Serological survey of Neospora caninum and Toxoplasma gondii in shelter-housed cats infected with feline immunodeficiency virus, Brazil / Inquérito sorológico para Neospora caninum e Toxoplasma gondii em um abrigo de gatos infectados com o vírus da imunodeficiência felina, Brasil

Felines play a leading role in the epidemiology of Toxoplasma gondii infection, but there is scarce information about the epidemiology of Neospora caninum, particularly in feline immunodeficiency virus (FIV)-infected cats. Cats seropositive to T. gondii do not usually show symptoms unless they are immunosuppressed, such as FIV-infected cats. The same relationship remains poorly known for N. caninum, although it has been associated with neurological disorders in HIV-infected people. Since FIV-infected cats are prone to develop encephalitis of unknown etiology, this study aimed to evaluate the presence of specific antibodies to T. gondii and N. caninum in a shelter for stray cats naturally infected with FIV. A total of 104 serum samples from cats living in a shelter, located in São Paulo city (Brazil), was assessed for T. gondii and N. caninum specific antibody by indirect fluorescent-antibody test (IFAT). Of the 104 cats, 25 (24%) were infected with FIV and, aside from these, 8 (32%) had antibodies against T. gondii (titers from 16 to 128). Only 1 (4%) of the FIV-infected cats had antibodies against N. caninum, which was the first record of coinfection. Among the FIV-naïve cats, 11 (14%) were positive for T. gondii(titers from 16 to 256) and only 1 (1.2%) had antibodies against N. caninum. Serologically positive reactions to T. gondii and N. caninum were not correlated with age or sex (p>0.05), and there was no correlation between FIV and the occurrence of anti-T. gondii or anti-N. caninum antibodies (p>0.05). Further studies encompassing larger cat populations from different origins and locations are essential to clarify the prevalence of T. gondii and N. caninum antibodies in FIV-positive cats.(AU)

Os felinos têm um papel importante na epidemiologia da infecção por Toxoplasma gondii, mas pouco se sabe sobre a epidemiologia da infecção por Neospora caninum em gatos, particularmente em gatos infectados com o vírus da imunodeficiência felina (FIV). Gatos soropositivos para Toxoplasma gondii geralmente não apresentam sintomas a não ser que estejam imunossuprimidos, como gatos infectados com FIV. A mesma relação ainda é pouco conhecida para N. caninum, embora tenha sido associada a distúrbios neurológicos em pessoas infectadas pelo HIV. Considerando que gatos infectados com FIV são propensos a desenvolver encefalite de etiologia desconhecida, o presente estudo teve como objetivo avaliar a presença de anticorpos específicos para T. gondii e N. caninum em gatos infectados com FIV. Um total de 104 amostras de soro de gatos residentes em um abrigo na cidade de São Paulo, Brasil, foram avaliadas para a presença de anticorpos contra T. gondii e N. caninum pelo teste de imunofluorescência indireta (RIFI). Dos 104 gatos, 25 (24%) estavam infectados com FIV e destes 8, (32%) tinham anticorpos contra T. gondii (titulação entre 16 e 128). Apenas 1 (4%) dos gatos infectados com FIV apresentava anticorpos contra N. caninum, sendo este o primeiro registro dessa coinfecção. Entre os gatos não infectados com FIV, 11 (14%) foram positivos para T. gondii (titulação entre 16 e 256) e apenas 1 (1,2%) tinha anticorpos contra N. caninum. A reação sorologicamente positiva para T. gondii e N. caninum não foi correlacionada com a idade ou sexo (p> 0,05), nem houve correlação entre FIV e ocorrência de anticorpos para T. gondii ou N. caninum(p> 0,05). Estudos subsequentes abrangendo populações maiores de gatos de diferentes origens e locais são essenciais para esclarecer a prevalência de anticorpos contra T. gondii e N. caninum em animais acometidos por FIV.(AU)

Clinical features, fungal load, coinfections, histological skin changes, and itraconazole treatment response of cats with sporotrichosis caused by Sporothrix brasiliensis.

Zoonotic sporotrichosis caused by the fungus Sporothrix brasiliensis is usually severe in cats. This study investigated the associations between clinical features, fungal load, coinfections, histological skin changes, and response to itraconazole in cats with sporotrichosis caused by S. brasiliensis. Fifty-two cats with skin lesions and a definitive diagnosis of sporotrichosis were treated with itraconazole for a maximum period of 36 weeks. The animals were submitted to clinical examination and two subsequent collections of samples from the same skin lesion for fungal diagnosis and histopathology, as well as serology for feline immunodeficiency (FIV) and leukaemia (FeLV) viruses. Thirty-seven (71%) cats were clinically cured. Nasal mucosa lesions and respiratory signs were associated with treatment failure. Cats coinfected with FIV/FeLV (n = 12) had a lower neutrophil count in the lesion. A high fungal load in skin lesions was linked to young age and treatment failure, as well as to a longer time of wound healing, poorly formed granulomas and fewer neutrophils, macrophages and lymphocytes in these lesions. These results indicate that itraconazole is effective, but nasal mucosal involvement, respiratory signs and high fungal loads in skin lesions are predictors of treatment failure that will assist in the development of better treatment protocols for cats.

Feline immunodeficiency virus in South America.

The rapid emergence of AIDS in humans during the period between 1980 and 2000 has led to extensive efforts to understand more fully similar etiologic agents of chronic and progressive acquired immunodeficiency disease in several mammalian species. Lentiviruses that have gene sequence homology with human immunodeficiency virus (HIV) have been found in different species (including sheep, goats, horses, cattle, cats, and several Old World monkey species). Lentiviruses, comprising a genus of the Retroviridae family, cause persistent infection that can lead to varying degrees of morbidity and mortality depending on the virus and the host species involved. Feline immunodeficiency virus (FIV) causes an immune system disease in domestic cats (Felis catus) involving depletion of the CD4+ population of T lymphocytes, increased susceptibility to opportunistic infections, and sometimes death. Viruses related to domestic cat FIV occur also in a variety of nondomestic felids. This is a brief overview of the current state of knowledge of this large and ancient group of viruses (FIVs) in South America.

Immune-endocrine interactions in treated and untreated cats naturally infected with FIV.

Feline immunodeficiency virus (FIV) is a lentivirus that causes a progressive disruption of immune function in cats. The neuroendocrine and immune systems communicate bidirectionally, mediated by cytokines such as tumour necrosis factor-α (TNF), several interleukins (IL-1, IL-6, IL-10), and through signals induced by the ratio of IL-10 to IL-12. FIV can affect both pituitary adrenal and thyroid axis function. Twenty FIV-infected cats in similar stages of the disease were evaluated for six months. A cross-sectional study in which the twenty cats were divided into two groups was performed. Ten were treated with Zidovudine (ZDV: 5mg/kg/d, PO, q12h, for six months) and 10 were untreated. Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, T4, FT4, T3, IL-10, IL-12 and viral load (VL) were evaluated after six months. ACTH was found in significantly lower concentrations (p<0.0001) in the treated group whereas cortisol did not show significant differences between the two groups. Both T4 and FT4 had high values in untreated individuals (p<0.001) compared with Zidovudine treated cats. T3 did not show significant differences between the two groups. Both IL-10 and IL-12 were found in significantly higher concentrations in ZDV treated cats (p<0.001). By contrast, the IL10/IL-12 ratio values were significantly lower in untreated cats. Viral load was significantly lower in the treated cats after six months of therapy, compared with values detected pre-treatment (p<0.002). Untreated cats showed a significant increase of VL (p<0.04) compared with the values at the beginning of the study. In treated cats, VL showed lower numbers of viral copies than in untreated cats (p<0.01). In summary, Zidovudine treatment appeared to contribute to the normalization of both the adrenal and thyroid axes. This effect could be attributed to the decrease observed in VL, resulting in a change in cytokine patterns.

Cutaneous mycoflora and CD4:CD8 ratio of cats infected with feline immunodeficiency virus.

This study was designed to compare cutaneous mycoflora isolation and CD4+:CD8+ ratio in feline immunodeficiency virus (FIV)-infected cats with that in FIV-uninfected cats. Sixty cats were examined. Twenty-five were FIV-infected cats and 35 were FIV-uninfected cats. All 60 cats were FeLV-negative. Fungi were speciated and immunophenotyping of peripheral CD4+ and CD8+ T lymphocytes was performed. At least one fungal colony was isolated from 22/25 (88%) FIV-infected cats. Among the FIV-uninfected cats fungal colonies were recovered from 13/35 (37%) specimens. Dermatophytes were recovered from 2/25 (8%) FIV-infected cats (one Microsporum gypseum, one Microsporum canis) and 3/35 (8.5%) FIV-uninfected cats (M gypseum). Malassezia species was the most commonly isolated organism from both groups of cats (51.6%). Malassezia species was more commonly isolated from FIV-infected cats than FIV-uninfected cats (84% vs 28.6%). The CD4+ to CD8+ lymphocyte ratio for FIV-infected cats was significantly lower than the CD4+ to CD8+ ratio in the FIV-uninfected cats. The CD4+ to CD8+ lymphocyte ratio for FIV-infected cats with cutaneous overall fungal isolation was significantly lower than the CD4:CD8 lymphocyte ratio in the FIV-infected cats but without cutaneous fungal isolation. We can conclude that immunologic depletion due to retroviral infection might represent a risk factor to cutaneous fungal colonization in cats.

Feline immunodeficiency virus: a concise review.

Among non-primate vertebrates, feline immunodeficiency virus (FIV) infection in the cat may be the closest model of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). Clinical evolution and immunological and virological relationships between human HIV/AIDS and disease produced by FIV infection in cats are very close. These similarities should facilitate progress in the understanding of mechanisms of viral infection and immunopathology, and make this model potentially very valuable in evaluation of experimental therapeutic approaches to AIDS in man. Development of feline immunodeficiency virus vectors bearing therapeutic genes targeting different human diseases is a promising strategy for gene therapy, despite some recent studies which suggest that despite lack of evidence of infection of man by FIV, additional epidemiological surveillance may be indicated to determine if transmission can occur from this close companion to humans in some circumstances.