impaginato piccolo - Società Italiana di Parassitologia (SoIPa)

Parassitologia 50: 109-111, 2008
Arboviruses in Italy
L. Nicoletti, M.G. Ciufolini, C. Fortuna, F. Magurano, C. Fiorentini, A. Marchi, E.
Benedetti, P. Bucci
Department of Infectious, Parasitic and Immune mediated diseases, Istituto Superiore di Sanità, Rome,
Introduction
Abstract. A brief review of the arboviruses isolated In Italy is presented and discussed. Some of the
Arboviruses considered in this paper are endemic in the country and are transmitted by arthropods that play
actually a role of vectors, (sand flyes, hard ticks and mosquitoes); other arboviruses, sporadically isolated,
are potential agents of emerging human or zoonotic diseases
Keywords: Vector Borne Diseases, Sandfly, Ticks, Mosquitoes
Italy extends approximately between latitudes 36 and
47°N. It is almost completely surrounded by sea and bordered
in the north by mountains. There is a north-south
central mountain range (Appennines) with highest altitudes
of over 2600 m. Consequently, climatic conditions
vary considerably within Italy: from mountainous, to
continental, and to coastal. The southern extremity of
Italy is greatly influenced by its proximity to North
Africa, sometimes producing subtropical climatic conditions.
Furthermore, the formation of an abundant and
varied arthropod population, the presence of domestic
and small wild animals in fairly large numbers in certain
parts of the country, and a usually very temperate climate
could maintain natural foci of arboviruses. The periodic
migration of several species of birds between Europe and
Africa across Italy can also contribute to the introduction
and dissemination of arboviruses in the country.
The presence of arboviruses in Italy was first documented
during World War II in epidemiological studies
on the American troops by Sabin: two viruses of the
Phlebotomus fever group were isolated, Sandfly Fever
Sicilian and Sandfly Fever Neapolitan. For 20 years
after these isolations, however, only limited amount of
data on the activity of arboviruses in Italy was recorded.
Then, beginning in 1965, our Department started a
surveillance program for arboviruses in selected Italian
regions. The program’s studies centred on the collection
of virologic and serologic data related to the presence
of arboviruses as well as on determination of their
importance in the public health of the population.
Mosquito-borne viruses:
A periodical mosquito collection was regularly performed
during the years 1966 to 1968 in Northern Italy
and in 1980-1987 in Central Italy. The dominant mos-
Correspondence: Loredana Nicoletti
Department of Infectious, Parasitic and Immune mediated
disease, Istituto Superiore di Sanità, Viale Regina Elena 299
00161 Rome, Italy
Tel +39 06 49903242/3235, Fax Fax: +39 06 49902082,
e-mail: loredana.nicoletti@iss.it
quito species were Culex pipiens, Aedes vexans and Ae.
caspius. More than 70,000 mosquitoes were processed
in 1967-1968 and more than 13,000 in 1980-1987.
Two strains of Tahyna virus (California group) were
isolated in 1967 from mixed pools of Ae. caspius and
Ae. vexans, which were collected in Northern Italy.
Neutralizing antibodies (by mouse neutralization test)
against Tahyna virus have been found in high percentage
(70%) among people living near the areas where
mosquitoes were trapped. (Balducci et al, 1968)
Antibodies against other mosquito-borne viruses have
also been found. Human sera from Northern and
Central Italy reacted with West Nile virus in HI. The
virus caused and outbreak of meningoencephalitis in
horses in 1999 in Tuscany Region. (Autorino et al,
1999). Retrospective studies have shown that during
this episode some humans could have been infected by
the virus with only minor symptoms of disease.
In July and August 2007, the local health unit of the
province of Ravenna (region of Emilia Romagna,
north-eastern Italy) detected an unusually high number
of cases of febrile illness. Early in the outbreak investigation,
infection with Chikungunya was suspected
because of clinical symptoms and the fact that the first
patient with febrile illness was a man from a country
affected by an outbreak. Furthermore, the presence of
A. albopictus in the area was known. Of the 334 suspected
or probable Chikungunya cases involved in the
outbreak, samples were examined of 281 and 204 were
laboratory-confirmed. The virus was isolated from the
serum of patients and from a pool of A. albopictus collected
in the affected area. (Rezza et al, 2007)
Viruses isolated from birds
Bahig and Matruh viruses (Tete group) were isolated
from the blood of birds captured by nets in the
autumns of 1968 and 1969 (23). Each virus was isolated
in both years and both from Fringilla coelebs
(chaffinch) and Fringilla montifringilla (brambling
finch). The birds were captured in North-eastern Italy
during their fall migration. The same viruses had been
previously isolated in Egypt from autumn migrants,
suggesting that the site of initial infection was probably
somewhere in Eastern Europe or Western Asia. The cir-