Update on the diagnosis and management of Toxoplasma gondii infection in cats

Seropositivity for Toxoplasma gondii in cats with clinical signs and living in households with women of childbearing age

Toxoplasmosis caused by Toxoplasma gondii is a protozoal zoonosis with high sanitary risk for pregnant women and immunocompromised people. Felids, including domestic cats, are the only definitive hosts of T. gondii. They shed oocysts which, in the environment, become infectious for a wide range of animals, including humans, acting as intermediate hosts. This study evaluated the frequency of acute toxoplasmosis in domestic cats with compatible clinical signs and living in households with women of childbearing age. Individual serum samples were collected from 150 cats and analyzed for IgM and IgG against T. gondii. Statistical analyses were performed to evaluate associations between seropositivity and potential risk factors. Overall, 31 cats (20.7 %) were seropositive for anti-T. gondii antibodies, i.e. 9 (6.0 %) for IgM, 17 (11.3 %) for IgG and 5 (3.3 %) for both. The cats showed different combinations of clinical pictures. The following statistically significant associations were found: male sex and positivity for IgM and/or IgG (p=0.0248; OR= 0.3537; 95 % CI= 0.1528-0.8675), presence of 2 or more clinical signs and positivity to IgM only (p=0.0003; OR= +infinity; 95 % CI= 3.924 to +infinity), presence of either neurological signs (p=0.0025; OR= 13.30; 95 % CI= 3.409-61.39) or ocular signs (p=0.0228; OR= 5.835; 95 % CI= 1.631-22.37) and positivity to IgM only, presence of gastrointestinal signs and positivity to IgG only (p=0.0083; OR= 5.508; 95 % CI= 1.503-18.54). Male sex also resulted a possible risk factor in the binomial logistic regression (p= 0.011; OR= 3.336; 95 % CI= 1.131-8.44). These results indicate that cats living with women of childbearing age are at risk of infection with T. gondii. The presence of certain clinical signs can be helpful in identifying recent and/or current infections using laboratory analyses. Awareness on toxoplasmosis should be kept high to protect animal and public health.

Prevalence of Toxoplasma gondii IgM and IgG positive cats in Los Angeles County, California

Objectives

The objective of this study was to determine the prevalence of Toxoplasma gondii IgM and IgG positive cats in Los Angeles County, California. T gondii antibodies are common in sera from cats in most reported studies around the world. Although the majority of infected cats never develop clinical disease, development of acute infection and recrudescence of latent infection secondary to immunosuppression has been reported. Knowledge of the serologic status of T gondii may be important when considering immunosuppressive treatments.

Methods

T gondii IgM and IgG antibody titers were measured in 225 cats. Sera from owned cats tested at a multispecialty veterinary hospital were included both retrospectively and prospectively (n = 125). Sera from feral cats tested through a collaborating humane society were included prospectively (n = 100).

Results

Of the 13 (5.8%) cats with IgM titers, 10 were positive at the minimal cut-off titer (1:64), one cat was clinically ill and none were currently positive for IgG antibodies, suggesting false-positive results for nine cats, giving an adjusted IgM prevalence rate of 1.8% (95% CI 0.7-4.5). A total of five (2.2%) cats were positive for IgG antibodies and no cat was positive for both antibodies.

Conclusions and relevance

Most studies of T gondii antibodies in cat sera from California have shown higher prevalence rates, suggesting the cats in this municipality have a low risk of exposure. The study emphasizes that serological test results do not necessarily correlate to the presence of clinical illness.

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.

A preliminary study to develop a lateral flow assay using recombinant GRA1 protein for the diagnosis of toxoplasmosis in stray cats

Toxoplasma gondii is a protozoan parasite that may infect many mammals including humans. Cats are one of the main sources of infection for humans. Therefore, routine screening of cats with tests that are inexpensive, rapid, and do not require sophisticated laboratory equipment is important. In this study, a lateral flow assay (LFA) was designed to rapidly diagnose toxoplasmosis in cats. For this purpose, we selected GRA1 protein of T. gondii due to its high antigenicity in diagnostic and vaccine studies. We further analyzed the immunological properties of GRA1 protein using in silico tools. Then, we expressed and purified recombinant GRA1 (rGRA1) protein and used it during the development of LFA to detect toxoplasmosis in serum samples (n = 40) of cats. According to the results, rGRA1 protein has negative GRAVY value, high aliphatic index, alpha helix, random coil and 12 B cell epitopes. The in silico data supported the high antigenic properties of rGRA1 protein and showed that it can be a good antigen candidate for LFA. Among 30 cat positive serum samples, 27 were found positive by the LFA while seronegative sera (n = 10) were negative by the LFA. The preliminary data showed that the LFA has high sensitivity (90 %) and specificity (100 %). When we used high responsive cat sera (i.e. sera that have optical density > 0.5 with ELISA) the sensitivity value reached 100 %. These results showed that rGRA1 protein is a good candidate to develop a LFA for rapid diagnosis of toxoplasmosis in cats.

Toxoplasma gondii spinal granuloma in a cat

Case summary

A 7-year-old female spayed domestic shorthair cat was presented with a history of progressive pelvic limb ataxia. A CT scan of the thoracic spine identified an extradural, left lateralised and compressive soft tissue mass at the level of T9. A decompressive hemilaminectomy at the level of T8-T10 and tissue sampling of the mass were performed. Histopathological examination revealed a parasite granuloma caused by Toxoplasma gondii infection. Postoperatively, the cat improved consistently, but mild left pelvic limb lameness remained. At 5 weeks, a recheck CT scan showed a small, enhancing soft tissue lesion in the left epidural space at T9, causing a mild left lateral compression of the spinal cord. After 9 months, the cat acutely deteriorated neurologically and was euthanased without postmortem examination.

Relevance and novel information

To our knowledge, this is the first report of a T gondii spinal granuloma in a cat. Such a granuloma should be considered as a differential in cats with evidence of an extradural soft tissue mass.

Molecular detection and dense granule antigen 6 genotyping of feline Toxoplasma gondii in Phayao, Thailand

Background and Aim:

Globally, toxoplasmosis is an important zoonotic parasite infection of many warm-blooded animals (including humans). Toxoplasma gondii oocysts are widespread, and their contamination can be primarily attributed to the members of the Felidae family. This study aimed to estimate the prevalence and determine the dense granule antigen 6 (GRA6) genotype of T. gondii among domestic cats in the Phayao Province, Thailand.

Materials and Methods:

A total of 124 fecal samples were collected from owned cats in the Muang district, Phayao, Thailand, from January to December 2020. Fecal samples were tested for the presence of T. gondii DNA using targeted B1 gene polymerase chain reaction (PCR) amplification, and positive samples were subsequently analyzed for their T. gondii genotype through PCR-restriction fragment length polymorphism (RFLP) analysis and sequencing of the GRA6 gene.

Results:

Among the 124 samples, 46 (37.1%) were tested positive for T. gondii. Only 10 positive DNA samples were successfully amplified for the GRA6 marker. Subsequent PCR-RFLP and sequence analyses indicated that all T. gondii isolates from cats in Phayao belonged to GRA6 genotype I.

Conclusion:

Data revealed that toxoplasmosis is remarkably distributed among (studied) domestic cats in Phayao, Thailand. Moreover, the virulent GRA6 allele was found to be circulated among domestic cats in this area. However, no significant correlation was observed between infection rates and different risk factors, which indicated that pet cats of any age, gender, or breed have similar risks of being infected with T. gondii. Our results further suggested that infective oocysts of T. gondii are widely distributed and that environmental contamination with these oocysts will introduce more risks of disease transmission to humans and other animals.

Histoplasma capsulatum, Toxoplasma gondii, Bartonella henselae and Bartonella clarridgeiae coinfections in an indoor-only Siamese cat

Case summary

A 6-year-old male castrated Siamese cat was referred for acute-onset blindness and mydriasis. Physical examination revealed serous retinal detachment with panuveitis and systemic hypertension. Abdominal ultrasound showed suspected dilation of the cisterna chyli and abdominal lymphadenopathy. Aspirates of mesenteric lymph nodes revealed intrahistiocytic yeast organisms with mild-to-moderate pyogranulomatous inflammation. Fungal culture and ITS1 sequencing of the lymph node aspirates confirmed infection with Histoplasma capsulatum. PCR performed on whole blood was positive for Bartonella henselae and Bartonella clarridgeiae, and Toxoplasma gondii IgG and IgM antibodies were detected in serum. The cat was prescribed prednisolone (0.5 mg/kg PO q24h), itraconazole (10 mg/kg PO q24h), clindamycin (13 mg/kg PO q12h), amlodipine (0.625 mg PO q24h), prednisolone acetate 1% drops (q6h) and ophthalmic lubricant for both eyes (q6h). The cat was doing well at home after 2 weeks of prednisolone, itraconazole and clindamycin administration, and no abnormalities were detected on repeat abdominal ultrasound 3 months later. The retinal detachment showed mild-to-moderate improvement at that time, but vision was not regained.

Relevance and novel information

This is the first report of coinfection of H capsulatum, T gondii, B henselae and B clarridgeiae in an indoor-only cat living in a H capsulatum non-enzootic area with no known travel history.

Fatal disseminated toxoplasmosis in a feline immunodeficiency virus‐positive cat receiving oclacitinib for feline atopic skin syndrome

Toxoplasma gondii is a ubiquitous protozoan, for which felids are the definitive host. Immunocompromised individuals are susceptible to recrudescent toxoplasmosis. This case describes a 6‐year‐old, feline immunodeficiency virus‐positive domestic short hair cat with feline atopic skin syndrome that developed fatal toxoplasmosis after treatment with oclacitinib for five months.

Systemic toxoplasmosis in a cat under cyclosporine therapy

Toxoplasma gondii, an obligatory intracellular protozoan parasite infecting warm-blooded animals, can cause toxoplasmosis, a major zoonosis. A male neutered, domestic cat was referred to the Hebrew University Veterinary Teaching Hospital due to dyspnea after long term treatment with cyclosporine for obsessive self-grooming and pruritis. After thorough diagnostics, including non - invasive imaging, broncho-alveolar lavage, blood serology, hematology and biochemistry, and evaluation of the aspirated fluid components, a severe pneumonia and abdominal effusion were detected with observation of free tachyzoites under light microscopy from lavage fluids. PCR and DNA sequencing of broncho-alveolar lavage was positive for T. gondii. Despite aggressive treatment with antibiotics, oxygen supplementation and T. gondii specific antimicrobials, the cat died. It is suggested that potential candidates for cyclosporine be screened for T. gondii antibodies, kept entirely indoors and not fed uncooked meat in order to prevent exposure to T. gondii infection.

Experimental infection with Toxoplasma gondii in broiler chickens (Gallus domesticus): seroconversion, tissue cyst distribution, and prophylaxis

Toxoplasma gondii is a widespread zoonotic protozoan that infects most species of mammals and birds, including poultry. This study aimed to investigate the course of T. gondii infection and the efficacy of diclazuril and Artemisia annua in preventing infection in experimentally infected chickens. Seventy-five 1-month-old chickens, female and male, were randomly divided into five groups (n = 15 each) as follows: (1) uninfected untreated (negative control, NC); (2) infected with T. gondii genotype II/III isolated from a wild cat (group WC); (3) infected with T. gondii genotype II isolated from a domestic cat (group DC); (4) infected with T. gondii domestic cat strain and treated with the anticoccidial diclazuril (group DC-D); and (5) infected with T. gondii domestic cat strain and treated with the medicinal plant Artemisia annua (group DC-A). Clinical signs, body temperature, mortality rate, weight gain, feed conversion ratio, hematological parameters, and the presence of T. gondii-specific IgY antibodies were recorded in all groups. Five chickens per group were euthanized 28 days post-infection (p.i.) and their brains, hearts, and breast muscle tested for T. gondii by mouse bioassay and polymerase chain reaction (PCR). No clinical signs related to the experimental infection were observed throughout the study period. T. gondii-specific antibodies were detected by day 28 p.i., but not in all infected chickens. Overall, T. gondii DNA was detected (bioassay or tissue digests) in all infected and untreated chickens (10/10), while viable parasite (bioassay) was isolated from 7 out of 10 chickens. The parasite was most frequently identified in the brain (7/10). There were no differences in the T. gondii strains regarding clinical infection and the rate of T. gondii detection in tissues. However, higher antibody titers were obtained in chickens infected with T. gondii WC strain (1:192) comparing with T. gondii DC strain (1:48). A. annua reduced replication of the parasite in 3 out of 5 chickens, while diclazuril did not. In conclusion, broiler chickens were resistant to clinical toxoplasmosis, irrespective of the strain (domestic or wild cat strain). The herb A. annua presented prophylactic efficacy by reduced parasite replication. However, further studies are required aiming at the efficacy of diclazuril and A. annua for the prevention of T. gondii infection in chickens using quantitative analysis methods.

Antibody kinetics and exposure to Toxoplasma gondii in cats: a seroepidemiological study

Domestic cats are the most important definitive hosts for Toxoplasma gondii, the agent of an important global zoonosis. Serial sera from cats orally inoculated either withT. gondii tissue cysts (n = 3) or sporulated oocysts (n = 3) and from 65 client-owned cats, plus sera from 1,757 client-owned cats presented to veterinarians in Switzerland were analysed for an antibody response to T. gondii by ELISA. Risk factors for seropositivity and prevalence were estimated with a generalised linear and beta regression model. The first model examined the association of an OD₄₀₅ value as the dependent variable, with gender, age, and outside access as possible independent variables. In the second model, we first analysed the data assuming a bimodal distribution representing two overlapping distributions of OD₄₀₅ values from positive and negative cats, enabling the assignment of a probability of true infection status to each cat. Mean probabilities of true infection status across groups represent an estimate of true prevalence. These probabilities were then regressed against age, gender and outside access. Antibody kinetics in cats orally inoculated with tissue cysts, shedding oocysts, did not differ significantly from those of cats inoculated with sporulated oocysts without detectable oocyst excretion, suggesting extraintestinal parasite invasion and exposure to tachyzoites in both situations at an early stage of infection. Analysis of serial serum samples suggested a persisting long-term humoral immune response. Of the client-owned cats, 42.4% (95% confidence interval (CI): 40.1-44.6) had a positive true infection status. This was higher (56.3% (95% CI: 53.2-59.6)) in cats with outside access than in those without (22.1% (95% CI: 18.9-25.4)). In the first model, the factors age (P < 0.0001), gender (male: P = 0.046), and outside access (P < 0.0001) were independently associated with significantly higher OD₄₀₅ values. In the second model, the probability of having a positive true infection status increased with age (P < 0.0001), was higher with outside access (P < 0.0001) and in outdoor male cats (P = 0.0006).

Z. Frequency of Toxoplasma gondii and Risk Factors Associated with the Infection in Stray Dogs and Cats of Panama

Stray animals such as dogs and cats have an important role in maintaining the transmission cycles and dissemination of Toxoplasma gondii. Therefore, the objective of this study was to evaluate the frequency of T. gondii in stray dogs and cats in six different regions of Panama and determine risk factors associated with the dynamics of infection in each of the studied regions. Data were obtained using serological tests for the detection of anti-T. gondii IgG and IgM antibodies. The results of this study revealed an overall infection frequency of 23.73%. The infection frequencies found in dog and cat populations were 25.70% and 21.93% respectively, showing no statistically significant difference. Risk factor correlations suggested different infection dynamics depending on the region analyzed. The San Miguelito, North and West regions were more associated with positive cases in dogs with an age range greater than 13 months. Conversely, the Metro, Central and East regions were more associated with negative cases in cats with age ranging between 0 and 5 months. Infection of the parasite in stray animals can be influenced by intrinsic characteristics of each region, which can potentiate different risk factors associated with the different routes of transmission.

2019 AAFP Feline Zoonoses Guidelines

AIM

The overarching purpose of the 2019 AAFP Feline Zoonoses Guidelines (hereafter referred to as the 'Guidelines') is to provide accurate information about feline zoonotic diseases to owners, physicians and veterinarians to allow logical decisions to be made concerning cat ownership.

SCOPE AND ACCESSIBILITY

The Panelists are physicians and veterinarians who worked closely together in an attempt to make these Guidelines a document that can be used to support the International One Health movement. This version of the Guidelines builds upon the first feline zoonosis panel report, published in 2003 ( catvets.com/guidelines ), and provides an updated reference list and recommendations. Each of the recommendations received full support from every Panelist. Primary recommendations are highlighted in a series of 'Panelists' advice' boxes.

Comparison of a commercial modified direct agglutination test and a commercial enzyme-linked immunosorbent assay for screening for antibodies against Toxoplasma gondii in naturally exposed domestic cats

Domestic cats and other felids are definitive hosts for the zoonotic protozoan parasite Toxoplasma gondii. Serology is widely used in epidemiological studies conducted to estimate the proportion of domestic cats that have encountered the parasite. However, a limited number of such studies are available from some regions, including eastern parts of Europe and Russia. Various serological tests have been applied for T. gondii serology for feline samples. Seropositivity indicates previous exposure, and seropositive cats are presumed to have shed oocysts of the parasite earlier and to be chronically infected. In this study, we included a random sample of 200 sera and plasma samples from a larger sampling frame comprising samples from domestic cats from Estonia, where T. gondii is common. The samples, which had been previously screened for anti-T. gondii immunoglobulin G antibodies using a commercial modified direct agglutination test (DAT: Toxo-Screen DA; bioMérieux SA, Marcy-l'Étoile, France), were screened using a commercial enzyme-linked immunosorbent assay (ELISA: VectoToxo-antibodies [VektoTokso-antytila], VectorBest, Novosibirsk, Russian Federation). The cut-off for seropositivity with DAT was titer of 40. Of the 200 samples, 120 (60.0%) tested positive with DAT and 114 (57.0%) tested positive with ELISA; 112 samples (56.0%) tested positive with both tests. Percent agreement of 95.0% and Kappa 0.8971 indicated an almost perfect agreement between the screening results using the two methods. The results of this study can be useful for comparison, evaluation, and interpretation of results obtained with these two tests in seroepidemiological studies and may encourage more studies on the topic from eastern parts of Europe and Russia.

A case of pulmonary toxoplasmosis resembling multiple lung metastases of nasal lymphoma in a cat receiving chemotherapy

An 11-year-old cat presented with nasal discharge and lacrimation and was diagnosed with nasal lymphoma. Although the cat showed favorable progression after undergoing chemotherapy, CT imaging demonstrated enlarged pulmonary nodules caused by Toxoplasma gondii. Following the cessation of chemotherapy, the cat was prescribed clindamycin hydrochloride for toxoplasmosis treatment; however, the cat developed kidney lymphoma and died. No T. gondii organisms were observed in the whole body necropsy specimens. It is known that immunocompromised human patients, including those who undergo chemotherapy, are considered at risk for toxoplasmosis. However, the risk of developing toxoplasmosis in cats undergoing chemotherapy is currently unknown. Findings from this case report suggest that cats with chemotherapy-resistant pulmonary masses might have a T. gondii infection rather than metastatic disease.

A multi-event capture-recapture analysis of Toxoplasma gondii seroconversion dynamics in farm cats

Background

Domestic cats play a key role in the epidemiology of the parasite Toxoplasma gondii by excreting environmentally-resistant oocysts that may infect humans and other warm-blooded animals. The dynamics of Toxoplasma gondii seroconversion, used as a proxy for primo-infection dynamics, was investigated in five cat populations living on farms.

Methods

Serological tests on blood samples from cats were performed every three months over a period of two years, for a total of 400 serological tests performed on 130 cats. Variations in seroconversion rates and associated factors were investigated using a multi-event capture-recapture modelling approach that explicitly accounted for uncertainties in cat age and serological status.

Results

Seroprevalence varied between farms, from 15 to 73%, suggesting differential exposure of cats to T. gondii. In farms with high exposure, cats could become infected before reaching the age of six months. Seroconversion rates varied from 0.42 to 0.96 seroconversions per cat per year and were higher in autumn and winter than in spring and summer.

Conclusion

Our results suggest inter-farm and seasonal variations in the risks of exposure to T. gondii oocysts for humans and livestock living on farms. The paper also discusses the role of young cats in the maintenance of environmental contamination by T. gondii oocysts on farms.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2834-4) contains supplementary material, which is available to authorized users.

Zoonotic disease transmission associated with feral cats in a metropolitan area: A geospatial analysis

Feral cats raise public health concerns due to their large population numbers and ability to harbour pathogens that cause disease in people, pets, and wildlife. Information regarding the potential for feral cats to intersect with areas frequented by humans is lacking. This study examined the potential for feral cats and human territories to overlap in the Richmond metropolitan area of Central Virginia. Feral cats (n = 275) were trapped for monthly trap-neuter-release (TNR) clinics from July to November 2016. A geographic information system (GIS) was used to map feral cat trapping locations, elementary and preschools, public parks, and community gardens, and to evaluate the potential for cat interaction with these areas, presuming a maximum habitat radius of 0.44 miles. We found that 8.0% of feral cats in the Richmond metropolitan area had potential to range onto public elementary or preschool property, and 81.5% of feral cats trapped in Richmond City had potential to roam into one or more places of interest, including elementary and preschool grounds, public parks, and community gardens. This provides public health, veterinary, and human health professionals with important information that can be used to focus resources in an effort to reduce zoonosis associated with feral cat populations.

Skin as a marker of general feline health: Cutaneous manifestations of infectious disease

Practical relevance: Infectious disease in feline patients often presents a diagnostic challenge. This article reviews the most relevant viral, bacterial and protozoal diseases and their cutaneous manifestations. Many of the diseases discussed have overlapping presentations or may mimic more common noninfectious disease processes. The purpose of the article is to reinforce knowledge of common and uncommon infectious diseases, help practitioners identify possible infectious dermatoses, create a comprehensive and prioritized differential list, and provide guidance for the diagnosis of these diseases. A working knowledge of these clinical syndromes is important if what is thought to be a case of a common disease does not respond to conventional management.

AUDIENCE

This review is aimed at veterinarians who treat cats and especially those with an interest in feline dermatology. Tables are included to allow the reader to formulate a concise list of differential diagnoses for clinically similar presentations. The diagnostic approach to a case of ulcerative facial dermatitis is reviewed in a Case Notes quiz. Evidence base: This article includes up-to-date information regarding dermatologic manifestations of less commonly encountered feline cutaneous infectious diseases. Information has been drawn from the published, peer-reviewed literature and the most recent textbook chapters with a particular aim of describing and differentiating clinical lesions and the diagnostic approach to cutaneous disease, especially in unusual cases.

Fatal toxoplasmosis in an immunosuppressed domestic cat from Brazil caused by Toxoplasma gondii clonal type I

Abstract The objective of the study was to report on a fatal case of feline toxoplasmosis with coinfection with the feline leukemia virus (FeLV). A domestic cat (Felis silvestris catus) presented intense dyspnea and died three days later. In the necropsy, the lungs were firm, without collapse and with many white areas; moderate lymphadenomegaly and splenomegaly were also observed. The histopathological examination showed severe necrotic interstitial bronchopneumonia and mild necrotic hepatitis, associated with intralesional cysts and tachyzoites of Toxoplasma gondii that were positive by anti-T. gondii immunohistochemical (IHC) evaluation. The bone marrow showed chronic myeloid leukemia and the neoplastic cells were positive by anti-FeLV IHC evaluation. DNA extracted from lungs was positive for T. gondii by PCR targeting REP-529. T. gondii was characterized by PCR-RFLP and by the microsatellites technique. ToxoDB-PCR-RFLP #10, i.e. the archetypal type I, was identified. Microsatellite analysis showed that the strain was a variant of type I with two atypical alleles. This was the first time that a T. gondii clonal type I genotype was correlated with a case of acute toxoplasmosis in a host in Brazil.

Detection of Toxoplasma gondii in faeces of privately owned cats using two PCR assays targeting the B1 gene and the 529-bp repetitive element

Toxoplasma gondii infection is a worldwide parasitic zoonosis with a high-health risk for humans. The key epidemiological role played by felids is related to oocyst shedding. The present study compared two amplification protocols for the molecular diagnosis of Toxoplasma infection in owned cats. A total of 78 owned cats referred to an Italian university-teaching hospital and exposed to various T. gondii-associated risk factors were sampled for blood and faeces. Faecal specimens were processed by flotation and tested using 2 copro-PCRs targeting the widely used B1 gene and the 529-bp repetitive element (RE). The sera were tested by the indirect immunofluorescent antibody test (IFAT) for the detection of immunoglobulins against T. gondii. Sixteen faeces (20.52%) tested positive for T. gondii DNA; 12 samples were positive only at B1-PCR, two at 529-bp RE-PCR and two at both genetic targets (overall agreement = 82.11%). The amplicons obtained were sequenced, and the Basic Local Alignment Search Tool analysis showed a high homology with the T. gondii strains available in reference databases. Two stool samples were microscopically positive for T. gondii-like oocysts and also tested positive by both B1 and 529-bp RE-PCRs. Thirty-three (42.3%) sera tested positive for antibodies; of which, seven were found to have T. gondii DNA-positive results using the B1 genetic target (overall agreement = 57.77%). The amplification sets targeting B1 and 529-bp RE showed substantially different yields. Further research is needed to better understand the significance and the sensitivities of using these multi-copy-targeted molecular methods from cat faeces before being used for routine diagnosis.

Toxoplasma gondii seroprevalence in pet cats in Norway and risk factors for seropositivity

OBJECTIVES

The aims of the study were to estimate Toxoplasma gondii seroprevalence in pet cats in Norway and to evaluate risk factors for seropositivity. Additionally, serum biochemistry and haematological variables for T gondii seropositive and seronegative cats were compared.

METHODS

A convenience sample of surplus sera submitted to the Central Laboratory, Norwegian University of Life Sciences, was collected. The samples were from healthy cats and cats with a variety of diseases. Analyses for IgG antibodies to T gondii were performed with a commercial direct agglutination test, with 1:40 as the threshold value. For risk factor analysis a logistic regression model of the relationship between predictors and the outcome was applied.

RESULTS

One hundred and ninety-six of 478 cats were seropositive for T gondii, and the estimated seroprevalence in the study sample was 41.0% (95% confidence interval 36.6-45.4). Compared with domestic cats, pedigree cats had reduced risk for Toxoplasma seropositivity (odds ratio [OR] 0.42). Males had increased risk (OR 1.63) compared with females. The effect of age was highly significant, and an increase in the cats' age across the interquartile range (IQR; 52-160 months/4-13 years of age) doubled the risk of Toxoplasma seropositivity (OR 2.11). The risk for Toxoplasma seropositivity among cats living in Oslo was significantly reduced (OR 0.51) when compared with the rest of Norway.

CONCLUSIONS AND RELEVANCE

Pet cats in Norway appear to be commonly exposed to T gondii. Signalment and geographical region influenced the odds of Toxoplasma seropositivity, whereas health status did not.

A survey study on gastrointestinal parasites of stray cats in Azarshahr, (East Azerbaijan province, Iran)

Gastrointestinal parasites are among the most common parasitic infections found in stray cats, which might act potential helminthic parasites to domestic cats. The objective of this study was to determine the prevalence of gastrointestinal parasites in stray cats in the city of Azarshahr, which is located in East Azerbaijan province, Iran. A cross-sectional study was conducted on 50 necropsied stray cats, trapped and collected from different geographic regions of Azarshahr. From a total 50 stray cats examined, 15 (30 %) were female and 35 (70 %) were male. Overall 47 cats (94 %) were identified as infected with at least one of the endoparasites. The prevalence of parasites found were: Taenia taeniaeformis (60 %), Dipylidium caninum (58 %), Taenia hydatigera (24 %), Mesocestoides lineatus (78 %), Ancylostoma tubaeforme (14 %), Toxascaris leonina (30 %), Toxocara cati (78 %), Physaloptera praeputialis (10 %), and Syphacia obvelata (10 %). Contamination rate for zoonotic parasites of cat was greater than expected in AzarShahr region. Therefore, appropriate control measures should be taken and preventive methods should be applied.

Genetic characterization of Toxoplasma gondii isolates and toxoplasmosis seroprevalence in stray cats of İzmir, Turkey

Currently, some Toxoplasma gondii genotypes are being associated with serious clinical presentations. A recent report showing the Africa 1 genotype in two local congenital toxoplasmosis cases acquired in Turkey formed the basis of this study because atypical Africa 1 genotype is most frequently detected in animals and patients from sub-Saharan Africa. Since stray cats are considered as the linkage between wild life and urban life in T. gondii transmission, the present study aimed to isolate and characterize T. gondii strains circulating in stray cats of İzmir (Western Turkey). A secondary objective was to determine toxoplasmosis seroprevalence in this cat population. Tissues obtained from 100 deceased stray cats were bioassayed and isolated strains were genotyped using 15 microsatellite markers. In addition, toxoplasmosis seroprevalence was analyzed in 1121 cat sera collected from several large veterinary clinics in İzmir. Among the 22 isolates, 19 were Type II (86.3%), two were Type III (9%) and one was Africa 1 genotype (4.5%). The overall seropositivity rates in cats were 42-48% and 33.4-34.4% according to IFA and ELISA, respectively. Seroprevalence in deceased cats was significantly higher than in healthy cats (P = 0.0033). Finding both the major clonal Type II lineage together with the Type III lineage also found in Middle East, and an atypical genotype, Africa 1 appears consistent with the specific geographic location of Turkey between three continents and raises the possibility of transportation of these strains between continents through trade routes or long distance migratory birds. In addition, the first large study of toxoplasma seroprevalence in a stray cat population was also reported. The relatively high seropositivity rates and the variety of T. gondii genotypes confirm the local stray cat population as a risk factor for human toxoplasmosis in İzmir.

Toxoplasmosis--a global threat. Correlation of latent toxoplasmosis with specific disease burden in a set of 88 countries

BACKGROUND

Toxoplasmosis is becoming a global health hazard as it infects 30-50% of the world human population. Clinically, the life-long presence of the parasite in tissues of a majority of infected individuals is usually considered asymptomatic. However, a number of studies show that this 'asymptomatic infection' may also lead to development of other human pathologies.

AIMS OF THE STUDY

The purpose of the study was to collect available geoepidemiological data on seroprevalence of toxoplasmosis and search for its relationship with mortality and disability rates in different countries.

METHODS AND FINDINGS

Prevalence data published between 1995-2008 for women in child-bearing age were collected for 88 countries (29 European). The association between prevalence of toxoplasmosis and specific disease burden estimated with age-standardized Disability Adjusted Life Year (DALY) or with mortality, was calculated using General Linear Method with Gross Domestic Product per capita (GDP), geolatitude and humidity as covariates, and also using nonparametric partial Kendall correlation test with GDP as a covariate. The prevalence of toxoplasmosis correlated with specific disease burden in particular countries explaining 23% of variability in disease burden in Europe. The analyses revealed that for example, DALY of 23 of 128 analyzed diseases and disease categories on the WHO list showed correlations (18 positive, 5 negative) with prevalence of toxoplasmosis and another 12 diseases showed positive trends (p<0.1). For several obtained significant correlations between the seroprevalence of toxoplasmosis and specific diseases/clinical entities, possible pathophysiological, biochemical and molecular explanations are presented.

CONCLUSIONS

The seroprevalence of toxoplasmosis correlated with various disease burden. Statistical associations does not necessarily mean causality. The precautionary principle suggests however that possible role of toxoplasmosis as a triggering factor responsible for development of several clinical entities deserves much more attention and financial support both in everyday medical practice and future clinical research.

High prevalence of Toxoplasma gondii oocyst shedding in stray and pet cats (Felis catus) in Virginia, United States

Background

The protozoan Toxoplasma gondii is the causative agent of toxoplasmosis, with complications varying from mental disease to death. While human infection can occur via ingestion of tissue cysts from infected meat, most human infection comes from oocysts. Cats are the only definitive host, and thus shedding of oocysts by cats provides the ultimate source of toxoplasmosis.

Methods

While most studies in the area use seroprevalence to monitor Toxoplasma incidence in cat populations, this provides only a history of infection. This study used PCR detection of oocysts from cat feces to more accurately estimate the numbers of cats producing oocysts and thus posing an active health risk. DNA sequencing was use to confirm the identity of the PCR products.

Results

Of the 49 cats tested, 9 yielded PCR products of the expected size. Six of the nine were determined by sequence analysis to be false positives, while three products were true positives. Overall, 6% of cats examined were found to be actively shedding oocysts.

Conclusions

The incidence of oocyst shedding in the cat population studied was significantly higher than expected and higher than found in most cat populations world-wide. Of equal importance, the primers tested were shown to produce PCR products of multiple sizes and non-target products of expected size. We detected false positives at a higher rate than true positives, emphasizing the need for confirmatory analysis. Further research may produce better protocols for Toxoplasma detection from cat fecal samples.