Beware of mosquitoes: what is known about the chikungunya virus spreading around the world. 7 questions and answers about the disease, a pandemic of which the WHO fears

Chikungunya is a viral disease transmitted to humans by the bites of infected Aedes aegypti and Aedes albopictus mosquitoes. The latter, known as the tiger mosquito, is moving further north due to climate change. It bites mainly during daylight hours, with peak activity often in the early morning and late afternoon. The virus was first recorded in 1952 in Tanzania, and the name comes from the Makonde word for «to bend» — a characteristic symptom due to severe joint pain.

In regions where the population has low or no immunity, the virus can quickly cause significant epidemics, affecting up to three-quarters of the population.

Indian Ocean Islands (French departments)

• Reunion Island has recorded more than 47,500 confirmed cases of the disease and more than 170,000 suspected cases since August 2024.

• In Mayotte, there are over 1,100 cases, of which over 50% are local infections, and an epidemic phase has been declared.

Europe (May–July 2025)

• According to the ECDC, since the beginning of 2025, 38 cases of local transmission have been reported in France in 12 regions (PACA, Corsica, Occitania, Grand Est, etc.), with ten clusters remaining active. In Italy, one local case has been reported in the province of Piacenza.

• Reuters and WHO report over 800 imported cases in France and at least 12 local transmissions in the early summer season of 2025. Italy has also confirmed one autologous case.

• A previous case in Alsace, France — without travel — was the first local infection in the region near the German border.

All signs indicate that Aedes albopictus is actively spreading in southern regions of the EU with high temperatures and humidity, creating a favorable environment for local transmission.

Chikungunya’s symptoms are similar to those of dengue or Zika, making it difficult to diagnose. In severe cases, the disease can be fatal, although the fatality rate remains below 1%.

The incubation period lasts from 2 to 12 days. The most common symptoms:

• sharp high fever

• severe pain in the joints and muscles

• headache

• skin rashes

• joint swelling

• sometimes nausea and fatigue

Joint pain can last for weeks, and in some cases even months. Fatalities are rare, but possible among the elderly or patients with chronic diseases.

The virus is transmitted exclusively through mosquito bites. A person cannot infect another person directly. Aedes mosquitoes are active during the day, especially in the morning and before sunset.

There is no specific treatment. Treatment is aimed at relieving symptoms: reducing fever, pain, and inflammation. There is no vaccine against chikungunya yet, but several pharmaceutical companies are working on one.

Chikungunya is usually spread in tropical and subtropical regions. However, due to climate change, Aedes mosquitoes are now found in Europe, particularly in Mediterranean countries. Ukraine is not currently in an area of active transmission, but cases of imported infection are possible.

Chikungunya is another signal that global climate change is affecting the map of infectious diseases. And although the risk in Ukraine is currently minimal, doctors advise not to lose vigilance, especially when traveling.

Here are some recommendations that can protect against the disease:

• use repellents

• wear clothing that covers the body

• avoid mosquito-prone areas

• eliminate standing water where mosquitoes can breed