[Special Feature: The COVID Crisis and the University] Records of Nosocomial Infection Control at Keio University Hospital / Naoki Hasegawa

COVID-19, an emerging infectious disease caused by SARS-CoV-2 (novel coronavirus) that originated in Wuhan, Hubei Province, China, in December 2019, was designated as a statutory infectious disease. At Keio University Hospital, the decision to establish a response headquarters headed by the Hospital Director was made on February 5, and information gathering and countermeasure planning began. As a medical institution cooperating in infectious disease treatment for the Tokyo Metropolitan Government, our hospital prepared two former negative-pressure tuberculosis beds and established a response system.

In February, our hospital accepted its first mild cases of COVID-19 from the cruise ship Diamond Princess in Yokohama Port. Furthermore, we renovated closed clinical spaces and the emergency department to account for infection control, including patient flow and zoning. We established a clinical system based on severity, centered on the Departments of Pulmonary Medicine and Emergency Medicine, managed pneumonia patients in private rooms, and monitored the number of faculty and staff with fevers at the Health Center, and the number of inpatients with fevers at our department. On February 27, through the efforts of the clinical laboratory department, an in-hospital system for PCR testing was established.

Keeping in mind the existence of infectious asymptomatic carriers, we prohibited international travel for students and medical professionals starting March 9, and from March 18, we prohibited all returnees from overseas from entering the Shinanomachi Campus for 14 days. However, on March 19, a patient who was asymptomatic and confirmed to have no pneumonia via chest CT was transferred to our hospital; on the 23rd, they tested positive via PCR. It was discovered that four patients, including three roommates, and four medical workers were infected. We closed other wards and continued medical care in the affected ward using staff from those wards, but a subsequent investigation revealed that several roommates at the previous hospital had developed COVID-19 and were already infected at the time of transfer.

In the midst of this, on March 31, several junior residents developed fevers simultaneously, and one was found to be PCR positive at another hospital. Prepared for the great inconvenience to those involved, the Hospital Director made the bold decision to stop all junior residents from starting their assignments the following day. Furthermore, considering the possibility of contact with them, we temporarily suspended the off-campus work of all doctors at our hospital. Contacting each department and individual lasted late into the night, but as a result, this response—which managed to stop the spread of infection from our hospital to other facilities just in time—became the ultimate infection control measure. Later, it was revealed to be a cluster infection among residents via an informal dinner party held by some of them. From these two clusters occurring inside and outside the hospital, I truly felt the dread of infectious diseases and the difficulty of infection control.

This resulted in a significant reduction in outpatient and inpatient medical services. However, since there are no vaccines or effective drugs for SARS-CoV-2, we focused on breaking the chain of infection, making every effort to ensure people do not get infected, do not infect others, and do not spread the infection.

For the early detection of infected individuals, we made maximum use of the in-hospital PCR testing system, actively testing all scheduled inpatients and symptomatic individuals; the number of in-facility PCR tests performed was among the highest in the country. Stockpiles of personal protective equipment (PPE) essential for infection control were rapidly consumed, and like other hospitals, the shortage was serious. However, we placed them under the management of the Center for Infectious Disease and Infection Control, provided guidance on appropriate use to gain understanding, and proceeded with making handmade gowns processed from plastic bags. Infection through the eyes drew attention, and we ensured thorough eye protection during aerosol generation. While eye guards were also in short supply, we were greatly helped by the provision of face shields with headbands made by 3D printers from related research institutions. Infection control nurses who trained in our department were temporarily assigned to promote training on the correct way to put on and take off PPE.

Since the virus is also contained in saliva, dining and conversations that generate droplets were considered infection risks. We notified both patients and medical workers to wear masks, avoid the so-called "Three Cs," and practice social distancing, conducting rounds to ensure compliance. However, as a countermeasure against the virus surviving for long periods on environmental surfaces, hand washing and hand hygiene are fundamental. We are working to ensure this through the setting of reinforcement periods, mutual reminders, and video messages from department heads. For cleaning hospital rooms after discharge, we introduced a disinfection system using ultraviolet radiation.

In addition, self-health management by medical workers themselves, who are constantly exposed to infection risks, is important. We ensured that individuals perform self-temperature checks and stay home to consult if they have a fever or feel unwell. Furthermore, the systems department is developing a system for online temperature entry via the intranet, third-party temperature checks, and the installation of high-sensitivity, rapid temperature sensors in outpatient areas.

The occurrence of COVID-19 clusters inside and outside the hospital caused great inconvenience and concern to many people, but we would like to express our heartfelt gratitude and appreciation for the warm words of encouragement and support from many members of the Juku and benefactors. Moving forward, the Hospital Director and all staff will continue to work together on infection control, balancing COVID-19 treatment with our duties as a Special Functioning Hospital to fulfill our responsibilities.