Reptile vector-borne diseases of zoonotic concern

Reptile vector-borne diseases (RVBDs) of zoonotic concern are caused by bacteria, protozoa and viruses transmitted by arthropod vectors, which belong to the subclass Acarina (mites and ticks) and the order Diptera (mosquitoes, sand flies and tsetse flies). The phyletic age of reptiles since their origin in the late Carboniferous, has favored vectors and pathogens to co-evolve through millions of years, bridging to the present host-vector-pathogen interactions. The origin of vector-borne diseases is dated to the early cretaceous with Trypanosomatidae species in extinct sand flies, ancestral of modern protozoan hemoparasites of zoonotic concern (e.g., Leishmania and Trypanosoma) associated to reptiles. Bacterial RVBDs are represented by microorganisms also affecting mammals of the genera Aeromonas, Anaplasma, Borrelia, Coxiella, Ehrlichia and Rickettsia, most of them having reptilian clades. Finally, reptiles may play an important role as reservoirs of arborivuses, given the low host specificity of anthropophilic mosquitoes and sand flies. In this review, vector-borne pathogens of zoonotic concern from reptiles are discussed, as well as the interactions between reptiles, arthropod vectors and the zoonotic pathogens they may transmit

Molecular detection of Wolbachia endosymbiont in reptiles and their ectoparasites

Wolbachia, a maternally transmitted Gram-negative endosymbiont of onchocercid nematodes and arthropods, has a role in the biology of their host; thus it has been exploited for the filariasis treatment in humans. To assess the presence and prevalence of this endosymbiont in reptiles and their ectoparasites, blood and tail tissue as well as ticks and mites collected from them were molecularly screened for Wolbachia DNA using two sets of primers targeting partial 16S rRNA and Wolbachia surface protein (wsp) genes. Positive samples were screened for the partial 12S rRNA and cytochrome c oxidase subunit 1 (cox1) genes for filarioids. Of the different species of lizards (Podarcis siculus, Podarcis muralis and Lacerta bilineata) and snakes (Elaphe quatuorlineata and Boa constrictor constrictor) screened from three collection sites, only P. siculus scored positive for Wolbachia 16S rRNA. Among ectoparasites collected from reptiles (Ixodes ricinus ticks and Neotrombicula autumnalis, Ophionyssus sauracum and Ophionyssus natricis mites), I. ricinus (n = 4; 2.8%; 95% CI, 0.9–7) from P. siculus, N. autumnalis (n = 2 each; 2.8%; 95% CI, 0.9–6.5) from P. siculus and P. muralis and O. natricis (n = 1; 14.3%; 95% CI, 0.7–55.4) from Boa constrictor constrictor scored positive for Wolbachia DNA. None of the positive Wolbachia samples scored positive for filarioids. This represents the first report of Wolbachia in reptilian hosts and their ectoparasites, which follows a single identification in the intestinal cells of a filarioid associated with a gecko. This data could contribute to better understand the reptile filarioid-Wolbachia association and to unveil the evolutionary pattern of Wolbachia in its filarial host

Illegal Wildlife Trade: A Gateway to Zoonotic Infectious Diseases

The illegal wildlife trade (IWT) is a criminal practice bringing several ecological and public health consequences, such as the spreading of zoonotic pathogens and/or the introduction of exotic species of animals into new geographical areas. Here, we discuss potential risks of IWT on the spreading and emergence of zoonotic pathogens

Efficacy of a spot-on formulation containing moxidectin 2.5%/imidacloprid 10% for the treatment of Cercopithifilaria spp. and Onchocerca lupi microfilariae in naturally infected dogs from Portugal

Background: Onchocerca lupi and Cercopithifilaria spp. are vector-borne filarioids of dogs, which harbour skin microfilariae (mfs), the former being of zoonotic concern. Proper treatment studies using compounds with microfilaricidal activity have not been performed. Therefore, this study aimed to assess the efficacy of a commercially available spot-on formulation containing moxidectin 2.5%/imidacloprid 10% for the treatment of O. lupi or Cercopithifilaria spp. skin-dwelling mfs in naturally infected dogs. Methods: Privately owned dogs (n = 393) from southern Portugal were sampled via skin biopsies to identify and count mfs in 20 µl of skin sediment. A total of 22 mfs-positive dogs were allocated to treatment group (n = 11; G1) or left untreated as a control (n = 11; G2). As a pilot investigation to test the treatment efficacy, five dogs assigned to G1 were treated four times at monthly intervals with moxidectin 2.5%/imidacloprid 10% spot-on formulation on SDs 0, 28 (± 2), 56 (± 2), and 84 (± 2). Based on the negative results for both O. lupi and/or Cercopithifilaria spp. mfs of dogs in the pilot study from SD28 onwards, the remaining six dogs in G1 were treated at SD0 and assessed only at SD28. Results: Of the 393 animals sampled, 78 (19.8%) scored positive for skin-dwelling mfs. At the pilot investigation, a mean number of 19.6 mfs for O. lupi was recorded among five infected dogs whereas no mfs were detected at SD28. At SD0, the mean number of Cercopithifilaria spp. larvae was 12.6 for G1 and 8.7 for G2. The mean number of mfs for G2 was 20.09. Conclusions: Results herein obtained suggest that a single treatment with moxidectin 2.5%/imidacloprid 10% spot-on formulation is efficacious against skin-dwelling mfs in dogs. The microfilaricidal effect of moxidectin could also be useful in reducing the risk of O. lupi infection for humans.[Figure not available: see fulltext.

Leishmania tarentolae and leishmania infantum in humans, dogs and cats in the pelagie archipelago, southern italy

Visceral leishmaniasis (VL) caused by Leishmania infantum is endemic in the Mediterranean basin with most of the infected human patients remaining asymptomatic. Recently, the saurian-associated Leishmania tarentolae was detected in human blood donors and in sheltered dogs. The circulation of L. infantum and L. tarentolae was investigated in humans, dogs and cats living in the Pelagie islands (Sicily, Italy) by multiple serological and molecular testing. Human serum samples (n = 346) were tested to assess the exposure to L. infantum by immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) and to L. tarentolae by IFAT. Meanwhile, sera from dogs (n = 149) and cats (n = 32) were tested for both Leishmania species by IFAT and all blood samples, including those of humans, by specific sets of real time-PCR for L. infantum and L. tarentolae. The agreement between serological tests performed for human samples, and between serological and molecular diagnostic techniques for both human and animal samples were also assessed. Overall, 41 human samples (11.8%, 95% CI: 8.9–15.7) were positive to L. infantum (5.2%, 95% CI: 3.3–8.1), L. tarentolae (5.2%, 95% CI: 3.3–8.1) and to both species (1.4%, 95% CI: 0.6–3.3) by serology and/or molecular tests. A good agreement among the serological tests was determined. Both Leishmania spp. were serologically and/or molecularly detected in 39.6% dogs and 43.7% cats. In addition to L. infantum, also L. tarentolae circulates in human and animal populations, raising relevant public health implications. Further studies should investigate the potential beneficial effects of L. tarentolae in the protection against L. infantum infection

Clinical, haematological and biochemical findings in tigers infected by leishmania infantum

Background: A large number of animal species are susceptible to Leishmania infantum (Kinetoplastida, Trypanosomatidae) in endemic areas, including domestic and wild felids such as tigers (Panthera tigris). Knowledge on the infection of this endangered species is still at its infancy, and therefore this study aims to identify clinical presentation and clinicopathological findings of tigers naturally infected by L. infantum. Results: Tigers either L. infantum-positive (group A) or -negative (group B) were apparently healthy or presented visceral leishmaniasis unrelated conditions, except for one animal in which a large non-healing cutaneous lesion was observed. However, histological exam and immunohistochemistry carried out on the lesion excluded the presence of L. infantum amastigotes. Biochemical analysis showed that the average concentration of total proteins, globulins and haptoglobin were significantly higher (p < 0.01, p = 0.01 and p = 0.02, respectively), while the albumin/globulin ratio significantly lower (p = 0.05) in group A compared with group B. The biochemical alterations were partially confirmed by the serum protein electrophoresis results revealing a significant increase in the total protein value (p = 0.01) and hypergammaglobulinemia (p = 0.03) but an unmodified albumin/globulin ratio in group A. Conclusions: In this study tigers infected by L. infantum have shown to be mainly asymptomatic. The absence of clinical signs may lead veterinarians to overlook leishmaniasis in animals kept in captivity. Therefore, diagnostic and screening tests as serology should be part of routinely surveillance programs to be performed on tigers in zoological gardens located in endemic areas. Though only few protein-related laboratory abnormalities were recorded in infected animals, they could provide diagnostic clues for a first suspicion of L. infantum infection in tigers. Indeed, considering the high risk of zoonotic transmission in heavily frequented environment as zoos, a prompt diagnosis of L. infantum infection is of pivotal importance

Ectoparasites of hedgehogs: From flea mite phoresy to their role as vectors of pathogens

Hedgehogs are synanthropic mammals, reservoirs of several vector-borne pathogens and hosts of ectoparasites. Arthropod-borne pathogens (i.e., Rickettsia spp., Borrelia spp., and Anaplasmataceae) were molecularly investigated in ectoparasites collected on hedgehogs (n = 213) from Iran (161 Hemiechinus auritus, 5 Erinaceus concolor) and Italy (47 Erinaceus europaeus). In Iran, most animals examined (n = 153; 92.2%) were infested by ticks (Rhipicephalus turanicus, Hyalomma dromedarii), and 7 (4.2%) by fleas (Archeopsylla erinacei, Ctenocephalides felis). Of the hedgehogs infested by arthropods in Italy (i.e., 44.7%), 18 (38.3%) were infested by fleas (Ar. erinacei), 7 (14.9%) by ticks (Haemaphysalis erinacei, Rh. turanicus, Rhipicephalus sanguineus sensu lato), and 6 (12.8%) by mites (Caparinia tripilis, Acarus nidicolous, Ornithonyssus spp.). Phoretic behavior of C. tripilis on Ar. erinacei was detected in two flea specimens from Italy. At the molecular analysis Rickettsia spp. was detected in 93.3% of the fleas of Italy. In Iran, Rickettsia spp. was detected in 8.0% out of 212 Rh. turanicus ticks, and in 85.7% of the Ar. erinacei fleas examined. The 16S rRNA gene for Ehrlichia/Anaplasma spp. was amplified in 4.2% of the 212 Rh. turanicus ticks. All sequences of Rickettsia spp. from fleas presented 100% nucleotide identity with Rickettsia asembonensis, whereas Rickettsia spp. from Rh. turanicus presented 99.84%–100% nucleotide identity with Rickettsia slovaca, except for one sequence, identical to Rickettsia massiliae. The sequences of the 16S rRNA gene revealed 99.57%–100% nucleotide identity with Anaplasma spp., except for one, identical to Ehrlichia spp. A new phoretic association between C. tripilis mites and Ar. erinacei fleas has been herein reported, which could be an important route for the spreading of this mite through hedgehog populations. Additionally, spotted fever group rickettsiae were herein detected in ticks and fleas, and Anaplasma/Ehrlichia spp. in ticks, suggesting that hedgehogs play a role as reservoirs for these vector-borne pathogens

Hyperendemic Dirofilaria immitis infection in a sheltered dog population: an expanding threat in the Mediterranean region

A study on the occurrence of Dirofilaria immitis and its vectors was carried out in order to assess the prevalence of the disease in dogs in previously non-endemic areas of southern Italy. Blood samples (n = 385) and mosquitoes (n = 1540) were collected in two dog shelters and analysed by Knott's test and duplex real-time PCR, respectively. Dirofilaria immitis was the most prevalent filarioid (44.2%), while Culex pipiens was the most prevalent mosquito species (68.8%). This high prevalence of D. immitis infection confirms this location as one of the most hyperendemic foci of dirofilariosis in Europe

A checklist of chiggers from Brazil, including new records (Acari: Trombidiformes: Trombiculidae and leeuwenhoekiidae)

A checklist of the family Trombiculidae and Leeuwenhoekiidae is presented, containing 63 species in 30 genera of chiggers from 80 different hosts and 146 localities in Brazil. The type locality and depository are provided, including new locality and host records for the country