Sunday, December 01, 2019

Chikungunya fever: transmission and symptoms

Chikungunya is a mosquito-borne viral disease, caused by the Chikungunya virus (family: Togaviridae, genus: Alphavirus). The disease was documented first time in the form of an outbreak in Tanzania. The name is derived from the ‘makonde’ dialect which means ‘that which bends up’, indicating the physical appearance of a patient with severe clinical features.

In recent decades the Aedes mosquitoes carrying chikungunya have spread to the European Region. In 2007, a chikungunya outbreak was reported for the first time in Italy. In 2013, chikungunya was found for the first time in the Americas and has spread to the Caribbean, South and Central America, and North America.

The virus is transmitted from human to human by the bites of infected female mosquito. Aedes aegypti is the common vector responsible for transmission in urban areas whereas Aedes albopictus has been implicated in rural areas. Recent studies indicate that the virus has mutated enabling it to be transmitted by Aedes albopictus. The Aedes mosquito breeds in domestic settings such as flower vases, water-storage containers, air coolers, etc. and peri-domestic areas such as construction sites, coconut shells, discarded household junk items (tyres, plastic and metal cans, etc.).

Both mosquitoes can be found biting throughout day lighthours, though there may be peaks of activity at dawn and dusk. Both species are found biting outdoors, but Aedes aegypti will also readily feed indoors.

What are the symptoms?
Common symptoms include fever and severe joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash.ŠSymptoms usually begin 3—7 days after being bitten by an infected mosquito.ŠMost patients will feel better within a week. In some people, the joint pain may persist for months. Death is rare.

Outbreaks are most likely to occur in post-monsoon period when the vector density is very high. Human beings serve as the chikungunya virus reservoir during epidemic periods. During inter-epidemic periods, a number of vertebrates have been implicated as reservoirs. These include monkeys, rodents, birds, and other vertebrates.
Chikungunya fever: transmission and symptoms

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