Three recent outbreaks of COVID-19 – and data content on how to prevent a large outbreak of cases – PUBLIC HEALTH INSIDER

Unfortunately, the recent delta-led surge in COVID-19 cases affecting our region and country has not given up. Last week, Public Health — Seattle and King County reported an average of 344 new cases daily. This is more than double that of just two weeks ago and nearly six times that of a month ago.

In addition to this increase in the number of cases, it has been reported that more cases often occur than in the beginning of summer before the widespread distribution of Delta. Most outbreaks occur in indoor workplaces and social events among people who do not wear masks and are poorly ventilated. Many outbreaks involve situations where both unvaccinated and vaccinated people are together in an indoor space. Outbreaks for which everyone is vaccinated have not yet been identified.

Increased outbreak

Overall, in the last three weeks, public health has observed most of the outbreaks reported in non-healthcare workplaces, including offices with 61 employees and 27 reported cases. Outbreaks have also occurred in institutions hosting large-scale social events, such as a 100-person birthday party at a country club, with 25 cases reported.

In all recent outbreaks, most cases occurred in unmasked people. Vaccinated individuals who tested positive reported mild symptoms. All hospitalized cases exposed at social events belong to unvaccinated individuals and no deaths have been confirmed.

“Over the past few weeks, public health investigation and epidemiology teams have received significant reports of outbreaks. Gather indoors in public places, do not wear masks, and other precautions to prevent COVID-19. If taken, many people will be infected, “said Meagan Kay, Deputy Chief of the Public Health Infectious Disease Epidemiology and Immunization Section. “This is a concern given that reports may only be a subset of the total number of outbreaks that occur and expose our community.”

look carefully Three recent notable outbreaks

Looking at three examples of recent outbreaks, public health data are beginning to reveal some patterns. Public health appreciates the willingness of these three organizations to emerge soon and helps clarify what can be done to make the entire community safer.

Indoor music club: In mid-July, public health conducted an outbreak investigation when several people who tested positive for COVID-19 participated in the same indoor event. Since then, a total of 26 cases have been confirmed among the 374 people who participated in the event. The investigation is still underway, but 18 of the 26 cases have been reported to have been vaccinated. No hospitalizations or deaths have been reported from this outbreak.

The event organizer reported that the club required participants to submit vaccination documents, but staff vaccination status was not confirmed and some staff were not vaccinated. It was. The mask was optional and the event included a song. We couldn’t go away because there were so many participants. Ventilation was impaired as some fans failed and tried to draw fresh air into the space without being able to open the windows.

This tells us: Occurrences in crowded, poorly ventilated indoor spaces indicate that these spaces are still at risk. Even if vaccinated, public health recommends wearing a mask indoors in public places to reduce the risk. State-approved method It is used to ensure that all internally authorized persons are fully vaccinated. Nevertheless, participants may choose to wear a mask to further reduce the risk of COVID-19.

Indoor fitness center: The fitness center hosted a charity workout event with approximately 70 participants and approximately 35 participants in two segments. To date, a total of 16 cases have been identified, including 13 participants, 2 staff, and 1 household member. Fourteen of the 16 cases were confirmed to be completely vaccinated. All 16 patients developed symptoms of COVID-19, but none were hospitalized. During the training session, physical distance was not maintained and masks were optional.

Public health visited the site to assess indoor ventilation. The site was intended to install a large floor fan inside the building, but the public health team discovered that the facility’s ventilation system could be improved to allow for better airflow. did.

This tells us: Inadequate ventilation It continues to emerge as a factor in public health outbreak investigations.

The virus accumulates in an enclosed space as infected people breathe. And when people are singing, screaming, or exercising, they come into closer contact, do not mask, and are at increased risk with longer exposures.

Open windows and doors as much as possible to maximize air movement. Buildings and business owners should evaluate HVAC systems to increase outside airflow, upgrade filtration where possible, and consider the need for portable HEPA filtration.Resources are available at Public health website From CDC..

This outbreak also reinforces importance Wear a mask and maintain physical distance in public indoors, regardless of vaccination status.. Our outbreak data suggest that vaccinated people were infected in a crowded indoor environment without masks. The COVID-19 vaccine is very effective, especially for serious illnesses, hospitalizations and deaths, and it is much less likely that a person will catch and infect COVID-19, but it is not impossible. With the more contagious delta mutants, when a vaccinated person is infected, it can also infect others. Therefore, wearing a mask indoors in public is currently a best practice for everyone.

Childcare program: In early July, public health was informed that two were tested positive for the virus at a nursery school serving 135 students. Public health worked with the center to determine that students or staff were exposed in all classrooms and recommended that everyone be tested negative before returning to the center. As of the end of July, a total of 36 cases have been confirmed (19 students, 3 staff, 14 household contacts). Childcare programs require that all persons over the age of 5 wear a mask, regardless of vaccination status. Policy compliance has been reported to be good. Studies have shown that the outbreak began when three students, who were young enough to not need to wear a mask, participated in childcare with symptoms. The public health team found that 60% of the staff were completely vaccinated. The team works with daycare centers to provide vaccination resources.

This tells us: Stay home when sick and keep symptomatic children at home This is a current best practice where the virus is still circulating. This is essential in a child-rearing environment where it is difficult to maintain physical distance and the mask is not worn by young children. For parents and guardians, this can be very difficult to keep a child at home. This is especially true if the child has mild symptoms.But Get COVID-19 testWaiting for negative results to return to work or childcare with a simple cotton swab that doesn’t go deep into your nose is the best way to prevent it from spreading to others.

“Currently, the incidence of COVID-19 is high in King County. The risk is highest for unvaccinated people, but in addition to being vaccinated, there are several ways to further reduce the risk. It’s a good time for everyone to remember that layered protection is the best protection, “says Dr. Jeff. Duchin, Public Health Officer – Seattle and King County.

“The most important way to end this pandemic is to increase vaccination coverage in our community. It saves lives, prevents illness and reduces the spread of COVID-19 in children and immunodeficiency. Vaccination is the only and most important thing we currently have to protect individuals and our communities, given that many people, including those in the world, are still at risk. Remember that it’s a great tool. In addition, there are other simple and effective tools such as masking, ventilation, staying at home in case of illness, physical distance, etc., and serious COVID-19 infection. You can further reduce your risk. “

Vaccination and layered protection remain the best approach

Approximately 370,000 residents of King County who are vaccinated and unvaccinated are at risk of being infected with the virus.Public health for all qualified people Get vaccinated As soon as possible to protect yourself and the people around you.

In addition to vaccination, layered protection is still the best protection. This means using multiple strategies to mitigate risk. There are excellent tools for fighting COVID-19. Vaccines are the first, but it is important to remember that there are other effective measures to further mitigate the risk until you reach a more stable and safe place.

• Wearing a high quality, fit mask indoors in public, regardless of vaccination status, provides all of us with an additional layer of protection.
• Improved indoor air quality and ventilation
• Stay home when sick, isolate from others, and take immediate test if exposed
• Maintaining physical distance in crowded environments, especially indoors
• Limit high-risk activities, such as avoiding or limiting the time spent in crowded indoor spaces

Original post August 5, 2021