Chikungunya Surges Globally: Australia on Alert

A significant uptick in chikungunya virus cases worldwide, flagged by the WHO, is prompting renewed attention on potential risks, particularly for Australia.

Global Outbreaks Escalate

The World Health Organization has voiced serious concerns over a notable rise in chikungunya infections. This mosquito-borne virus has triggered outbreaks in regions such as La Réunion and Mayotte in the Indian Ocean. Between August 2024 and May 2025, La Réunion reported over 47,500 confirmed cases and 12 fatalities. Mayotte documented 116 cases from March to May 2025. With over 100 countries now experiencing local transmission, the potential for chikungunya to establish itself in new territories is a growing concern.

Understanding Chikungunya: Symptoms and Spread

Chikungunya typically presents with fever and severe joint pain, which can be debilitating and persist for months or even years in some individuals. Other symptoms include headaches, rash, muscle aches, nausea, and fatigue. While most recover within weeks, vulnerable groups like infants, the elderly, and those with underlying health conditions face higher risks, including rare fatalities. Symptoms usually appear 3 to 7 days after a mosquito bite, though onset can be delayed up to 12 days. Currently, there is no specific antiviral treatment, with paracetamol recommended for symptom management.

The virus is transmitted by infected female mosquitoes, primarily the Aedes aegypti and Aedes albopictus species. These mosquitoes become infectious after biting a person with the virus and can then transmit it to others. They are known for their aggressive daytime biting, often targeting exposed legs and ankles, and are also vectors for dengue, yellow fever, and Zika.

Chikungunya in Australia: A Growing Presence

While Australia has not yet experienced widespread local transmission of chikungunya, imported cases among returning travelers are on the rise. In 2023, 42 cases were recorded, increasing to 70 in 2024, and 90 reported by early 2025. These figures, though still relatively low, coincide with the increasing presence of Aedes mosquitoes in parts of Queensland. Aedes aegypti has been established in northern Queensland since the 1800s, and Aedes albopictus was detected in the Torres Strait in 2005.

Climate change is exacerbating the situation by creating more favorable conditions for mosquito breeding. Warmer temperatures, altered rainfall, and increased humidity expand mosquito habitats, heightening the risk of chikungunya spreading further within Australia. Interestingly, some evidence suggests Australians may possess a degree of cross-immunity to chikungunya due to prior exposure to the local Ross River virus.

Prevention Strategies and Future Outlook

Two chikungunya vaccines have been approved in the United States, but availability in Australia is currently limited, with ongoing monitoring for wider distribution. For individuals traveling to regions with active chikungunya outbreaks, the most effective prevention is avoiding mosquito bites. This includes wearing loose, light-colored clothing that covers exposed skin, using effective insect repellent, and sleeping under mosquito nets, especially during daylight hours when Aedes mosquitoes are most active. These measures also provide protection against other mosquito-borne illnesses like dengue and Zika.

The increasing global incidence of chikungunya underscores the importance of robust public health surveillance and personal protective measures. As of June 2024, the Centers for Disease Control and Prevention (CDC) has reported over 10,000 chikungunya cases in the Americas, with active transmission noted in several Caribbean nations and South American countries (CDC, 2024).