Age-related cognitive impairments in domestic cats naturally infected with feline immunodeficiency virus.

BACKGROUND: Age-related dementia has been documented in domestic cats; however, its interaction with naturally occurring feline immunodeficiency virus (FIV) infection has been investigated minimally. METHODS: Visuospatial working memory (VSWM) and problem-solving (PS) ability were evaluated in FIV-infected (n = 37) and control cats (n = 39) using two cognitive tasks tested serially, which assessed the ability of cats to remember the location of a baited container after a set delay, then evaluated the capability of the cats to manipulate the container to obtain the food within a time limit. Cats were categorized using 7 years of age as a cut-off to determine age-related differences. The relationship between cognitive performance and FIV viral load was investigated using real-time PCR cycle threshold (Ct ) values. RESULTS: Age significantly affected VSWM and PS ability. Younger cats had better VSWM performance and PS ability compared to older cats with the same FIV status. There was no difference between younger FIV-positive and negative cats in either part of the task. While older FIV-positive cats had significantly worse VSWM than older FIV-negative cats, no differences were found in PS ability. Additionally, Ct values predicted VSWM but not PS ability. CONCLUSION: Age-related cognitive impairments and FIV infection appear synergetic, causing greater cognitive deficits in older FIV-infected cats.

Improved neurocognitive performance in FIV infected cats following treatment with the p75 neurotrophin receptor ligand LM11A-31.

HIV rapidly infects the central nervous system (CNS) and establishes a persistent viral reservoir within microglia, perivascular macrophages and astrocytes. Inefficient control of CNS viral replication by antiretroviral therapy results in chronic inflammation and progressive cognitive decline in up to 50% of infected individuals with no effective treatment options. Neurotrophin based therapies have excellent potential to stabilize and repair the nervous system. A novel non-peptide ligand, LM11A-31, that targets the p75 neurotrophin receptor (p75NTR) has been identified as a small bioavailable molecule capable of strong neuroprotection with minimal side effects. To evaluate the neuroprotective effects of LM11A-31 in a natural infection model, we treated cats chronically infected with feline immunodeficiency virus (FIV) with 13 mg/kg LM11A-31 twice daily over a period of 10 weeks and assessed effects on cognitive functions, open field behaviors, activity, sensory thresholds, plasma FIV, cerebrospinal fluid (CSF) FIV, peripheral blood mononuclear cell provirus, CD4 and CD8 cell counts and general physiology. Between 12 and 18 months post-inoculation, cats began to show signs of neural dysfunction in T maze testing and novel object recognition, which were prevented by LM11A-31 treatment. Anxiety-like behavior was reduced in the open field and no changes were seen in sensory thresholds. Systemic FIV titers were unaffected but treated cats exhibited a log drop in CSF FIV titers. No significant adverse effects were observed under all conditions. The data indicate that LM11A-31 is likely to be a potent adjunctive treatment for the control of neurodegeneration in HIV infected individuals.

The incidence of aggressive behavior in cats naturally infected with Feline Immunodeficiency Virus (FIV) and its interaction with FIV disease progression.

A study was undertaken to determine the possible interaction between aggressive behavior and Feline immunodeficiency virus (FIV) disease progression based on semi­quantitative viral load levels and health status in naturally FIV­infected cats. FIV status was determined in ninety­six owned and stray cats, using nested polymerase chain reaction (PCR). Aggressive tendencies were assessed based on observation and the cats' demeanor as determined by the owners and shelter caretakers. Results showed that forty­seven cats (49%) were PCR­positive for FIV infection and all aggressive cats were FIV­positive (100%). FIV infection was significantly linked to extreme aggressive tendencies and the extremely aggressive FIV­infected cats were more likely to have an unhealthy status compared to the non­aggressive individuals (p = 0.022). There was also a significant difference (p = 0.012) in the mean Cycle threshold (Ct) values between the aggressive and non­aggressive FIV­infected cats and also between the unhealthy FIV­infected cats with extreme aggressive tendencies and the healthy FIV­infected individuals without aggression (p = 0.001). Accordingly, results indicated that parameters associated with FIV disease progression are directly linked to aggression. The possible impact of FIV on the behavioral pattern of naturally infected cats should not be underestimated. However, there is an urgent need to conduct more experiments to support the assumptions about the possible exacerbation of aggression tendencies in naturally FIV­infected cats following the direct effect of FIV through the course of the infection.

Prevalence and risk factors for Felis catus gammaherpesvirus 1 detection in domestic cats in Italy.

Felis catus gammaherpesvirus 1 (FcaGHV1), a novel gammaherpesvirus of domestic cats identified in 2014, has been detected in different countries demonstrating a worldwide distribution. The aim of this study was to establish the prevalence of FcaGHV1 in Italy using a molecular epidemiological approach. FcaGHV1 DNA was detected with virus-specific real-time PCR in ≃1% of 2659 feline blood samples tested. Analysis of risk factors showed that being male and coinfection with feline immunodeficiency virus (FIV) increase the likelihood of FcaGHV1 detection. One-third of FcaGHV1-positive cats also tested positive for FIV provirus, whereas coinfections with feline panleukopenia virus were not demonstrated. Further studies are necessary to confirm the risk factors for FcaGHV1 detection and the pathobiology of the virus.

Effects of Regulatory T Cell Depletion on NK Cell Responses against Listeria monocytogenes in Feline Immunodeficiency Virus Infected Cats.

Regulatory T cells (Treg) are key players in the maintenance of peripheral tolerance, preventing autoimmune diseases and restraining chronic inflammatory diseases. Evidence suggests Treg cells and NK cells have important roles in feline immunodeficiency virus (FIV) pathogenesis; however, in vivo studies investigating the interplay between these two cell populations are lacking. We previously described innate immune defects in FIV-infected cats characterized by cytokine deficits and impaired natural killer cell (NK) and NK T cell (NKT) functions. In this study, we investigated whether in vivo Treg depletion by treatment with an anti-feline CD25 monoclonal antibody would improve the innate immune response against subcutaneous challenge with Listeria monocytogenes (Lm). Treg depletion resulted in an increased overall number of cells in Lm-draining lymph nodes and increased proliferation of NK and NKT cells in FIV-infected cats. Treg depletion did not normalize expression of perforin or granzyme A by NK and NKT cells, nor did Treg depletion result in improved clearance of Lm. Thus, despite the quantitative improvements in the NK and NKT cell responses to Lm, there was no functional improvement in the early control of Lm. CD1a+ dendritic cell percentages in the lymph nodes of FIV-infected cats were lower than in specific-pathogen-free control cats and failed to upregulate CD80 even when Treg were depleted. Taken together, Treg depletion failed to improve the innate immune response of FIV-infected cats against Lm and this may be due to dendritic cell dysfunction.

Multiple, Independent T Cell Lymphomas Arising in an Experimentally FIV-Infected Cat during the Terminal Stage of Infection.

Our laboratory has serially reported on the virologic and immunopathologic features of a cohort of experimental feline immunodeficiency virus (FIV)-infected cats for more than eight years. At 8.09 years post infection (PI), one of these animals entered the terminal stage of infection, characterized by undulating hyperthermia, progressive anorexia, weight loss, and pancytopenia; the animal was not responsive to therapeutic interventions, necessitating euthanasia six weeks later (8.20 years PI). Subsequent analyses indicated that neoplastic lymphocytes infiltrated multiple cervical lymph nodes and a band-like region of the mucosal lamina propria within a segment of the intestine. Immunohistochemistry and T cell clonality testing determined that the nodal and intestinal lesions were independently arising from CD3 T cell lymphomas. In-situ RNA hybridization studies indicated that diffuse neoplastic lymphocytes from the cervical lymph node contained abundant viral nucleic acid, while viral nucleic acid was not detectable in lymphocytes from the intestinal lymphoma lesion. The proviral long terminal repeat (LTR) was amplified and sequenced from multiple anatomic sites, and a common clone containing a single nucleotide polymorphism was determined to be defective in response to phorbol myristate acetate (PMA)-mediated promoter activation in a reporter gene assay. This assay revealed a previously unidentified PMA response element within the FIV U3 region 3' to the TATA box. The possible implications of these results on FIV-lymphoma pathogenesis are discussed.

Concomitant feline immunodeficiency virus (FIV) and Mycoplasma haemofelis in a barn cat.

A 5-year-old male barn cat was presented with lethargy and excessive bleeding following castration. The patient developed hemolytic anemia and diagnostic tests revealed infection with feline immunodeficiency virus and Mycoplasma haemofelis. This case serves as a reminder of the importance of testing for infectious diseases and educating owners on feline infectious disease prevention and management.

Présence concomitante du virus de l'immunodéficience féline (FIV) et de Mycoplasma hæmofelis chez un chat de grange. Un chat de grange mâle âgé de 5 ans a été présenté avec de l'abattement et des saignements excessifs après la castration. Le patient a développé de l'anémie hémolytique et le diagnostic a révélé l'infection par le virus de l'immunodéficience féline et Mycoplasma hæmofelis. Ce cas peut servir de rappel de l'importance du dépistage de la présence de maladies infectieuses et de l'éducation des propriétaires sur la prévention et la gestion des maladies infectieuses félines.(Traduit par Isabelle Vallières).

Preventable adverse drug events in critically ill HIV patients: Is the detection of potential drug-drug interactions a useful tool?

OBJECTIVES: The aim of this study was to develop a strategy to identify adverse drug events associated with drug-drug interactions by analyzing the prescriptions of critically ill patients. METHODS: This retrospective study included HIV/AIDS patients who were admitted to an intensive care unit between November 2006 and September 2008. Data were collected in two stages. In the first stage, three prescriptions administered throughout the entire duration of these patients' hospitalization were reviewed, with the Micromedex database used to search for potential drug-drug interactions. In the second stage, a search for adverse drug events in all available medical, nursing and laboratory records was performed. The probability that a drug-drug interaction caused each adverse drug events was assessed using the Naranjo algorithm. RESULTS: A total of 186 drug prescriptions of 62 HIV/AIDS patients were analyzed. There were 331 potential drug-drug interactions, and 9% of these potential interactions resulted in adverse drug events in 16 patients; these adverse drug events included treatment failure (16.7%) and adverse reactions (83.3%). Most of the adverse drug reactions were classified as possible based on the Naranjo algorithm. CONCLUSIONS: The approach used in this study allowed for the detection of adverse drug events related to 9% of the potential drug-drug interactions that were identified; these adverse drug events affected 26% of the study population. With the monitoring of adverse drug events based on prescriptions, a combination of the evaluation of potential drug-drug interactions by clinical pharmacy services and the monitoring of critically ill patients is an effective strategy that can be used as a complementary tool for safety assessments and the prevention of adverse drug events.

Systolic blood pressure, routine kidney variables and renal ultrasonographic findings in cats naturally infected with feline immunodeficiency virus.

Objectives Hypertension is a common cause of proteinuria in HIV-infected people. In cats, feline immunodeficiency virus (FIV) infection appears to be associated with proteinuria. Therefore, the results from systolic blood pressure (SBP) measurements in naturally infected FIV-positive cats were reviewed to assess whether hypertension contributes to the observed proteinuria in these cats. Ultrasonographic findings in FIV-positive cats were reviewed to complete renal assessment and to extend the scant knowledge on renal ultrasonography in cats. Methods Data from client-owned, naturally infected FIV-positive cats were retrospectively reviewed. To obtain a control group, records were reviewed from age-matched, privately owned, FIV-negative cats. Results Data from 91 FIV-infected and 113 control cats were compared. FIV-infected cats showed a significantly lower SBP ( P <0.0001) and significantly fewer FIV-infected cats were hypertensive (⩾160 mmHg) compared with control cats ( P = 0.025). The prevalence of renal azotaemia did not significantly differ between groups, although FIV-infected cats had significantly lower urine specific gravity (USG) ( P = 0.0273) and a higher incidence of USG below 1.035 ( P = 0.043). Urinary protein:creatinine ratio (UPC) was significantly higher in FIV-infected cats ( P = 0.0005) and proteinuria (UPC >0.4) occurred more frequently in FIV-infected cats ( P <0.001). Renal ultrasonography showed abnormalities in 60/91 FIV-infected cats, with hyperechogenic cortices in 39/91 and enlarged kidneys in 31/91. Conclusions and relevance Hypertension can be excluded as a common cause of renal damage leading to proteinuria in FIV-infected cats. Proteinuria and poorly concentrated urine are common in naturally infected FIV-positive cats, in contrast to azotaemia. Clinicians should cautiously interpret ultrasonographic abnormalities as these occur in over half of FIV-infected cats.

Overweight and abdominal obesity in adults living with HIV/AIDS / Excesso de peso e obesidade abdominal em adultos vivendo com HIV/aids

Summary Objective: To investigate the prevalence of overweight, abdominal obesity and associated factors in people living with HIV/AIDS (PLWHA). Method: Cross-sectional study with 270 PLWHA. A questionnaire was applied to investigate sociodemographic, clinical and lifestyle characteristics. Weight, height and waist circumference were measured. BMI ≥25 kg/m2 was considered overweight, while abdominal obesity referred to waist circumference ≥102 cm for men and ≥88 cm for women. The authors used multiple Poisson regression with 5% significance level. Results: The prevalence of overweight and abdominal obesity was 33.7% and 12.6%, respectively, referring to 37.9% of women and 5.7% of men (p<0.001). Overweight was associated with age of 40-49 years and ≥50 years, non-use of ARV therapy, and lower tertile of consumption of risk foods. Abdominal obesity was associated with: female gender, age of 40-49 years and ≥50 years, income greater than four times the minimum wage, and CD4+ lymphocyte count >350 cells/mm3. Conclusion: There was a high prevalence of overweight and abdominal obesity associated with sociodemographic and clinical conditions, and consumption of risk foods. This scenario indicates the need for reorientation of the health care focus in this population.

Resumo Objetivo: investigar em pessoas vivendo com HIV/aids (PVHA) a prevalência de excesso de peso, obesidade abdominal e fatores associados. Método: estudo transversal com 270 PVHA. Aplicou-se questionário para investigar características sociodemográficas, clínicas e estilo de vida. Coletaram-se peso, altura e circunferência de cintura. Consideraram-se excesso de peso o IMC ≥25 kg/m2 e obesidade abdominal a circunferência de cintura ≥102 cm para homens e ≥88 cm para mulheres. Utilizou-se regressão de Poisson múltipla com nível de significância de 5%. Resultados: a prevalência de excesso de peso foi de 33,7% e de obesidade abdominal foi de 12,6%, sendo 37,9% nas mulheres e 5,7% nos homens (p<0,001). Excesso de peso foi associado com idade de 40 a 49 anos e ≥50 anos, não uso de terapia antirretroviral (TARV) e menor tercil de consumo de alimentos de risco. Obesidade abdominal se associou com sexo feminino, idade de 40 a 49 anos e ≥50 anos, renda própria maior que quatros salários mínimos e contagem de linfócitos T CD4+ >350 células/mm3. Conclusão: constatou-se elevada prevalência de excesso de peso e obesidade abdominal, associados a condições sociodemográficas, clínicas e consumo de alimentos de risco. Esse panorama sinaliza a necessidade de reorientação do foco de atenção à saúde dessa população.

Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

Prevalence and risk factors of gammaherpesvirus infection in domestic cats in Central Europe.

BACKGROUND: Gammaherpesviruses (GHVs) are a large group of dsDNA viruses that can infect humans and several animal species. The two human GHVs, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus are known for their oncogenic properties in individuals with immunodeficiency. Recently, the first feline GHV, Felis catus gammaherpesvirus 1 (FcaGHV1) was discovered and frequently found in domestic cats in Australia, Singapore and the USA. FcaGHV1 is more likely to be detected in cats co-infected with the feline immunodeficiency virus (FIV). FINDINGS: The prevalence of FcaGHV1 in pet cats from Germany and Austria was 16.2 % (95 % CI = 12.38-20.02). The odds for GHV infection were greater for FIV positive (OR = 4.5), male (OR = 13.32) and older (OR = 2.36) cats. Furthermore, FcaGHV1 viral loads were significantly higher in FIV-infected cats compared to matched controls. CONCLUSIONS: GHV infections are common in domestic cats in Central Europe. The worldwide distribution of FcaGHV1 can be assumed. A potential role as a co-factor in FIV-induced pathogeneses is supported.

South African report of first case of chromoblastomycosis caused by Cladosporium (syn Cladophialophora) carrionii infection in a cat with feline immunodeficiency virus and lymphosarcoma.

This report describes a 6-year-old neutered male feline immunodeficiency-positive cat with repeated abdominal and thoracic effusions. The cat was diagnosed with and treated for lymphosarcoma but remission was short-lived and, on re-evaluation, a fungal peritoneal exudate was noted. Cytology of the organisms is described and the culture elucidated Cladosporium carrionii, an important cause of chromoblastomycosis. Treatment with itraconazole was unsuccessful in this case.

Diversity of trends of viremia and T-cell markers in experimental acute feline immunodeficiency virus infection.

OBJECTIVE: The early events of human immunodeficiency virus infection seem critical for progression toward disease and antiretroviral therapy initiation. We wanted to clarify some still unknown prognostic relationships between inoculum size and changes in various immunological and virological markers. Feline immunodeficiency virus infection could be a helpful model. METHODS: Viremia and T-cell markers (number of CD4, CD8, CD8ß(low)CD62L(neg) T-cells, CD4/CD8 ratio, and percentage of CD8ß(low)CD62L(neg) cells among CD8 T-cells) were measured over 12 weeks in 102 cats infected with different feline immunodeficiency virus strains and doses. Viremia and T-cell markers trajectory groups were determined and the dose-response relationships between inoculum titres and trajectory groups investigated. RESULTS: Cats given the same inoculum showed different patterns of changes in viremia and T-cell markers. A statistically significant positive dose-response relationship was observed between inoculum titre and i) viremia trajectory-groups (r = 0.80, p<0.01), ii) CD8ß(low)CD62L(neg) cell-fraction trajectory-groups (r = 0.56, p<0.01). Significant correlations were also found between viremia and the CD4/CD8 ratio and between seven out of ten T-cell markers. CONCLUSIONS: In cats, the infectious dose determines early kinetics of viremia and initial CD8+ T-cell activation. An expansion of the CD8ß(low)CD62L(neg) T-cells might be an early predictor of progression toward disease. The same might be expected in humans but needs confirmation.

Relevance of feline interferon omega for clinical improvement and reduction of concurrent viral excretion in retrovirus infected cats from a rescue shelter.

Feline Immnunodeficiency (FIV) and Feline Leukemia (FeLV) viruses are common infectious agents in stray cats and shelter environments. Recombinant feline interferon-ω (rFeIFNω) has shown an antiviral action not only against FIV and FeLV but also against herpesvirus (FHV-1) and calicivirus (FCV). Sixteen naturally infected FIV/FeLV cats were followed during rFeIFNω therapy in order to monitor clinical signs and to correlate with excretion of concomitant viruses (FCV, FHV-1, feline coronavirus (FCoV) and parvovirus (FPV)). Cats were submitted to clinical evaluations and concomitant virus excretion assessement. Comparing D0-D65, 10/16 cats improved clinical scores. Of the 10 cats positive for FHV-1 on D0, 4 were negative and 6 reduced viral loads. Of the 11 FCoV positive cats, 9 reduced viral loads. The 13 FCV positive cats and the FPV positive cat were negative on D65. In conclusion, rFeIFNω improves clinical signs and reduces concurrent viral excretion in naturally infected retroviral cats.

Renal disease in cats infected with feline immunodeficiency virus.

BACKGROUND: Feline immunodeficiency virus (FIV) and human immunodeficiency virus (HIV) infection cause similar clinical syndromes of immune dysregulation, opportunistic infections, inflammatory diseases, and neoplasia. Renal disease is the 4th most common cause of death associated with HIV infection. OBJECTIVE: To investigate the association between FIV infection and renal disease in cats. ANIMALS: Client-owned cats (153 FIV-infected, 306 FIV-noninfected) and specific-pathogen-free (SPF) research colony cats (95 FIV-infected, 98 FIV-noninfected). METHODS: A mixed retrospective/prospective cross-sectional study. Blood urea nitrogen (BUN), serum creatinine, urine specific gravity (USG), and urine protein:creatinine ratio (UPC) data were compared between FIV-infected and FIV-noninfected cats. In FIV-infected cats, total CD4+ and CD8+ T lymphocytes were measured using flow cytometry, and CD4+:CD8+ T lymphocyte ratio was calculated. Renal azotemia was defined as a serum creatinine ≥ 1.9 mg/dL with USG ≤ 1.035. Proteinuria was defined as a UPC > 0.4 with an inactive urine sediment. RESULTS: Among the client-owned cats, no association was detected between FIV infection and renal azotemia (P = .24); however, a greater proportion of FIV-infected cats were proteinuric (25.0%, 16 of 64 cats) compared to FIV-noninfected cats (10.3%, 20 of 195 cats) (P < .01). Neither neuter status nor health status were risk factors for proteinuria in FIV-infected cats, but UPC was positively correlated with the CD4+:CD8+ T lymphocyte ratio (Spearman's rho = 0.37, P = .01). Among the SPF research colony cats, no association was detected between FIV infection and renal azotemia (P = .21) or proteinuria (P = .25). CONCLUSIONS AND CLINICAL IMPORTANCE: Proteinuria but not azotemia was associated with natural FIV infection.

Early detection of neuropathophysiology using diffusion-weighted magnetic resonance imaging in asymptomatic cats with feline immunodeficiency viral infection.

HIV infection results in a highly prevalent syndrome of cognitive and motor disorders designated as HIV-associated dementia (HAD). Neurologic dysfunction resembling HAD has been documented in cats infected with strain PPR of the feline immunodeficiency virus (FIV), whereas another highly pathogenic strain (C36) has not been known to cause neurologic signs. Animals experimentally infected with equivalent doses of FIV-C36 or FIV-PPR, and uninfected controls were evaluated by magnetic resonance diffusion-weighted imaging (DW-MRI) and spectroscopy (MRS) at 17.5-18 weeks post-infection, as part of a study of viral clade pathogenesis in FIV-infected cats. The goals of the MR imaging portion of the project were to determine whether this methodology was capable of detecting early neuropathophysiology in the absence of outward manifestation of neurological signs and to compare the MR imaging results for the two viral strains expected to have differing degrees of neurologic effects. We hypothesized that there would be increased diffusion, evidenced by the apparent diffusion coefficient as measured by DW-MRI, and altered metabolite ratios measured by MRS, in the brains of FIV-PPR-infected cats relative to C36-infected cats and uninfected controls. Increased apparent diffusion coefficients were seen in the white matter, gray matter, and basal ganglia of both the PPR and C36-infected (asymptomatic) cats. Thalamic MRS metabolite ratios did not differ between groups. The equivalently increased diffusion by DW-MRI suggests similar indirect neurotoxicity mechanisms for the two viral genotypes. DW-MRI is a sensitive tool to detect neuropathophysiological changes in vivo that could be useful during longitudinal studies of FIV.

Seroprevalence of Toxoplasma gondii and concurrent Bartonella spp., feline immunodeficiency virus, feline leukemia virus, and Dirofilaria immitis infections in Egyptian cats.

Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLv) are related to human immunodeficiency virus and human leukemia virus, respectively, and these viruses are immunosuppressive. In the present study, the prevalence of antibodies to T. gondii , Bartonella spp., FIV, as well as FeLv and Dirofilaria immitis antigens was determined in sera from feral cats (Felis catus) from Cairo, Egypt. Using a modified agglutination test, antibodies to T. gondii were found in 172 (95.5%) of the 180 cats with titers of 1∶5 in 9, 1∶10 in 9, 1∶20 in 3, 1∶40 in 5, 1∶80 in 5, 1∶160 in 15, 1∶320 in 22, and 1∶640 or higher in 104. Thus, 57.4% had high T. gondii titers. Antibodies to Bartonella spp. were found in 105 (59.6%) of 178, with titers of 1∶64 in 45, 1∶128 in 39, 1∶256 in 13, 1∶512 in 3, 1∶1,024 in 4, and 1∶2,048 in 1 cat. Antibodies to FIV were detected in 59 (33.9%) of 174 cats. Of 174 cats tested, antigens to FeLv, and D. immitis were detected in 8 (4.6%) and 6 (3.4%) cats, respectively. The results indicate a high prevalence of T. gondii, Bartonella spp., and FIV infections in cats from Cairo, Egypt. This is the first report of Bartonella spp., and D. immitis infection in cats in Egypt.