan Hospital was rapid and severe, so that as many as 114 ward assistants, 17 medical students, 39 patients and 42 visitors were infected by Lu Zhu, of whom nearly 140 ward assistants, medical students and patients were all in the hospital. Ward 8A was infected.
However, at that time, the medical, engineering and even the public did not understand SARS and its transmission route, and only inferred that it was very likely that the virus was transmitted through the air in the ward under certain circumstances.
Later, some local experts speculated that SARS was mainly transmitted by biological aerosols, droplets or direct personal contact.
To examine these claims, they studied in detail the environmental evidence of possible airborne transmission in the wards of Hong Kong's largest hospital during the SARS outbreak in March 2003, and published a report in 2005.
The report disclosed that after retrospective on-site inspections of ventilation design and air distribution systems, limited on-site measurements of bioaerosol dispersion were carried out, followed by computational fluid dynamics simulations to analyze bioaerosol distribution and dispersal in the ward, showing that The predicted bioaerosol concentration distribution appears to be in good agreement with the spatial infection pattern of SARS cases.
Furthermore, few studies in those years focused on analyzing the relationship between airborne infections and building ventilation. Some like-minded people believed that this field should be reviewed. Therefore, 15 people including the author set up a review team consisting of microbiology, medical It consists of medical and engineering experts in the fields of , epidemiology, indoor air quality and building ventilation.
Most of the members had experience fighting SARS in 2003, and the team screened 40 items for in-depth research from the literature between 1960 and 2005 through individual assessments and two-day meetings.
The results show that building ventilation is associated with airborne infections in 10 of 40 studies, and there is strong evidence that ventilation, air movement in buildings, is associated with measles, tuberculosis, chickenpox, influenza, smallpox and SARS. The spread of infectious diseases is linked.
Nonetheless, there is insufficient data to quantify the minimum ventilation requirements that can effectively block airborne viruses in environments such as hospitals, schools, and offices.
The results of this research were finally published in the world's most influential international journal "Indoor Air" related to indoor ventilation in 2007, and have been cited more than 600 times.
The author took the lead with experts and researchers to build a physical six-person general ward for experiments, simulated the airflow direction with computer, and examined how the installation of mobile HEPA (high-efficiency particle filter) air purifiers in general wards can effectively improve the situation. The overall cleaning performance of the room.
These findings reflect the need for the authorities to improve ventilation and air-conditioning systems in general wards, as it is not easy to identify potentially highly infectious patients in the wards. The study also shows that there is room for improvement in the prevention and control of cross-infection in wards of large general hospitals at that time.
This is also a topic that the author has spent a lot of time focusing on, and has used his subsequent engineering doctoral research results to improve the ventilation design of general wards in hospitals. The author also won the 2012 Hong Kong Institution of Engineers Engineering Innovation Award.
Looking back now, if the research on indoor environment ventilation and air extraction was not triggered after SARS, it would help to improve the design of isolation wards in Hong Kong and achieve higher infection prevention capabilities. Hong Kong may face greater difficulties in dealing with the new crown epidemic. The construction of large-scale isolation facilities, including the conversion of second-line isolation wards or the construction of community treatment centers, may not be so quick and smooth. It is possible to cope with several waves of new crown epidemics, and support for epidemic prevention work may also become more progressive. difficult.
"01 Medical Clinic" cooperates with senior engineer Yuan Bailiang to launch a column "Yuantu With You" every Monday to share the big and small matters of engineering and medical care.
Yuan Bailiang has always been committed to promoting the professional development of the engineering field. He is the former president of the Hong Kong Institution of Engineers.
Decades of professional journey are really worth remembering, and I am convinced that later generations may be able to understand the key points of the engineering profession.
Yuantu has you, let everyone experience it together.
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