Changing distribution patterns of canine vector borne diseases in Italy: leishmaniosis vs. dirofilariosis.

Domenico Otranto,Claudio Genchi,Gioia Capelli

doi:10.1186/1756-3305-2-s1-s2

Abstract

Ecological and climatic changes, human and animal population dynamics are among the several factors that have favoured the spread or the (re)introduction and establishment of "novel" vector species and pathogens they transmit in previously disease-free geographical areas. As key examples of the changing pattern of distribution of canine vector borne diseases (CVBDs), the current distribution of canine leishmaniosis (CanL) by Leishmania infantum and dirofilariosis by Dirofilaria immitis causing heart worm disease (HW) in Italy is discussed on the basis of retrospective historical reports until the 90's and later on until 2009. For long time, D. immitis has been considered mainly present along the Po River Valley and northward areas, while L. infantum in south-central Italy and Sicily and Sardinia. Comparison of current available and historical data (up to 1989) confirms that HW and CanL, although with different prevalence rates, have been changing their distribution patterns in Italy as a result of many biological and ecological factors, including those related to vector distribution and introduction of new species (e.g. the Asian tiger mosquito Aedes albopictus, a competent vector of D. immitis). New autochthonous foci of HW in southern Italy (i.e. Apulia and Calabria regions) have recently been reported.Although analysing retrospective data may represent a difficult task, the "paradigm" about the dual distribution of HW and CanL in northern and southern Italy cannot yet be considered valid. The research needs for managing HW and CanL in previously uninfected areas are discussed.

Highlights

The global spread of parasitic arthropods and of canine vector borne diseases (CVBDs) have no more boundaries across the planet
Movement of people and increased exchange of goods through a range of types of transportation may play a crucial role for theintroduction and establishment of “novel” vector species and pathogens in previously disease free areas [3]. Such was the case of the Asian tiger mosquito Aedes albopictus which is a competent vector of Dirofilaria immitis to dogs [4] and of West Nile virus, Japanese B encephalitis, Chikungunya virus and other arboviruses to humans [5]
The occurrence and establishment of a CVBD is regulated by a complex chain of interactions among pathogens, vectors and the environment

Summary

Background

The global spread of parasitic arthropods and of canine vector borne diseases (CVBDs) have no more boundaries across the planet. The above phenomena might have contributed in favouring the establishment into previously free areas or in increasing insect density into already colonized areas of phlebotomine competent species of L. infantum and might represent an important issue to be considered while predicting the spreading of sandflies northward through central European continental countries. In Italy the perception and the awareness of researchers and practitioners on many aspects of CVBD have increased over the last decade, many issues still need to be better investigated These include basic knowledge http://www.parasitesandvectors.com/content/2/S1/S2 on vector, pathogen and host interactions which would provide new information to manage CVBD in endemic areas reducing the risk of occurrence of new foci in non endemic zones. While stray dogs represent an easy feeding source for arthropods and reservoir of pathogens, the scant economic resources (which are further worsened by the global economic crisis), the current legislation that obliges the health public authorities to maintain municipal kennel for stray dogs (in which animals remain often untreated against ectoparasites), probably represent the major impairments toward the control of HW and CanL in Italy as well as in other Mediterranean countries

Rezza G

23. Killick-Kendrick R

48. Cassini R

Findings

53. Killick –Kendrick R