| Background and aim of the study|
Chikungunya fever is an acute infection of abrupt onset, characterized by high fever and painful arthralgia. CHIKV is geographically distributed in Africa, India, and South-East Asia, and periodic outbreaks have been described in the past 50 years. The most recent epidemic in Africa was documented in 1999-2000 in Kinshasa, where an estimated 50,000 persons were infected. The most recent epidemic outbreak in Asia was documented in 2001 in Java and is still on-going. Phylogenetic studies have revealed the existence of three CHIKV phylogroups (West Africa, Asia, East-Central-South Africa).
Since the end of 2004, CHIKV has emerged in the islands of the south-western Indian Ocean (i.e Comoros, Mayotte, Reunion, Mauritius, Madagascar) and is causing one of the largests outbreaks described in the past 40 years. The most affected island was the Reunion island with an estimated 263,000 cases since March 2005. Previously undescribed clinical forms have been reported. 1 to 1000 patients with a confirmed CHIKV infection developed severe clinical signs (neurological signs, myocarditis or fulminant hepatitis). Cases of neonatal encephalopathy and major algic syndrome associated with vertical transmission of the virus were also reported. Phylogenetic studies indicated that the Indian Ocean outbreak was caused by a strain related to East, Central and South African viruses. A specific change at position 226 of the E1 glycoprotein occured during the Reunion epidemic and is supposed to favour the multiplication of the virus in mosquitoes.
Chikungunya is certainly underestimated as a causative agent of febrile and arthralgic illness in European travellers coming back from endemic areas. Moreover, the broad geographic distribution of the mosquito vectors Aedes albopictus and Aedes aegyptii may allow the expansion of CHIKV to new areas, such as Americas and to a lesser extent Europe.
By searching more systematically CHIKV in European travellers it could be inferred some epidemiological information about worldwide chikungunya activity, changes in the local epidemiology of the disease and genotype worldwide distribution. The information gathered by this kind of study may benefit both travellers and the host countries as well.
If you wish to contribute to this study please contact:
Centre National de Référence des Arbovirus
21, avenue Tony Garnier
69365 Lyon cedex 07
Phone : + 33-4-37-28-23-81
Fax : + 33-4-37-28-24-51
Mail : firstname.lastname@example.org
For the sequencing of CHIKV, both acute phase serum samples (1-7 days), CSF and isolated viruses are welcome.
Some clinical, epidemiological and biological informations are requested i.e:
Shipping information Biological samples should be packaged in a triple packaging system and transported according to the international regulations for infectious substances transport. Sera should be sent as diagnostic specimens (IATA 650) and viral isolates as infectious substances (class 6.2) (IATA 602).
Samples should be sent on dry ice. Shipping cost could be covered by our laboratory.