A Serological Survey of Feline Immunodeficiency Virus and Toxoplasma Gondii in Stray Cats

Veterinary Research Communications -     

Severe Neutropenia Associated With Griseofulvin Therapy in Cats With Feline Immunodeficiency Virus Infection

Griseofulvin administration was associated with the development of absolute neutropenia in six of seven (86%) cats with feline immunodeficiency virus (FIV) infection. The neutropenia was severe (less than 400 neutrophils/microliter) in four of the six affected cats, and one cat died from sepsis. Neutrophil counts returned to baseline values within 15 days after drug withdrawal in all surviving cats. No symptoms or hematologic abnormalities were observed in four normal (FIV-seronegative) cats treated with the same lot of griseofulvin at equivalent doses. Neutropenia recurred in two of two FIV-seropositive cats upon griseofulvin rechallenge. Cats with FIV infections appear to be at increased risk for griseofulvin-associated neutropenia. This phenomenon may be analogous to the increased frequency of antibiotic-induced neutropenias observed in humans infected with the human immunodeficiency virus.     

Prospective Hematologic and Clinicopathologic Study of Asymptomatic Cats With Naturally Acquired Feline Immunodeficiency Virus Infection

Prospective studies were performed over a 28- to 77-month period (median, 66 months) on 5 cats with naturally acquired feline immunodeficiency virus (FIV) infection in an attempt to correlate hematologic and Clinicopathologic changes with the emergence of clinical disease. On presentation, all cats were asymptomatic; free of opportunistic infections; and had normal complete blood counts, bone marrow morphologies, marrow progenitor frequencies, and progenitor in vitro growth characteristics. During study, 2 cats remained healthy, 2 cats showed mild clinical signs, and 1 cat developed a malignant neoplasm (ie, bronchiolar-alveolar adenocarcinoma). Although persistent hematologic abnormalities were not observed, intermittent peripheral leukopenias were common. In 3 of 5 FlV-seropositive cats, lymphopenia (< 1,500 lymphs/μL; normal reference range, 1,500 to 7,000 lymphs/μL) was a frequent finding and the absolute lymphocyte counts had a tendency to progressively decline. One of the other 2 cats had consistently low to low-normal absolute neutrophil counts (1,300 to 4,800 segs/μL; mean, 2,730 segs/μL; normal reference range, 2,500 to 12,500 segs/μL), and the remaining cat had consistently normal leukograms, except for a transient period (ie, 11 months) of benign lymphocytosis (7,200 to 13,430 lymphs/μL) early in the study. Periodic examinations of bone marrow aspirates revealed normal to slightly depressed myeloid-to-erythroid ratios with normal cellular morphology and maturation. Bone marrow abnormalities observed late in the study included mild dysmor-phic changes (ie, megaloblastic features) in 2 cats, and a significant decrease (60% of controls, P < .001) in the frequencies of burst-forming units erythroid (BFU-E) in marrow cultures of FIV-seropositive cats compared with uninfected control cats. Serum biochemical profiles were unremarkable throughout the study, with the exception of hyperglobulinemia (ie, polyclonal gammopathy) in 2 of 5 cats. Peripheral blood and bone marrow findings were of no apparent prognostic value. These results confirm the long latency between natural FIV infection and the development of life-threatening clinical disease. Chronic FIV infection, like infection with human immunodeficiency virus, can be associated with derangements in peripheral blood cell counts, as well as pertubations in marrow cell morphologies and hematopoietic progenitor frequencies before the terminal symptomatic stages of retroviral disease, when persistent cytopenias are prominent.     

Relationship of Lower Urinary Tract Signs to Seropositivity for Feline Immunodeficiency Virus in Cats

A group of 41 cats with signs of lower urinary tract disease was compared to a group of 41 cats without any history of disease for prevalence of seropositivity for feline immunodeficiency virus (FIV). The group of healthy cats was similar in age and gender to the group of cats with signs of lower urinary tract disease. Three of the cats with lower urinary tract disease and one control cat were seropositive for FIV.
This difference was not statistically significant. The most common cause of lower urinary tract signs was idiopathic. Only 7 cats had urinary tract infection, most associated with perineal urethrostomy or catheterization. Six of the cats with bacterial urinary tract infections were FIV negative. J Vet Intern Med 1996;10:34–38. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Role of Latent Feline Leukemia Virus Infection in Nonregenerative Cytopenias of Cats

Background: Nonregenerative cytopenias such as nonregenerative anemia, neutropenia, and thrombocytopenia in cats with feline leukemia virus (FeLV) antigen are assumed to be caused by the underlying FeLV infection. In addition, cats with negative FeLV antigen-test results that have cytopenias of unknown etiology often are suspected to suffer from latent FeLV infection that is responsible for the nonregenerative cytopenias.
Objective: The purpose of this study was to assess the role of latent FeLV infection by polymerase chain reaction (PCR) in bone marrow of cats with nonregenerative cytopenias that had negative FeLV antigen test results in blood.
Animals: Thirty-seven cats were included in the patient group. Inclusion criteria were (1) nonregenerative cytopenia of unknown origin and (2) negative FeLV antigen test result. Antigenemia was determined by detection of free FeLV p27 antigen by ELISA in serum. Furthermore, 7 cats with positive antigen test results with nonregenerative cytopenia were included as control group I, and 30 cats with negative antigen test results without nonregenerative cytopenia were included as control group II.
Methods: Whole blood and bone marrow samples were tested by 2 different PCR assays detecting sequences of the envelope or long terminal repeat genes. FeLV immunohistochemistry was performed in bone marrow samples.
Results: Two of the 37 cats (5.4%) in the patient group were positive on the bone marrow PCR results and thus were latently infected with FeLV.
Conclusions and Clinical Importance: The findings of this study suggest that FeLV latency is rare in cats with nonregenerative cytopenias.     

Hematology and Serum Biochemistry of Feline Immunodeficiency Virus-Infected and Feline Leukemia Virus-Infected Cats

Background: Hematological and biochemical values in cats naturally infected by feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV) are not completely documented. Objective: Report differences in laboratory values between FIV‐ or FeLV‐infected and noninfected and between FIV‐ and FeLV‐infected cats. Animals: Three thousand seven hundred and eighty client‐owned cats tested for FIV and FeLV. Methods: Retrospective study. Evaluation of clinicopathologic changes in cats with defined FIV and FeLV status and for which laboratory data were available. Results: FIV‐infected cats were more likely to be neutropenic (odds ratio [OR]=3.6, 95% confidence interval [95% CI] 2.1–6.2, P < .0001) and had lower serum activities of aspartate aminotransferase and glutamate dehydrogenase than control cats; serum total protein (8.1 ± 1.1 versus 7.6 ± 1.3 g/dL, P < .001) and γ‐globulin concentrations (2.2 ± 1.1 versus 1.7 ± 1.3 g/dL, P < .001) were higher than in uninfected cats. Compared with controls, FeLV‐infected cats had a higher risk of anemia (OR = 3.8, 95% CI 2.4–6.0, P < .0001), thrombocytopenia (OR = 5.0, 95% CI 3.0–8.4, P < .0001), neutropenia (OR = 3.6, 95% CI 2.1–6.1, P < .0001), lymphocytosis (OR = 2.8, 95% CI 1.6–4.8, P= .0002), and lower erythrocyte counts (6.13 ± 2.95 × 10³ versus 8.72 ± 2.18 × 10³/μL, P < .001), thrombocyte counts (253.591 ± 171.841 × 10³ versus 333.506 ± 156.033 × 10³/μL, P < .001), hematocrit (28.72 ± 12.86 versus 37.67 ± 8.90%, P < .001), hemoglobin and creatinine concentration. Conclusions and Clinical Importance: Hematologic abnormalities are common in FeLV‐infected but not in FIV‐infected cats. Clinicopathologic abnormalities are less frequent in FIV‐infected cats and might reflect an unspecific immunologic response.     

Concurrent Infection with Toxoplasma gondii and Feline Leukemia Virus: Antibody Response and Oocyst Production

Four adult cats (two testing positive and two negative for feline leukemia virus FeLV) were fed Toxoplasma gondii tissue cysts collected from the brains of mice. Two control cats (1 FeLV+, 1 FeLV-) were not fed cysts. The cats infected with T. gondii shed thousands of oocysts but remained clinically and physically normal, with hemograms and clinical chemistry values essentially unchanged irrespective of their FeLV status. Infection with FeLV did not increase the duration of oocyst shedding. At necropsy no significant lesions were found. T. gondii antibodies were detected by three serologic tests in the cats fed tissue cysts. The time necessary for an antibody response to T. gondii was not altered by the FeLV infection. Indirect hemagglutination (IHA) was the least reliable of the serologic tests studied; it detected antibodies later in the infection, and titers were less than in the other tests. Latex agglutination (LA) detected antibodies a few days before IHA, but titers were less than in modified direct agglutination (MAT). MAT detected antibodies earliest in the infection and also measured antibodies in aqueous humor and cerebrospinal fluid.     

Coinfection of Leishmania chagasi with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in cats from an endemic area of zoonotic visceral leishmaniasis

The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302 (9.93%), by serology in 46/302 (15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66 (18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66 (7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p<0.0001), but not with T. gondii (p>0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with FIV, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections.     

A Study of Toxoplasma Infection in Chickens and Cats on a Family Farm

Presumptive evidence of toxoplasmosis was obtained following histological and serological studies of tissues from chickens and cats kept on a family farm. This was confirmed by transmission of the infection to experimental laboratory animals and back to chickens. The significance of the low grade serological reaction in one of the persons living on the farm was not clear.     

Serological survey of Toxoplasma gondii, Dirofilaria immitis, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) infections in pet cats in Bangkok and vicinities, Thailand

The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand.     

GS-441524对自然感染的猫传染性腹膜炎的治疗效果观察

试验旨在观察GS-441524对自然感染的猫传染性腹膜炎（FIP）病例的临床疗效,为临床用药提供参考。试验招募了25只于中国农业大学动物医院确诊为FIP的患猫,随机分为高剂量组（5 mg/（kg·d））（12只）和低剂量组（2.5 mg/（kg·d））（13只）,每日皮下注射GS-441524治疗并记录体重、体温、注射药物的疼痛反应及每周的实验室及影像学检查结果以评价药物疗效。设定治疗周期为4周,部分病例根据实际情况延长治疗时间。结果显示,共计20只湿性FIP和3只干性FIP患猫完成试验,2只患猫退出。治疗时间为4~18周。20只湿性FIP患猫中,2只在1周内死亡,1只体腔积液增加,17只用药1周后积液减少,用药2~3周后积液消失。3只干性FIP患猫中,2只患猫的肠系膜淋巴结在用药1~2周后减小,1只无明显变化。所有患猫的精神和食欲在用药3~5 d内改善;体重在1~2周内开始增长;5只发烧的患猫用药2~3 d后体温恢复正常;14只贫血的患猫用药1~10周后恢复正常;16只患猫出现白细胞数量升高且淋巴细胞数量下降或中性粒细胞数量升高,用药1~2周内开始好转。所有患猫血清中白蛋白和球蛋白的比值（白球比）均<0.8,其中9只总蛋白升高,4只白蛋白降低,14只球蛋白升高,用药1~2周后开始好转。高剂量组的患猫4周药物有效率和治愈率分别为81.8%和60.0%,低剂量组的患猫4周药物有效率和治愈率分别为75.0%和22.2%。用药4周前后,高剂量组的患猫除白细胞总数（WBC）和白蛋白（ALB）外,其余指标均差异显著或极显著（P<0.05;P<0.01）;而低剂量组的患猫仅体重差异显著。除血红蛋白（HGB）、WBC和ALB外,药物对患猫的体重、红细胞（RBC）、红细胞压积（HCT）、淋巴细胞（LYM）、中性粒细胞（NEU）、总蛋白（TP）、球蛋白（GLOB）及白球比（A/G）改善情况差异显著（P<0.05）,且高剂量药物效果更佳。综上,GS-441524能有效治疗自然感染的FIP,高剂量（5 mg/（kg·d））疗效更佳,最短治疗周期为4周。     

氟化物对动物体液免疫功能影响研究进展

氟化物对免疫功能的影响,是近些年来氟研究的热点之一,但相关报道主要集中于细胞免疫功能的研究上,对于体液免疫功能的研究报道不多,仍处于感性认识阶段。论文主要对氟化物对体液免疫功能的影响及机制进行了论述。     

Comparison of Latex Agglutination, Indirect Hemagglutination, and ELISA Techniques for the Detection of Toxoplasma gondii-specific Antibodies in the Serum of Cats

The primary purpose of this study was to determine whether commercially available latex agglutination and indirect hemagglutination kits for the detection of Toxoplasma gondii-specific antibodies were capable of detecting T. gondii-specific immunoglobulin M (IgM) in the serum of cats. Serum samples from 35 cats containing either T. gondii-specific IgM, T. gondii-specific immunoglobulin G (IgG), or both were collected. Each serum sample was assayed using a latex agglutination kit, an indirect hemagglutination kit, an enzyme-linked immunosorbent assay (ELISA) for the detection of T. gondii-specific IgG, and an ELISA for the detection of T. gondii-specific IgM. When serum samples containing only T. gondii-specific IgM as determined by ELISA were assayed, the latex agglutination kit and the indirect hemagglutination kit detected antibodies in 33.3% and 13.3%, respectively. When T. gondii-specific IgG was present in a serum sample, the results from the latex agglutination kit, the indirect hemagglutination kit, and the IgG-ELISA were similar; however, there was a wide variation in titer magnitude results between the three assays. It was concluded that the latex agglutination kit and the indirect hemagglutination kit did not adequately detect T. gondii-specific IgM in feline serum.     

实验性感染H9亚型禽流感病毒对鸡的免疫机能及免疫器官的影响

以 H9亚型禽流感病毒 (AIV) Ck/YZ株人工感染罗曼蛋鸡 ,在其免疫器官中仅引起法氏囊部分淋巴滤泡髓质区内的淋巴细胞轻度减少 ,而胸腺、脾脏、哈氏腺、盲肠扁桃体均未出现病变。与对照组相比 ,感染组鸡的外周血淋巴细胞在白细胞中的分类计数未出现明显变化。实验性感染 AIV Ck/YZ株后 ,再进行新城疫 系苗免疫 ,可引起罗曼蛋鸡血清中抗 NDV的 HI抗体滴度轻度下降 ,但免疫后 18d用 NDV强毒攻击时 ,仍能完全保护。     

隐性弓形虫感染小鼠诱发急性弓形虫病模型的研究

为建立环磷酰胺诱导隐性弓形虫感染小鼠复发为急桂弓形虫病的模型,20只ICR小鼠腹腔注射弓形虫Prugniaud株包囊10个/只鼠,10只小鼠注射等量无菌PBS.2个月后给所有小鼠每天腹腔注射环磷酰胺100 mg/kg,连续注射14d.隔天监测小鼠体重、全血中白细胞数和弓形虫基因,同时取濒死小鼠肝、脾和肺组织,进行HE染色和免疫荧光检测.结果发现,感染小鼠注射环磷酰胺后第8天开始出现急性弓形虫病的症状;与试验前比较,小鼠体重和白细胞数明显下降;第10天时全血中再次发现弓形虫基因;第10天后濒死小鼠组织中检测到弓形虫基因,HE染色发现明显病理损伤,免疫荧光检测到弓形虫抗原.证明环磷酰胺可成功诱导隐性弓形虫感染小鼠复发为全身性的急性弓形虫病.     

Serologic and Urinary PCR Survey of Leptospirosis in Healthy Cats and in Cats with Kidney Disease

Background

Although there is serologic evidence of exposure of cats to Leptospira spp., clinical disease is rarely reported in cats.

Objective

To compare the seropositivity and urinary polymerase chain reaction (PCR) status for Leptospira spp. between healthy (H) cats and cats with kidney disease (KD), to investigate the serovars potentially involved, and to evaluate potential risk factors.

Animals

Two hundred and forty client‐owned cats.

Methods

Cats were prospectively recruited and classified based on physical examination, complete blood count, serum biochemistry profile, and urinalysis (125 H and 115 KD cats). Leptospira spp. serology (titers ≥1 : 100 considered positive) and urinary PCR were performed in all cats. Data assessing risk factors, obtained from a questionnaire, were evaluated using logistic regression models.

Results

Seropositivity for Leptospira spp. was statistically different between groups: 7.2% (9/125) and 14.9% (17/114) in the H and KD, respectively (P = .05). The proportion of PCR‐positive cats was not. The most common serovars detected serologically were Pomona (n = 16) and Bratislava (n = 8). Risk factors for seropositivity included outdoor and hunting lifestyles (P = .03 and P < .001, respectively), the presence of another cat in the household (P < .01), and the sampling period, with the greatest number of cases identified between June and August (P =.02).

Conclusions

Seropositivity was significantly greater in KD cats, suggesting that the role of Leptospira spp. in KD in cats should be further investigated. The detection of urinary shedding of leptospires in several cats identifies a potential role in the transmission of the organism.