Dirofilaria immitis and Onchocercidae spp. in wild felids from Brazil

Among the species described within the Onchocercidae family, Dirofilaria immitis is regarded as the most common worldwide, causing severe and often fatal conditions in dogs, cats, and occasionally humans. Dirofilaria spp. are vectored by mosquitoes, simulids, and culicoids, with their epidemiology dependent on the geographical distribution of competent vectors. Eight species of Dirofilaria have been reported so far in Brazil, of which six parasitize non-human primates, deer, procyonids, and marsupials. Here, we investigated the occurrence of Onchocercidae in wild felids (i.e., Panthera onca, Puma concolor, Herpailurus yagouaroundi, Leopardus geoffroyi, Leopardus guttulus, Leopardus pardalis, Leopardus wiedii, Leopardus munoai) from different locations in Brazil. Overall, 82 samples (n = 63 blood; n = 19 tissues) were molecularly screened for cytochrome c oxidase subunit-1 (cox1) gene. Four (i.e., 4.8%) wild felid samples were positive, and at BLAST analysis, the obtained sequences showed varying percentage of nucleotide identity with the genera Brugia (i.e., 87-88%), Setaria (i.e., 89%), and D. immitis (i.e., 94.4%). Phylogenetic analyses clustered sequences obtained into three distinct clades, one with D. immitis and the remaining two with other Onchocercidae spp. Data herein obtained highlight the need for a more comprehensive understanding of the diversity and biology of Onchocercidae in South America in order to assess the potential impact that these species may have for domestic and wild animals, as well as humans.

Molecular Characterization of Spirometra erinaceieuropaei from Jungle Cat (Felis chaus) in North of Iran

PURPOSE

The aim of this study is to conduct a molecular characterization of Spirometra tapeworm from jungle cat (Felis chaus) in Guilan Province, north of Iran using DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (Cox1) and 12S rDNA sequences.

METHODS

Morphological features of the adult tapeworm of Spirometra were evaluated using specific staining and light microscopy. The molecular characterization was performed using partial Cox1 and 12S rDNA regions. Genetic diversity was calculated and phylogenetic trees of the obtained sequences were constructed.

RESULTS

Morphological features were compatible with previous description of adult Spirometra erinaceieuropaei. The Cox1 sequence of the specimen showed 100% similarity with S. erinaceieuropaei sequences in GenBank from Korea, China and Iran. Also, the 12S rDNA sequence revealed 99.7% similarity with S. erinaceieuropaei isolates from China and Japan. Intra-species variation within isolates of S. erinaceieuropaei was 0-1.4% and 0-4.6% for Cox1 and 12S rDNA genes, respectively.

CONCLUSION

This is the first report of molecular characterization of S. erinaceieuropaei in jungle cat, F. chaus in Iran. Jungle cat probably plays a major role as reservoir host in maintaining of this parasite in this area with favorable climate condition. Needs for further assessment on the role of appropriate hosts, especially intermediate/paratenic hosts as well as the potential risk of human infectivity with sparganosis is emphasized.

Toxoplasma gondii in small exotic felids from zoos in Europe and the Middle East: serological prevalence and risk factors

BACKGROUND

Toxoplasma gondii infections and cases of clinical toxoplasmosis have been recorded in zoo animals. Wild felids in human care can serve as definitive hosts that shed oocysts, but also as intermediate hosts for the parasite. Some felid species, such as the Pallas's cat (Otocolobus manul) or sand cat (Felis margarita), may suffer from clinically apparent toxoplasmosis. In the present study, our main aim was to assess risk factors for T. gondii infections in small exotic felids.

METHODS

A seroepidemiological study was conducted using the reduviid bug Dipetalogaster maxima for blood sample collection, a method previously evaluated on domestic cats. A total of 336 samples from 17 felid species were collected in 51 institutions, 48 of which were within Europe and the remaining three in the Middle East (United Arabic Emirates and Qatar). These samples were analyzed for T. gondii antibodies by immunoblotting and an immunofluorescent antibody test. Potential risk factors in zoos for seropositivity regarding T. gondii among members of the European Association of Zoos and Aquaria (EAZA) were evaluated using a questionnaire and individual data from the Zoological Information Management System (ZIMS).

RESULTS

The sampled felids showed an overall seroprevalence for T. gondii of 63%. The risk factor study including data of 311 small exotic cats of 10 species resulted in a final generalized linear mixed model comprised of five variables: the likelihood of seropositivity increased statistically significantly with "Age", while feeding "Cattle: frozen" relative to "Cattle: fresh", "Outdoor housing fenced in on all sides", "Mesh size 2-5 cm" relative to "Mesh size > 5 cm" and "Wearing gloves: yes" had statistically significant protective effects.

CONCLUSIONS

Wild felids, including endangered species, kept in human care in European and Middle Eastern institutions, are widely exposed to T. gondii. Risk factor analysis revealed that feeding previously frozen tissues, keeping animals in enclosures that are fenced on all sides using fences with small mesh sizes, and wearing gloves when working inside enclosures seem to be the most relevant protective measures to prevent T. gondii infections in these animals .

Outcomes of Trypanosoma cruzi and Trypanosoma evansi infections on health of Southern coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis) in the Brazilian Pantanal

The occurrence of Trypanosoma spp. in wild carnivore populations has been intensively investigated during the last decades. However, the impact of these parasites on the health of free-living infected animals has been largely neglected. The Pantanal biome is the world’s largest seasonal wetland, harboring a great diversity of species and habitats. This includes 174 species of mammals, of which 20 belong to the order Carnivora. The present study aimed to investigate the effect of Trypanosoma evansi and Trypanosoma cruzi infections and coinfections on the health of the most abundant carnivores in the Pantanal: coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis). We captured 39 coatis, 48 crab-eating foxes, and 19 ocelots. Diagnostic tests showed T. cruzi infection in 7 crab-eating foxes and 5 coatis. Additionally, 7 crab-eating foxes, 10 coatis, and 12 ocelots were positive for T. evansi. We observed coinfections in 9 crab-eating foxes, 8 coatis, and 2 ocelots. This is the first report of T. evansi and T. cruzi infection on the health of free-living ocelots and crab-eating foxes. We showed that single T. evansi or T. cruzi infection, as well as coinfection, caused some degree of anemia in all animals, as well as an indirect negative effect on body condition in coatis and crab-eating foxes via anemia indicators and immune investment, respectively. Furthermore, the vigorous immune investment observed in sampled coatis, crab-eating foxes and ocelots infected by T. evansi, T. cruzi and coinfected can be highly harmful to their health. Overall, our results indicate that single and combined infection with T. evansi and T. cruzi represent a severe risk to the health of wild carnivores in the Pantanal region.

Toxoplasma gondii infection in wild mustelids and cats across an urban-rural gradient

The increase in human population and domestic pets, such as cats, are generating important consequences in terms of habitat loss and pathogen pollution of coastal ecosystems with potential to generate negative impacts in marine biodiversity. Toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated with cat abundance and anthropogenic disturbance. The presence of T. gondii oocysts in the ocean has negatively affected the health status of the threatened Southern sea otter (Enhydra lutris nereis) populations. The present study analyzed seroprevalence and presence of T. gondii DNA in American mink (Neovison vison), Southern river otters (Lontra provocax) and domestic cats (Felis silvestris catus) in four different areas in Southern Chile comprising studies in rivers and lakes in Andean foothills and mountains, marine habitat and island coastal ecosystems. Mean seroprevalence of T. gondii in the study was 64% of 151 total animals sampled: 59% of 73 American mink, 77% of 13 Southern river otters, 68% of 65 domestic cats and in two of two kodkods (Leopardus guigna). Toxoplasma gondii DNA was detected in tissues from one American mink and one Southern river otter. The present study confirms the widespread distribution of T. gondii in Southern Chile, and shows a high exposure of semiaquatic mustelids and domestic cats to the parasite. Cats and anthropogenic disturbance have a role in the maintenance of T. gondii infection in ecosystems of southern Chile.

The effects of demographic, social, and environmental characteristics on pathogen prevalence in wild felids across a gradient of urbanization

Transmission of pathogens among animals is influenced by demographic, social, and environmental factors. Anthropogenic alteration of landscapes can impact patterns of disease dynamics in wildlife populations, increasing the potential for spillover and spread of emerging infectious diseases in wildlife, human, and domestic animal populations. We evaluated the effects of multiple ecological mechanisms on patterns of pathogen exposure in animal populations. Specifically, we evaluated how ecological factors affected the prevalence of Toxoplasma gondii (Toxoplasma), Bartonella spp. (Bartonella), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) in bobcat and puma populations across wildland-urban interface (WUI), low-density exurban development, and wildland habitat on the Western Slope (WS) and Front Range (FR) of Colorado during 2009-2011. Samples were collected from 37 bobcats and 29 pumas on the WS and FR. As predicted, age appeared to be positively related to the exposure to pathogens that are both environmentally transmitted (Toxoplasma) and directly transmitted between animals (FIV). In addition, WS bobcats appeared more likely to be exposed to Toxoplasma with increasing intraspecific space-use overlap. However, counter to our predictions, exposure to directly-transmitted pathogens (FCV and FIV) was more likely with decreasing space-use overlap (FCV: WS bobcats) and potential intraspecific contacts (FIV: FR pumas). Environmental factors, including urbanization and landscape covariates, were generally unsupported in our models. This study is an approximation of how pathogens can be evaluated in relation to demographic, social, and environmental factors to understand pathogen exposure in wild animal populations.

Echinococcus oligarthrus in the subtropical region of Argentina: First integration of morphological and molecular analyses determines two distinct populations

Echinococcosis is a parasitic zoonosis that is considered as a neglected disease by the World Health Organization. The species Echinococcus oligarthrus is one of the causative agents of Neotropical echinococcosis, which is a poorly understood disease that requires a complex medical examination, may threaten human life, and is frequently associated with a low socioeconomic status. Morphological and genetic diversity in E. oligarthrus remains unknown. The aim of this work is to identify and characterize E. oligarthrus infections in sylvatic animals from the Upper Paraná Atlantic Forest in the province of Misiones, Argentina, by following an integrative approach that links morphological, genetic and ecological aspects. This study demonstrates, for the first time, one of the complete life cycles of E. oligarthrus in an important ecoregion. The Upper Paraná Atlantic Forest constitutes the largest remnant continuous forest of the Atlantic Forest, representing 7% of the world's biodiversity. This is the first molecular determination of E. oligarthrus in Argentina. In addition, the agouti (Dasyprocta azarae), the ocelot (Leopardus pardalis) and the puma (Puma concolor) were identified as sylvatic hosts of Neotropical echinococcosis caused by E. oligarthrus. Mitochondrial and nuclear molecular marker analyses showed a high genetic diversity in E. oligarthrus. Moreover, the genetic distance found among E. oligarthrus isolates is higher than the one observed among Echinococcus granulosus genotypes, which clearly indicates that there are at least two different E. oligarthrus populations in Argentina. This study provides valuable information to understand the underlying conditions that favour the maintenance of E. oligarthrus in sylvatic cycles and to evaluate its zoonotic significance for devising preventive measures for human and animal wellbeing.

The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part II: Helminths and arthropods

Over the last few decades, ecological factors, combined with everchanging landscapes mainly linked to human activities (e.g. encroachment and tourism) have contributed to modifications in the transmission of parasitic diseases from domestic to wildlife carnivores and vice versa. In the first of this two-part review article, we have provided an account of diseases caused by protozoan parasites characterised by a two-way transmission route between domestic and wild carnivore species. In this second and final part, we focus our attention on parasitic diseases caused by helminth and arthropod parasites shared between domestic and wild canids and felids in Europe. While a complete understanding of the biology, ecology and epidemiology of these parasites is particularly challenging to achieve, especially given the complexity of the environments in which these diseases perpetuate, advancements in current knowledge of transmission routes is crucial to provide policy-makers with clear indications on strategies to reduce the impact of these diseases on changing ecosystems.

Toxoplasma gondii, source to sea: higher contribution of domestic felids to terrestrial parasite loading despite lower infection prevalence

Environmental transmission of Toxoplasma gondii, a global zoonotic parasite, adversely impacts human and animal health. Toxoplasma is a significant cause of mortality in threatened Southern sea otters, which serve as sentinels for disease threats to people and animals in coastal environments. As wild and domestic felids are the only recognized hosts capable of shedding Toxoplasma oocysts into the environment, otter infection suggests land-to-sea pathogen transmission. To assess relative contributions to terrestrial parasite loading, we evaluated infection and shedding among managed and unmanaged feral domestic cats, mountain lions, and bobcats in coastal California, USA. Infection prevalence differed among sympatric felids, with a significantly lower prevalence for managed feral cats (17%) than mountain lions, bobcats, or unmanaged feral cats subsisting on wild prey (73-81%). A geographic hotspot of infection in felids was identified near Monterey Bay, bordering a high-risk site for otter infection. Increased odds of oocyst shedding were detected in bobcats and unmanaged feral cats. Due to their large populations, pet and feral domestic cats likely contribute more oocysts to lands bordering the sea otter range than native wild felids. Continued coastal development may influence felid numbers and distribution, increase terrestrial pathogens in freshwater runoff, and alter disease dynamics at the human-animal-environment interface.

First report of Ctenocephalides felis felis on the Asiatic Golden Cat, Catopuma temminckii in Thailand

The cat flea, Ctenocephalidesfelisfelis (Siphonaptera: Pulicidae) has been reported to parasitize many species of wild and domestic animals and could serve as a vector of zoonotic pathogens. This is the first report of the presence of cat fleas on the Asiatic Golden Cat, Catopuma temminckii (Carnivora: Felidae), quarantined in Khao Pratabchang Wildlife and Breeding Center, Ratchaburi Province, Thailand. The findings of this report may be helpful in evaluating the potential risks associated with increased contact between wild and domestic animals and humans in this region.

Siphonaptera associated with wild mammals from the Central Atlantic Forest Biodiversity Corridor in southeastern Brazil

We collected 379 samples of eight flea species from 235 specimens of wild mammals captured in three areas of the Central Atlantic Forest Corridor in the state of Espírito Santo, southeastern Brazil, between August 2006 and February 2008. Among the 22 mammal species, we found eight species of marsupials (order Didelphimorphia), 13 species of rodents (order Rodentia), and one species of wild cat (order Carnivora). The total prevalence of infestation was 28.1%, with similar percentages in rodents (26.4%) and marsupials (29.5%). The infestation in the southern area was 3 times higher than that observed in the northern area. The infestation by single flea species was > 6 times higher than the total number of double and triple infestations. The mean abundance of fleas was 1.61. The flea female/male ratio was 1.38, ranging from 0.95 in Adoratopsylla (Tritopsylla) intermedia intermedia (Wagner) to 1.81 in Hechtiella nitidus (Johnson) in the most flea species infested. We report three new records of flea species in the state of Espírito Santo, and eight new host records.

The important zoonoses in the protected areas of the Tatra National Park (TANAP)

The northern part of Slovakia constitutes an important tourist and recreational area of the country. Protected localities of the Tatra National Park (TANAP) are characterised by specific ecological conditions. The high numbers of animals inhabiting protected areas of the TANAP and their potential encounters with tourists contribute to a risk of transmission of important parasitic zoonoses. The aim of presently reported study was to perform a long-lasting and detailed survey on the occurrence of zoonotic agents (in particular Echinococcus multilocularis and Trichinella spp.) with particular emphasis on the interactions between the environment, the host, and the parasite as well as the adaptation mechanisms in individual ecosystems. Within the pilot part of the study, which started in 2007, in total 397 samples of wild predators representing 10 species belonging to families Canidae, Felidae, Mustelidae and Ursidae were investigated. Helminthological necropsy (modified sedimentation and counting technique) and artificial digestion method were used for the parasites detection. Multiplex PCR approach has been used for species identification of Trichinella isolates obtained from infected animals. E. multilocularis was found in 42.7% of foxes and 1 raccoon dog. Trichinella larvae were present in 16.7% of foxes, 37.9% of martens, 33.3% of polecats, 1 bear and 1 lynx. All animals were infected by T. britovi.

Experimental infection of domestic cats (Felis domesticus) with Cytauxzoon manul from Pallas' cats (Otocolobus manul)

In a random, blind study, six domestic cats were assigned to two treatment groups that received either sterile water or dexamethasone by subcutaneous injection prior to intravenous inoculation with Pallas' cat (Otocolobus manul) blood infected with Cytauxzoon manul. A seventh domestic cat served as a control and was inoculated only with sterile water. Cats were monitored for clinical signs consistent with cytauxzoonosis, and periodically screened for hemoparasitemia. All domestic cats (6/6) that received Pallas' cat blood infected with C. manul developed a low but detectible parasitemia by 9 days post-inoculation, yet remained clinically healthy. All domestic cats (7/7) were subsequently challenged with Cytauxzoon felis and developed clinical signs typical of cytauxzoonosis within 5 days post-challenge. Affected animals were euthanized and cytauxzoonosis was confirmed by histopathology. While inoculation of domestic cats with Pallas' cat blood infected with C. manul induced a parasitemia, it did not cause disease or provide protection against challenge with C. felis. Further studies are warranted to determine the potential for interspecies transmission and disease with C. manul.

Risk factors associated with sero-positivity to Toxoplasma gondii in captive neotropical felids from Brazil

From September 1995 to February 2001, blood samples were collected from 865 neotropical felids belonging to 8 different species. These animals were housed in 86 institutions located in 78 cities of 20 Brazilian states. Our goal was to identify the risk factors associated with sero-positivity to Toxoplasma gondii in captive neotropical felids from Brazil. All serum samples were tested by the modified agglutination test (MAT), using formalin-fixed whole tachyzoites and mercaptoethanol. For each animal an individual questionnaire was filled with questions about tattoo number, felid species, age, sex, origin, number of animals in the group, introduction of new animals in the group, time in the institution, eating meat previously frozen for a period <7 days in the last 6 months, eating meat of run-over or euthanized animals in the last 6 months, predation of rodents or birds in the last 6 months and presence of domestic cats near the enclosures in the last 6 months. The total sero-prevalence was 55% (95% CI: 52%, 57%). We estimated a prevalence of 46% (95% CI: 40%, 54%) for jaguarundi (Puma yagouaroundi); 58% (95% CI: 53%, 63%) for ocelot (Leopardus pardalis); 50% (95% CI: 45%, 56%) for oncilla (L. tigrinus); 54% (95% CI: 46%, 62%) for margay (L. wiedii); 12% (95% CI: 4%, 31%) for Pampas-cat (L. colocolo); 83% (95% CI: 65%, 93%) for Geoffroy's-cat (L. geoffroyi); 64% (95% CI: 50%, 68%) for jaguar (Panthera onca) and 48% (95% CI: 42%, 54%) for puma (Puma concolor). Multiple logistic regression was used to evaluate the association between the variables in the questionnaire and sero-positivity to T. gondii. We concluded that the independent risk factors for toxoplasmosis were: age >3 years (OR=4.75 [2.75; 8.2]), eating meat previously frozen for a period <7 days (OR=2.23 [1.24; 4.01]), and consumption of animals that were run-over or euthanized (OR=1.64; [1.14; 2.37]).

Seroprevalence of Toxoplasma gondii in captive felids in Thailand

The prevalence of antibodies against Toxoplasma gondii was investigated by commercial latex agglutination test kit (Toxocheck-MT 'Eiken') in captive felids maintained at zoos and a wildlife breeding center in different geographic regions of Thailand. Sera from a total of 136 captive felids of 12 species was obtained between 2002 and 2004. The overall seroprevalence of T. gondii was found in 21 of 136 (15.4%) felids. The titers varied from 1:64 (eight samples) to 1:8192 (one sample). The seroprevalence in different geographic regions were from 0% in the northern area to 23% in the southern area. This study suggested a widespread exposure of captive felids to T. gondii in Thailand and this is the first report of serologic analysis for T. gondii in captive felids in Southeast Asia.

Detection of Toxolasma gondii in captive wild felids

Toxoplasma gondii can infect all species of warm-blooded animals, including humans, and causes serious diseases in immunocompromized hosts. Live tachyzoites derived from serial passage in HeLa culture were used in the Sabin-Feldman dye test for detection of Toxoplasma gondii antibody in serum samples of 21 captive wild felids including one fishing cat (Prion nailurus viverrina), one leopard (Panthera pardus), two flat-headed cats (Prion nailurus planiceps), 6 tigers (Panthera tigris), two leopard cats (Felis bengalensis), two clouded leopards (Felis nebulosa), 3 pumas (Puma concolor), and 4 jungle cats (Felis chaus). Antibodies to Toxoplasma gondii were founded in 9 of 21 felids (42.8%). This study revealed that cell culture-derived tachyzoites can be used successfully as a source of live organisms in a gold standard Sabin-Feldman dye test, which is simpler, cheaper and less ethically sensitive than in vivo inoculation.

Prevalence of naturally occurring Dirofilaria immitis infection among nondomestic cats housed in an area in which heartworms are endemic

OBJECTIVE

To determine prevalences of heartworm exposure (ie, positive heartworm antibody test results) and heartworm infection (ie, positive heartworm antigen test results or identification of mature heartworms at necropsy) among nondomestic cats housed in an area in rural North Carolina where Dirofilaria immitis is known to be endemic and among nondomestic cats housed in areas with a low prevalence of dirofilariasis or in an area considered to be free from heartworms.

DESIGN

Cross-sectional prevalence survey.

ANIMALS

97 nondomestic cats in North Carolina (study population) and 29 nondomestic cats in Colorado; Queensland, Australia; or Auckland, New Zealand (control population).

PROCEDURE

Results of serologic tests and postmortem examinations were reviewed.

RESULTS

Results of heartworm antibody tests were positive for 57 of 75 (76%) study cats and 1 of 29 (3%) control cats. Male study cats had a significantly higher risk of heartworm exposure than did female study cats (relative risk, 1.3). Results of heartworm antigen tests were negative for all 47 study cats and 16 control cats that were tested. Postmortem examinations were performed on 21 study cats, and 1 (5%) was found to be infected with heartworms.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that nondomestic cats housed outdoors in the southeastern United States are at risk for heartworm exposure and infection, with male cats having a greater risk of exposure than female cats.

A NEW SPECIES OF CYTAUXZOON FROM PALLAS' CATS CAUGHT IN MONGOLIA AND COMMENTS ON THE SYSTEMATICS AND TAXONOMY OF PIROPLASMIDS

DNA was extracted and the 18S ribosomal RNA gene was amplified and sequenced from the blood of 2 Pallas' cats (Otocolobus manul) infected with small intraerythrocytic piroplasms. Sequences of the parasite were found to be identical with that of a previously reported Cytauxzoon-like piroplasm from a Pallas' cat. Phylogenetic analyses of the parasite DNA sequences obtained from the 3 Pallas' cats to other piroplasms revealed a sister group relationship to C. felis. The mean corrected percent sequence divergence between the Pallas' cat parasite and C. felis was 1.490%, which is greater than that for most other piroplasms in which species status has been accepted. On the basis of the sequence variation, we propose to name the Pallas' cat parasite C. manul. Phylogenetic analyses of C. manul also revealed a close relationship with the Spanish Cytauxzoon-like isolate because they exhibited only 0.389% sequence divergence, yet these sequences exhibit a mean of 1.690% sequence divergence from the New World isolate of C. felis. Our phylogenetic analyses also revealed several taxonomic problems that have impeded the development of a classification that accurately reflects evolutionary history of piroplasms. As currently arranged, Babesia and Theileria are paraphyletic taxa and are in need of reorganization.