Evaluation of indirect immunofluorescence antibody test and enzyme-linked immunosorbent assay for the diagnosis of infection by Leishmania infantum in clinically normal and sick cats

Coinfection with Leishmania infantum and Toxoplasma gondii in Domestic Cats from a Region with a High Prevalence of Feline Immunodeficiency Virus

The aim of this study was to investigate the coinfection of feline retroviruses (feline immunodeficiency virus-FIV, and the feline leukemia virus-FeLV) with Leishmania infantum and Toxoplasma gondii and the factors associated with these pathogens in domestic cats from Mossoró, a city endemic for canine and human leishmaniasis situated in the semiarid region of Northeast Brazil. Blood samples from 120 cats were collected, and an epidemiological questionnaire was applied to investigate the risk factors associated with the infections. Retroviruses, L. infantum, and T. gondii infections were assessed using a point-of-care ELISA and quantitative PCR (qPCR), indirect fluorescent antibody test (IFAT) and qPCR, and IFAT, respectively. The overall seroprevalences observed were 35% (95% CI = 27.0-43.8%) for FIV, 0.8% (95% CI = 0.1-4.5%) for FeLV, 25.8% (95% CI = 18.8-34.3%) for T. gondii, and 4.2% (95% CI = 1.7-9.3%) for L. infantum. Coinfection with FIV and L. infantum was observed in 2.5% (3/120) of the assessed cats, while 12.5% (15/120) were coinfected with FIV and T. gondii. No significant association was found among the investigated agents (p > 0.05). The factors associated with FIV infection in the multivariable analysis were male sex and age above 78 months. The findings of this study demonstrated a high rate of FIV infection in cats from the Brazilian semiarid region and the exposure of these animals to zoonotic and opportunistic agents. Due to the immunosuppressive potential of FIV, cats infected with this retrovirus should be screened for coinfections with L. infantum and T. gondii, and preventative measures should be adopted.

FeliLeish: An Update on Feline Leishmaniosis and Factors Associated with Infection in Different Feline Populations from Italy

Feline leishmaniosis is a worldwide infection caused by the parasite of the genus Leishmania transmitted by sandflies. Based on the complexity of epidemiology and diagnosis of this infection, the role of cats in the epidemiology and clinical impact of disease is still under debate. By using serological and molecular methods, this study aimed to update the epidemiology of the infection in different feline populations from various areas of Italy and to study factors associated with the infection. Of 1490 cats tested, 124 (8.3%, 95% CI 6.9-9.9) were infected, 96 had only specific L. infantum IgG, 18 were only positive for parasite DNA and 10 were both IFAT and qPCR positive. Risk factors for infection were sampling in the winter season (OR = 3.2, 95% CI 2.2-4.8), originating from the Sicily region (OR = 2.0, 95% CI 1.3-3.0), male gender (OR = 1.8, 95% CI 1.1-3.2), outdoor lifestyle (OR = 2.3, 95% CI 0.9-5.6) and seropositivity for FIV antibodies (OR = 2.2, 95% CI 1.2-4.2), while sampling in the spring (OR = 0.5, 95% CI 0.3-0.7) and summer (OR = 0.3, 95% CI 0.1-0.7), and originating from the Lazio region (OR = 0.1, 95% CI 0.05-0.4) were protective factors for infection. In endemic areas, Leishmania infection should be investigated by using both serological and molecular methods and cats should be protected from sandfly bites, particularly if they are FIV infected.

Seroprevalence of and Risk Factors for Toxoplasma gondii Infection in Cats from Greece

Toxoplasmosis is one of the most important protozoan diseases with a global impact on the health of domestic cats and with zoonotic significance. The aims of this study were to determine the prevalence of seropositivity for Toxoplasma gondii in different populations of cats in Greece and to assess risk factors for seropositivity. A total of 457 cats were prospectively enrolled, and a commercially available indirect immunofluorescence antibody testing (IFAT) kit was used for the detection of anti-T. gondii immunoglobulin G (IgG) in serum. Overall, 95 (20.8%) of the 457 cats were seropositive for T. gondii. Based on multivariate analysis, factors associated with seropositivity included older age [Odds ratio (OR), 1.33; p < 0.001]; a history of cat-fight trauma (OR, 3.88; p = 0.004); and lack of vaccination against calicivirus, herpesvirus-1, panleukopenia, and rabies (OR, 10; p = 0.002). This study shows a high prevalence of seropositivity for T. gondii in cats in Greece. This implies that toxoplasmosis is still a major public health concern and that optimal strategies for the prevention of infection with T. gondii in cats should be established.

Seroprevalence of and risk factors for feline coronavirus infection in cats from Greece

Feline coronavirus (FCoV) is a highly contagious and ubiquitous virus of domestic cats and wild felids. Feline infectious peritonitis (FIP) is a fatal, systemic disease caused by FCoV infection when spontaneous mutations of the viral genome take place. The aims of this study were primarily to determine the prevalence of seropositivity for FCoV in different populations of cats in Greece and assess risk factors for seropositivity. A total of 453 cats were prospectively enrolled in the study. A commercially available IFAT kit was used for the detection of FCoV IgG antibodies in serum. Overall, 55 (12.1 %) of the 453 cats were seropositive for FCoV. Based on multivariable analysis, factors associated with FCoV-seropositivity included cats adopted as strays and contact with other cats. This is the first extensive study on the epidemiology of FCoV in cats from Greece and one of the largest worldwide. Feline coronavirus infection is relatively common in Greece. Therefore, it is necessary to establish optimal strategies for the prevention of FCoV infection, considering the high-risk groups of cats identified in this study.

Long-term follow-up of a case of feline leishmaniosis treated with a combination of allopurinol and meglumine antimoniate

A 9-year-old domestic cat, positive for antibodies to feline immunodeficiency virus (FIV), was brought to a veterinary clinic with alopecia, ulcerative skin lesions, and upper respiratory tract (URT) signs. This was after being treated for suspected allergic dermatitis, without clinical improvement, for 2 y. Biopsy of the skin and fine-needle aspirates of the spleen and of the lymph nodes were taken which detected the presence of Leishmania amastigotes. Leishmania infection was further confirmed by detection of a high titer of anti-Leishmania antibodies (≥ 3200) with an indirect fluorescent antibody technique (IFAT) serology. After the diagnosis of feline leishmaniosis (FeL) was made, allopurinol and meglumine antimoniate were started and led to quick and complete clinical improvement. After 7 mo, allopurinol administration was briefly interrupted but was resumed following relapse of the skin lesions. One month later, the cat was treated for suspected acute kidney injury, which prompted reduction of the total daily dose of allopurinol by 50%. The cat remained clinically well, with complete resolution of the cutaneous and URT signs, for nearly 24 mo after the diagnosis of FeL; at which point it was euthanized for worsening cardiac disease. To our knowledge, this represents a rare case of successful treatment of FeL with a suspected nephrotoxic effect associated with long-term use of allopurinol. Further studies are required to clarify the relationship, if any, between leishmaniosis and congestive heart failure in cats.

Leishmania infantum Specific Humoral and Cellular Immune Responses in Cats and Dogs: A Comparative Cross-Sectional Study

Dogs are the main reservoir of Leishmania infantum and display different immunological patterns correlating with the progression of infection to disease. Data about feline L. infantum adaptive immune response are scant. This study aimed to compare the prevalence and immune response in cats and dogs from the same endemic area of canine leishmaniosis. Stray cats (109) and rescued dogs (59) from Córdoba (Spain) were enrolled. Data about their exposure to L. infantum were analyzed by detection of parasite DNA, measurements of Leishmania-specific interferon-γ (whole blood assay in 57 cats and 29 dogs), and antibodies (enzyme-linked immunosorbent assay and immunofluorescence antibody test). An overall L. infantum prevalence of 30.5% in dogs and 30% in cats were found according to serology and PCR tests. Prevalence was 44.8% in dogs and 35.1% in cats tested also for interferon-γ production. Dogs showed higher anti-L. infantum antibody levels compared to cats. More than one-third of cats had contact with or were infected by L. infantum and they may contribute to the endemicity of leishmaniosis in the investigated region. The immunopathogenesis of feline L. infantum infection has similarities with dogs but cats show a lower level of adaptive immune response compared to dogs.

Prevalence and Risk Factors for Bartonella spp. and Haemoplasma Infections in Cats from Greece

Simple Summary

Bartonellosis and haemoplasmosis are diseases with global impact on the health of domestic cats and of zoonotic importance. This is the first study investigating the risk factors for Bartonella spp. and haemoplasma species infections in cats from Greece. In addition, this study determined the serologic and molecular prevalence of Bartonella spp. and haemoplasma species infections in different populations of cats living in different regions of Greece. A total of 452 cats were enrolled into the study. Blood was collected from each cat for the serological detection of Bartonella henselae antibodies and the molecular detection of Bartonella spp. and haemoplasma species infections. Overall, the seroprevalence of B. henselae was 35.4%, while the molecular prevalence of Bartonella spp. and haemoplasma species was 2.9% and 19%, respectively. The results of this study indicate that cats with partial or exclusive outdoor access and cats with flea infestation are at the greatest risk for B. henselae seropositivity. Furthermore, cats living in warmer regions such as Attica and Crete are at the greatest risk. Lack of ectoparasiticide use was identified as a risk factor for haemoplasma species infection. This suggests that the use of ectoparasiticides in cats may be an effective means of preventing haemoplasma species infection in cats.

Abstract

Bartonellosis and haemoplasmosis are vector-borne diseases with global impact on the health of domestic cats and of zoonotic importance. The aim of this study was to describe the epidemiological aspects of various populations of cats infected with Bartonella spp. or haemoplasma species. The populations evaluated included client-owned cats, stray cats and cats that live in breeding catteries in Greece. A total of 452 cats were prospectively enrolled into the study. A commercially available indirect immunofluorescence antibody testkit was used for the detection of Bartonella henselae IgG antibodies in serum. PCRs for the detection of Bartonella spp. and haemoplasma species DNA in the blood were also performed in a subgroup of 242 of the 452 cats. Risk factors for B. henselae seropositivity and infection with the haemoplasma species were determined using multivariable analysis. Overall, 160 (35.4%) of the 452 cats were seropositive for B. henselae. Seven (2.9%) and 46 (19%) of the 242 cats were PCR-positive for Bartonella spp. and haemoplasma species, respectively. The factors associated with B. henselae seropositivity, based on multivariate analysis, included older age, outdoor access, living region and flea infestation. Non-administration of ectoparasiticides was associated with haemoplasma species infection. This study shows a high prevalence of seropositivity for B. henselae and a relatively high prevalence of infection with haemoplasma species. Therefore, it is necessary to establish optimal strategies for the prevention of Bartonella spp. and haemoplasma species infections, considering the high-risk groups of cats identified in this study.

Association between feline immunodeficiency virus and Leishmania infantum infections in cats: a retrospective matched case-control study

BACKGROUND

Feline leishmaniosis caused by Leishmania infantum is often associated with feline immunodeficiency virus (FIV) infection; however, the role and clinical significance of this coinfection remain unknown. This study aimed to assess whether FIV is associated with L. infantum infection in cats from canine leishmaniosis endemic areas and to report the clinical signs and hematological alterations associated with coinfection.

METHODS

A retrospective matched case-control study (ratio 1:2) was conducted. Data of clinical examination and complete blood count (CBC) were selected from a cohort of 705 cats examined for epidemiological studies on feline leishmaniosis conducted between 2012 and 2019. Ninety-one FIV seropositive cases and 182 FIV seronegative control cats were selected. Matching was done according to age, sex, lifestyle and geographic provenience of case cats. Rapid ELISA devices were mainly used to detect anti-FIV antibodies. Anti-Leishmania IgG antibodies were detected by indirect-immunofluorescence test (IFAT). Leishmania DNA was searched in blood, oral and conjunctival swabs by quantitative real-time PCR.

RESULTS

Feline immunodeficiency virus seropositive cats had no hematological abnormalities suggestive of an advanced stage of FIV infection and were statistically more frequently IFAT positive, and their risk of being L. infantum antibody positive was 2.8 greater than in the FIV seronegatives. The association of FIV seropositivity with L. infantum antibody positivity was confirmed in the univariable model of logistic regression. A multivariate model found FIV infection and L. infantum PCR positivity as predictors of a positive L. infantum IFAT result. Male outdoor cats from rural or suburban areas were at risk for FIV and L. infantum antibody positivity. Clinical signs more frequently associated with the coinfection were oral lesions, pale mucous membranes and low body condition score (BCS).

CONCLUSIONS

This study documents that FIV seropositive cats with no hematological abnormalities suggestive of an advanced stage of FIV infection are more prone to be L. infantum seroreactive by IFAT in endemic areas. Therefore, FIV seropositive cats should be tested for L. infantum antibodies and treated for preventing sand fly bites. Pale mucous membranes, low BCS and oral lesions but no CBC abnormalities were significantly associated with the coinfection.

Feline Leishmaniosis in Northwestern Italy: Current Status and Zoonotic Implications

Leishmaniasis remains one of the major neglected tropical diseases. The epidemiological profile of the disease comprises a wide range of hosts, including dogs and cats. Despite several studies about feline Leishmaniosis, the role of cats in disease epidemiology and its clinical impact is still debated. The present study raises awareness about the impact of leishmaniasis in cats from an endemic region in of Northwestern Italy (Liguria). A total number of 250 serum and 282 blood samples were collected from cats, then assessed for Leishmania infantum (L. infantum) serologically using western blot (WB) and molecularly using polymerase chain reaction (PCR). We also tested the association of Leishmania infection with some infectious agents like haemotropic Mycoplasma, Feline immunodeficiency virus (FIV) and Feline leukemia virus (FeLV) together with the hematobiochemical status of the examined animals. Interestingly, all tested animals were asymptomatic and out of 250 examined serum samples, 33 (13.20%) samples (confidence interval (CI) 95% 9.56-17.96%) were positive at WB for L. infantum, whereas of the 282 blood samples, 80 (28.36%) returned a positive PCR (CI 95% 23.43-33.89%). Furthermore, there was a statistical association between PCR positivity for L. infantum and some hematological parameters besides FIV infection as well as a direct significant correlation between Mycoplasma infection and WB positivity. Taken together, the present findings report high prevalence of L. infantum among cats, which reinforces the significance of such positive asymptomatic animals and confirms the very low humoral response in this species. In addition, the laboratory values provide evidence that infection by the parasite is linked to alteration of some hematological parameters and is correlated to some infectious agents. These data are of interest and suggest future research for accurate diagnosis of such zoonosis.

A prospective epidemiological, clinical, and clinicopathologic study of feline leukemia virus and feline immunodeficiency virus infection in 435 cats from Greece

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses causing significant morbidity and mortality in cats. The aim of this study was to describe the epidemiological, clinical and clinicopathologic aspects of FeLV and FIV infections in different populations of cats in Greece, including client-owned cats, stray cats and cats who live in catteries. A total of 435 cats were prospectively enrolled. Serological detection of FeLV antigen and FIV antibody was performed using a commercial in-house ELISA test kit. The results showed that 17 (3.9 %) and 40 (9.2 %) of the 435 cats were positive for FeLV antigen and FIV antibody, respectively, whereas 5 (1.1 %) had concurrent infection with FeLV and FIV. Factors that were associated with FeLV antigenemia, based on multivariate analysis, included vomiting, rhinitis, infection with FIV, neutropenia, decreased blood urea nitrogen and increased serum cholesterol and triglyceride concentrations. Factors associated with FIV seropositivity included male gender, older age, outdoor access, weight loss, fever, gingivostomatitis, skin lesions and/or pruritus and hyperglobulinemia. Various clinical signs and laboratory abnormalities were found to be significantly associated with retroviral infections, suggesting that current guidelines to test all sick cats should be followed, taking into particular consideration the high-risk groups of cats found in this study.

Leishmania infantum Infection in a Domestic Cat: A Real Threat or an Occasional Finding?

PURPOSE

Visceral Leishmaniasis (VL) has been considered one of the most important neglected zoonosis in the world. In Brazil, this disease passed for an urbanization process and currently pets (dogs and cats) animals have acquired a great importance on its epidemiology. Studies on dogs have been extensively performed throughout the country, but information about infection in cats has been concentrated in few areas. Therefore, the aim of this study was to investigate the occurrence of infection by Leishmania infantum in domestic cats living in endemic areas for Canine Visceral Leishmaniasis (CVL) in the state of Pernambuco, Northeastern Brazil.

METHODS

Domiciled cats (n = 128) were sampled for different biological samples (i.e., blood, conjunctival swab and fine needle aspiration of lymph nodes) that were microscopically and molecularly analyzed through PCR and sequencing.

RESULTS

Amastigote forms of Leishmania sp. were detected in a single animal (fine needle aspiration of lymph node). This same animal scored positive at molecular examination (blood and lymph node) and the sequence analysis revealed an identity higher than 99% with L. infantum sequences DNA available in Genbank database.

CONCLUSION

This is the first molecular characterization of L. infantum infecting domestic cats in Pernambuco. Therefore, veterinary practitioners should consider this putative infection in cats living in areas where canine and human Leishmaniasis has been reported.

Leishmania mexicana in a central Texas cat: clinical presentation, molecular identification, sandfly vector collection and novel management

Case summary

This case report documents the clinical appearance, diagnosis and novel treatment of a central Texas cat with cutaneous leishmaniosis. The cat presented with a linear erosion on the right pinnal margin, an ulcerated exophytic nodule on the right hock and a swelling in the right nostril. Cytological and histopathological findings were consistent with leishmaniosis. PCR confirmed the presence of Leishmania mexicana, a species endemic to Texas. An epidemiological investigation was conducted by trapping sandflies from the cat’s environment. Sandflies collected were identified as Lutzomyia species, known vectors of Leishmania species. Given the lack of validated medical therapies for L mexicana in cats, treatments typically prescribed for canine leishmaniosis were administered. Allopurinol achieved clinical success but was discontinued due to suspected drug-related neutropenia. Topical imiquimod also improved lesional skin but was not sustainable due to application difficulty. Oral administration of artemisinin resulted in significant clinical improvement of cutaneous lesions without reported adverse events. Nearly 8 months after the initiation of artemisinin therapy, the cat remained systemically healthy with stable lesions.

Relevance and novel information

This case report demonstrates endemic feline leishmaniosis in central Texas and provides the clinician with alternative therapeutic options for medical management.

A cross-sectional study of Leishmania infantum infection in stray cats in the city of Zaragoza (Spain) using serology and PCR

BACKGROUND

Feline leishmaniosis is a vector-borne parasitic disease caused by Leishmania spp. Leishmania infection in dogs is prevalent in the Mediterranean basin, but in other animals, such as cats, it could also play a role in the epidemiology of the disease. Information on the geographical distribution and epidemiological features of L. infantum infection in cats is scarce, particularly in urban stray cats living in regions where canine leishmaniosis is endemic. As diagnosis can be challenging, combining different serological and molecular methods is a useful approach. Our aim was to investigate the prevalence of infection of L. infantum in apparently healthy stray cats in an endemic region of Spain (Zaragoza city) using serological and molecular methods, and to compare the results of the different techniques.

METHODS

The prevalence of Leishmania infection was studied in stray cats captured in urban and peri-urban areas of Zaragoza. Blood was collected from each animal for serology and molecular analysis. Three serological methods, namely the immunofluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and western blot (WB), were used to detect L. infantum antibodies and a real-time PCR (qPCR) assay was used to detect L. infantum DNA. The results were analyzed by Fisher's exact test and Cohen's kappa statistic (κ)  to assess the level of agreement between the diagnostic techniques.

RESULTS

Serological analysis of blood samples from 180 stray cats revealed 2.2% (4/179) Leishmania infection positivity by IFAT, 2.8% (5/179) by ELISA and 14.5% (26/179) by WB. Leishmania DNA was detected by qPCR in 5.6% (10/179) of the cats. Sixteen cats (8.9%) tested positive by only one serological technique and four tested positive by all three serological methods used. The overall rate of infected cats (calculated as the number of cats seropositive and/or qPCR positive) was 15.6%, and only two cats tested positive by all the diagnostic methods. A significant association was found between male cats and a positive qPCR result. Comparison of the techniques revealed a fair agreement in seropositivity between blood qPCR and IFAT (κ = 0.26), blood qPCR and ELISA (κ = 0.24), WB and ELISA (κ = 0.37) and WB and IFAT (κ = 0.40). The highest agreement between seropositive results was between IFAT and ELISA (κ = 0.89), and the lowest was between blood qPCR and WB (κ = 0.19). The prevalence of the feline leukemia virus antigen was 4.49% (8/178 cats) and that of the feline immunodeficiency virus (FIV) antibody was 6.74% (12/178), while co-infection with both retroviruses was observed in one female cat (1/178). Leishmania ELISA and IFAT seropositivity were statistically associated with FIV status by the chi-square test.

CONCLUSIONS

The results obtained in this study, using serological tests and qPCR, indicate the existence of L. infantum asymptomatic infection in apparently healthy stray cats in the city of Zaragoza, an endemic area in Spain.

New Epidemiological Aspects of Animal Leishmaniosis in Europe: The Role of Vertebrate Hosts Other Than Dogs

Infection with Leishmania parasites can lead to severe disease in humans and dogs, which act as a reservoir in zoonotic transmission. An increasing number of reports suggest that leishmaniosis is not restricted to dogs, but also affects many other mammalian and avian species. Consequently, this expands the potential reservoir and is of great public and veterinary health concern. The present study reviews, based on a comprehensive search of scientific literature published from 1 January 2001 to 31 December 2020, the currently available information on animal leishmaniosis in vertebrates in Europe, other than dogs and humans. This review provides an exhaustive list of mammals and birds in which infections with or exposure to Leishmania parasites have been detected in European countries. Most cases are reported from the Mediterranean region. Domestic animals, in particular cats, pose a concern because of close contact with humans. The wildlife reservoir is less likely to contribute to zoonotic transmission, with the exception of hares. This potentially large reservoir needs to be taken into account when developing control measures for zoonotic leishmaniosis. From a veterinary point of view, it is important that veterinarians are better aware of leishmaniosis and trained in its management.

Retrospective evaluation of vector-borne pathogens in cats living in Germany (2012-2020)

Background

Blood-feeding arthropods can transmit parasitic, bacterial, or viral pathogens to domestic animals and wildlife. Vector-borne infections are gaining significance because of increasing travel and import of pets from abroad as well as the changing climate in Europe. The main objective of this study was to assess the percentage of cats with positive test results for selected vector-borne pathogens in Germany and explore any possible association of such results with time spent abroad.

Methods

This retrospective study included test results from cats included in the “Feline Travel Profile” established by the LABOKLIN laboratory at the request of veterinarians in Germany between April 2012 and March 2020. This diagnostic panel includes the direct detection of Hepatozoon spp. and Dirofilaria spp. via PCR as well as indirect detection assays (IFAT) for Ehrlichia spp. and Leishmania spp. The panel was expanded to include an IFAT for Rickettsia spp. from July 2015 onwards.

Results

A total of 624 cats were tested using the “Feline Travel Profile.” Serum for indirect detection assays was available for all 624 cats; EDTA samples for direct detection methods were available from 618 cats. Positive test results were as follows: Ehrlichia spp. IFAT 73 out of 624 (12%), Leishmania spp. IFAT 22 out of 624 (4%), Hepatozoon spp. PCR 53 out of 618 (9%), Dirofilaria spp. PCR 1 out of 618 cats (0.2%), and Rickettsia spp. IFAT 52 out of 467 cats (11%) tested from July 2015 onwards. Three cats had positive test results for more than one pathogen before 2015. After testing for Rickettsia spp. was included in 2015, 19 cats had positive test results for more than one pathogen (Rickettsia spp. were involved in 14 out of these 19 cats).

Conclusions

At least one pathogen could be detected in 175 out of 624 cats (28%) via indirect and/or direct detection methods. Four percent had positive test results for more than one pathogen. These data emphasize the importance of considering the above-mentioned vector-borne infections as potential differential diagnoses in clinically symptomatic cats.

Leishmania infection in cats and feline leishmaniosis: An updated review with a proposal of a diagnosis algorithm and prevention guidelines

Leishmaniosis is a vector-borne disease caused by protozoans of the genus Leishmania, which are transmitted to vertebrates, including cats, through the bites of female phlebotomine sand flies. An increasing number of epidemiological and experimental studies concerning Leishmania infection in cats, as well as case reports of clinical leishmaniosis in these felids, have been published in recent years. In the present study, a comprehensive review was made by sourcing the National Library of Medicine resources to provide updated data on epidemiology, immunopathogenesis, diagnosis, treatment, and prevention of feline leishmaniosis. Cats were found infected with Leishmania parasites worldwide, and feline leishmaniosis appears as an emergent disease mostly reported in countries surrounding the Mediterranean Sea and in Brazil. Cats with impaired immunocompetence seem to have a higher risk to develop clinical disease. The main clinical and clinicopathological findings are dermatological lesions and hypergammaglobulinemia, respectively. Diagnosis of feline leishmaniosis remains a challenge for veterinarians, in part due to the lack of diagnosis support systems. For this reason, a diagnostic algorithm for clinical decision support is herein proposed. No evidence-based treatment protocols are currently available, and these remain empirically based. Control measures are limited and scarce. Thus, a set of prevention guidelines are herein suggested.

Arthropod-Borne Pathogens in Stray Cats from Northern Italy: A Serological and Molecular Survey

Cats may be affected by a wide range of arthropod-borne pathogens (ABPs) of medical and veterinary interest. Between February 2018 and October 2019, 85 blood samples were collected from stray cats from the Emilia Romagna region (northern Italy). Ticks (n = 28) on the examined cats were also collected. Serological and molecular methods were applied to search for infection by Anaplasma phagocytophilum, Bartonella henselae, Coxiella burnetii, Ehrlichia canis, Leishmania spp., Babesia spp., Hepatozoon spp., and Cytauxzoon spp. A total of 71 sera (83.5%) had antibodies to at least one investigated pathogen: 39 (45.9%) were positive for B. henselae, 32 (37.6%) positive for C. burnetii, 12 (14.1%) positive for E. canis, four (4.7%) positive for A. phagocytophilum, and two (2.4%) positive for Leishmania spp. A total of 47 (55.3%) DNA samples were positive by PCR for at least one investigated pathogen: 25 (29.4%) were positive for C. burnetii, 23 (27.1%) positive for B. henselae, two (2.4%) positive for E. canis, five (5.9%) positive for Leishmania spp., and two (2.4%) positive for Cytauxzoon spp. Coinfections were observed in 21 cats (24.7%). No positivity was found for A. phagocytophilum, Babesia spp., or Hepatozoon spp. All ticks were negative. A widespread presence of ABPs in the investigated area of northern Italy was shown. Accurate information on their prevalence may be relevant for feline veterinary medicine, as well as from a One Health perspective.

Feline Leishmania spp. Infection in a Non-Endemic Area of Northern Italy

Simple Summary

Leishmaniosis caused by Leishmania infantum is a parasitic disease of people and animals transmitted by sand fly vectors. Although dogs in south and central Italy are most affected, in recent decades feline leishmaniosis (FeL) has become an emerging disease. This study aimed to update information on the presence of FeL in stray cats in Milan, in northern Italy; to compare these results with previous studies performed in the same area; and to report aspects of Leishmania infection in cats. A total of 117 stray cats were included and 10 (8.6%) had L. infantum infection. The parasite was identified in popliteal lymph nodes in five cats and five had antibodies against L. infantum. Most infected cats were from a specific area of Milan. Increased gammaglobulins were seen in infected cats, which also had antibodies against the pathogens Anaplasma phagocytophilum, Chlamydophila felis, and Toxoplasma gondii. There was a high prevalence of FeL in the surveyed area of northern Italy. Further studies are needed to understand if these infected cats are being imported from other areas, or if there is a real Leishmania focus in Milan. Investigation of the presence of sand fly vectors in Milan would be useful.

Abstract

Feline leishmaniosis (FeL) is an emerging vector-borne feline disease, with increasing numbers of cases reported and studies performed internationally. This study aimed to update the epidemiological status for FeL in stray cats in Milan, northern Italy; compare these results with previous studies in Northern Italy; and report clinicopathologic findings and coinfections in cats infected with Leishmania spp. A total of 117 cats were tested for L. infantum and retrovirus infection, hematological, and biochemical parameters. Demographic and clinical data were collected and FeL affected cats screened for selected coinfections. Overall, 10/117 (8.6%) cats tested positive for L. infantum: in five cats L. infantum DNA was found in popliteal lymph nodes and five were IFAT seropositive at titers from 1:80 to 1:160. Infected cats were concentrated in a specific area of Milan (p = 0.0154). No specific clinicopathologic abnormalities or retroviral infections were significantly linked to the infection, other than hypergammaglobulinemia (p = 0.0127). Seroreactivity to Anaplasma phagocytophilum, Chlamydophila felis, and Toxoplasma gondii was found in some infected cats. A high prevalence of FeL was found in a non-endemic area of northern Italy and future studies should continually monitor this data to understand whether these cases are imported or if Leishmania vectors are present in this area.

Validation of a new immunofluorescence antibody test for the detection of Leishmania infantum infection in cats

The prevalence data of Leishmania infantum infection in cats are characterized by a large variability mainly attributed to the differences in diagnostic techniques. In the absence of consensus about the method of choice for diagnosing feline leishmaniosis, the performance of a new immunofluorescence antibody test (IFAT) was herein analytically described by the comparison with IFAT commonly used for the diagnosis of canine leishmaniosis (i.e., IFAT-OIE) and a laboratory enzyme-linked immunosorbent assay (ELISA). Sera of cats living in visceral leishmaniosis-endemic (n = 105) and visceral leishmaniosis-non-endemic (n = 50) areas were tested by the above methodologies and real-time PCR (qPCR). The most frequent result was represented by triple negativity to the three tests (IFAT-OIE, ELISA, and qPCR) in 42.9% and 80% cats from endemic and non-endemic areas, respectively. Bayes latent class analysis gave an output probability of 34.1% (posterior standard deviation, psd = 5.4%) of true L. infantum cases (TCL) which represent the true estimated prevalence of infection. The sensitivity of each variable contributing to define the TCL was 24% (psd = 6.3%) for qPCR, 78.8% (psd = 8.7%) for ELISA and 91.8% (psd = 5.2%) for IFAT-OIE. The probability to be a TCL was 94.5% for the sample from an endemic area. The cross-validation of the new IFAT by a logistic model correctly identified as positive 80.7% of subjects defined as TCL and negative 89.9% as not TCL, respectively, by the Bayesian model. The study results estimate a good accuracy of the IFAT in predicting cats exposed to L. infantum. Therefore, this procedure may be beneficial for screening cat populations for a better understanding of the epidemiology of feline leishmaniosis.

Is the cat an important reservoir host for visceral leishmaniasis? A systematic review with meta-analysis

In recent years feline leishmanial infections (FLI) have been studied more than ever before in various parts of the world. However, evidence-based knowledge on FLI has remained unavailable. The main objectives of this study were to investigate the status of felines infected by Leishmania spp. worldwide. Data were extracted from 10 available databases over the period of 1982 to 2017. Overall, 78 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review. The overall FLI prevalence by both serological and molecular methods was estimated at 10% (95% CI: 8%-14%). In Italy, both the seroprevalence (24 %) and PCR prevalence (21 %) were found to be higher than in other countries. The most common diagnostic test used was the indirect fluorescent antibody test (38.5%). Studies on mixed-breed felines were more common than those on other breeds, while the most common parasite species was L. infantum (63%). Our findings suggest that cats act as primary and/or secondary reservoir hosts in the transmission of the Leishmania spp. to humans and also to dogs, by sandflies, at least in endemic foci. Moreover, available data confirm the enzootic stability situation of FLI in several countries including some in Europe.

Emerging feline vector-borne pathogens in Italy

Background

The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools.

Results

A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy. Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects. Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens. DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR. Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp. Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens. The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64–1/128). No antibodies against B. microti were detected. Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays. Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR. Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27).

Conclusions

The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen. Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored. The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).

Ocorrência de anticorpos anti-Leishmania spp. em felinos em área endêmica do estado de São Paulo

RESUMO A leishmaniose visceral (LV) é uma zoonose de grande impacto em saúde pública. A infecção nos gatos tem sido relatada nos países onde a doença é endêmica. Seu papel como reservatório não está satisfatoriamente elucidado, embora a transmissão do parasito de um felino infectado para vetor tenha sido reportada por xenodiagnóstico. O objetivo do trabalho foi avaliar a presença de anticorpos anti-Leishmania spp. em animais da espécie felina em área endêmica para LV (Bauru-SP), por meio dos testes sorológicos de reação de imunofluorescência indireta (RIFI) e ensaio imunoenzimático (ELISA), e associá-los às variáveis: gênero, idade, raça e forma de criação. Foram testados soros de 276 felinos, dos quais 82 foram reagentes pelo método ELISA (29,71%), 17 pelo RIFI (6,15%) e 10 em ambos os testes (3,6%). Houve associação estatística significativa para a variável forma de criação, em que 100% dos animais errantes foram soropositivos a pelo menos um dos testes (P<0,005). Tal associação não foi encontrada para as demais variáveis analisadas (P>0,05). Não houve concordância entre o resultado dos testes, pois o método ELISA é mais sensível que o método RIFI.

Antibody response to Phlebotomus perniciosus saliva in cats naturally exposed to phlebotomine sand flies is positively associated with Leishmania infection

Background

Zoonotic leishmaniosis, caused by the protozoan Leishmania infantum, is a public and animal health problem in Asia, Central and South America, the Middle East and the Mediterranean Basin. Several phlebotomine sand fly species from the subgenus Larroussius are vectors of L. infantum. Data from dogs living in endemic areas of leishmaniosis advocate the use of antibody response to phlebotomine sand fly saliva as an epidemiological biomarker for monitoring vector exposure. The aim of this study was to analyse the exposure of cats to phlebotomine sand flies using detection of IgG antibodies to Phlebotomus perniciosus saliva. The association between phlebotomine sand fly exposure and the presence of Leishmania infection was also investigated.

Results

IgG antibodies to P. perniciosus saliva were detected in 167 (47.7%) out of 350 cats; higher antibody levels were present in sera collected during the period of phlebotomine sand fly seasonal activity (OR = 19.44, 95% CI: 9.84–38.41). Cats of 12–35 months had higher antibody levels than younger ones (OR = 3.56, 95% CI: 1.39–9.16); this difference was also significant with older cats (for 36–95 months-old, OR = 9.43, 95% CI: 3.62–24.48; for older than 95 months, OR = 9.68, 95% CI: 3.92–23.91). Leishmania spp. DNA was detected in the blood of 24 (6.9%) cats, while antibodies to L. infantum were detected in three (0.9%). Only one cat was positive to Leishmania by both techniques. Cats presenting IgG antibodies to P. perniciosus had a significantly higher risk of being positive for Leishmania infection.

Conclusions

To our knowledge, this is the first study demonstrating anti-sand fly saliva antibodies in cats. The evaluation of the contact of this animal species with the vector is important to the development of prophylactic measures directed to cats, with the aim of reducing the prevalence of infection in an endemic area. Therefore, studies evaluating whether the use of imidacloprid/flumethrin collars reduces the frequency of P. perniciosus bites in cats are needed. It is also important to evaluate if there is a correlation between the number of phlebotomine sand fly bites and IgG antibody levels.

Serological, molecular, and microscopic detection of Leishmania in cats (Felis catus) in Belo Horizonte, Minas Gerais State, Brazil

The role of cats in the epidemiological cycle of leishmaniasis remains unclear. To better understand the occurrence of leishmaniasis in cats, we studied the frequency of Leishmania in serum samples of 100 cats living in an endemic region for canine and human leishmaniasis by serological, parasitological, and molecular methods. Of the 100 cats, 54 were seropositive for Leishmania antibodies by immunofluorescence antibody test. None of the bone marrow aspirates collected from these cats tested positive for the parasite in culture or upon polymerase chain reaction (PCR) analysis. Biopsy samples of the ears also tested negative for Leishmania upon PCR analysis. These findings may indicate that the region is endemic for canine leishmaniasis and cats are infected by Leishmania; or that cross-reaction with antibodies against other parasites increases the frequency of seropositivity; or that cats respond to Leishmania infection by producing antibodies when few or no parasites are present in bone marrow and tissue samples. Overall, our results suggest that cats can be infected by Leishmania ; however, we failed to demonstrate feline parasitosis. These findings highlight the need to study leishmaniasis in cats, since sandflies feed on cats, these animals may act as a reservoir for the parasite.

Serological and molecular detection of Leishmania infantum in cats of Northern Sardinia, Italy

Leishmania infections are endemic in dogs in central and southern regions of Italy while feline leishmaniosis has only been sporadically described in these areas and few studies have been reported on serological and molecular investigation of infections in domestic cats. The purpose of this study is to assess the presence of Leishmania infantum infection in cats from Sardinia, a typical endemic area of leishmaniasis in Italy. Ninety cats attended at the Veterinary Teaching Hospital of the University of Sassari, Italy, were tested for L. infantum using the indirect immunofluorescent antibody (IFA) test and PCR. Serological (10%) and molecular (5.5%) detection in this population was low, with antibody titres ranging from 1/40 to 1/80. Only one cat was simultaneously positive by IFAT and PCR. This study shows the presence of L. infantum infection in cats living in Sardinia, with a prevalence that falls within the ranges described in other endemic areas and confirms the need of further research to better characterize the epidemiologic role of cats in the transmission of this infection.

Feline leishmaniosis: Is the cat a small dog?

Leishmania infantum is a vector-borne zoonotic disease transmitted by phlebotomine sand flies and dogs are considered the main reservoir of the parasite. Feline leishmaniosis (FeL) caused by L. infantum is an emergent feline disease more and more frequently reported in endemic areas. This review summarizes current knowledge focusing similarities and differences with canine leishmaniosis (CanL). Cats are infected by the same Leishmania species than dogs but prevalence of the infection is lower and cases of disease are less frequently reported. Scarce information is available on adaptive immune response of cats naturally exposed to L. infantum infection and mechanisms responsible for susceptibility or resistance of feline hosts. However, about half of clinical cases of FeL are reported in cats with possible impaired immunocompetence. Coinfections or comorbidities are frequently detected in sick cats and they can contribute to a misrepresentation of clinical FeL albeit lesions associated with the presence of the parasite have been detected in skin, lymph nodes, spleen, bone marrow, liver, oral mucosa, stomach, large bowel, kidney, nasal exudate, lung, eye. As for dogs, skin or mucocutaneous lesions are the most common reason for veterinary consultation and finding on physical examination in cats with leishmaniosis.

Molecular investigations of Leishmania DNA and anti- Leishmania antibody detection are largely used with the same methodologies for both CanL and FeL, however few information is available about their diagnostic performance in feline hosts. Treatment of cats with clinical FeL is still empirically based and off label by using the most common drugs prescribed to dogs. Life expectancy of cats with clinical FeL is usually good unless concurrent conditions or complications occur and prognosis does not seem significantly influenced by therapy or retroviral coinfection.

According to current knowledge, cats can play a role as additional reservoir host of L. infantum and, in a « One Health » perspective, preventative measures should be taken.

In conclusion, albeit feline infection and the associated cat disease caused by L. infantum is increasingly reported in endemic areas and have many similarities with CanL, consolidated evidence-based knowledge is not available and we cannot exclude that important differences between dogs and cats exist about transmission, immunopathogenesis and best practice for management and prevention.

Molecular detection of vector-borne pathogens in Greek cats

Infectious diseases have been increasingly recognized in cats worldwide. The objective of this study was the molecular investigation of the prevalence of selected pathogens in healthy and sick cats from Greece, a country highly endemic for several canine vector-borne pathogens. Blood and/or bone marrow samples from 50 clinically healthy and 50 sick adult (>1 year-old) cats were retrospectively examined for the amplification of Bartonella spp., haemoplasmas, Ehrlichia spp., Anaplasma spp., Babesia spp., and Cytauxzoon spp. DNA. Overall, 14.9% of the cats were found to be infected or co-infected by haemoplasmas, including Candidatus Mycoplasma haemominutum and M. haemofelis. In addition, 8.5% of the cats were infected by Bartonella henselae, Bartonella clarridgeiae or Bartonella koehlerae. In contrast, DNA of Ehrlichia spp., Anaplasma spp., Babesia spp. and Cytauxzoon spp. was not amplified from the blood or bone marrow of any cat. There was no significant difference in either haemoplasma or Bartonella infection rates when comparing healthy and sick cats. This study represents the first description of Bartonella koehlerae in Greek cats.

Prevention of feline leishmaniosis with an imidacloprid 10%/flumethrin 4.5% polymer matrix collar

Background

Leishmaniosis caused by Leishmania infantum is one of the most important vector-borne diseases affecting animals and humans worldwide. Dogs are considered main reservoirs of the zoonotic forms, though in the last years the role of cats as reservoirs has been increasingly investigated. Feline leishmaniosis (FeL) occurs in endemic areas and no specific preventive measures have been investigated so far. In this study the efficacy of a 10% imidacloprid/4.5% flumethrin polymer matrix collar, licensed for tick and flea prevention, has been assessed against FeL in a longitudinal study on 204 privately owned cats from the Aeolian islands (Sicily), an area highly endemic for the disease. From March to May 2015 [Study Day 0 (SD 0)], cats negative for FeL were collared (G1, n = 104) or left untreated (G2, n = 100). Diagnosis consisted of serology and qPCR on blood and conjunctival swabs, which were collected at baseline (SD 0) and at the end of the study (SD 360). Interim clinical examinations were performed on SD 210 (when collars were replaced in G1) and SD 270.

Results

Of the 159 cats which completed the study, 5 in G1 and 20 in G2 were positive for L. infantum infection, in at least one of the diagnostic tests leading to a yearly crude incidence of 6.3% and 25.0% in G1 and G2, respectively (P = 0.0026). This translates into an efficacy of the collar of 75.0% in preventing feline Leishmania infection. The collar was generally well tolerated with no systemic adverse reactions and few local skin reactions were observed in the application area in four out of 104 treated cats (3.8%).

Conclusions

The 10% imidacloprid/4.5% flumethrin collar significantly reduced the risk of L. infantum infection in cats. To our knowledge, this is the first study in which a preventative strategy against feline Leishmania infection is assessed under natural conditions. These findings close a gap in veterinary medicine, in that they confirm this collar as a tool in reducing the risk of Leishmania infection in cats. Such a preventative tool could contribute to the reduction of the risk of the disease in animal and in human populations when included in integrated leishmaniosis control programmes.

Diagnostic performance of ELISA, IFAT and Western blot for the detection of anti-Leishmania infantum antibodies in cats using a Bayesian analysis without a gold standard

Background

Anti-Leishmania antibodies are increasingly investigated in cats for epidemiological studies or for the diagnosis of clinical feline leishmaniosis. The immunofluorescent antibody test (IFAT), the enzyme-linked immunosorbent assay (ELISA) and western blot (WB) are the serological tests more frequently used. The aim of the present study was to assess diagnostic performance of IFAT, ELISA and WB to detect anti-L. infantum antibodies in feline serum samples obtained from endemic (n = 76) and non-endemic (n = 64) areas and from cats affected by feline leishmaniosis (n = 21) by a Bayesian approach without a gold standard.

Methods

Cut-offs were set at 80 titre for IFAT and 40 ELISA units for ELISA. WB was considered positive in presence of at least a 18 KDa band. Statistical analysis was performed through a written routine with MATLAB software in the Bayesian framework. The latent data and observations from the joint posterior were simulated in the Bayesian approach by an iterative Markov Chain Monte Carlo technique using the Gibbs sampler for estimating sensitivity and specificity of the three tests.

Results

The median seroprevalence in the sample used for evaluating the performance of tests was estimated at 0.27 [credible interval (CI) = 0.20–0.34]. The median sensitivity of the three different methods was 0.97 (CI: 0.86–1.00), 0.75 (CI: 0.61–0.87) and 0.70 (CI: 0.56–0.83) for WB, IFAT and ELISA, respectively. Median specificity reached 0.99 (CI: 0.96–1.00) with WB, 0.97 (CI: 0.93–0.99) with IFAT and 0.98 (CI: 0.94–1.00) with ELISA. IFAT was more sensitive than ELISA (75 vs 70%) for the detection of subclinical infection while ELISA was better for diagnosing clinical leishmaniosis when compared with IFAT (98 vs 97%).

Conclusions

The overall performance of all serological techniques was good and the most accurate test for anti-Leishmania antibody detection in feline serum samples was WB.

Evaluation of Immunofluorescence Antibody Test Used for the Diagnosis of Canine Leishmaniasis in the Mediterranean Basin: A Systematic Review and Meta-Analysis

With an expected sensitivity (Se) of 96% and specificity (Sp) of 98%, the immunofluorescence antibody test (IFAT) is frequently used as a reference test to validate new diagnostic methods and estimate the canine leihmaniasis (CanL) true prevalence in the Mediterranean basin. To review the diagnostic accuracy of IFAT to diagnose CanL in this area with reference to its Se and Sp and elucidate the potential causes of their variations, a systematic review was conducted (31 studies for the 26-year period). Three IFAT validation methods stood out: the classical contingency table method, methods based on statistical models and those based on experimental studies. A variation in the IFAT Se and Sp values and cut-off values was observed. For the classical validation method based on a meta-analysis, the Se of IFAT was estimated in this area as 89.86% and 31.25% in symptomatic and asymptomatic dogs, respectively. The Sp of IFAT was estimated in non-endemic and endemic areas as 98.12% and 96.57%, respectively. IFAT can be considered as a good standard test in non-endemic areas for CanL, but its accuracy declines in endemic areas due to the complexity of the disease. Indeed, the accuracy of IFAT is due to the negative results obtained in non-infected dogs from non-endemic areas and to the positive results obtained in sera of symptomatic dogs living in endemic areas. But IFAT results are not unequivocal when it comes to determining CanL infection on asymptomatic dogs living in endemic areas. Statistical methods might be a solution to overcome the lack of gold standard, to better categorize groups of animals investigated, to assess optimal cut-off values and to allow a better estimate of the true prevalence aiming information on preventive/control measures for CanL.

Prevalence of Leishmania infantum and co-infections in stray cats in northern Italy

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A study of stray cats in Italy expands epidemiologic data regarding leishmaniosis.

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Leishmania infantum IFAT seroreactivity was found in 12.2% of cats at 1:80 titer.

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This seropositivity rate is comparable to that in areas endemic for leishmaniosis.

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Leishmania co-infection with FIV, FeLV, FCoV was 0.0%, 2.4%, 8.5%, respectively.

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Co-infection with T. gondii, B. henselae, C. felis was 3.7%, 2.4%, 3.7%, respectively.

Stray cats in the city of Milan, Italy, were tested for Leishmania infantum and other selected infections. Twenty-seven cats (30.0%) were seroreactive by indirect fluorescent antibody test (IFAT), with an antibody titer of 1:40 for 16 (17.7%) cats and 1:80 (cut-off for feline L. infantum infection) for 11 (12.2%) cats. One blood (1.1%) and one popliteal lymph node (1.1%) sample tested positive by real-time polymerase chain reaction; no oculoconjunctival swabs tested positive. Feline immunodeficiency virus, feline leukemia virus, and feline coronavirus (FCoV) seroprevalence determined by enzyme-linked immunosorbent assay was 6.1, 6.1, and 39.0%, respectively. Toxoplasma gondii, Bartonella henselae, and Chlamydophila felis prevalence determined by IFAT was 29.3, 17.1, and 17.1%, respectively. The frequency of seroreactivity to L. infantum was significantly higher in FCoV-seropositive cats (OR = 4.4, P = 0.04). L. infantum-infected stray cats in Milan have a high seropositivity rate, comparable to that of cats in areas endemic for leishmaniosis.

New delivery systems for amphotericin B applied to the improvement of leishmaniasis treatment

Leishmaniasis is one of the six major tropical diseases targeted by the World Health Organization. It is a life-threatening disease of medical, social and economic importance in endemic areas. No vaccine is yet available for human use, and chemotherapy presents several problems. Pentavalent antimonials have been the drugs of choice to treat the disease for more than six decades; however, they exhibit high toxicity and are not indicated for children, for pregnant or breastfeeding women or for chronically ill patients. Amphotericin B (AmpB) is a second-line drug, and although it has been increasingly used to treat visceral leishmaniasis (VL), its clinical use has been hampered due to its high toxicity. This review focuses on the development and in vivo usage of new delivery systems for AmpB that aim to decrease its toxicity without altering its therapeutic efficacy. These new formulations, when adjusted with regard to their production costs, may be considered new drug delivery systems that promise to improve the treatment of leishmaniasis, by reducing the side effects and the number of doses while permitting a satisfactory cost-benefit ratio.

Cross-Sectional Serosurvey and Risk Factors Associated with the Presence of Toxoplasma gondii Antibodies in Pigs in Greece

INTRODUCTION

Toxoplasmosis is a worldwide reported zoonotic infection caused by the protozoon Toxoplasma gondii. Pigs may become infected by ingesting feed or water contaminated with cat faeces, by cannibalism, and/or by eating infected rodents. T. gondii infected edible tissues of pigs are a source of infection for humans. This study was undertaken to detect seropositivity of pigs against T. gondii and identify possible risk factors as well as to compare two serological methods.

METHODS

A total of 609 blood samples were collected from 10% of the sows from 65 pig farms located in mainland Greece. Information about the geographical location, size, and biosecurity level of the herd was recorded. Samples were tested for the presence of antibodies against T. gondii employing the indirect fluorescent antibody test and the enzyme-linked immunosorbent assay.

RESULTS

Twenty-six positive samples were detected (4.3%) in 17 out of the 65 farms tested (26.2%). The average seroprevalence in affected herds was 26.8% (95% confidence interval 21.0-32.6%). Among the categorical data evaluated, the biosecurity level (odds ratio 0.17, p < 0.01) and the geographical characteristics (odds ratio 13.55, p < 0.05) significantly affected the presence of toxoplasmosis in the herd. Toxoplasmosis was recorded in significantly higher percentages in mountainous farms as compared to lowlands (p < 0.05) and in those with poor biosecurity levels than in those with very good (p < 0.05). A very good agreement (κ = 0.958) was observed between the two serological methods.

CONCLUSION

The presence of antibodies in pigs is indirect information on the risk of the infection and an indication of the necessity of biosecurity measures to be taken in order to control infection at least in the areas at highest risk.

Detection of Leishmania-specific DNA and surface antigens using a combination of functionalized magnetic beads and cadmium selenite quantum dots

Leishmaniosis is a zoonotic disease that affects millions of people especially in resource-poor settings. The development of reliable diagnostic assays that do not require dedicated equipment or highly trained personnel would improve early diagnosis and effective control. For this purpose, a combination of magnetic bead and cadmium selenite quantum dot probes was applied for the detection of Leishmania-specific surface antigens (proteins) and DNA. Both analytes are isolated from the solution using magnetic bead capture probes whereas the presence of the targeted molecules is demonstrated by quantum dot detection probes. The sensitivity and specificity of this method reached 100% based on an assessment performed on 55 cultured isolates of various microbial pathogens. The low limit of detection was 3125 ng/μl and 10(3)cells/ml for Leishmania DNA and protein, respectively. The method shows considerable potential for clinical application in human and veterinary medicine, especially in resource-poor settings.

LeishVet update and recommendations on feline leishmaniosis

Limited data is available on feline leishmaniosis (FeL) caused by Leishmania infantum worldwide. The LeishVet group presents in this report a review of the current knowledge on FeL, the epidemiological role of the cat in L. infantum infection, clinical manifestations, and recommendations on diagnosis, treatment and monitoring, prognosis and prevention of infection, in order to standardize the management of this disease in cats. The consensus of opinions and recommendations was formulated by combining a comprehensive review of evidence-based studies and case reports, clinical experience and critical consensus discussions. While subclinical feline infections are common in areas endemic for canine leishmaniosis, clinical illness due to L. infantum in cats is rare. The prevalence rates of feline infection with L. infantum in serological or molecular-based surveys range from 0% to more than 60%. Cats are able to infect sand flies and, therefore, they may act as a secondary reservoir, with dogs being the primary natural reservoir. The most common clinical signs and clinicopathological abnormalities compatible with FeL include lymph node enlargement and skin lesions such as ulcerative, exfoliative, crusting or nodular dermatitis (mainly on the head or distal limbs), ocular lesions (mainly uveitis), feline chronic gingivostomatitis syndrome, mucocutaneous ulcerative or nodular lesions, hypergammaglobulinaemia and mild normocytic normochromic anaemia. Clinical illness is frequently associated with impaired immunocompetence, as in case of retroviral coinfections or immunosuppressive therapy. Diagnosis is based on serology, polymerase chain reaction (PCR), cytology, histology, immunohistochemistry (IHC) or culture. If serological testing is negative or low positive in a cat with clinical signs compatible with FeL, the diagnosis of leishmaniosis should not be excluded and additional diagnostic methods (cytology, histology with IHC, PCR, culture) should be employed. The most common treatment used is allopurinol. Meglumine antimoniate has been administered in very few reported cases. Both drugs are administered alone and most cats recover clinically after therapy. Follow-up of treated cats with routine laboratory tests, serology and PCR is essential for prevention of clinical relapses. Specific preventative measures for this infection in cats are currently not available.