The fragments were found in a sample collected from the Altona sewage catchment, in the city’s southwest, on Wednesday, the state’s Department of Health and Human Services said.

Samples of untreated wastewater are analysed for fragments of SARS-CoV-2 – the virus that causes COVID-19 – are taken from more than 40 sites across the state.

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Residents and visitors to Altona and surrounding suburbs from Monday, November 16 to Wednesday, November 18 are urged to get tested if they have any symptoms, no matter how mild.

Suburbs in the wastewater catchment include Altona, Altona Meadows, Seaholme and Sanctuary Lakes, and parts of Laverton, Point Cook and Williams Landing.

The DHHS said the result was “unexpected given that it has been about eight weeks since the last known resident in the area had a coronavirus illness or diagnosis”.

“A positive wastewater test result may be due to someone with coronavirus (COVID-19) being in the early active infectious phase or someone who is no longer infectious continuing to ‘shed’ the virus,” the department states.

“It can take several weeks for someone to stop shedding the virus.

“The person or people shedding the virus may be local or visiting a community.”

Saturday marked the 22nd consecutive day of zero coronavirus cases across Victoria.

LOCAL TESTING LOCATIONS FOR ALTONA CATCHMENT

Drive through testing facility: Wyndham City Council Civic Centre

Outdoor Carpark, 45 Princes Highway, Werribee 3030

Monday to Sunday, 9am-5pm

Walk through testing centre: Werribee South Foreshore Reserve

Werribee South Foreshore Reserve, Beach Rd (opposite Werribee Coast Guard, near corner O’Connors Rd),

Saturday, November 21 to Sunday, November 22, 9am-4pm

Walk through testing centre: Tarneit Community and Learning Centre

150 Sunset Views Boulevard, Tarneit 3029

Saturday, November 21 to Sunday, November 22, 9am-4pm

Drive through testing facility: IPC Health – Wootten Road Reserve

Wootten Rd Reserve, 25-51 Wootten Road, Tarneit 3029

Saturday to Sunday, 10am-4pm