Causes of Chikungunya

Chikungunya has a single cause - the chikungunya virus - and a single route: the bite of an infected Aedes mosquito. Understanding the mosquito is understanding the disease.

The virus

CHIKV is an alphavirus. Once inside, it multiplies in the blood, provokes the fever, and homes to joint tissues - where the immune battle around joints produces the signature pain and, in some, months of inflammation afterward.

The mosquito: know your enemy

• Aedes aegypti and Aedes albopictus: the striped "tiger" mosquitoes
• Day-biters: peak biting early morning and late afternoon - unlike malaria's night-biting Anopheles, so daytime protection matters most
• Container breeders: they lay eggs in clean stagnant water - cooler lids, plant pots, tyres, tanks, bird baths; the mosquito biting you likely grew up within your own compound
• Short flight range: the source is usually within a few hundred metres - your house or your neighbour's

How infection happens

A mosquito bites someone in their first week of illness (when virus floods the blood), incubates the virus for several days, then injects it into its next victims. One infected traveller returning to a mosquito-rich colony can seed an outbreak.

Who gets severe disease

• Newborns infected around delivery
• Adults over 65
• People with high blood pressure, diabetes or heart disease
• Anyone exposed to a heavy first infectious dose

What does NOT cause it

Not cold drinks, not rain water touching skin, not "bad air", not person-to-person casual contact. Without the mosquito, no chikungunya - which is exactly why mosquito control is the whole prevention.

One-line summary

Chikungunya comes only from the bite of a day-biting, container-breeding Aedes mosquito carrying the virus - kill the stagnant water and the bite, and the disease has no road in.