Feline leishmaniasis in an animal shelter in northeastern Brazil: Clinical aspects, coinfections, molecular detection, and serological study of a new recombinant protein.

Infection and clinical cases of leishmaniasis caused by Leishmania infantum in cats have been increasingly reported in several countries, including Brazil. In this study, we used an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic test (ICT) based on a recombinant antigen (rKDDR-plus) to detect anti-Leishmania antibodies in cats from an animal shelter in northeastern Brazil. We compared the results with an ELISA using L. infantum crude antigen (ELISA-CA). We also investigated the presence of Leishmania DNA in blood or ocular conjunctival samples as well as the association between Leishmania PCR positivity and serological positivity to feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and Toxoplasma gondii. Concerning serological assays, a higher positivity was detected using the ICT-rKDDR-plus (7.5%; 7/93) as compared to ELISA-rKDDR-plus (5.4%; 5/93) and ELISA-CA (4.3%; 4/93). Upon PCR testing, 52.7% (49/93) of the ocular conjunctival swabs and 48.3% (44/91) of the blood samples were positive. Together, PCR and serological testing revealed overall positivities of 73.1% (68/93) and 12.9% (12/93), respectively. Among PCR-positive samples, 45.5% (31/68) showed co-infection with FIV, 17.6% (12/68) with FeLV, and 82.3% (56/68) with T. gondii. More than half of the PCR-positive cats showed at least one clinical sign suggestive of leishmaniasis (58.8%; 40/68) and dermatological signs were the most frequent ones (45.5%; 31/68). Both tests employing the recombinant antigen rKDDR-plus (i.e., ICT-rKDDR-plus and ELISA-rKDDR-plus) detected more positive cats than the ELISA-CA but presented low overall accuracy. PCR testing using either blood or ocular conjunctival samples detected much more positive cats than serological tests.

Leishmania spp. diagnosis and therapeutic management in a cat from urban area in Ibagué (Colombia).

BACKGROUND: Leishmania spp., a protozoan transmitted by sandflies, widely affects humans and dogs in Colombia, nevertheless feline leishmaniasis (FeL) remains understudied. OBJECTIVE: This study reports a case of feline leishmaniasis in Colombia and its therapeutic management. METHODS: Complete blood count, renal and hepatic serum biochemistry, nodular lesion cytology, FeLV/FIV snap test, abdominal ultrasound, and molecular diagnosis of Leishmania spp. 16 s rRNA gene amplification by real-time-PCR (qPCR), ITS-1 and hsp70 gene by endpoint-PCR and Sanger sequencing were performed. RESULTS: The patient was negative for FIV/FeLV and showed leukocytosis, lymphocytosis, thrombocytopenia, neutrophilia, monocytosis, hypergammaglobulinemia, increased gamma-glutamyl-transferase, cortical nephrocalcinosis, diffuse heterogeneous splenic parenchyma, and cholangitis. Nodular lesion cytology, qPCR and Sanger sequencing confirmed the diagnosis of Leishmania spp. The patient was treated with allopurinol and miltefosine. After treatment, clinical signs disappeared. CONCLUSION: Clinical examination, cytology, and molecular tests allowed a rapid and sensitive FeL diagnosis. Allopurinol and miltefosine improved the clinical condition of the cat.

Detection of Leishmania spp. in Cats: Analysis of Nasal, Oral and Conjunctival Swabs by PCR and HRM.

BACKGROUND AND OBJECTIVES: Feline leishmaniasis (FeL) is caused by several species of parasites of the genus Leishmania. The disease can occur with the presence or absence of clinical signs, similar to those observed in other common infectious diseases. In endemic regions for FeL, the infection has been associated with dermatological lesions. Therefore, considering the search for less invasive and more effective diagnostic techniques, we aimed to investigate the presence of Leishmania spp. in domestic cats through Polymerase Chain Reaction (PCR) and high-resolution melting (HRM) analyses of conjunctival, oral, and nasal epithelial cells, and we detected the presence of anti-Leishmania IgG antibodies from serological techniques of the Immunofluorescent Antibody Test (IFAT) and ELISA. METHODS: The PCR and HRM for detection of Leishmania spp. were performed on 36 samples of epithelial cells from the conjunctiva of male and female cats, collected using sterile swabs. The serological tests IFAT and ELISA were also performed. RESULTS: The prevalence of Leishmania donovani infection was 11.1% (4/36) by PCR assay, and those results were confirmed for Leishmania species using the HRM technique. Twenty-four cats (24/36 = 66.7%) were reactive to the IFAT and twenty-two cats were reactive by the ELISA technique (22/36 = 61.1%). INTERPRETATION AND CONCLUSIONS: The use of conjunctival swabs was shown to be a non-invasive, practical, and easy-to-perform technique, and in addition to the genetic sequencing and HRM, it was able to identify the parasitic DNA of L. donovani in cats. This technique can be used for screening diagnosis in future epidemiological surveys of FeL and can be used as a complement to clinical and/or serological tests, as well as associating the clinical history of the animal, for the diagnostic conclusion.

First molecular detection of Leishmania (Leishmania) infantum chagasi in a domestic cat (Felis catus) from an urban area in eastern Amazon.

Background: Domestic cats have been implicated as accidental hosts of Leishmania sp. However, in recent years, the recurrent description of new cases in endemic and nonendemic areas draw attention to the potential epidemiological role of cats as reservoir hosts. Although dogs are considered urban reservoirs, cats could act as a secondary natural reservoirs in these areas. Thus, feline leishmaniasis has become an emerging disease in several countries worldwide. Case presentation: This study aimed to describe the first case of feline leishmaniasis in a stray animal that presented lesions compatible with the disease in Belém, Pará, Brazil, an important urban area in eastern Amazon. Serological tests for Leishmania infantum (ELISA and IFA) were nonreactive, whereas histopathological examination indicated infectious dermatitis caused by Leishmania spp. or Toxoplasma gondii. Cytopathological study of lesion aspirate confirmed the presence of Leishmania sp. amastigotes within macrophages. Finally, molecular analyses revealed that the feline infection was caused by Leishmania (Leishmania) infantum chagasi. Conclusion: To the best of the authors' knowledge, this study reports the first case of natural infection by Leishmania (Leishmania) infantum chagasi in a feline from eastern Amazon. These findings suggest domestic cats as potential secondary reservoir hosts of Leishmania spp. in Belém, which reinforces the importance of further epidemiological investigation of feline leishmaniasis, especially in urban areas with human cases.

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.

Leishmaniasis.

Leishmaniasis caused by Leishmania infantum is an important zoonotic disease transmitted by sand flies with a high prevalence of infection in dogs and cats in regions whereby transmission occurs. Clinical disease is systemic with variable presenting signs and degrees of severity. It affects the skin, lymph nodes, eyes, bone marrow, kidneys, and other organs. The clinical findings in dogs and cats with L. infantum infection are generally similar. Subclinical infection of canines and felines in endemic areas is frequent. Long-term treatment of the disease with allopurinol, or combination of allopurinol with meglumine antimoniate or miltefosine, is needed, and clinical relapse is probable.

Retrospective Analysis of Leishmaniasis in Sicily (Italy) from 2013 to 2021: One-Health Impact and Future Control Strategies.

Leishmaniasis is an important vector-borne disease that represents a serious public health problem, including in Sicily (Italy), which is considered an endemic area. We collected canine, feline and human data from 2013 to 2021 in Sicily, while entomological surveys were conducted only in 2013 and 2021. Overall, 23,794/74,349 (34.4%) of dogs and 274/4774 (11.8%) of cats were positive in one or more diagnostic tests. A total of 467 cases of human Leishmaniasis were reported, with 71% showing cutaneous and 29% visceral involvement. The provinces with the largest number of patients were Agrigento (45.4%) and Palermo (37%). In 2013, Phlebotomus perfiliewi was the dominant sandfly species in Sicily (68.7%), followed by Phlebotomus perniciosus (17.2%) and Sergentomya minuta (14%). In 2021, Phlebotomusperfiliewi was confirmed as the most common species (61.6%), followed by Phlebotomusperniciosus (33.1%) and Sergentomyaminuta (4.7%). Of particular interest was the identification of Phlebotomus papatasi (0.41%) in Agrigento. Our retrospective study can inform health authorities for the development of appropriate screening, treatment and control strategies to reduce Leishmania incidence rate. This study examined the present state of Leishmaniasis control, surveillance, and prevention in Sicily, but also highlighted deficiencies that could be addressed through the application of One-Health principles.

Cutaneous leishmaniosis due to Leishmania mexicana in a cat treated with cryotherapy.

We report the novel use of cryosurgery to treat cutaneous feline leishmaniosis (FeL) in a domestic cat from mid-western Venezuela. Amastigotes, evident by microscopy in aspirates from the nodular, erythematous nose lesions, were identified as Leishmania mexicana by cytochrome b gene sequence analysis. Lesions resolved completely without relapse after 14 months.

Nous décrivons une nouvelle utilisation de la cryochirurgie pour traiter la leishmaniose féline cutanée (FeL) chez un chat domestique du centre-ouest du Venezuela. Les amastigotes, observés par microscopie dans les cytoponctions des lésions nodulaires et érythémateuses du nez, ont été identifiés comme Leishmania mexicana par analyse de la séquence du gène du cytochrome b. Les lésions ont complètement disparu sans rechute après 14 mois.

Describimos el uso novedoso de la criocirugía para tratar la leishmaniosis cutánea felina (FeL) en un gato doméstico del medio oeste de Venezuela. Los amastigotes, evidentes por microscopía en los aspirados de las lesiones nasales nodulares eritematosas, se identificaron como Leishmania mexicana mediante el análisis de la secuencia del gen del citocromo b. Las lesiones se resolvieron completamente sin recidiva tras 14 meses.

Neste estudo, relatamos a utilização inédita de criocirurgia para tratar leishmaniose felina cutânea (FeL) em um gato doméstico no centro-oeste da Venezuela. Amastigotas, evidentes à microscopia de aspirados da lesão nodular e eritematosa na região nasal, foram identificadas como Leishmania Mexicana por sequenciamento do gene do citocromo b. As lesões se resolveram completamente sem recidiva após 14 meses.

Xenodiagnosis in four domestic cats naturally infected by Leishmania infantum.

Leishmaniasis is a neglected tropical disease that continues to pose a serious public health problem. Albeit dogs have long been held as the major reservoirs of Leishmania infantum, the involvement of domestic cats in the zoonotic cycle of visceral leishmaniasis has gained prominence. Here, 240 cats were evaluated by clinical signs and haematological/biochemical changes compatible with leishmaniasis and were diagnosed by serological, molecular, and parasitological techniques. Thus, four cats naturally infected by L. infantum were submitted to xenodiagnosis. A total of 203 females of Lutzomyia longipalpis were subjected to feeding on four cats, with all females completing the blood meal. Parasitological and molecular assays were carried out to evaluate the presence of L. infantum in the sand flies' midgut. Promastigotes were observed in 10 females (6.5%) that fed on one cat, and L. infantum DNA was detected in 17 (8.4%) females that fed on two cats. Our results strengthen the evidence that naturally infected cats are capable of transmitting L. infantum to sand flies.

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.

Computed tomographic features of destructive granulomatous rhinitis with intracranial extension secondary to leishmaniasis in a cat.

A 5-year-old castrated male Domestic Shorthair cat presented for evaluation of chronic history of nasal discharge and nasal stridor. On computed tomography (CT), a destructive ill-defined mass of soft tissue attenuation was occupying the right nasal cavity and extending into the left nasal cavity, nasopharynx, and rostral cranial cavity. Histopathology of the rhinoscopically excised samples consisted with destructive granulomatous rhinitis secondary to Leishmania spp. Chronic granulomatous rhinitis with intracranial and nasopharyneal extension secondary to Leishmania spp. infection should be included as a differential diagnosis for a destructive nasal mass of soft tissue attenuation, especially in endemic regions for leishmaniasis.

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.

Serological, molecular, and microscopic detection of Leishmania in cats (Felis catus) in Belo Horizonte, Minas Gerais State, Brazil / Detecção sorológica, molecular e microscópica de Leishmania em gatos (Felis catus) em Belo Horizonte, Minas Gerais, Brasil

Abstract 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.

Resumo O papel dos gatos no ciclo epidemiológico da leishmaniose ainda não está claro. Para entender melhor a ocorrência de leishmaniose em gatos, estudou-se a frequência de Leishmania em amostras de soro de 100 gatos, os quais vivem em uma região endêmica para leishmaniose canina e humana, por métodos sorológicos, parasitológicos e moleculares. Dos 100 gatos, 54 foram soropositivos para anticorpos de Leishmania por teste de anticorpos de imunofluorescência. Nenhum dos aspirados de medula óssea coletados desses gatos mostrou-se positivo para o parasita em cultura, ou após a realização da reação em cadeia da polimerase (PCR). Amostras de biópsia das orelhas também foram negativas para Leishmania submetidas a PCR. Esses achados indicam que na região estudada endêmica para leishmaniose canina, os gatos podem se infectar por Leishmania; ou que a reação cruzada com anticorpos contra outros parasitas aumenta a frequência de soropositividade; ou que os gatos respondem à infecção por Leishmania produzindo anticorpos quando poucos ou nenhum parasita estão presentes na medula óssea e em amostras de tecido. Em geral, os resultados sugerem que os gatos podem ser estar infectados por Leishmania spp. No entanto, não foi possível demonstrar parasitismo felino. Essas descobertas evidenciam a necessidade de estudar a leishmaniose em gatos, uma vez que, como os flebotomíneos se alimentam em gatos, e esses animais podem atuar como um reservatório para o parasita.

Molecular characterization of Leishmania infantum in domestic cats in a region of Brazil endemic for human and canine visceral leishmaniasis.

Leishmaniasis is a "neglected tropical disease" and serious public health issue in Brazil. While dogs are recognized as particularly important reservoirs, recent reports of domestic cats infected with Leishmania sp. in urban areas suggest their participation in the epidemiological chain of the parasite in endemic areas. The aim of this study was to screen domestic cats for Leishmania sp. infection in an area where human and canine visceral leishmaniasis are endemic, followed by the identification of the species circulating in cats. We collected peripheral blood, lymph-node aspirates and bone marrow from 100 adult animals, both male and female, and analyzed the samples using cytological and molecular (PCR) detection techniques. We detected Leishmania in 6% of animals, which were then analyzed by RFLP-PCR to identify the species. Leishmania infantum (synonym: L. chagasi), a species responsible for visceral leishmaniasis in humans and other animals, was identified from all six samples. Amastigotes were observed in the peripheral blood, bone marrow and lymph-node aspirates in 4 of the 6 PCR-positive animals. The presence of infected cats in endemic areas should not be neglected, because it demonstrates the potential role of these animals in the biological cycle of the pathogen.

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

Abstract 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.

Resumo O papel dos gatos no ciclo epidemiológico da leishmaniose ainda não está claro. Para entender melhor a ocorrência de leishmaniose em gatos, estudou-se a frequência de Leishmania em amostras de soro de 100 gatos, os quais vivem em uma região endêmica para leishmaniose canina e humana, por métodos sorológicos, parasitológicos e moleculares. Dos 100 gatos, 54 foram soropositivos para anticorpos de Leishmania por teste de anticorpos de imunofluorescência. Nenhum dos aspirados de medula óssea coletados desses gatos mostrou-se positivo para o parasita em cultura, ou após a realização da reação em cadeia da polimerase (PCR). Amostras de biópsia das orelhas também foram negativas para Leishmania submetidas a PCR. Esses achados indicam que na região estudada endêmica para leishmaniose canina, os gatos podem se infectar por Leishmania; ou que a reação cruzada com anticorpos contra outros parasitas aumenta a frequência de soropositividade; ou que os gatos respondem à infecção por Leishmania produzindo anticorpos quando poucos ou nenhum parasita estão presentes na medula óssea e em amostras de tecido. Em geral, os resultados sugerem que os gatos podem ser estar infectados por Leishmania spp. No entanto, não foi possível demonstrar parasitismo felino. Essas descobertas evidenciam a necessidade de estudar a leishmaniose em gatos, uma vez que, como os flebotomíneos se alimentam em gatos, e esses animais podem atuar como um reservatório para o parasita.