Chikungunya Virus Threat Looms in Belgium as Climate Changes

Belgium faces a growing risk of chikungunya, a viral disease transmitted by the tiger mosquito, as climate change expands the potential for transmission. Authorities have raised the alert level and are implementing surveillance measures to mitigate the threat.

Rising Alert Level and Initial Concerns

In mid-January, the Risk Management Group (RMG) in Belgium elevated the alert level to orange due to a surge in respiratory infections. Sciensano coordinates the monitoring of these threats. Simultaneously, concerns arose regarding the potential introduction of chikungunya, a virus historically uncommon in the Belgian climate.

Chikungunya: A Growing Risk Due to Warming Temperatures

Recent research indicates that the transmission of chikungunya from mosquitoes to humans is now possible at temperatures as low as 13.8°C (2.5°C lower than previously estimated). This widening of the temperature threshold extends the period and geographical areas at risk within Europe, including Belgium. Previously, the Belgian climate limited the survival of infected mosquitoes, but this is no longer necessarily the case.

Transmission Season and Regional Variations

Researchers now predict that chikungunya transmission could occur in Belgium during June, July, and August. While the Ardennes region is expected to remain relatively spared, areas like Campine face a risk as early as June.

Symptoms and Health Implications

Chikungunya typically presents with flu-like symptoms, including fever, headache, and rash. A defining characteristic is joint pain, which can persist for months or even years. Approximately 40% of those infected develop chronic arthritis. Although fatalities are rare, they are possible, particularly among children and the elderly.

European Cases and Surveillance Efforts

Several European countries have already experienced chikungunya cases. In 2025, France reported 788 cases, and Italy recorded 384, primarily around the Mediterranean. The European Centre for Disease Prevention and Control has also reported cases in regions as far north as Paris and the Vosges. Currently, no indigenous cases have been reported in Belgium.

Belgium’s Response: Monitoring and Prevention

Belgian authorities are focusing on surveillance to track the spread of the tiger mosquito and the virus. Sciensano coordinates the MEMO+ platform, allowing citizens to report tiger mosquito sightings through muggensurveillance.be. The goal is to slow the establishment of the mosquito population and reduce breeding grounds by eliminating stagnant water around homes.

Key Takeaways

• Chikungunya is an emerging threat in Belgium due to climate change.
• Lower temperature thresholds for transmission expand the risk area and season.
• Symptoms include flu-like illness and potentially chronic joint pain.
• Surveillance and mosquito control are crucial for prevention.