Risk Mapping of Visceral Leishmaniasis: A Spatial Regression Model for Attica Region, Greece.

Visceral Leishmaniasis (VL) is endemic to the Attica region of Greece. The geographical distribution of VL cases was analyzed employing methods of spatial analysis in a GIS environment. A geographic database was constructed including data for the disease cases and environmental factors, such as land cover types, stray dog population, and socioeconomic factors. Classic and spatial regression models are presented that suggest the factors contributing most to the incidence of leishmaniasis are green urban areas and the population of stray dogs in the municipalities of Attica region. The results of the spatial regression model were more accurate, thus were used to produce a disease risk map. This map indicates the high-risk municipalities in which surveillance for the control of leishmaniasis is necessary.

Species composition, distribution, ecological preference and host association of ticks in Cyprus.

Tick population and species depend on the effect of biotic and abiotic factors, especially vegetation, climate and host density; Cyprus, due to the mild climate, favors the appearance and spread of tick-borne infections. Our objective was to identify the tick species present in the island, to investigate their geographical distribution and their epidemiological implications. During a three-year study (2004-2006) we collected ticks from domestic and wild animals over the island of Cyprus. Data on temperature, humidity, altitude and vegetation, were also recorded. Each tick was identified by species using existing taxonomic keys. The results were mapped on a county level. During the current study 3057 ticks belonging to 11 tick species and four genera were collected from 441 (24.6%) infested animals. Rhipicephalus sanguineus was the predominant species (38.5%), followed by R. turanicus (21.3%) and R. bursa (17.8%). Most infestations occurred in May (24.0%), followed by March (13.6%) and June (12.2%). Rhipicephalus sanguineus had a positive correlation with humidity and temperature, R. bursa and Ixodes gibbosus had a positive correlation with altitude and a negative correlation with temperature. Contrary, Hyalomma excavatum had a negative correlation with altitude. Climate and the availability of hosts are among the major factors influencing ticks.

Spotted fever group Rickettsiae in ticks in Cyprus.

In two surveys conducted from March 1999 to March 2001 and from January 2004 to December 2006, a total of 3,950 ticks (belonging to ten different species) were collected from seven domestic and wild animals (goat, sheep, cattle, dog, fox, hare, and mouflon) from different localities throughout Cyprus. In order to establish their infection rate with Spotted Fever Rickettsiae (SFG), ticks were pooled and tested by polymerase chain reaction targeting gltA and ompA genes, followed by sequencing analysis. When tick pools tested positive, individual ticks were then tested one by one, and of the 3,950 ticks screened, rickettsial DNA was identified in 315 ticks (infection rate, 8%). Five SFG Rickettsiae were identified: Rickettsia aeschlimannii in Hyalomma marginatum marginatum, Rickettsia massiliae in Rhipicephalus turanicus and Rhipicephalus sanguineus, Rickettsia sibirica mongolotimonae in Hyalomma anatolicum excavatum, and a Rickettsia endosymbiont of Haemaphysalis sulcata (later described as Rickettsia hoogstraalii) in Haemaphysalis punctata. Two additional genes, 17 kDa and ompB, were targeted to characterize a new genotype of "Candidatus Rickettsia barbariae" genotype in R. turanicus, designated here as "Candidatus Rickettsia barbariae" Cretocypriensis. These results confirm the presence of a spectrum of SFG Rickettsiae on the island. Further studies are necessary to gain better knowledge on the epidemiology of SFG Rickettsiae in Cyprus.

Tick-borne bacteria in mouflons and their ectoparasites in Cyprus.

The Cypriot mouflon (Ovis orientalis ophion), a once almost extirpated species of wild sheep, is under strict surveillance because it can be threatened by likely transmission of pathogenic bacteria, such as Anaplasma spp., Rickettsia spp., and Coxiella burnetii, primarily from domestic ungulates. We collected 77 blood samples from Cypriot mouflons and 663 of their ectoparasites (Rhipicephalus turanicus, Rhipicephalus sanguineus, Rhipicephalus bursa, Hyalomma anatolicum excavatum, Hyalomma marginatum, Haemaphysalis punctata, Haemaphysalis sulcata, and Ixodes gibossus) and tested them by polymerase chain reaction and sequencing. Twenty-three mouflon blood samples (30%) were positive for C. burnetii, 23 (30%) for Rickettsia spp., and 8 (10%) for Anaplasma ovis. Of 109 pools of ectoparasites, 32.1% were positive for C. burnetii, 28.4% for Rickettsia spp., and 10.9% for A. ovis; 11.9% were positive for both C. burnetii and Rickettsia spp., 6.4% for both Rickettsia spp. and A. ovis, and 2.8% for all three pathogens. This is the first survey that records the presence of tick-borne pathogens, both in the Cypriot mouflon and in ticks parasitizing it.

Leishmaniases and the Cyprus paradox.

In Cyprus, leishmaniasis has been considered exclusively a veterinary problem. It was prevalent before 1945, and until its recent reemergence, it was nearly eradicated by 1996 as a consequence of the destruction of reservoir hosts and vectors. A survey carried out to provide an unbiased estimate of current transmission rates in dogs and humans showed a 9-fold increase in dog seroprevalence (reaching 14.9%) compared with 10 years ago. However, no human cases caused by Leishmania infantum were detected, although L. donovani cases were reported recently. The 62 strains isolated from dogs were typed as L. infantum MON-1 (98.4%), which is the predominating zymodeme in the Mediterranean region, and MON-98 (1.6%). The Phlebotomus species P. tobbi (vector of L. infantum in Cyprus), P. galilaeus, and P. papatasi were the predominant species captured. Two transmission cycles seem to run in parallel in Cyprus: in dogs with L. infantum and in humans with L. donovani.

Fourteen-year seroepidemiological study of zoonoses in a Greek village.

A seroepidemiological study carried out in a high-risk village in Crete in 1985-1987 and 1998 showed that although the awareness of the people concerning zoonoses had increased during this period, the situation did not improve: there was a significant increase of the spread of seroprevalence in time and space of Coxiella burnetii, Rickettsia typhi, Brucella sp., and Entamoeba histolytica. Toxoplasma gondii, Rickettsia conorii, Borrelia burgdorferi, Echinococcus granulosus, Leishmania sp., and Fasciola hepatica stayed at the same levels. This first study of Bartonella henselae in Crete showed that 15.9% of the children tested were seropositive. The results indicate that reservoirs and vectors of the pathogens studied are widespread in the environment, and the way of life of the people favors contact with them. Seven of 30 milk samples were positive for Brucella sp. by seminested polymerase chain reaction.