Southwestern Public Health was reporting 16 confirmed new cases of COVID-19 in Elgin, St. Thomas and Oxford on Thursday, Sept. 16, up from 10 on Wednesday.
The number of ongoing cases being tracked by the health unit also rose, to 72 Wednesday from 60 Tuesday.
Just under half of all ongoing cases involve those 29 years old and younger.
St. Thomas and area increased to 12 ongoing cases Thursday from nine Wednesday, and West Elgin to five from three, while one new case each was discovered in Central Elgin and Malahide.
Aylmer and area stayed at eight and Bayham at two.
In Oxford, Woodstock and area rose to 21 from 19, Tillsonburg and area to seven from five and Ingersoll and area to five from four, while one new case was discovered in Zorra.
South-West Oxford remained at eight and East Zorra-Tavistock at one.
Four Southwestern residents are hospitalized with COVID-19, one in an intensive care unit.
The infection rate for the Southwestern region stands at 34 cases per 100,000 of population, up from 28.4 on Wednesday.
Across Ontario, 864 new cases of COVID-19 were confirmed on Thursday, up from 593 on Wednesday.