The lack of exposure sites around the Covid cases identified last week has had some people scratching their heads.

Bass Coast Health CEO Jan Child said there could be any number of reasons why cases wouldn’t generate public exposure sites.

“For example, the person could be a primary close contact of an existing case, so was already in isolation during their infectious period.”

Ms Child said in some situations it was possible to identify everyone the person came into contact with while infectious, so there was no risk to the general public.

The period of highest infectiousness is within about five days of symptoms starting.

A spokesperson for the Gippsland Region Public Health Unit said exposure sites were identified through contact tracing interviews.

“A venue is deemed an exposure site if the positive case attended that site only while infectious,” they said.

As part of contact tracing, the person provides a detailed history of their contacts and places they visited up to three days before they developed systems or tested positive (if they didn’t have symptoms).

The GRPHU spokesperson said exposure sites were then classified as high, medium or low depending on the risk of transmission.

Places considered high risk include crowded places (indoors carry a greater risk than outdoors), close-contact settings, especially where people have close range conversations, such as in a bar, and confined and enclosed spaces (specifically indoor spaces with poor ventilation).

The more time a case spent at a site, the higher the risk.

A list of public exposure sites is available at www.coronavirus.vic.gov.au/case-alerts-public-exposure-sites#exposure-site-table