Prevalence of Murray Valley encephalitis virus antibodies in northern Victoria following the 2023 outbreak: a cross-sectional serological survey

Authors

  • Marie Heloury Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia; Australian National University, Canberra, 2600, Australia
  • Joshua Szanyi Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia
  • Maxwell Braddick Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia; Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, 3000, Australia
  • Alexander Fidao Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia; Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, 3000, Australia
  • Madeleine J Marsland Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia; Australian National University, Canberra, 2600, Australia
  • Tilda N Thomson Communicable Diseases Section, Victorian Deparment of Health, Melbourne, 3000, Australia; Australian National University, Canberra, 2600, Australia
  • Mitchell Batty Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia
  • Suellen Nicholson Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia; Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, 3000, Australia
  • Theo Karapanagiotidis Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia
  • Kylie S Carville Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia; Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, 3000, Australia
  • Anna-Jane Glynn-Robinson Australian National University, Canberra, 2600, Australia
  • Chuan Kok Lim Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia; Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, 3000, Australia
  • Naveen Tenneti Loddon Mallee Public Health Unit, Bendigo Health, Bendigo, 3550, Australia; Violet Vines Centre for Rural Health Research, La Trobe Rural Health School, La Trobe University, P.O. Box 199, Bendigo, VIC, 3552, Australia
  • Anthony Zheng Ovens Murray Public Health Unit, Albury Wodonga Health, Wodonga, 3690, Australia; School of Clinical Medicine, University of New South Wales, 559 East St, East Albury NSW 2640 Australia
  • William Cross Goulburn Valley Public Health Unit, Goulburn Valley Health, Shepparton, 3630, Australia
  • Jim Black Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia
  • Helen O'Brien Communicable Diseases Section, Victorian Department of Health, Melbourne, 3000, Australia

DOI:

https://doi.org/10.33321/cdi.2025.49.020

Keywords:

Murray Valley encephalitis virus, serology, seroprevalence, flavivirus infections, vector control, mosquito vectors, epidemiology, Victoria, cross-sectional studies

Abstract

Following the first outbreak of Murray Valley encephalitis in Victoria, Australia, since 1974, a serological survey was conducted in 2023 and 2024 to estimate the seroprevalence of Murray Valley encephalitis virus (MVEV) antibodies among residents in the north of the state. Between October 2023 and April 2024, a total of 507 residents from 11 local government areas in northern Victoria — Mildura, Swan Hill, Campaspe, Gannawarra, Greater Bendigo, Loddon, Greater Shepparton, Moira, Wodonga, Wangaratta, and Indigo — were tested for MVEV total antibody. Seroprevalence was 2.0% (95% confidence interval: 1.1–3.6%), comparable to background levels of seropositivity prior to the 2023 outbreak. No strong associations were identified between a range of potential risk or protective factors and MVEV seropositivity. Low seroprevalence suggests that the population in this region remains immunologically vulnerable to MVEV infection. Ongoing vector control and efforts to prevent mosquito bites will be critical in preventing flavivirus transmission in northern Victoria during future mosquito seasons.

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Published

25/03/25

How to Cite

Heloury, Marie, Joshua Szanyi, Maxwell Braddick, Alexander Fidao, Madeleine J Marsland, Tilda N Thomson, Mitchell Batty, et al. 2025. “Prevalence of Murray Valley Encephalitis Virus Antibodies in Northern Victoria Following the 2023 Outbreak: A Cross-Sectional Serological Survey”. Communicable Diseases Intelligence 49 (March). https://doi.org/10.33321/cdi.2025.49.020.

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Vol. 49 (2025)

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Original article

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