It was after being involved in the diagnostic conundrum presented by a friend returning from the Amazon basin that I came across this paper recently published by eurosurveillance. It examines the investigation of a traveller returning from the Amazon Basin with a PUO, arthralgia and myalgia. This would normally ring the dengue bell in my mind, however the paper showed that serology for dengue was negative as were his serological status for Yellow fever and Chikungunya (which I didn't realise had reached South America.) However serology was positive for another alphavirus called Mayaro Virus.

It is a hitherto rare mosquito-borne zoonosis which has a similar sylvatic transmission cycle to Yellow Fever. It presents with symptoms similar to dengue and should be another vector borne disease we should keep in mind when dealing with acute self-limiting dengue-like illness in those travellers returning from South America.

http://www.eurosurveillance.org/images/dynamic/EE/V15N18/art19563.pdf