Chikungunya Virus: Understanding Its Threat Level in Australia

As the World Health Organization (WHO) raises alarms over a resurgence of chikungunya virus cases globally, Australia faces increasing scrutiny regarding its potential risk. The WHO reported over 47,500 confirmed cases and 12 fatalities from chikungunya in La Réunion between August 2024 and May 2025, alongside rising cases in Mayotte and other regions. This mosquito-borne viral infection, characterized primarily by fever and severe joint pain, has been known to travel through human vectors to various parts of the world, including Australia.

Chikungunya was first identified in Tanzania in 1952, and its outbreaks have historically been concentrated in Africa and Asia. However, recent climatic shifts have facilitated the global spread of the virus. According to Dr. Diana Rojas Alvarez, a medical officer at WHO, climate change is a significant contributor to the proliferation of chikungunya, as warmer temperatures and increased humidity create optimal breeding conditions for its vectors, primarily the Aedes aegypti and Aedes albopictus mosquitoes.

In Australia, the presence of Aedes aegypti mosquitoes has been documented since the 1800s, while Aedes albopictus was first noted in the Torres Strait in 2005. Despite the presence of these species, there have been no recorded instances of local chikungunya transmission. However, travelers returning from affected areas have tested positive for the virus, with 42 cases reported in 2023, increasing to 90 in early 2025.

Experts, including Jacqueline Stephens, Associate Professor in Public Health at Flinders University, emphasize that while the risk of local transmission remains low, the situation is dynamic. "Climate change will likely increase the risk of transmission as these mosquitoes expand their range due to favorable conditions," she noted. The potential for chikungunya to establish a foothold in Australia is heightened by factors such as increased travel and environmental changes.

Moreover, Jill Carr, a Professor at the College of Medicine and Public Health at Flinders University, pointed out that the public should be vigilant. "Travelers to endemic regions must take precautions to avoid mosquito bites, as there is currently no approved vaccine available in Australia."

The Australian government has been proactive in raising awareness about chikungunya and its symptoms, which include fever, joint pain, rash, and fatigue. Public health officials recommend wearing protective clothing, using insect repellents, and monitoring for symptoms after returning from regions where the virus is present.

In light of the evolving landscape of chikungunya's transmission and the impacts of climate change, experts urge continued vigilance and public education as key strategies to manage potential outbreaks. As climate models predict ongoing changes, understanding and mitigating the risks associated with chikungunya will be critical for public health in Australia and beyond.