The Chikungunya epidemic in Italy and its repercussion on the blood system.
BACKGROUND
The Chikungunya virus (CHIKV) is transmitted by Aedes mosquitoes and recently caused a massive epidemic on La Réunion Island, in the Indian Ocean. Between July and September 2007 it caused the first autochthonous epidemic outbreak in Europe, in the Region of Emilia-Romagna in the north-east of Italy.


METHODS
After the first reports of an unusually high number of patients with a febrile illness of unknown origin in two contiguous villages, an outbreak investigation was carried out to identify the primary source of infection, the modes of transmission and the dynamics of the epidemic. An active surveillance system was also implemented. Laboratory diagnosis was performed through serology and polymerase chain reaction (PCR) analysis. Blood donation was discontinued in the areas involved from September to October 2007 and specific precautionary blood safety and self-sufficiency measures were adopted by the regional health and blood authorities and the National Blood Centre. An estimate method to early assess the risk of viraemic blood donations by asymptomatic donors was developed, as a tool for "pragmatic" risk assessment and management, aiming at providing a reliable order of magnitude of the mean risk of CHIKV transmission through blood transfusion.


RESULTS
Two hundred and seventeen cases of CHIKV infection were identified between 4th July and 28th September. The disease was fairly mild in most of the cases. The precautionary measures adopted in the blood system caused a considerable reduction of the collection of blood components and of the delivery of plasma to the pharmaceutical industry for contract manufacturing. The estimated risk of CHIKV transmission through blood transfusion peaked in the third week of August.


CONCLUSIONS
ACHIKV epidemic poses considerable problems for public health authorities, who not only need good routine programmes of vector control and epidemiological surveillance but also local and national emergency plans to sustain the blood supply, so as to promptly deal with the potentially severe effects of an epidemic outbreak, especially when affected areas locally require a significant blood inventory and at the same time represent a critical resource for other areas depending on external supplies of blood components.
Liumbruno
Giancarlo Maria
GM
Centro Nazionale Sangue, Istituto Superiore di Sanità, Roma, Italy. giancarlo@liumbruno.it
Calteri
Deanna
D
Petropulacos
Kyriakoula
K
Mattivi
Andrea
A
Po
Claudio
C
Macini
Pierluigi
P
Tomasini
Ivana
I
Zucchelli
Paolo
P
Silvestri
Anna Rita
AR
Sambri
Vittorio
V
Pupella
Simonetta
S
Catalano
Liviana
L
Piccinini
Vanessa
V
Calizzani
Gabriele
G
Grazzini
Giuliano
G
D000330:Aedes / Q000821:virology; D000368:Aged; D000369:Aged, 80 and over; D018354:Alphavirus Infections / Q000097:blood / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D000818:Animals; D001782:Blood Donors; D002646:Chikungunya virus / Q000302:isolation & purification*; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D065227:Transfusion Reaction