Antibody testing shows COVID-19 has been in Ohio since January, health officials say

New antibody testing shows that symptoms for several cases of the novel coronavirus were present in Ohio in January, according to state health officials.

Ohio Department of Health Director Dr. Amy Acton said Monday that symptoms for at least five confirmed cases of COVID-19 in five different counties began in January, the earliest of which dates back to January 7.

Previous data showed the earliest onset date for the virus in Ohio was in February, with the first positive test having been announced in early March.

2982fd8c-COVID-19 Antibody Testing in DeLand, US

A file image shows a health care worker handling a blood sample for COVID-19 antibody testing. (Photo credit: Paul Hennessy / Echoes WIre/Barcroft Media via Getty Images)

“We’re doing a lot more investigation,” Acton said. “Our disease detectives are going back to take a look at that and see if they were associated with travel.”

Acton said as additional antibody testing is done, health officials will learn more about how long COVID-19 has been in the state and how long it has been spreading. The department will begin testing 1,200 volunteers in the state next week for coronavirus antibodies as part of its research.

Meanwhile, Ohio began the process of reopening its economy, with retailers being allowed to conduct business starting on May 12. Salons, barbershops, outside restaurants and patios can open starting May 15, followed by restaurant dine-in locations beginning on May 21.

RELATED: Contact tracing: Process could prove pivotal in lifting widespread COVID-19 stay-at-home orders

Ohio reported nearly 25,000 confirmed cases and 1,357 deaths from COVID-19 as of Monday.

Nationwide, there were more than 1.3 million confirmed cases and over 80,000 deaths from COVID-19, according to data from the Johns Hopkins Coronavirus Resource Center.

RELATED:, FOX launches national hub for COVID-19 news and updates

This story was reported from Cincinnati.