A recent study demonstrated how a virus could quickly spread across hospital surfaces. While researchers utilized a plant-infecting virus, their experiment showed that in less than 12 hours, such a pathogen could put an entire ward at risk of infection.
The demonstration of how long a virus could spread throughout a hospital ward was conducted by researchers at the University College London (UCL), a public research university in the UK. They showed that a virus could spread in a hospital ward in 10 hours. Specifically, the DNA of the pathogen was detected on various surfaces. While the DNA was confirmed on those surfaces, they could not determine if an individual might be infected, in case it was a human-infecting virus. They published their findings in the Journal of Hospital Infection.
The Spread of a Virus Demonstrated in a Hospital Ward
Microbes are everywhere and the majority do not cause harm to humans. However, in hospitals, the persistence of specific microbes can be the start of an infection. Certain microbes like Staphylococcus aureus and Candida albicans are found inside the human body. They normally live peacefully in designated parts of the body. Sometimes, they even do tasks human cells cannot accomplish. But if they manage to enter other body parts, they can become opportunistic pathogens. This is one example of how hospital-acquired infections occur.
For instance, opportunistic microbes that contaminate a breathing tube or catheter may invade an organ system. In the lungs, the opportunistic pathogens can induce respiratory conditions, including pneumonia. In the urethra, the pathogens can start urinary tract infections that may escalate to a kidney problem. As such, people who are admitted to hospitals for a long time are at risk of hospital-acquired infections.
At UCL, researchers conducted an experiment to reproduce the spread of a virus. This was done in light of SARS-CoV-2, the virus of COVID-19. They artificially replicated a section of the DNA of a plant-infecting virus, instead of using the novel coronavirus. This allowed them to safely simulate a virus spreading on several hospital surfaces without risking human infection. The substitute was added in a milliliter of water to mimic the concentration of SARS-CoV-2 in the respiratory samples of COVID-19 patients.
In the study, the researchers focused on other means of disease transmission. Researchers acknowledged that a distance of two meters between people could reduce the transmission of contagious diseases via respiratory droplets, but they emphasized that fomites or objects and surfaces could also spread pathogens, which many might not be aware of. So, they integrated the standards on cleaning surfaces used to combat COVID-19 and early findings on the persistence of SARS-CoV-2 on materials, such as up to 72 hours on plastic and steel, and eight hours on cardboard and copper.
To demonstrate how fast a virus could spread in a hospital ward, they placed the water containing the substitute on the handrail of one hospital bed in an isolation room. Next, they allowed the viral DNA to spread on different surfaces. Since the human hand could easily pick it up and drop it off, it was expected that the DNA had reached surfaces outside the original site.
For the next five days, they sampled 44 sites in the hospital ward and tested each sample to determine the speed and pattern of the spread. Results showed that in just 10 hours after the placement of the water, the viral DNA already spread in 41% of sampled sites. The DNA was detected on several bed rails, door handles, and armrests in the waiting room. The same DNA was even found on children's toys, books, and parts of the play area. Three days later, 59% of the sites were confirmed with the viral DNA but on the fifth day, the DNA presence dropped to 41% of all sampled sites.
"Our study shows the important role that surfaces play in the transmission of a virus and how critical it is to adhere to good hand hygiene and cleaning. Our surrogate was inoculated once to a single site and was spread through the touching of surfaces by staff, patients, and visitors. A person with SARS-CoV-2, though, will shed the virus on more than one site, through coughing, sneezing, and touching surfaces," said Dr. Lena Ciric, the senior author of the study and senior lecturer at the Department of Civil, Environmental, and Geomatic Engineering.
The researchers found that the sites that mostly tested positive for the DNA were in the immediate bed space area, such as the nearby room with multiple beds and clinical areas that included treatment rooms. Around 86% of clinical areas tested positive on the third day while 60% of sites in the immediate bed space area tested positive on day four.
Similar to SARS-CoV-2, the viral DNA could be removed easily by common disinfectants and proper handwashing. The study findings expressed the importance of hygiene and handwashing in reducing the spread of pathogens. Although the viral DNA was spread via water, the COVID-19 virus could be spread through respiratory droplets. Researchers said that the stickier the medium containing a virus is, the easier it could spread on surfaces.
COVID-19 Deaths Almost Half a Million
In the 140th Situation Report of the World Health Organization of the United Nations, the total global confirmed cases of COVID-19 reached 6,931,000, as of June 8, 2020. On the other hand, the total global deaths due to the disease peaked at 400,857. Because no vaccine has been made yet, new cases and new deaths are expected to be reported in the coming days. The total deaths might reach 500,000 worldwide if the situation fails to improve.
The Americas remained with the highest confirmed cases at 3,311,387, followed by Europe at 2,286,560 cases, the Eastern Mediterranean at 641,429 cases, Southeast Asia at 364,196 cases, the Western Pacific at 191,275 cases, and Africa at 135,412 cases. Within the past 24 hours, 76,512 new cases in the Americas, 18,258 new cases in Europe, 17,745 new cases in the Eastern Mediterranean, 13,654 new cases in Southeast Asia, 1,039 new cases in the Western Pacific, and 4,088 new cases in Africa were reported.
Researchers concluded that they only demonstrated how fast a virus could spread from surface to surface, but how it would infect a person was not determined in their study. Several factors could play an integral role in the chances of a person becoming sick from a pathogen.