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1.  Risk of canine and human exposure to Dirofilaria immitis infected mosquitoes in endemic areas of Italy 
Parasites & Vectors  2013;6:60.
The occurrence of infections by Dirofilaria immitis in canine and human populations depends on several factors linked to both the definitive and intermediate hosts. Little data are available on the risk of human and dog exposure to D. immitis in endemic areas. Data collected on dog- and human-bait traps in endemic areas of north-eastern Italy were used to estimate the likelihood of a receptive host coming into contact with an infected vector.
From 1997 to 1999, mosquitoes were collected from three sampling sites of north-eastern Italy on D. immitis microfilaraemic dogs and on human baits. The bite/night/host rates were determined based on the number of feeding and probing mosquitoes on dogs and humans, respectively. The survival/mortality rates of different species of mosquitoes following the blood meal, and the rate of natural Dirofilaria infection in unfed specimens were estimated. The risk of exposure of dogs and humans to infected mosquito species was determined by combining the bite/host/night and the mosquito infection rates.
A total of 1,165 mosquitoes were collected on human (n = 815) and dog (n = 350) baits with varying species composition (i.e., Culex pipiens, 87.3% and Ochlerotatus caspius, 11.6%). Overall, dogs were more attractive to Cx pipiens than humans (feeding rate 70.2% vs probing rate 25.9%). The highest bite/night/host rate was 84.0 for dogs and 26.5 for humans. Cx pipiens displayed a mortality rate of 76.3% within 13 days and Oc. caspius of 100% within two days following the infective blood meal. In addition, D. immitis DNA was detected in unfed Cx pipiens (infection rate of 0.26%-2.07%). The infection rate adjusted for mosquito mortality was 0.38%. Based on data collected, the contact between an infected mosquito and a host can occur as often as every four nights for D. immitis infected-mosquitoes in dogs and within two weeks for humans.
Cx pipiens was confirmed as the most efficient natural vector of D. immitis in the studied area. In endemic areas, the risk of transmission can be very high for dogs and relevant for humans. Despite the increased awareness of veterinarians and owners on canine dirofilarioses, dogs from rural areas still maintain the natural life cycle of Dirofilaria spp., therefore acting as a source of infection to humans through vector bites.
PMCID: PMC3599681  PMID: 23510597
Dirofilaria immitis; Mosquito vectors; Dogs; Humans; Risk of exposure
2.  Occurrence and identification of risk areas of Ixodes ricinus-borne pathogens: a cost-effectiveness analysis in north-eastern Italy 
Parasites & Vectors  2012;5:61.
Ixodes ricinus, a competent vector of several pathogens, is the tick species most frequently reported to bite humans in Europe. The majority of human cases of Lyme borreliosis (LB) and tick-borne encephalitis (TBE) occur in the north-eastern region of Italy. The aims of this study were to detect the occurrence of endemic and emergent pathogens in north-eastern Italy using adult tick screening, and to identify areas at risk of pathogen transmission. Based on our results, different strategies for tick collection and pathogen screening and their relative costs were evaluated and discussed.
From 2006 to 2008 adult ticks were collected in 31 sites and molecularly screened for the detection of pathogens previously reported in the same area (i.e., LB agents, TBE virus, Anaplasma phagocytophilum, Rickettsia spp., Babesia spp., "Candidatus Neoehrlichia mikurensis"). Based on the results of this survey, three sampling strategies were evaluated a-posteriori, and the impact of each strategy on the final results and the overall cost reductions were analyzed. The strategies were as follows: tick collection throughout the year and testing of female ticks only (strategy A); collection from April to June and testing of all adult ticks (strategy B); collection from April to June and testing of female ticks only (strategy C).
Eleven pathogens were detected in 77 out of 193 ticks collected in 14 sites. The most common microorganisms detected were Borrelia burgdorferi sensu lato (17.6%), Rickettsia helvetica (13.1%), and "Ca. N. mikurensis" (10.5%). Within the B. burgdorferi complex, four genotypes (i.e., B. valaisiana, B. garinii, B. afzelii, and B. burgdorferi sensu stricto) were found. Less prevalent pathogens included R. monacensis (3.7%), TBE virus (2.1%), A. phagocytophilum (1.5%), Bartonella spp. (1%), and Babesia EU1 (0.5%). Co-infections by more than one pathogen were diagnosed in 22% of infected ticks. The prevalences of infection assessed using the three alternative strategies were in accordance with the initial results, with 13, 11, and 10 out of 14 sites showing occurrence of at least one pathogen, respectively. The strategies A, B, and C proposed herein would allow to reduce the original costs of sampling and laboratory analyses by one third, half, and two thirds, respectively. Strategy B was demonstrated to represent the most cost-effective choice, offering a substantial reduction of costs, as well as reliable results.
Monitoring of tick-borne diseases is expensive, particularly in areas where several zoonotic pathogens co-occur. Cost-effectiveness studies can support the choice of the best monitoring strategy, which should take into account the ecology of the area under investigation, as well as the available budget.
PMCID: PMC3337281  PMID: 22452970
Ixodes ricinus; tick-borne diseases; surveillance; economic evaluation; Italy.
3.  Heartworm (Dirofilaria immitis) infection in a leopard (Panthera pardus pardus) housed in a zoological park in north-eastern Italy 
Parasites & Vectors  2010;3:25.
Canine heartworm (cHW) disease is now recognised as potential cause of serious disease in cats and other felids, especially in endemic areas. In March 2009, a 23-years-old male African leopard (Panthera pardus pardus) housed in a zoological park located in the Province of Padova (Veneto Region), a cHW endemic area of the north-eastern Italy, died and was immediately necropsied. A cloth completely occluding the pyloric lumen was considered the presumptive cause of death. During necropsy, six nematodes (4 males and 2 females) were found within the right ventricle of the heart and the pulmonary artery. Diagnosis of HW (Dirofilaria immitis) infection was carried out by morphological features of adult worms and microfilariae, and then confirmed by detection of circulating HW antigens using a commercial SNAP kit (IDEXX Laboratories inc., USA). D. immitis infection was also confirmed by PCR amplification of the 5S ribosomal spacer region, performed on worm fragments and microfilaraemic blood samples obtained from the right ventricle of the heart. A glomerulonephritis of immuno-mediated origin and most likely associated with the HW infection is also reported. HW chemoprophylaxis and annual serological testing on wild felids housed outdoors in endemic cHW disease areas are recommended. This is the first diagnosis of D. immitis infection in an exotic felid in Italy.
PMCID: PMC2858128  PMID: 20377859

Results 1-3 (3)