The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in several lockdowns announced by government authorities globally. These lockdowns have involved either partial or complete suspension of activities in a country to mitigate the pandemic. Reopening after the lockdown is essential to preserve the country's economic well-being; however, precautions should be taken to prevent the transmission of SARS-CoV-2.
Study: COVID-19 transmission during swimming-related activities: a rapid systematic review. Image Credit: Anna K Mueller / Shutterstock.com
After a lockdown, public health authorities recommend various strategies, along with rules and regulations, to reopen public places and to perform activities that may involve social interactions like swimming in a facility, lake, or beach. Swimming-associated activities promote the physical and mental well-being of individuals; however, they should be performed with necessary precautions during this pandemic.
In a recent systematic review published in the journal BMC Infectious Diseases, scientists explore the evidence available on COVID-19 transmission associated with swimming-related activities and the effect of recommended strategies to restrict it.
The present review on both the association and effect of strategies was performed in the Living OVerview of Evidence (L·OVE) platform for COVID-19. This platform maps population, intervention, comparison, and outcome (PICO) questions pertaining to COVID-19 to a repository that was built by Epistemonikos Foundation. The searches on the L·OVE platform covered the duration up to April 19, 2021.
Is there an association between swimming-related activities and COVID-19 transmission?
Three studies retrieved from the L·OVE platform were identified to be eligible for review of association after a strict screening process.
The first study, involving Danish swimming clubs, attempted to explore the extent of transmission of SARS-CoV-2 during indoor swimming activities between August and December 2020. A SARS-CoV-2 positive subject in a swimming activity was considered a risk episode.
A total of 162 risk episodes occurred, out of which eight led to the transmission of SARS-CoV-2 that affected 23 individuals. This study also reported 23 swimmers who belonged to the same club were affected in a training camp.
Notably, members of other clubs training in the same swimming pool during the same period were unaffected, thereby suggesting that the transmissions may be due to other activities in the training camp like dining, sleeping in dormitories, and socializing.
This study also assessed the efficacy of the safety strategies. To this end, no association was observed between the implementation of safety measures and the risk of SARS-CoV-2 transmission for indoor swimming. However, the study was found to be biased and therefore provided inconclusive evidence.
The second study was an epidemiological study investigating a COVID-19 outbreak at an entertainment site that included a public bath. It identified one SARS-CoV-2 infected individual who had used a public bath for two consecutive days. The individual was associated with 12 bath-related infections, of which 10 people had used the public bath, and two were workers at the location.
Secondary transmissions were also reported, and, interestingly, the secondary transmission rates were less at the entertainment site when compared to the locations outside, like dinner gatherings with colleagues and friends. This may be attributed to the maintenance of the entertainment site at high temperature (between 18 and 42 °C) and humidity (60-80%) which may have prevented virus transmission.
The third study observed nine SARS-CoV-2 positive patients admitted to a hospital in the Jiangsu Province of China and had all used the same bath center. Of those infected, eight had used the facilities in the bath center, while one was a worker. The study contradicted the second study and concluded that warm (25-41 °C) and humid conditions (60%) in the bath center did not prevent transmission of the virus.
The researchers performing the systematic review concluded that the evidence from the three studies was inconclusive and did not address the confounding factors.
Strategies for preventing COVID-19 transmission
For performing the systematic review of current strategies, 50 guidance documents published in 76 documents by 50 organizations retrieved from the L·OVE platform were selected after a strict screening process. Finally, the recommendations from the guidance documents were summarized and 11 topics were identified.
All of the guidance documents addressed ensuring social distancing. Further, 88% of the guidance documents suggested limiting capacities of the facilities through either implementing a reservation system or reduction in the number of facilities available for use.
Distancing measures were also recommended, with most of the documents suggesting six feet of distance between individuals, which can be implemented through several ways, including physical barriers, visual cues, pool and area monitoring, and limiting one person per lane in the swimming pool.
Amongst the documents reviewed, 90% recommended personal hygiene practices to prevent disease transmission including handwashing, avoiding touching of the face and unwashed hands, advocating respiratory etiquette, ensuring that individuals use a facility that has access to hand sanitizers and other hygiene supplies, and following payment procedures that are considered safe during the pandemic.
Personal protective equipment (PPE)
Taken together, 76% of the reviewed guidance documents suggested the use of PPE, particularly in cases where physical distancing cannot be followed. Recommended PPE included face coverings such as masks at the facility, as well as gloves, especially for the staff when they are handling towels and cleaning the facility. It was also specified in the documents to avoid wearing masks in damp areas and inside water.
Consuming food and water
Of the guidance documents reviewed, 50% addressed precautions for eating and drinking. Some of the recommendations were pre-packaged food services, discouraging sharing of food among patrons and staff, and social distancing in eating areas.
While the majority of documents allowed the use of drinking fountains, some recommended suspending or restricting their use and requested that visitors bring their own water or fluid supply.
Maintenance of the facility
About 67% of the guidance documents recommended disinfecting the pool. Chlorine was suggested as a disinfectant by the majority of the documents, followed by bromine.
Monitoring the pool chemistry and maintaining records of pol disinfection was suggested by the guidance documents as a quality control measure. Additionally, ensuring that the facility complied with the rules and regulations of the governing bodies, World Health Organization (WHO) strategies, The United States Centers for Disease Control and Prevention (CDC) recommendations, and guidelines suggested by manufacturers are other quality control procedures to be followed.
Frequently touched surfaces
The systematic review showed that 96% of the documents addressed the issues concerning surfaces that are frequently touched such as toilets, restrooms, dressing rooms, waiting rooms, doorknobs, pool and beach area, decks, equipment, pool ladders, etc. The recommended frequency for cleaning the surfaces was highly variable between the documents.
Measures that were suggested to restrict contaminating the surfaces include preventing the sharing of objects, limiting access to facilities that cannot be disinfected, promoting contactless payments, and providing foot pedals to reduce touching.
It was found that 42% of the documents addressed issues of ventilation of the indoor spaces in the swimming facilities. Some of the recommendations include ensuring the proper functioning of the ventilation system and promoting circulation of outdoor air by leaving the windows and doors open.
Screening and management of the sick
Measures for the screening and management of suspected or confirmed COVID-19 cases were suggested in 90% of the guidance documents. The documents recommended that the patrons and staff should remain at home in case of symptom onset or if they had contacted a suspected or confirmed COVID-19 infected individual.
The suggested timeline for returning to work for employees who were exposed varied between documents. In the case of high-risk individuals, it was recommended that they be given special access time, asked to take extra precautions, and, if needed, restrict their entry into the pool.
Delivering first aid
Measures for delivering first aid were suggested in 43% of the documents. Those who require first aid were recommended to be treated as COVID-19 positive until confirmed.
Other measures include providing cardiopulmonary resuscitation (CPR) equipment at the facility, revising the CPR protocol to suit the pandemic needs, and PPE for lifeguards. Some documents also suggested that lifeguards should follow social distancing measures and limit physical contact.
Taken together, 72% of the reviewed guidance documents had recommended disseminating awareness messages and regulations to be followed in the swimming facilities employed posting or broadcasting. For example, information about social distancing, hand washing, and the steps to be taken if a symptomatic individual is identified should be presented. The information should be posted in numerous locations, thus making it understandable to the target audience.
Strategies for preventing SARS-CoV-2 transmission during swimming-related activities.
Only 6% of guidance documents addressed vaccinations. Recommendations included continuing to follow the COVID-19 preventive measures, irrespective of the vaccination status of patrons and staff.
The findings from this study indicate a lack of enough evidence confirming an association between swimming-related activities, SARS-CoV-2 transmission, and for supporting the safety and efficacy of strategies that are recommended to prevent the spread of SARS-CoV-2 while using swimming facilities.
There was consistency in the documents for recommendations regarding social distancing, use of PPE, personal hygiene, and cleaning surfaces. However, inconsistencies were observed, especially when addressing whether food services have to open, drinking fountains should be allowed to function, and whether social distancing should be recommended for lifeguards.
Despite inconclusive evidence, the current study has successfully highlighted the appropriate strategies that need to be adopted in swimming facilities and for swimming-related activities to reduce SARS-CoV-2 transmission by synthesizing information from the guidance documents. The information discussed in this study may help in the management of swimming-associated activities for planning re-openings after lockdown.