Exasperated health chiefs say they are shocked at reports of adults and children turning up at work or school despite having Covid-19 symptoms.
Many are carrying on as normal without waiting for results of a PCR test to confirm if they have the virus or not.
The first Covid case was reported in Northamptonshire on March 3, 2020 — 643 days ago.
And advice since then for anyone with symptoms — a high temperature, continuous cough or loss or change in sense of smell or taste — has been to lock yourself indoors and assume you've got Covid-19 until a test tells you otherwise.
But Lucy Wightman, the county's Director of Public Health, revealed: "We have received reports of both adults and children going to work or school, despite showing symptoms of the virus and not having taken a PCR test.
"This is very risky behaviour which puts the health of the individual and their work colleagues and fellow pupils and their families in jeopardy.
"If you have symptoms you must book a PCR test to rule out the virus and ideally stay at home and isolate until you receive a negative result."
■ Click HERE for details on how to get tested for Covid-19.
Experts believe there is a greater risk of passing on the virus since restrictions were lifted in July and the emergence of fast-spreading Delta and Omicron variants.
Mrs Wightman fears many are still confused over two types of test for the virus.
She added: “The type of Covid-19 test you need depends on why you're getting tested.
"PCR tests are for those WITH symptoms, they're sent to a lab to be checked for variants and are more sensitive to the virus.
"Rapid lateral flow tests are only for people who do NOT have symptoms."
The number of people testing positive across the county rose to nearly 4,400 over the last seven days — up by 46 percent compared to a month ago — with spikes in areas of Corby, Kettering and south Northamptonshire.
NHS England confirmed on Friday (December 3) that three more patients sadly died while being treated for Covid-19 in Kettering General Hospital — one on Tuesday and two on Wednesday.
Nearly two-thirds of all the hospital deaths linked to Covid in the county since November 1 have been at KGH — 32 compared to 19 at Northampton General Hospital.
Three more Covid-related deaths were reported in North Northamptonshire care settings last month, according to regulators Care Quality Commission.