What is chikungunya?
Chikungunya is an infectious disease caused by an alphavirus called the chikungunya virus. This virus is spread by mosquitoes that bite during the day.
Generally, people infected with the chikungunya virus will experience symptoms. The incubation period ranges from one day to 12 days. On average, the incubation period is between three and seven days. The acute phase of chikungunya is typically characterised by:
- the sudden onset of high fever;
- severe joint pain;
- muscle ache;
- skin rash;
- various eye conditions, including conjunctivitis.
Chikungunya symptoms may range from mild to severe. Generally, the skin rash develops a few days after the onset of the fever. Severe symptoms are more common in newborns, elderly people and adults with comorbidities. Acute symptoms following chikungunya virus infection generally pass within one to three weeks, but the joint pain (arthritis) may persist for months or years. Complications and mortality due to chikungunya virus infection are relatively rare.
How to prevent being infected with the chikungunya virus
People are generally infected with the chikungunya virus through the bite of Aedes mosquitoes, particularly yellow fever mosquitoes (Aedes aegypti) and Asian tiger mosquitoes (Aedes albopictus), which bite during the day. These mosquitoes are also known to transmit other viruses, such as the dengue and Zika viruses.
At present, no vaccines against the chikungunya virus are available. Chikungunya prevention should focus first and foremost on preventing getting bitten by mosquitoes, particularly in the early morning and late afternoon, when Aedes mosquitoes are active. You can minimise your chances of getting infected by wearing clothes that cover your entire body and by applying a mosquito repellent containing diethyltoluamide (DEET). We also advise sleeping under a mosquito net impregnated with a mosquito repellent.
How common is the chikungunya virus?
The chikungunya virus is endemic to Africa, Asia, Central and South America, the southern part of North America, the Caribbean and the countries in and around the Indian Ocean. In Europe, locally transmitted cases of the chikungunya virus have been reported in Italy (2007, 2017) and southern France (2011, 2017). A few dozen or sometimes a few hundred chikungunya cases are reported each year in the Caribbean Netherlands. The map below shows the regions in which chikungunya is endemic [Source CDC Centers for Disease Control and Prevention, April 2016].
So far, the European (or continental) Netherlands has only seen cases of the chikungunya virus that had been imported from other countries. Since Asian tiger mosquitoes (Ae. albopictus) have not yet established themselves here on a permanent basis, the risk of local transmission is negligible for the time being.
Figure 1. Countries where locally transmitted cases of chikungunya have been reported (May 2018) [Source: CDC].