PHOENIX (June 25, 2020)—Officials from Maricopa County Department of Public Health (MCDPH) detailed the three tactics that are currently most critical to addressing the increased spread of COVID-19 in Maricopa County.
Current data for Maricopa County cases show a different picture of disease spread than was seen earlier in the pandemic. As of this week, Maricopa County is now averaging just over 1,800 new COVID-19 cases reported each day, a six-fold increase over the number of cases being reported six weeks ago. Additionally, more than half of all reported cases are in people age 20-44, up from one-third previously. This is likely the result of increased exposure for that age group when at work or in public places.
“I want everyone in Maricopa County to understand that every adult has an equal chance of getting infected if exposed to COVID-19, and we can all spread it to people who are at higher risk of severe illness and send them to the hospital even if we just have mild illness,” said Dr. Rebecca Sunenshine, medical director for disease control at MCDPH.
With COVID-19 spreading rapidly through the community, MCDPH is focusing its efforts on three public health tactics that are critical to controlling disease spread:
- Case investigation and contact tracing
- Social distancing
Tactic 1: Case Investigation and Contact Tracing
“Case investigation” refers to the process of interviewing people who test positive to learn more details about their illness, determine their infectious period, and identify who they came in contact with while they were infectious.
“Contact tracing” refers to reaching out to all close contacts (someone who was in contact with a positive case while they were infectious, and had contact closer than six feet for more than 10 minutes) to notify them of their exposure, the importance of quarantine, and what steps to follow next.
“It’s important that people know they are positive, know what to do to prevent spreading the disease and that people who are close contacts know to watch for symptoms,” said Marcy Flanagan, executive director for MCDPH. “That’s why we at Public Health are still reaching out to every positive case we have contact information for within 12-24 hours of receiving their test result.”
The shift in who is infected is changing how MCDPH must work. “With more than 50% of cases between the ages of 20 and 44, we’ve found investigations and contact tracing to be most effective through text messages,” explained Dr. Sunenshine. MCDPH is implementing a text-based option to inform people of their positive result and provide a link to a secure online questionnaire about their illness. This allows investigations to be completed more effectively and efficiently if people prefer text over phone.
- Case investigation:
- People who test positive can isolate and not expose others
- Any exposures that already happened can be identified, including potentially high-risk exposures
- Contact tracing:
- Close contacts can quarantine so they don’t create exposures before symptoms begin
- Case investigation:
- About 5-7% of all positive cases in Maricopa County are never reachable
- Asymptomatic cases who don’t get tested are not known by Public Health
- Contact tracing:
- Any delays in lab reporting time make contact tracing less effective
Case investigation and contact tracing alert positive cases and their contacts about risk so they can isolate or quarantine to avoid spreading the virus to others.
Because case investigation and contact tracing have limitations, and because they can only be used after someone tests positive, MCDPH is asking the public to support two other tactics that can help decrease the number of new cases that occur.
Tactic 2: Social Distancing
COVID-19 is spread when people spend more than 10 minutes within 6 feet of a person who is infected. By practicing social distancing—that is, by staying home as much as possible and minimizing close contact with people outside of their household—individuals can reduce their exposures and slow the rapid spread of COVID-19 in Maricopa County.
“We know that around 40% of individuals who are infected with COVID-19 are asymptomatic, so they may be spreading the disease without realizing it because they do not feel sick,” Dr. Sunenshine reminded. With this many people contributing to asymptomatic spread, it’s important that everyone maintain distance when they can, even when they don’t feel sick.
- People are not exposed unknowingly by being around people who appear healthy but are infectious (around 40% of all COVID-19 cases do not show symptoms)
- Fewer exposures reduces the opportunities the disease has to spread
- Fewer sick people reduces exposures to people age 65 and up and those with underlying medical conditions, who are most at risk of severe illness, hospitalization, and death
- People are returning to work and may not have the option to work remotely
- Schools will be reopening in the fall, and not all students may be able to do distance learning
- People may feel emotionally and socially isolated if they are not engaging in other ways to connect with loved ones such as video chats, virtual group activities, or drive-by visits
Social distancing helps prevent new COVID-19 cases by keeping infectious people away from healthy people.
Tactic 3: Masks
When people cannot practice social distancing, masks add another layer of protection.
Masks, including cloth face coverings, have now been proven to reduce the spread of COVID-19 in two ways. Droplets produced by sneezing, coughing, and talking carry the virus from infected individuals to healthy individuals. Masks reduce the spread of droplets carrying the virus from infected individuals to healthy individuals (“source control”), and masks can also prevent healthy individuals from taking in droplets that are in the air. The Maricopa County Board of Supervisors passed regulations last week that require all people in Maricopa County to wear a mask in public.
“A requirement is a big step and we value people’s right to make decisions. That’s why we needed enough good scientific evidence before we supported a requirement. We have the evidence to support the effectiveness of wearing cloth face masks to prevent COVID spread,” said Dr. Sunenshine.
“This is not forever—it is until we have the spread of COVID-19 under control in Maricopa County,” she added.
- Masks offer protection to healthy people and to people around infected individuals
- Cloth masks are breathable, safe for most people, and effective at controlling the spread of COVID-19
- Cloth masks are available to the general public through many sources
- Masks are not recommended for children under age 2, individuals who have trouble breathing, or individuals who are unconscious, incapacitated, or otherwise unable to remove a mask without assistance
Mask-wearing is the public health tactic that balances protection against infection with people’s ability to go out when necessary.
Combined, case investigation and contact tracing, social distancing, and masks can help prevent new infections and slow the growth rate in COVID-19 cases in Maricopa County. Social distancing and mask-wearing can be done by virtually every member of the community.
A few other simple actions can also help reduce the spread of COVID-19:
- Stay home and away from others when sick
- Wash hands frequently and use hand sanitizer when washing hands is not possible
- Get tested if you are sick
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