According to data collected by the department, an influx of cases is appearing in grocery stores, major big-box stores and warehouses throughout the entire area despite various mitigation efforts to prevent the spread of the virus. However, the largest increases are among general worksites such as warehouses, manufacturing facilities and logistics companies, officials said.
Outbreaks at these sites increased from nine per week on Nov. 1 to upward of 44 per week on Dec. 6, indicating a "nearly a fivefold increase," according to the department.
"These increases reflect a pattern of transmission: from worksite to home and back to worksites, health officials wrote in a notice. "As the percentage of people who are positive with COVID-19 increase, there is a larger pool of infected people walking around without symptoms who now expose a greater and greater percentage of people to this virus."
To date, the virus has infected more than 1,370 essential workers within various Costco, Home Depot, and Target stores as well as Amazon warehouses throughout the county, according to data, last updated Tuesday.
The health department defines an outbreak as three or more lab-confirmed coronavirus cases.
At least six Amazon facilities have reported outbreaks. While there are five confirmed cases at an Amazon Bookstore in Cerritos, there are 102 cases at a warehouse in El Monte, according to the health department. Two other warehouses in the county have over 50 confirmed cases among staff.
Ten Costco warehouses throughout the county have also reported outbreaks, each with at least 16 confirmed cases. A location in Marina Del Rey, however, has reported at least 71 cases.
At least nine Home Depot locations have outbreaks. A majority of their stores have already seen more than two dozen cases. However, a warehouse in North Hollywood reported at least 50 cases.
Sixteen Target stores are also facing outbreaks. Each location has at least 11 confirmed cases. However, a location in Los Angeles reported at least 55 cases.
The health department is encouraging any employee to report any concerns over a workplace's safety protocols.
However, each of the aforementioned companies has implemented efforts throughout the past year to try to keep employees safe while supplying the community with essential goods and services.
According to an Amazon blog post, the e-commerce behemoth made over 150 process updates including enhanced cleaning and social distancing measures. The company also says it distributed personal protective gear, implemented disinfectant spraying and temperature checks across its global operations.
Amazon also said it's offering extra time off with full pay for those diagnosed with COVID-19 and established an employee relief fund for delivery drivers and seasonal associates facing financial hardship or quarantine.
A Target spokesperson told FOX Business that the company has increased safety protocols across all its facilities throughout the pandemic, including at the 79 stores located in Los Angeles County. The company also said that the cases within its stores are "consistent with the trends reported for the U.S. population and the communities" in which they operate.
As part of its safety procedures, the company has provided masks, gloves and thermometers to all its team members, installed partitions at check lanes in stores and employed a variety of social distancing measures.
"We’ve been in close communication with the LA County Department of Health, and we regularly share safety information and guidance with our team and work with leaders at our stores to ensure coronavirus best practices are in place," a Target spokesperson said.
Home Depot told FOX Business that it is following guidance from the CDC and increased the frequency of cleaning across all its locations. This includes disinfecting high-touch locations throughout the store. Employees and guests are required to wear masks and employees are required to complete a health check when they come into work, Home Depot said.
If an employee does not feel well, they will be asked to stay home. However, they will be offered pay during this time, the company said.
Costco is also following CDC recommendations to minimize risk to its employees and members. The company also requires that everyone two years and older to wear a mask at all times, according to its website.
As of Tuesday, the health department reported 958,497 positive cases of COVID-19 across all areas of Los Angeles County.
Representatives for Amazon did not respond to FOX Business' request for comment.