Feline leishmaniosis: Is the cat a small dog?

Serological, molecular and clinicopathological findings associated with Leishmania infantum infection in cats in Northern Italy

OBJECTIVES

The aims of this study were to investigate the prevalence of Leishmania species infection in cats in Northern Italy and to evaluate the associations between infection and signalment and clinicopathological data.

METHODS

The study was carried out in a veterinary university hospital from June to November 2017. Blood, urine, conjunctival swabs and hair were collected from all randomly selected cats. Leishmania species infection was evaluated using the indirect fluorescent antibody test (IFAT), setting a cut-off value of 1:80, and using real-time PCR on blood, conjunctival and hair samples. A complete blood count, serum chemistry profile, serum electrophoresis and urinalysis were also carried out. The cats were grouped on the basis of the results of the diagnostic criteria adopted in positive, negative and unconfirmed Leishmania cases. Non-parametric variables and continuous data were compared among the study groups using the χ2 test and the Mann-Whitney U-test, respectively.

RESULTS

One hundred and fifty-two cats were included. Nineteen of the 152 (12.5%) cats were positive (18/152 [11.8%] showed an IFAT titre of ⩾1:80 and 1/152 [0.7%] was real-time PCR-positive from a hair sample); 106/152 (69.7%) cats were negative; and 27/152 (17.8%) cats were unconfirmed for Leishmania species. Total proteins, beta2-globulin and gamma-globulin were significantly increased in the positive Leishmania group compared with the negative group.

CONCLUSIONS AND RELEVANCE

The results of the present study demonstrated the spread of Leishmania infantum infection in cats in Northern Italy. Hyperproteinaemia and hypergammaglobulinaemia appeared to be significant clinicopathological abnormalities in this population of cats with L infantum infection.

Leishmaniasis in cat shelters: A serological, molecular and entomological study

An epidemiological Leishmania spp. and entomological Phlebotomine sandflies survey was performed in cat shelters at leishmaniasis endemic area of Brazil. Blood and conjunctival swab (CS) samples were collected from 94 cats in two animal protection shelters. These samples were subjected to serological tests using the indirect immunofluorescence antibody test (IFAT) and indirect enzyme-linked immunosorbent assay (ELISA) and to molecular test by polymerase chain reaction (PCR). In addition, a Phlebotomine sandflies survey was performed in the same shelters. The analyses revealed a positivity of 31.91% (30/94) through ELISA and 29.79% (28/94) through IFAT. The two serological tests showed a positive association with perfect agreement (k = 0.925). None of the cats were positive by Leishmania spp. DNA. One Lutzomyia (Lutzomyia) longipalpis male was found in one of the cat shelters. The results and the implications of our findings are discussed below.

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

Background

A large number of animal species are susceptible to Leishmania infantum (Kinetoplastida, Trypanosomatidae) in endemic areas, including domestic and wild felids such as tigers (Panthera tigris). Knowledge on the infection of this endangered species is still at its infancy, and therefore this study aims to identify clinical presentation and clinicopathological findings of tigers naturally infected by L. infantum.

Results

Tigers either L. infantum-positive (group A) or -negative (group B) were apparently healthy or presented visceral leishmaniasis unrelated conditions, except for one animal in which a large non-healing cutaneous lesion was observed. However, histological exam and immunohistochemistry carried out on the lesion excluded the presence of L. infantum amastigotes. Biochemical analysis showed that the average concentration of total proteins, globulins and haptoglobin were significantly higher (p < 0.01, p = 0.01 and p = 0.02, respectively), while the albumin/globulin ratio significantly lower (p = 0.05) in group A compared with group B. The biochemical alterations were partially confirmed by the serum protein electrophoresis results revealing a significant increase in the total protein value (p = 0.01) and hypergammaglobulinemia (p = 0.03) but an unmodified albumin/globulin ratio in group A.

Conclusions

In this study tigers infected by L. infantum have shown to be mainly asymptomatic. The absence of clinical signs may lead veterinarians to overlook leishmaniasis in animals kept in captivity. Therefore, diagnostic and screening tests as serology should be part of routinely surveillance programs to be performed on tigers in zoological gardens located in endemic areas. Though only few protein-related laboratory abnormalities were recorded in infected animals, they could provide diagnostic clues for a first suspicion of L. infantum infection in tigers. Indeed, considering the high risk of zoonotic transmission in heavily frequented environment as zoos, a prompt diagnosis of L. infantum infection is of pivotal importance.

Treatment and follow-up of a domestic ferret (Mustela putorius furo) with clinical leishmaniosis caused by Leishmania infantum

Leishmania infantum infection including treatment and follow up in domestic animals other than dogs and cats has not been described at this moment. This article describes the anti-Leishmania treatment and follow-up of a ferret (Mustela putorius furo) with leishmaniosis. A combined therapeutic protocol established for the patient, not yet approved for ferrets, was a combination of meglumine antimoniate plus allopurinol. A follow-up was established monthly during the first year in order to monitor the health condition of the patient. Six months after commencing allopurinol therapy, xanthine crystalluria was observed in urine sediment with no other urine alterations detected by urine analysis. The ferret worsened progressively with diarrhoea and weight loss after cohabiting with another ferret diagnosed with cryptosporidiosis. Cryptosporidium parvum was isolated in faecal samples from the patient detected by three different methods including Ziehl-Neelsen staining, a qualitative test to detection of C. parvum antigens and finally a specific molecular analysis to characterize the species. To the best of the authors´ knowledge, this is the first report providing information about anti-Leishmania protocol therapy used and follow-up in a domestic ferret with clinical leishmaniosis. Veterinarians practicing in endemic areas should be aware of this infection in ferrets at risk and their susceptibility especially when immunosuppressive conditions are present.

Focus on Common Small Animal Vector-Borne Diseases in Central and Southeastern Europe

Vector-borne diseases are one of the main causes of morbidity and mortality in small animals in Europe. Many of these diseases are well-known among veterinary practitioners and some of them are called emerging diseases as prevalence, temporal and spatial distribution seem to increase in Europe. The number of newly recognized pathogens, transmitted by a variety of arthropod vectors, that are relevant for dogs and cats, is also increasing every year. The prevalence among infected vectors and hosts is a hot topic in veterinary science throughout the entire continent, as well as the development of efficient diagnostic procedures, therapy and prophylactic measures. Companion animal vector-borne diseases comprise a large group of pathogens including viruses, bacteria, protozoa and helminths. These pathogens are mainly transmitted by bloodsucking arthropods (ticks, fleas, mosquitos, sand flies), and more seldom by direct transmission between vertebrate hosts. Vector prevalence and activity is influenced by local climate conditions, host species density, changes in landscape and land use. Human parameters such as poverty and migration affect the use of prophylactic measures against pathogen transmission and infection as well as increasing the zoonotic risk to introducing pathogens by infected humans. Small animal associated factors such as pet trade and pet travel spread infection and certain vectors such as ticks and fleas. All these factors pose several complex and significant challenges for veterinarians in clinical practice to decide on efficient laboratory work-up and constructive diagnostic procedures.

Serological study of feline leishmaniasis and molecular detection of Leishmania infantum and Leishmania braziliensis in cats (Felis catus)

Blood samples and swabs from ocular conjunctiva and mouth were obtained from 64 cats. Of 64 serum samples, 19 were positive for Leishmania antibodies by ELISA (29.80%). Eight cats were positive by PCR (12.5%) in swab samples from mouth and/or ocular mucosa. Poor kappa agreement between serological and molecular results (k = 0.16) was obtained. From five positive PCR samples one was L. braziliensis and four were L. infantum. Phylogenetic analysis performed with the five isolates of Leishmania, showed that samples of L. infantum isolated from the cats were phylogenetically close to those isolated from domestic dogs in Brazil, while the L. braziliensis is very similar to the one described in humans in Venezuela. The study demonstrated that, despite high seropositivity for Leishmania in cats living in the study region, poor agreement between serological and molecular results indicate that positive serology is not indicative of Leishmania infection in cats. Parasite DNA can be detected in ocular conjunctiva and oral swabs from cats, indicating that such samples could be used for diagnosis. Results of phylogenetic analyzes show that L. infantum circulating in Brazil is capable of infecting different hosts, demonstrating the parasite's ability to overcome the interspecies barrier.

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.

A molecular survey of vector-borne pathogens and haemoplasmas in owned cats across Italy

BACKGROUND

Feline vector-borne pathogens (FeVBPs) have been increasingly investigated for their impact on cat health and their zoonotic potential. The aim of the present study was to assess the prevalence of FeVBPs and haemoplasmas in cats across Italy and to identify potential risk factors linked to their occurrence.

METHODS

Blood samples from 958 owned cats living in the North (n = 556), Centre (n = 173) and South (n = 229) of Italy were tested for Babesia spp., Hepatozoon spp., Ehrlichia spp., Anaplasma spp. and filarioids by conventional PCR (cPCR) and for haemoplasmas and Bartonella spp. by SYBR green real-time PCR. Cats included in the study represent a sub-sample from a larger number of animals enrolled in a previous study, which were selected based on the geographical origin. Data on cats' positivity for Leishmania infantum, feline leukaemia virus (FeLV) and for feline immunodeficiency virus (FIV), available from the previous study, were included and examined. Potential risk factors for pathogen infection were assessed in relationship to categorical variables including sex, geographical origin, breed, neutering status and age of cats.

RESULTS

Out of the 958 cats, 194 (20.2%) were positive for at least one of the tested pathogens, 89 (16%) from the North, 32 (18.5%) from the Centre and 73 (31.9%) from the South of Italy. A high prevalence of FeVBPs was detected in male cats (n = 125, 27.8%), living in the southern part of the country (n = 73, 31.9%), younger than 18 months of age (n = 24, 22.4%) and not neutered (n = 39; 27.5%). In particular, 24 cats (2.5%) tested PCR-positive for Bartonella spp., of which 1.6% for B. henselae and 0.9% for B. clarridgeiae. A total of 111 cats scored PCR-positive for haemoplasmas (11.6%), specifically "Candidatus Mycoplasma haemominutum" (n = 95, 9.9%), M. haemofelis (n = 14, 1.5%) and "Candidatus Mycoplasma turicensis" (n = 2, 0.2%). Moreover, 39, 31 and 8 cats were positive for FeLV (4.1%), L. infantum (3.2%) and FIV (0.8%), respectively. Co-infections were registered for 19 (9.8%) cats.

CONCLUSIONS

These results confirm the occurrence of haemoplasmas and FeVBPs throughout Italy. Preventive measures to protect both animal and human health should be carried out also for owned cats, even if no health status of animals has been assessed in this study.

Leishmania infection in cats and dogs housed together in an animal shelter reveals a higher parasite load in infected dogs despite a greater seroprevalence among cats

Background

An outbreak of leishmaniosis was studied in cats and dogs housed together with no separation in an animal shelter in Israel.

Methods

The study included recording of clinical signs, serology for Leishmania infection by ELISA, PCR of blood for Leishmania DNA by ITS1 HRM and kDNA PCR, parasite quantification, and trapping of sand flies around the shelter.

Results

Thirty-seven % (22/60) of the dogs and 75% (50/67) of the cats were seropositive to L. infantum with a significantly higher seropositivity rate in the cat population (χ² = 42.160, P < 0.0001). Twenty-five percent (15/60) of the dogs were positive for Leishmania by blood PCR, 12% by the Leishmania ITS1 HRM PCR and 22% by kDNA PCR. Of the cats, 16% (11/67) were positive by kDNA PCR and none by ITS1 HRM PCR. All the PCR-positive animals were infected by L. infantum verified by DNA sequencing and there was no significant difference between the PCR-positivity in the dog and cat populations. Altogether, 43% (26/60) of the dogs and 79% (53/67) of the cats were positive by serology or PCR for L. infantum. The average Leishmania parasite load in the blood of PCR-positive dogs (42,967 parasites/ml) was significantly higher than in PCR-positive cats (1259 parasites/ml) (t₍₁₂₎ = 2.33, P = 0.037). Dogs that were positive by the Leishmania ITS1 HRM PCR and kDNA PCR had significantly higher parasite loads than dogs positive only by the kDNA PCR (t₍₁₁₎ = − 3.186580, P < 0.009). No significant effect was found for FIV seropositivity on Leishmania infection in the cats (χ² = 0.506, P = 0.777). A higher percentage of Leishmania-positive dogs showed clinical signs compatible with leishmaniosis compared to Leishmania-positive cats (100 vs 52.8%, χ² =15.242, P < 0.0001). Phlebotomus perfiliewi, a proven vector of L. infantum, comprised 92% of trapped sand flies.

Conclusions

Comparisons of populations of cats and dogs exposed to sand flies and L. infantum under the same conditions indicated that although a high rate of exposure was detected in cats as manifested by a significantly greater degree of seropositivity, dogs had significantly higher blood parasite loads, and were likely to be more infectious to sand flies than cats.

Infection of Lutzomyia longipalpis in cats infected with Leishmania infantum

The clinical manifestations most frequently observed in cats with leishmaniasis caused by Leishmania infantum are cutaneous alterations, which suggest a high parasitic load in the skin and the possibility of infecting a vector. This study evaluated the infectiousness of to phlebotomine sand flies cats infected with L. infantum. A total of 12 cats with infection by L. infantum from the city of Teresina, Piauí, Brazil, were included in the study. Cats were diagnosed by direct visualization of the parasite. Laboratory-bred insects, free from infection by Leishmania spp. were offered a blood meal for 60 min on cats infected with L. infantum. On the fifth and sixth day after the blood meal, flies were dissected to assess promastigote forms of the parasite in the digestive system. Eight cats (67 %) were able to infect the vectors. The frequency of infected insects per cat ranged 0.0-94.4%. The mean frequency of insects feeding on cats was 95.2 %. Large numbers of the parasite were observed per insect, but were not quantified. The result confirm that cats are able to infect L. longipalpis, indicating that cats are part of the epidemiological chain of VL, acting as reservoir of the disease.

Molecular detection of vector-borne agents in cats in Southern Brazil

This study used serological and molecular methods to investigate the occurrence of vector-borne pathogens (VBP) with zoonotic potential in cats neutered at the University Veterinary Hospital in Canoinhas, Santa Catarina. The combined PCR and serological results revealed that 17 (56.6%) cats were positive for one or more pathogens. The sampled cats had antibodies to Ehrlichia spp. (7/30), Anaplasma phagocytophilum (3/30) and Leishmania infantum (2/30). The PCR assay detected DNA closely related to Ehrlichia canis in 6/30 cats, Mycoplasma haemofelis in 2/30 cats, A. phagocytophilum and Cytauxzoon sp. in one cat each. While Bartonella clarridgeiae and B. henselae were detected in two cats each, and B. koehlerae was detected in one cat.

Serological and molecular investigation of Leishmania spp. infection in cats from an area endemic for canine and human leishmaniasis in Northeast Brazil

The aim of this study was to investigate the occurrence of Leishmania spp. antibodies, and its association with feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV), in domestic cats from an area endemic for canine and human leishmaniasis in Rio Grande do Norte State, Brazil. Ninety-one cats were subjected to a complete clinical exam, and blood samples were collected. An epidemiological questionnaire was used to investigate the risk factors. IgG anti-Leishmania spp. antibodies were detected by immunofluorescence antibody test (IFAT), with a cut-off value of 1:40. Polymerase chain reaction (PCR) was performed to detect genetic material of Leishmania spp. in the blood samples. The presence of antibodies against FIV and antigens of FeLV was evaluated using an immunochromatographic test. Seropositivity for Leishmania spp., FIV, and FeLV was observed in 14/91 (15.38%), 26/91 (28.57%), and 3/91 (3.29%) cats, respectively. All samples gave negative results on PCR analysis. Based on these data, no significant statistical association was observed between seropositivity for Leishmania spp., and sex, age, presence of clinical signs, evaluated risk factors, and positivity for retroviruses. These findings demonstrated for the first time that cats from Mossoró, Rio Grande do Norte, are being exposed to this zoonosis and might be part of the epidemiological chain of transmission of visceral leishmaniasis.

Role of vector-borne pathogens in the development of fever in cats: 2. Tick- and sandfly-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens vectored by ticks or sandflies, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats associated with pathogens known or suspected to be vectored by fleas was discussed within Part 1 of this two-part article series.

Phylogenetic insights on Leishmania detected in cats as revealed by nucleotide sequence analysis of multiple genetic markers

Cats have been found infected by the same Leishmania species that also infect dogs and humans in both the New and Old Worlds, and their role as additional reservoir hosts of L. infantum has been previously suggested. Currently, the genetic diversity of Leishmania spp. detected in cats is poorly understood. In this cross-sectional study, the partial nucleotide sequences of four gene markers (cytB, g6pdh, hsp70 and ITS-rDNA) were explored to investigate the genetic diversity and the phylogenetic relationships of Leishmania parasites detected in cats. A total of 25 cat buffy coat samples where the presence of Leishmania SSU-rDNA was revealed by PCR (from a convenience sample of 465 cats screened), as well as six Leishmania strains previously isolated from cats, were included in this study. Phylogenetic analyses showed that the majority of Leishmania parasites detected in cats did not display distinctive genetic features, sharing the same genetic types with L. infantum strains isolated from humans, dogs and phlebotomine sand flies. Unexpectedly, DNA of L. major and/or of a L. major/L. donovani sensu lato hybrid was detected in buffy coat samples of two cats from different regions of Portugal. However, a mix infection hypothesis cannot be formally excluded. To our knowledge, this study represents the first evidence for the presence of DNA of Leishmania hybrid parasites in cats. The results reported here not only reinforce the idea that cats play a role in the epidemiology of zoonotic leishmaniosis but also indicate the circulation of L. major and/or L. major/L. donovani s.l. hybrid parasites in Portugal. Also, whenever sequencing of whole Leishmania genomes regularly cannot be accomplished, and while their complete genomes remain under-represented in the nucleotide sequence databases, the combined use of multiple genetic markers, including kinetoplast maxicircle DNA, seems to be essential for typing of Leishmania parasites.

Infection of the equine population by Leishmania parasites

Infection of equids by Leishmania (L.) parasites was previously described in both the Old and New World, particularly in Central and South America. Equine cutaneous leishmaniasis (CL) is caused by the Leishmania species, L. Viannia (V.) braziliensis and L. infantum, previously identified in humans and other parasite hosts living in the same geographic endemic areas. Sporadic autochthonous clinical cases, with no travel history, were documented in several countries including Germany, Portugal, Spain, Texas and Brazil; L. infantum and L. (Mundinia) martiniquensis were the infectious species. Prevalence of subclinical infections is extremely low and CL is observed in only a small proportion of infected animals with the appearance of single or multiple cutaneous lesions located on the head, external ear, scrotum, legs and the neck. To date, there has been no report of visceral abnormalities. However, the mild clinical profile of the disease and its spontaneous regression may indicate that skin lesions related to Leishmania infection is underdiagnosed. Importantly, although the prevalence of Leishmania infections in the equine population is low, a risk may rise from its potential involvement in the parasite transmission cycles as a source of infection for phlebotomine vectors and susceptible mammalian hosts. This review article summarises our current knowledge of the epidemiology, clinical presentation and diagnosis of Leishmania-infected equids.

An Unusual Case of Feline Leishmaniosis With Involvement of the Mammary Glands

We report an unusual case of leishmaniosis with the involvement of mammary glands in an old cat with what seems to be a concurrent regressive feline leukemia virus infection. Leishmania donovani complex parasites were identified for the first time in inflammatory breast fluid during a clinical recurrence manifested about 4 years after the first diagnosis of feline leishmaniosis. Combined treatment with allopurinol and meglumine antimoniate resulted in clinical cure of mammary lesion and a concurrent uveitis.

Diagnosis and epidemiology of Leishmania infantum in domestic cats in an endemic area of the Amazon region, Brazil

Visceral leishmaniasis is a zoonotic disease caused by Leishmania infantum for which dogs are the main reservoir. In South America, presence of this disease is expanding along with increasing dispersion of its principal vector, the sand-fly Lutzomyia longipalpis. Feline leishmaniasis is an emerging disease in domestic cats, but epidemiological studies in endemic areas of the Amazon region of Brazil are scarce and the role of cats as reservoirs of L. infantum has been debated. The aim of this study was to investigate L. infantum infection in cats living in the Amazon biome region, using serological and molecular methods. A total of 105 cats were subjected to clinical examination and blood samples were taken for immunofluorescent-antibody (IFAT) serological evaluation, to determine anti-Leishmania antibody titers. Conventional PCR and Sanger's sequencing targeting L. infantum chitinase and Leishmania species ribosomal internal transcribed spacer (ITS-1) encoding genes were performed on conjunctival swabs from these cats. Seropositivity was detected in 32 animals (30.48%), thus confirming that contact between these cats and the parasite was occurring. PCR followed by amplicon sequencing showed that three samples (2.86%) were positive for a chitinase gene and six (5.71%) were positive for the ITS-1 gene. Parasite-positive diagnoses presented a statistically significant association with free access to the streets (p = 0.0111), cohabitation with dogs affected previously by VL (p = 0.0006) and absence of backyard cleaning and garbage collection (p = 0.00003). These results emphasize that cats should be included in epidemiological surveys of leishmaniasis, especially in endemic areas, if not as the reservoir host (unproven), at least as a "sentinel host" that is useful for revealing situations of endemic circulation of L. infantum. Moreover, in these areas, feline leishmaniasis needs to be considered in the differential diagnosis among domestic cats presenting alopecia, rarefied hair, lacerations and ulcerative dermatitis.

Exposure of client-owned cats to zoonotic vector-borne pathogens: Clinic-pathological alterations and infection risk analysis

Zoonotic Vector-Borne Diseases (VBDs) represent a relevant health issue for pets and humans. Italy is a major epidemiological hub for feline VBDs, because of suitable conditions for vector biology and disease transmission patterns. The present study investigated the exposure to major zoonotic arthropod-borne pathogens of cats in Italy, along with the evaluation of clinic-pathological features and a risk factor analysis. Out of 167 examined cats, 52 (31.1%) were seropositive for at least one vector-borne pathogen, being positivity for Bartonella henselae the most recorded (18%). Also, various cats seroreacted for Rickettsia felis (10.8%) and Rickettisa typhi (4.2%), Leishmania infantum (3%), Anaplasma phagocytophilum (2.4%) and Ehrlichia canis (2.4%). Forty-six cats were tested also for antibodies against D. immitis and two (4.3%) scored positive. The statistical analysis showed a positive association between flea infestation and seropositivity to B. henselae, other than an association between the administration of monthly ectoparasiticide treatments and seronegativity for Rickettsia spp.; seropositive cats were older than negative animals and the lifestyle (i.e. indoor vs outdoor) was not correlated with exposure to vector-borne pathogens. The majority of seropositive cats appeared clinically healthy or showed aspecific clinical signs. Around 80% of seropositive cats had one or more biochemical and/or complete blood count abnormalities. The present data confirm the endemicity of zoonotic feline VBDs in Italy and indicate that awareness on arthropod infections and transmitted pathogens should be kept high and possible implemented, towards the protection of animal and human health with adequate surveillance plans.

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).

Immunohistochemical characterization of cutaneous leishmaniasis in cats from Central-west Brazil

Feline leishmaniasis (FeL) is an emerging infectious disease of cats caused by Leishmania infantum with global distribution. This study investigated the cause of chronic progressive cutaneous lesions in two cats from Central-west Brazil by using cytological, histopathologic, and immunohistochemical (IHC) analyses. Clinically, both cats had ulcerative cutaneous lesions at the nasal planum and ear resulting in a tentative diagnosis of squamous cell carcinoma (SCC). Moreover, both cats had varying degrees of onychogryphosis. However, cytology revealed chronic inflammatory reactions associated with intralesional amastigotes; histopathology confirmed chronic ulcerative dermatitis associated with intralesional and intracytoplasmic parasitic organisms consistent with amastigotes of Leishmania spp. within histiocytes. The IHC assay demonstrated that the intralesional parasitic structures identified by cytology and histopathology were immunoreactive to antigens of Leishmania spp., confirming the participation of this infectious disease agent in the development of the cutaneous lesions of these cats. The observation of onychogryphosis must be highlighted, since this lesion is frequently observed in dogs with visceral leishmaniasis but is underreported in FeL. Collectively, the pathologic and IHC findings of the chronic cutaneous disease confirmed active infections due to Leishmania spp. in these cats. Additionally, FeL with associated lesions to the ear and nasal planum must be considered as differential diagnosis for SCC in cats.

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.

Treatment and long-term follow-up of a cat with leishmaniosis

BACKGROUND

Leishmania infection in cats is being increasingly reported in endemic areas. Nevertheless, only a few clinical cases have been described in cats, and even fewer have provided information on the response to treatment and a proper follow-up. Here we report a case of feline leishmaniosis not associated with any other disease or co-infection and document its response to allopurinol treatment and long-term follow-up data.

RESULTS

A 6-year-old domestic shorthair female cat was referred for nodular blepharitis, mucocutaneous ulcerative lesions of the mouth and lymph node enlargement. The cat was moderately anaemic, hyperglobulinaemic and tested negative for feline leukaemia virus and feline immunodeficiency virus. Fine needle aspirates of nodules and mucocutaneous lesions showed the presence of numerous amastigote forms of Leishmania. Leishmania infection was further confirmed by serology (IFAT test, 1:640) and real-time PCR (RT-PCR) on blood and conjunctival swabs. The cat was treated with allopurinol (20 mg/kg SID), which was clinically effective, although the cat remained Leishmania-positive in serology and RT-PCR on blood and conjunctival swabs. Allopurinol treatment was interrupted after seven months because of the healing of all lesions and lack of compliance by the owner. After two years, the cat relapsed displaying almost the same clinical signs and clinicopathological alterations. On this occasion, the parasite was isolated by culture and identified as belonging to L. infantum. Allopurinol treatment was started again but was interrupted several times because of the itching side effect observed. The cat worsened progressively and died two months after the relapse without any chance to shift the treatment to another molecule (e.g. meglumineantimoniate or miltefosine).

CONCLUSIONS

Out of all documented cases of feline leishmanosis, the present case has the longest follow-up period and it is one of the few in which the parasite was isolated and identified. It further confirms the potential progression of Leishmania infection to disease in cats even in the absence of comorbidities. Veterinarians practicing in endemic areas should be aware of this susceptibility, properly include feline leishmaniosis in the differential diagnosis and propose preventative measures to those cats at risk.

Granulomatous rhinitis secondary to feline leishmaniosis: report of an unusual presentation and therapeutic complications

Case summary

A 12-year-old male neutered domestic shorthair cat underwent rhinoscopy due to inspiratory dyspnoea and stertor. Rhinoscopy showed signs of chronic rhinitis and a multinodular nasopharyngeal mucosa. A marked infiltrate of macrophages that contained intracellular parasitic forms morphologically compatible with Leishmania amastigotes were observed on histopathological examination of nasal and nasopharyngeal biopsies. PCR from nasal tissue was positive for Leishmania infantum DNA, confirming the diagnosis of granulomatous rhinitis secondary to this parasite. Two eyelid nodules were identified 2 weeks later. Fine-needle aspiration revealed Leishmania amastigotes within macrophages and in the background. Allopurinol therapy was started, but 5 days later the cat developed dermatological signs compatible with a cutaneous adverse drug reaction. The drug was discontinued and meglumine antimoniate prescribed. Twenty-five days later, the cat presented with acute kidney injury and meglumine antimoniate was discontinued. Despite clinical improvement after fluid therapy, mild azotaemia persisted. The cat was subsequently treated with nucleotides and active hexose correlated compounds (N-AHCC). Four months later upper respiratory signs were exacerbated. A relapse of granulomatous rhinitis was suspected and miltefosine therapy started. Chronic kidney disease (CKD) worsened during miltefosine treatment, having improved under fluid therapy. Since then, the cat has been treated with N-AHCC and renal diet and at the time of writing shows stable CKD with no recurrence of respiratory signs.

Relevance and novel information

This case describes Leishmania infantum as a cause of granulomatous rhinitis in a cat without cutaneous lesions, reporting the alternative use of N-AHCC and miltefosine when allopurinol seemed to have induced a cutaneous rash and there was acute kidney injury (AKI) after meglumine antimoniate therapy.