Lambton Public Health is still working on establishing new COVID-19 case reporting by geographic zone.
Medical Officer of Health Dr. Sudit Ranade said one of the biggest challenges is making sure the population denominator is large enough to ensure an individual can't be identified.
"That's a bit of a challenge if you know a name and address that's linked to a municipality, that's very easy to do. Once you start parsing it within the municipalities and certain geographies, there's a little bit of complexity around doing that, so we're just trying to work through some of that."
Dr. Ranade said different municipalities are being grouped in zones of about 20,000 people and that includes subdividing cases in Sarnia and Point Edward.
"And then at that point you sort of say 'here's one case' with less concern about the fact that identifying one case might link to to the identification of an individual."
On September 16 Lambton County Council approved the more detailed reporting system to provide more information while still protecting privacy.
It's not yet known exactly when case reporting by zone will appear on the health unit website.