Lessons learned from conducting a serological survey for Japanese encephalitis after detecting the first cases in New South Wales, Australia, 2022

Problem: The first known locally acquired cases of Japanese encephalitis virus (JEV) infection in New South Wales (NSW), Australia, were identified in March 2022. NSW Health (the state entity for health care in NSW), with its partner agencies, conducted a serological survey to identify the prevalence of JEV antibody responses in high-risk communities in NSW. Context: JEV infection is rare in Australia; therefore, vaccination is not recommended for the majority of Australians. Less than 1% of JEV infections in humans result in clinical disease. Action: We conducted a cross-sectional serological survey of all age groups in five townships within NSW between June and July 2022. A summary report of the serosurvey methods and results was previously published by NSW Health. In this report, we describe the operations and lessons learned from rapidly gathering serological survey evidence to inform the public health management of JEV infection in NSW, within a country with well established health infrastructure. Lessons learned: Resource limitations had to be addressed pragmatically during this field epidemiology research. Community participation varied between towns. The knowledge of local public health staff was important for identifying appropriate locations for clinics and community engagement activities. The consistency of data collection needs to be emphasized when multiple teams are involved. Data quality assurance issues were limited during this survey, owing to ease of communication in the field with the coordinating research team. When possible, allowing additional time for community engagement and staff orientation would be beneficial before implementing a similar survey. Further consideration of reporting serology results during the study design stage might have prevented the need for manual processing upon study completion. Discussion: This serological survey highlights that a well trained and coordinated public health workforce can provide important, timely evidence when faced with an emerging public health issue.