A virus alert has been issued after detection in mosquitoes trapped at Narrabeen Lagoon.
Northern Beaches Council has advised residents to take extra precautions against mosquitoes following the detection of Ross River virus at Narrabeen Lagoon as part of a regular mosquito monitoring program.
Council participates in the NSW Arbovirus Surveillance and Mosquito Monitoring Program (ASMMP), which traps mosquitoes. The program monitors a number of harmful pathogens, such as Ross River virus, Barmah Forest virus, Stratford virus and Edge Hill virus.
Ross River virus was detected in the latest sample taken from mosquitoes trapped this week and follows detection of Stratford virus in mosquitoes trapped in March 2026 and April 2026. Although a different type of virus, Stratford is sometimes referred to as a ‘cousin’ of Ross River virus as their symptoms are nearly identical.
Neither of the viruses are spread through person-to-person contact. They are spread by the bite of infected mosquitoes that have fed on an infected host. The wallabies that are common in the bushland surrounding the lagoon are considered a likely reservoir for the viruses.