A mobile pandemic team has done 86 tests at six Lambton County farms the past two weeks with no positive results reported.
Lambton Public Health is working with Bluewater Health, Lambton EMS, Ontario Health and the Central Lambton Family Health Team.
The outreach is intended to protect local temporary foreign workers from COVID-19.
Voluntary testing is being offered to all Lambton County farms that hire migrant workers as seasonal employees.
In an update Friday, Lambton Public Health said 84 test results have been confirmed negative so far and two were pending lab confirmation.
In response to concerns about farm outbreaks in other areas of the province, most notably Windsor-Essex, Lambton Medical Officer of Health Dr. Sudit Ranade sent letters to all local farm operators in June.
"The response has been good and we are having regular conversations with local farm operators on how to prevent COVID-19 transmission and manage the risk for any possible outbreak," Ranade said in a news release.
Health Promotion Supervisor Anita Trusler said the mobile unit allows for on-site testing at the farm property.
"The support of Central Lambton Family Health Team has been an asset given their rural context and their ability to assist with the language needs of the workers," she said.
Lambton County is expecting to see between 200 and 300 temporary foreign workers travel to the community for seasonal work.