Chikungunya is a mosquito-borne disease that cause fever and joint pain.  The disease is only transmitted through mosquito bites, due to the Aedes albopictus, an aggressive specie of mosquito that can bear several diseases. Discovered in Tasmania in 1953, the word chikungunya comes from the Makonde language, meaning “which bends up”, to refer to the symptoms of this disease. 
Which areas are the most touched?
Southern countries with a sub-tropical climate tend to gather more reports but the Aedes albopictus, or tiger mosquito has benefited from human activities and has globally expanded thanks to the numerous trades. The Aedes albopictus is now considered as one of the most globally invasive species .
Legend: Geographic distribution of reported Chikungunya cases according to CDC.gov
The first cases of cChikungunya virus in Europe were declared in 2007 with the arrival of the mosquito in Italy and South of France. It later spread to America though the Antilla and Caribbean islands. In 2016, more than a hundred countries and territories were reported as having at least one case of virus transmission. You can see on the map provided by the Center for Diseases Control and Prevention the countries and territories where chikungunya cases have been reported [1,4].
Why is it dangerous?
Chikungunya virus is transmitted through mosquito-bites, by transfer of the blood properties. The disease's symptoms only begin 3-7 days after being bitten by an infected mosquito so it is difficult to determine immediately if someone is sick and thus to prevent the spreading of the disease. 
The symptoms are usually fever, joint pain, headache, muscle pain, joint swelling or rash. Although not deadly, the symptoms can last for an extended period, being months or years and result in constant joint pain and disabilities. If the immune system of the patient is weak, like older adults, new-borns or people with some medical conditions, can suffer severe complication that may lead to permanent disabilities.
The symptoms are similar to some other mosquito-borne diseases, dengue and Zika viruses.  Seek medical advice if you face these symptoms. The tiger mosquito can bear both diseases too so mosquito bites should be avoided in dangerous areas. Furthermore, the mosquito is constantly genetically evolving to counter human prevention.
Can it be treated?
As of today, no vaccines have been found against this disease so the best way to treat chikungunya virus is by preventing it.  The patient must be protected from further mosquito biting in order to prevent further spreading of the disease.
Avoid getting bitten by applying an effective and non-toxic mosquito repellent with a full coverage and avoid areas with a high risk of mosquito-borne diseases, especially without any protection such as protective clothing (long sleeves, pants) and mosquito nets. The hot and wet area tend to shelter more mosquitoes and the Aedes albopictus are spreading towards more countries so be careful when travelling!
1. “Chikungunya Virus”, Center for Diseases Control and Prevention, accessed January 15,2018 https://www.cdc.gov/chikungunya/
2. “Aedes albopictus – Factsheets for experts”, European Centre for Disease Prevention and Control, accessed January 15, 2018, https://ecdc.europa.eu/en/disease-vectors/facts/mosquito-factsheets/aedes-albopictus
3. “Chikungunya Fever”, Centre for Health Protection, accessed January 15 2018, https://www.chp.gov.hk/en/healthtopics/content/24/6122.html