Toxoplasma gondii spreading in an urban area evaluated by seroprevalence in free-living cats and dogs

Toxoplasma gondii seroprevalence and risk factors in cats in Rio de Janeiro

Seroprevalence studies on cats are essential for monitoring the occurrence of Toxoplasma gondii infection. The present research investigated anti-T. gondii antibodies, risk factors, clinical signs, hematology and serum biochemistry in cats from different regions of Rio de Janeiro. An overall 18.7% (17/91) of the cats were seroreactive, and age was associated with increased chances of seroprevalence of anti-T. gondii antibodies. Clinical signs, hematology and serum biochemistry parameters did not help achieve an antemortem diagnosis of cat toxoplasmosis. The parasite circulates in cats from three major regions of Rio de Janeiro, and the present data set will contribute to future epidemiological studies in this endemic state of Brazil.

Seroprevalence of IgG and IgM Antibodies against Toxoplasma gondii in Dogs in Greece

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a zoonotic disease that affects various animal species, including dogs, that can serve as sentinels for indirectly estimating the environmental contamination. The current study aimed to determine the seroprevalence of T. gondii IgG and IgM antibodies in dogs across different regions of Greece and assess their living area as a potential risk factor. In total, 1282 blood samples were collected from dogs in urban and rural areas of Greece, including Attica and Thessaloniki. Serum samples were tested for T. gondii-specific IgG and IgM antibodies using an indirect immunofluorescent antibody test. A chi-square test was performed to assess the association between seropositivity for T. gondii and geographical location (urban/rural). The overall T. gondii seroprevalence was 47.6%, while the seroprevalence of IgG and IgM antibodies was 34.3% and 22.2%, respectively. Dogs from rural areas exhibited a significantly higher seroprevalence (53.8%) than those from urban areas (43.9%) (p < 0.001), with the estimated odds ratio being equal to 1.49 (95% CI, 1.18 to 1.65) and the relative risk increased by 22.4%. Dogs in Greece are highly exposed to T. gondii, particularly in rural areas. Measures to prevent canine infections are necessary, and basic hygiene practices, such as hand washing after petting dogs, are required to reduce human infection risk and safeguard public health.

Geoepidemiology, seroprevalence and factors associated with Toxoplasma gondii infection in domicilied cats from Paraíba (Brazil)

Toxoplasma gondii is a parasite responsible for toxoplasmosis, an emerging and often neglected zoonosis in South America, particularly Brazil. Felines, the only definitive hosts, excrete oocysts in their feces, potentially infecting all homeotherms. Domestic cats are primarily responsible for contaminating human environments with these oocysts. Monitoring their populations is therefore essential to ensure proper toxoplasmosis prophylaxis. The aim of this study was to estimate the prevalence of T. gondii and exposure factors in a population of owner cats in the city of João Pessoa, Paraíba, Brazil. A total of 267 blood samples were collected from domestic cats aged between 1 and 15 years and tested with an immunofluorescence antibody test. The seroprevalence of antibodies against T. gondii was only 17.22% (46/267 individuals). This result therefore suggests a low contribution of domestic cats to T. gondii contamination of the urban environment. The cats' age and living environment were identified as risk factors for cat exposure to T. gondii.

Risk factors for Toxoplasma gondii infection in dogs: a serological survey

BACKGROUND

Dogs, as well as a wide variety of other warm-blooded animals, act as intermediate host of Toxoplasma gondii. In dogs, most cases of toxoplasmosis are subclinical, although clinical disease has been sporadically reported. Beyond its role in diagnostic pathways, seropositivity also functions as a reflection of the parasite's spread within the dog's living environment. The aim of the present study was to evaluate the possible risk factor associated with seropositivity to T. gondii in dogs in Central-Northern Italy, analysing 120 dogs sera for the presence of IgG antibodies by indirect fluorescence antibody test (IFAT).

RESULTS

The population examined was composed of 54.2% hunting dogs, 24.2% companion dogs, 14.2% truffle dogs and 7.5% watchdogs. Thirty-four (29.2%) dogs tested positive for T. gondii IgG, with titres ranging from 1:40 to 1:1280. Seroprevalence and antibodies titres were not related to dog gender, age or function. The logistic regression and ordered logistic regression results indicated that seroprevalence, and antibody titres were significantly higher in dogs cohabiting with cats, exhibiting coprophagy habits, and living constantly outdoors. Notably, the lifestyle factor showed the highest odds-ratios in the study: dogs living constantly outdoors were found to be at approximately 5 times greater risk of testing positive and having higher antibody titres compared to dogs living both indoors and outdoors.

CONCLUSION

Both logistic and ordered logistic regression results support the key role of living with cats, engaging in coprophagy behaviours, and maintaining an outdoor lifestyle in increasing the risk of T. gondii infection in dogs. These identified risk factors collectively suggest that both ingesting oocysts, as observed through cat cohabitation and coprophagy, and engaging in predatory behaviours, as possible for outdoor living dogs, are indicating likely sources of T. gondii infection in this host species.

Seroprevalence of Toxoplasma gondii Infection and Associated Risk Factors in Different Populations of Dogs from Aguascalientes, Mexico

CONTEXT AND PURPOSE

This work aimed to study the seroprevalence of natural infection by T. gondii in different population segments of dogs from Aguascalientes, Mexico as well as its possible association with some risk factors.

METHODS

The study included 210 clinically healthy dogs from three population segments: rural, stray and pet. A blood serum sample was collected on a single occasion and processed by indirect immunofluorescence considering a dilution of 1:16 as a positive reaction; the association between the presence of antibodies and the potential risk factors was estimated with logistic regression.

RESULTS

The overall prevalence of anti-T. gondii antibodies in the studied population was 59% (123/210; CI 95% 51-65) being different between population segments, in rural dogs 74% (59/80; CI 95% 62-82), in stray dogs 60% (48/80; CI 95% 48-70) and in pet dogs 32% (16/50; CI 95% 19-46), the titers of the positive sera were in a range of 1:16-1:128. In rural dogs the seroprevalence according to the municipality was in a range of 55% to 100% finding positive dogs in all the studied municipalities. The zootechnical function of guarding the property in rural dogs was identified as a risk factor (OR 2.4), while in pet dogs it was living with cats (OR 7) as well as sharing the drinking water container (OR 4); in stray dogs it was not possible to identify any risk factor.

CONCLUSIONS

This study documents the wide presence of anti-T. gondii antibodies in the population groups examined, this being more important in rural dogs.

Seroprevalence of and Risk Factors for Toxoplasma gondii Infection in Cats from Greece

Toxoplasmosis is one of the most important protozoan diseases with a global impact on the health of domestic cats and with zoonotic significance. The aims of this study were to determine the prevalence of seropositivity for Toxoplasma gondii in different populations of cats in Greece and to assess risk factors for seropositivity. A total of 457 cats were prospectively enrolled, and a commercially available indirect immunofluorescence antibody testing (IFAT) kit was used for the detection of anti-T. gondii immunoglobulin G (IgG) in serum. Overall, 95 (20.8%) of the 457 cats were seropositive for T. gondii. Based on multivariate analysis, factors associated with seropositivity included older age [Odds ratio (OR), 1.33; p < 0.001]; a history of cat-fight trauma (OR, 3.88; p = 0.004); and lack of vaccination against calicivirus, herpesvirus-1, panleukopenia, and rabies (OR, 10; p = 0.002). This study shows a high prevalence of seropositivity for T. gondii in cats in Greece. This implies that toxoplasmosis is still a major public health concern and that optimal strategies for the prevention of infection with T. gondii in cats should be established.

Feline Toxoplasmosis in Greece: A Countrywide Seroprevalence Study and Associated Risk Factors

Toxoplasma gondii is a ubiquitous zoonotic parasite, with felines being the only definitive hosts. Cats shed oocysts with their faeces, and seroprevalence studies can be used to indirectly assess the environmental contamination. The current study aimed to evaluate T. gondii seroprevalence in Greek cats and identify possible risk factors. In total, 1554 blood samples were analyzed from different cats across all nine geographic regions of Greece, and a short questionnaire was completed for each cat. A rapid immunochromatographic test was used to detect anti-T. gondii antibodies, IgG type, and 21.8% of cats were seropositive. Regarding risk factors, when chi-square tests were applied, seropositivity was significantly higher (p < 0.05) in rural cats, cats with outdoor access, and hunting cats. Gender, age, ownership, and raw feeding were not significant risk factors, although female, adult, stray, and raw-feeding cats had a higher seroprevalence than their counterparts. Binary logistic regression models were developed to adjust for the confounding effects of the initially recognized risk factors, and only hunting in urban areas remained a significant risk factor. Greek cats had lower seropositivity than the average European value, and the present research highlights the importance of updated seroprevalence and risk factor studies within the context of One-Health.

Comparison of a Commercial Enzyme-Linked Immunosorbent Assay (ELISA) with the Modified Agglutination Test (MAT) for the Detection of Antibodies against Toxoplasma gondii in a Cohort of Hunting Dogs

Toxoplasmosis is a zoonotic disease, caused by the protozoan Toxoplasma gondii, affecting most warm-blooded animals. Assessing the seroprevalence of T. gondii in different animal species gives a good estimate of the global circulation of the parasite and the risk for human infections. However, the seroprevalence of T. gondii in dogs is not studied as much as other species, despite their close contact with wildlife and humans in rural or urban environments and evidence that dogs can also be a potential source for human contaminations. A commercial enzyme-inked immunosorbent assay (ELISA) kit to detect anti-T. gondii antibodies in sera of hunting dogs potentially naturally infected, was compared to the modified agglutination test (MAT), used as the reference method. The ELISA presented a sensitivity of 76.5% (CI 95%: 60.0–87.6) and a specificity of 87.7% (CI 95%: 76.7–93.9) and a substantial agreement with the MAT for the detection of canine anti-T. gondii antibodies. Both tests can therefore be used widely for epidemiology studies on T. gondii infections in dogs. With a mean seroprevalence of T. gondii infection in hunting dogs from northern Algeria of 36.8% (CI 95%: 34.9–38.7), this study also highlights the importance of T. gondii seroprevalence studies in companion animals to assess infectious risk for human populations.

Seropositivity of Anti-Toxoplasma gondii Antibodies in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Southern Brazil

Although toxoplasmosis has been considered among the most neglected zoonoses worldwide, no study has focused on the frequency and associated risk factors of owners and their dogs living on an island and mainland seashore areas. Accordingly, anti-Toxoplasma gondii IgG antibodies were screened by indirect fluorescent antibody test (IFAT) in owners and dogs from three oceanic islands and two nearby mainland harbor areas, with associated risk factors for toxoplasmosis assessed by univariable and multivariable logistic regression models. Overall, anti-T. gondii seropositivity was observed in 59/328 (18.0%) owners and 66/283 (23.3%) dogs, with no statistical difference between owners (p = 0.360) and dogs (p = 0.655) from islands and mainland areas. Consumption of local water springs (p = 0.016; OR = 2.11) was an associated risk factor for T. gondii seropositivity, and owners with the habit of spring water intake were twice more likely seropositive (p = 0.014; OR = 2.14). Presence of anti-T. gondii antibodies in dogs was associated with seropositive owners (p = 0.008; OR = 2.81), household consumption of beef meat (p = 0.042; OR = 1.7) and chicken (p = 0.026; OR = 2.9). Despite being lower than the worldwide prevalence, toxoplasmosis seropositivity in owners and their dogs in southern Brazil was influenced by the positive owner, water source, and meat consumption, and not by inhabiting islands or seashore mainland areas, presence of dogs, cats, or both. In addition, drinking water quality should always be considered a critical risk factor for toxoplasmosis on islands.

Low Prevalence of Toxoplasma gondii in Dogs From Central China

Background

Toxoplasma gondii can infect almost all warm-blooded animals, including humans and dogs. Humans can become infected with T. gondii by petting dogs that have eaten or contacted infected cat feces. The aim of this study was to evaluate T. gondii infections in dogs from central China. From 2015 to 2021, a total of 536 dog samples (195 fecal, 81 hearts, and 260 serum samples) from Henan Province were collected. Heart juice or serum samples (n = 341) were tested for T. gondii antibodies using the modified agglutination test (MAT). Fresh myocardium (n = 6) and blood (n = 2) samples were bioassayed in mice.

Results

The present study showed that 4.40% (15/341) of the dogs were seropositive for T. gondii by MAT (cut-off, 1:25) and 4.10% (8/195) of dog feces contained T. gondii DNA. No T. gondii DNA was found in any myocardium (n = 81) or blood (n = 2) samples. The viable T. gondii strain was not isolated from any myocardium or blood samples (n = 8). Compared to the prevalence of T. gondii antibodies in dogs sampled from 2015 to 2018, the prevalence significantly declined from 2020 to 2021 (P &lt; 0.05). Gender and age were not risk factors for dogs infected with T. gondii in this study. However, compared to other sources, dogs from Zhoukou City (close to the Yellow River) or from pet shops showed significantly higher prevalence for T. gondii (P &lt; 0.05).

Conclusion

A total of 4.29% dogs were infected by T. gondii (23/536, 8 of 195 fecal samples, 2 of 260 serum, and 13 of 81 heart juice samples). This is the first survey of T. gondii infection in dog feces from China. Dogs were exposed to T. gondii, and they could act as mechanical transmitters of T. gondii.

Detección molecular de Toxoplasma gondii en carnes para consumo humano en Ibagué, Colombia

Introducción. Toxoplasma gondii es un parásito con gran potencial zoonótico que puede infectar un amplio rango de huéspedes de sangre caliente, incluidos los animales del sector pecuario, lo que causa pérdidas a la industria. En el humano, es patógeno en personas inmunosuprimidas y afecta el desarrollo del feto en infecciones congénitas. Además, se asocia con diversos trastornos del comportamiento en personas sanas. El humano puede adquirir T. gondii al consumir carnes contaminadas mal cocidas.Objetivo. Determinar la positividad de T. gondii en carnes de consumo humano (res, pollo y cerdo) en Ibagué, Colombia.Materiales y métodos. Se utilizó la PCR convencional anidada y la secuencia del gen B1 de T. gondii como blanco de amplificación. Se tomaron 186 muestras de carne comercializada en la zona urbana de Ibagué (62 de res, 62 de pollo y 62 de cerdo) y se obtuvo el porcentaje de positividad en cada tipo de carne evaluada.Resultados. Se encontró un porcentaje de positividad de 18,8 % en las muestras, siendo la carne de cerdo la del mayor porcentaje (22,5 %; 14/62), seguida por las muestras de carne de res (19,3 %; 12/62) y de pollo (14,5 %; 9/62). Los mejores productos amplificados fueron secuenciados en Macrogen, y alineados con las secuencias del gen B1 depositadas en el GenBank, con lo que se confirmó su identidad.Conclusiones. Este es el primer estudio sobre prevalencia de T. gondii en carnes para consumo humano en Ibagué y el departamento del Tolima. Se demostró que los tres tipos de carne representan un riesgo para la infección en humanos a nivel local.

Prevalence and risk factors of Toxoplasma gondii and Leishmania spp. infections in apparently healthy dogs in west Shewa zone, Oromia, Ethiopia

BACKGROUND

In urban settings, the presence of a high density of the human population and contact with domestic and/or stray animals such as dogs and cats can be risk factors for the transmission of zoonotic protozoa parasites. Toxoplasma gondii (T. gondii) and Leishmania spp. are zoonotic protozoon parasites with significant health burdens worldwide.

METHODS

A cross-sectional study was used to investigate the antibody prevalence and risk factors of T. gondii and Leishmania spp. infections in 385 randomly selected dogs of Ambo, Bako, and Gojo towns of West Shewa Zone, Oromia regional state, Ethiopia. A questionnaire survey was administered to households to collect data on potential risk factors. Dog sera samples were assayed for T. gondii IgG antibodies using the direct agglutination test while Leishmania spp. specific antibodies tested using an indirect enzyme-linked immunosorbent assay (ELISA). Logistic regression was used for data analysis.

RESULTS

Overall, T. gondii and Leishmania spp. infection seroprevalence was found to be 82.86% (95% confidence interval (CI): 78.71-86.49%) and 92.47% (95% CI: 89.36-94.90%), respectively. Seropositivity for both T. gondii and Leishmania spp. was found in 82.58% of the dogs. None of the investigated factors were associated with Leishmania spp. seropositivity (p > 0.05). The seroprevalence of T. gondii was significantly different among the study towns (p = 0.003). The risk of T. gondii infection was 2.71 times higher in adult dogs than juvenile dogs (p = 0.043). Dogs kept simultaneously with other domestic animals had increased odds of T. gondii seropositivity compared to those with no other domestic animals (Adjusted Odds ratio: 1.96, p = 0.021). However, altitude, sex, breed, housing, feeding, educational level of head of the household, and dog's living area were not significantly associated with T. gondii seropositivity (p > 0.05).

CONCLUSIONS

The high seropositivity and the simultaneous presence of antibodies of T. gondii and Leishmania spp. in dogs suggest the widespread nature of these parasites in the environment and the high potential of transmission to other animals and humans. Further epidemiological studies, isolation and molecular characterization of the parasites, and educational campaigns are suggested.

Toxoplasma gondii in domiciled dogs and cats in urban areas of Brazil: risk factors and spatial distribution

Toxoplasma gondii is a highly prevalent zoonotic parasite in Brazil capable of infecting mammals and birds. The increase in the urban populations of pets and the narrowing of the human-animal relationship can facilitate the transmission of important public health zoonoses, such as toxoplasmosis. This study aimed to evaluate the frequency and spatial distribution of T. gondii infection and its risk factors in domiciled dogs and cats attended at the Jorge Vaitsman Institute, Rio de Janeiro. Serum samples from 400 dogs and 272 cats were evaluated by an indirect fluorescent antibody test (IFAT) for IgG anti-T. gondii antibodies. Epidemiological questionnaires were used to interview the animals' owners to identify risk factors for infection. Of the total, 34% (136/400) of dogs and 8.1% (22/272) of cats had anti-T. gondii antibodies. Breed (OR: 2.10-95%, CI 1.27-3.46) was a risk factor for dogs, while sex (OR: 3.40-95%, CI 1.10-10.52) and homemade food consumption (OR: 8.49-95%, CI 2.48-29.05) were risk factors for cats. Offal consumption was considered a risk factor for both species evaluated (OR: 2.74-95%, CI 1.38-5.43 for dogs; OR: 7.66-95%, CI 1.24-47.29 for cats). The spatial analysis showed that T. gondii seropositive animals were widely distributed in the metropolitan region of Rio de Janeiro state, with a concentration observed mainly in the west and north zones of Rio de Janeiro city. The results emphasize the importance of adopting prophylactic measures to control T. gondii transmission in domiciled dogs and cats in Rio de Janeiro, contributing positively to public health.

Prevalence of Toxoplasma gondii Antibodies in Stray Dogs from Various Locations in West and East Malaysia

Toxoplasmosis is caused by an obligate intracellular protozoan parasite; Toxoplasma gondii, which is one of the most important zoonotic parasite worldwide. In dogs, the sexual reproductive cycle of T. gondii is lacking, and the animals are not widely consumed as food, but they are vital in the mechanical transmission of the parasite. However, there is no present data on the exposure of stray dogs to T. gondii in Malaysia. The objective of this serological survey was to determine the prevalence of T. gondii antibodies (IgG) and associated factors in stray dogs in East and West Malaysia. Antibodies to T. gondii were determined in serum samples from 222 stray dogs from 6 different states in East and West Malaysia (Peninsular Malaysia) using an Indirect ELISA. The seroprevalence for T. gondii was 23.4% (Confidence interval: CI 17.8-29.2%). Stray dogs from Selangor and Kuala Lumpur had the highest seroprevalence (32.4%; CI 13.2-45.5%) and lowest in those from Penang and Kedah (12.5%; CI 1.3-23.5%). Gender and breed were not associated with T. gondii seropositivity. However, adult dogs were more likely to be seropositive for T. gondii (OR=2.89; CI 1.1-7.7) compared with younger dogs. These results revealed that T. gondii is prevalent in stray dogs in the studied areas in Malaysia, and indicative of the level of environmental contamination of this parasite especially in urban areas.

Seroprevalence and incidence of Toxoplasma gondii and Neospora caninum infection in naturally exposed domestic dogs from a rural area of São Paulo state, Brazil

Dogs are hosts of the protozoans Toxoplasma gondii, which causes an important public health disease, and Neospora caninum. Studies that have evaluated toxoplasmosis and neosporosis for prolonged periods in dog populations are rare. We analyzed infection by both parasites in a domestic dog population over three consecutive years in São Paulo state, Brazil. In the 1st, 2nd and 3rd years of collection, 181, 193 and 172 domiciles were visited, and blood samples of 331, 371 and 348 dogs were collected for antibody serology, respectively. The seroprevalence of T. gondii in each year was 27.2%, 22.5% and 43.9%, respectively, and that of N. caninum was 7.8%, 4.8% and 6.8%, respectively. The incidence rates for T. gondii in the 2nd and 3rd collections were 13.2% and 30.0%, and those for N. caninum were 3.3% and 4.4%, respectively. Positive and negative serological conversions for both agents occurred at high frequencies during the study period. This study reveals the canine population's serological profile and demonstrates the constant exposure of dogs to the investigated pathogens, indicating the need for prevention and control measures in the region.

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.

Spatial serosurvey of anti-Toxoplasma gondii antibodies in individuals with animal hoarding disorder and their dogs in Southern Brazil

Despite vulnerability and unsanitary conditions of animal hoarding may predispose environmental contamination and spread of vectors and pathogens, no study to date has focused on their impact on public health and zoonotic diseases. Accordingly, this study aimed to assess the seroprevalence of anti-Toxoplasma gondii antibodies and associated factors in individuals with animal hoarding disorder (AHD) and their dogs in Curitiba, Southern Brazil. Blood samples were obtained from 264 dogs (21 households) and 19 individuals with AHD (11 households). Their blood was tested by indirect fluorescent antibody test (IFAT). Overall, anti-Toxoplasma gondii seropositivity was found in 21/264 dogs (7.95%; 95% CI: 4.69–11.22) with titers ranging from 16 to 4096, and in 7/19 individuals with AHD (36.84%; CI: 15.15–58.53) with titers ranging from 16 to 64. Serological analysis for anti-T. gondii antibodies were considered positive in at least one individual or dog in 9/11 (81.82%; 95% CI: 59.03–100.00) cases that were thoroughly assessed. Surprisingly, the seropositivity of individuals with AHD and their dogs was among the lowest reportedly observed in human and dog populations of Brazil. There was no significant association between positive owners and positive dogs or the presence of cats in the household. Regard epidemiological variables, a significant association was found between dog’s seropositivity and the type of dog food. To the authors’ knowledge, the present study represents the first investigation of T. gondii seroprevalence in individuals with hoarding disorder and their dogs. In conclusion, despite low sanitary conditions, anti-Toxoplasma gondii antibodies frequency in individuals with AHD and their dogs are lower than the general population likely due to low protozoan load in such isolated households.

A serological and parasitological study of Toxoplasma gondii infection in stray cats of Mashhad, Khorasan Razavi province, Iran

The aim of the present study was to determine seroprevalence of Toxoplasma gondii infection in stray cats and correlation with oocyst shedding and IFN-γ concentration. From April to August 2016, one hundred fifty-nine stray cats were captured from various localities in Mashhad area. The blood and fecal samples were collected from each cat. The serum samples were examined to detect antibodies against T. gondii infection by ELISA assay and the fecal samples were microscopically examined for T. gondii oocyst detection. The concentration changes of IFN-γ in serum samples of seropositive and seronegative cats were measured using ELISA kit. The results showed that 59.12% (94/159) of cats had antibodies against T. gondii infection. The seroprevalence of T. gondii infection in the adult cats above three years olds was higher than other groups. Regarding gender, month and region factors, the difference of seroprevalence of T. gondii infection was not significant. In this study, the Toxoplasma/Hammondia like oocyst (THLO) were detected in 2.56% (4/156) in fecal samples of one seropositive and three seronegative cats. Results also showed that the mean value for IFN-γ concentration in the seropositive cats was significantly higher than that of the seronegative cats. Based on the results, the high percentages of stray cats were infected with T. gondii in this area. The IFN-γ concentration of seropositive cats was higher than that of the seronegative cats.

Seroprevalence of Neospora caninum and Toxoplasma gondii in dogs from an urban area of North-eastern Brazil: a spatial approach

INTRODUCTION

The present study aimed to assess the seroprevalence and spatial distribution of Neospora caninum and Toxoplasma gondii in dogs.

METHODS

Blood samples (n = 241) were collected and analyzed for the presence of anti-N. caninum and anti-T. gondii antibodies. The spatial distribution was evaluated using kernel density estimation (KDE).

RESULTS

Anti-N. caninum and anti-T. gondii antibodies were detected in 24.06% (58/241) and 9.54% (23/241) of samples, respectively. A heterogeneous spatial distribution of positive dogs was observed across the city.

CONCLUSIONS

These data are pivotal for better understanding the dynamics of infection caused by these protozoa in the canine population.

Behavioral evaluation of BALB/c (Mus musculus) mice infected with genetically distinct strains of Toxoplasma gondii

In relation to behavioral changes in rodents infected with Toxoplasma gondii (T. gondii), it is believed that the genotype of the infecting strain can have some influence. In this sense, the present work has sought to evaluate the effect of chronic infection by genetically distinct cystogenic strains of T. gondii on the behavior of mice. For this, experimental models of infection with ME-49 (type II) and VEG (type III) strains were developed in isogenic BALB/c mice. ELISA test was performed to evaluate the humoral immune response and real-time PCR test to quantify parasites in the CNS. Behavioral tests such as passive avoidance, open-field and Y-maze tests were also used for, respectively, evaluation of learning and memory, locomotor activity and aversion to feline odor. The results showed that mice infected with VEG strain had higher total IgG level of anti-toxoplasma, higher tissue burden of T. gondii in the CNS, reduction in the long-term memory, lower activity (mobility) and lower aversion to cat urine and l-felinine than mice infected with ME-49 strain. The results suggest that different T. gondii genotypes have a differential impact on behavioral changes in infected mice.

Dogs (Canis familiaris) as Sentinels for Human Infectious Disease and Application to Canadian Populations: A Systematic Review

In a world where climate change, vector expansion, human activity, and pathogen dispersal do not respect boundaries, the human⁻animal⁻pathogen interface has become less defined. Consequently, a One Health approach to disease surveillance and control has generated much interest across several disciplines. This systematic review evaluates current global research on the use of domestic dogs as sentinels for human infectious disease, and critically appraises how this may be applied within Canada. Results highlighted a bias in research from high- and middle-income-economy countries, with 35% of the studies describing data from the Latin America/Caribbean region, 25% from North America, and 11% from the European/Central Asia region. Bacteria were the most studied type of infectious agent, followed by protozoa, viruses, helminths, and fungi. Only six out of 142 studies described disease in Canada: four researched a variety of pathogens within Indigenous communities, one researched Borrelia burgdorferi in British Columbia, and one researched arboviruses in Quebec. Results from this review suggest that dogs could provide excellent sentinels for certain infectious-disease pathogens in Canada, yet are currently overlooked. Further research into the use of dog-sentinel surveillance is specifically recommended for California serogroup viruses, Chikungunya virus, West Nile virus, Lyme borreliosis, Rickettsia spp., Ehrlichia spp., and Dirofilaria immitis.

Toxoplasma gondii infection in wild mustelids and cats across an urban-rural gradient

The increase in human population and domestic pets, such as cats, are generating important consequences in terms of habitat loss and pathogen pollution of coastal ecosystems with potential to generate negative impacts in marine biodiversity. Toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated with cat abundance and anthropogenic disturbance. The presence of T. gondii oocysts in the ocean has negatively affected the health status of the threatened Southern sea otter (Enhydra lutris nereis) populations. The present study analyzed seroprevalence and presence of T. gondii DNA in American mink (Neovison vison), Southern river otters (Lontra provocax) and domestic cats (Felis silvestris catus) in four different areas in Southern Chile comprising studies in rivers and lakes in Andean foothills and mountains, marine habitat and island coastal ecosystems. Mean seroprevalence of T. gondii in the study was 64% of 151 total animals sampled: 59% of 73 American mink, 77% of 13 Southern river otters, 68% of 65 domestic cats and in two of two kodkods (Leopardus guigna). Toxoplasma gondii DNA was detected in tissues from one American mink and one Southern river otter. The present study confirms the widespread distribution of T. gondii in Southern Chile, and shows a high exposure of semiaquatic mustelids and domestic cats to the parasite. Cats and anthropogenic disturbance have a role in the maintenance of T. gondii infection in ecosystems of southern Chile.

Anticorpos anti-Toxoplasma gondii em carcarás (Caracara plancus) procedentes da região aeroportuária do Recife, Pernambuco, Brasil

RESUMO Objetivou-se com este estudo pesquisar a ocorrência de anticorpos anti-Toxoplasma gondii em carcarás (Caracara plancus) capturados no Aeroporto Internacional do Recife/Guararapes Gilberto Freyre, Pernambuco, Brasil. Foram analisadas 115 amostras de soros sanguíneos pelo teste de aglutinação modificada (IgG, MAT≥25) utilizando taquizoítos inativados em formalina. Do total de amostras analisadas, 5,21% (6/115) foram positivas para presença de anticorpos anti-T. gondii, 16,67% com título 1:25 (1/06) e 83,33% (5/06) com título 1:50. A ocorrência de anticorpos em carcarás procedentes de região aeroportuária fomenta a preocupação em relação a aspectos ainda pouco elucidados, relacionados principalmente à inserção de aves silvestres na cadeia epidemiológica da toxoplasmose conectada à ação antrópica, tornando próxima a interação entre animais silvestres, domésticos e o homem. Dessa forma, é notória a necessidade de estudos relacionados à dinâmica de transmissão entre os diferentes genótipos existentes nessa tríade e sua relação com o meio ambiente, a fim de determinar a influência dessa espécie animal na cadeia epidemiológica da toxoplasmose.

Avaliação da técnica de ELISA para pesquisa de IgG anti-Toxoplasma gondii em exsudatos de carnes de sol

Resumo Toxoplasmose é uma importante zoonose de veiculação hídrica e alimentar, cujo agente é o Toxoplasma gondii. A toxoplasmose acomete seres humanos e animais de produção. É uma zoonose cosmopolita e sua prevalência está relacionada ao consumo de carne crua ou mal cozida, sendo este hábito considerado um dos principais fatores de risco. O controle do potencial de transmissão da toxoplasmose pela carne é relevante, principalmente em produtos artesanais, como as carnes de sol, que são processadas artesanalmente e podem ser consumidas cruas ou mal passadas. Neste estudo, propomos a avaliação da presença de imunoglobulinas da classe IgG anti-T. gondii pela técnica de imunoensaio ELISA, padronizando uma diluição do exsudato cárneo obtido pelo descongelamento das carnes de sol produzidas a partir de músculos de animais experimentais e também de carnes de sol comercializadas em “Casas do Norte”. Nossos resultados demonstram que o potencial do exsudato cárneo como um material biológico é limitado em carnes processadas, possibilitando o ensaio somente das amostras que obtiveram uma absorbância em densidade óptica (DO) igual ou superior a 0,116, faixa que garante a presença de sangue suficiente para o ensaio da ELISA, permitindo aferir imunoglobulinas específicas anti-T. gondii. Dentre as 32 amostras de carne de sol obtidas de cortes de bovinos experimentais, somente nove (28%) apresentaram sangue suficiente para ser ensaiadas, mensuradas pela DO igual ou superior a 0,116, sendo sete positivas, obtidas de cortes de animais infectados, e duas negativas, confeccionadas com cortes de animais controle. Dentre as 42 amostras de exsudatos de carne de sol obtidas no varejo, somente seis (14,28%) apresentaram sangue suficiente para serem ensaiadas e somente uma apresentou imunoglobulinas anti-T. gondii, concordante com dados da literatura. Nossos resultados são promissores e demonstram a importância do desenvolvimento de pesquisa e novas abordagens no controle sanitário dos alimentos ofertados à população.

Spatial and simultaneous representative seroprevalence of anti-Toxoplasma gondii antibodies in owners and their domiciled dogs in a major city of southern Brazil

Toxoplasmosis, caused by Toxoplasma gondii, has traditionally been considered an important water and foodborne protozoonosis with important public health considerations. Although felids play a well-established role as definitive hosts, canine epidemiological involvement in the parasite's life cycle remains questionable and controversial. The increasing closeness of the human-dog bond, particularly seen in urban settings, has been recognized as a historically unprecedented worldwide movement. Sharing daily lives in the same households, dogs may be exposed to similar associated risks of T. gondii infection as their owners. Thus, epidemiological assessment of the intra-domiciled environment, especially among socio-economically different human populations, may provide novel information regarding the actual role of dogs in animal and human toxoplasmosis. Despite spatial approaches being recently used for other water and foodborne diseases, no study has been conducted on the simultaneous spatial seroprevalence of both human and animal IgG anti-T. gondii antibodies in urban areas of major cities. Accordingly, the aim of the present study was to assess the seroprevalence and associated variables of Toxoplasma infection in owners and their domiciled dogs in Londrina, southern Brazil. Human and canine seroprevalence rates and variables associated with seroprevalence were investigated through representative random sampling among 564 households, which included 597 owners and 729 dogs. Overall, statistically significant differences between the seroprevalence of human and dog anti-T. gondii antibodies were found by Immunofluorescence Antibody Testing in 248/597 (41.54%) owners and 119/729 (16.32%) dogs. Through multiple analysis, significant concomitant variables for seropositivity of household individuals (people and dogs) were determined, including public sewer service, yard cleaning frequency, and having a dirty yard. Although no statistically significant multiple logistic model was observed among owners, univariate analysis detected associations with monthly income, soil contact, and occupation. Among dogs, the absence of other dogs and the absence of a dirty yard were concomitant significantly protective associated factors. Age differences between seropositive and seronegative individuals was significant only for human beings, with the median age of negative individuals significantly higher than positive individuals. Although no spatial clusters were identified for humans or residences, a significant cluster was identified for dogs. In conclusion, characteristics of urban toxoplasmosis may include significantly higher owner seroprevalence than their owned dogs, with canine seroprevalence directly associated with having more dogs and a dirty backyard, and spatial differences in both human and dog exposures. Although not a good indicator for human foodborne diseases, dogs may be a reliable sentinel for environmental infection. Moreover, such a holistic approach may provide crucial information for more focused prevention and monitoring programs, particularly in households with multiple pets and trash-filled backyards.

Serosurvey for Leishmania spp., Toxoplasma gondii, Trypanosoma cruzi and Neospora caninum in neighborhood dogs in Curitiba-Paraná, Brazil

Abstract Neighborhood dogs may act as reservoirs for several zoonotic protozoan infections, particularly in urban areas, thus constituting a potential public health threat. Accordingly, the aim of the present study was to evaluate the exposure of neighborhood dogs to four protozoan pathogens in public areas with high levels of human movement in Curitiba, southern Brazil. Blood samples from 26 neighborhood dogs were screened by means of the indirect immunofluorescent antibody test (IFAT) for Leishmania spp., Toxoplasma gondii, Trypanosoma cruzi and Neospora caninum, and a questionnaire was answered by the respective keeper. A total of 8/26 dogs (30.7%) seroreactive to T. gondii, 3/26 (11.5%) to N. caninum and 2/26 (7.7%) to both were identified. All the samples were seronegative for T. cruzi and Leishmania spp. Pathogen seroreactivity was not associated with the daily human movements or other epidemiological variables investigated (p > 0.05). In conclusion, the low seroprevalence for T. gondii and N. caninum indicated low environmental and food risk for animal infection and the seronegativity for Leishmania spp. and T. cruzi may reflect the absence of these pathogens in urban areas of Curitiba. Moreover, neighborhood dogs may be used as environmental sentinels for the presence of protozoan pathogens and their vectors.

Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean: Findings and diagnostic difficulties

The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and Germany, were tested for the presence of T. gondii. Brain samples were analysed by polymerase chain reaction (PCR) for detection of parasite DNA. Blood and muscle fluid samples were tested for specific antibodies using a modified agglutination test (MAT), a commercial multi-species enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Out of 193 animals tested by PCR, only two harbour porpoise (Phocoena phocoena) cerebrum samples, obtained from animals stranded on the Dutch coast, tested positive. The serological results showed a wide variation depending on the test used. Using a cut-off value of 1/40 dilution in MAT, 141 out of 292 animals (41%) were positive. Using IFA, 30 out of 244 tested samples (12%) were positive at a 1/50 dilution. The commercial ELISA yielded 7% positives with a cut-off of the sample-to-positive (S/P) ratio≥50; and 12% when the cut-off was set at S/P ratio≥20. The high number of positives in MAT may be an overestimation due to the high degree of haemolysis of the samples and/or the presence of lipids. The ELISA results could be an underestimation due to the use of a multispecies conjugate. Our results confirm the presence of T. gondii in marine mammals in The Netherlands and show exposure to the parasite in both the North Sea and the Eastern Atlantic Ocean. We also highlight the limitations of the tests used to diagnose T. gondii in stranded marine mammals.

Toxoplasma gondii: history and diagnostic test development

Toxoplasma gondiiis a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

Prevalence and genotyping of Toxoplasma gondii in naturally-infected synanthropic rats (Rattus norvegicus) and mice (Mus musculus) in eastern China

Background

Synanthropic rats and mice share the same environment with humans and play an important role in epidemiology of toxoplasmosis; however, there is limited information about prevalence and genetic characterization of Toxoplasma gondii in synanthropic rats and mice in China.

Findings

In the present study, the prevalence and genetic characterization of T. gondii naturally infected synanthropic rodents (Rattus norvegicus and Mus musculus) were investigated in the urban area of Xuzhou city, Eastern China between June 2013 and August 2014. DNA from the brain of each animal was prepared and screened by specific PCR assay targeting 35-fold repeated B1 gene (B1-PCR). PCR positive DNA samples were further genotyped by multi-locus PCR-RFLP. Overall, out of 123 synanthropic rodents, 29 samples were positive by B1 gene-targeted PCR (23.6%). Of these, 7 out of 31 (22.3%) M. musculus were positive, whereas the positive rate of R. norvegicus was 23.9% (22/92). Multi-locus PCR-RFLP analysis reveals that seven PCR-positive samples were completely genotyped and they were identified as type China 1 (ToxoDB# 9).

Conclusion

To our knowledge, this is the first report of molecular detection and genetic characterization of T. gondii infection in synanthropic rodents in Eastern China. The results of the present study showed a high infection pressure of T. gondii exists in the environment and synanthropic rodents infected by T. gondii may be an important source of infection for cats and other animals.

Toxoplasmosis in dogs: first report of Toxoplasma gondii infection in any animal species in Angola

Despite the worldwide importance of zoonotic parasite Toxoplasma gondii, nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also at assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a veterinary clinic in the city of Luanda were investigated. Serum samples were tested for antibodies to T. gondii with a modified agglutination test (MAT) commercial kit, at serial dilutions of 1∶20 to 1∶160. In accordance with the established cutoff value (MAT ≧20), 16 dogs [15·5%; 95% confidence interval (CI): 9·2-24·0%] had antibodies to T. gondii: 10 had a titer of 20, two had a titer of 40, and four had a titer of 80. Age (≧12 months) was found to be a risk factor for infection [odds ratio (OR) = 9·23; 95% CI: 1·16-73·27). For each 1-year increase in age, the risk of a dog being found seropositive significantly increased by an OR of 1·18 (95% CI: 1·02-1·36). The present study, which represents the first serological survey of T. gondii in any animal species from Angola, reveals a 15·5% seroprevalence of infection in pet dogs in Luanda. Further studies are needed to better understand the epidemiology of zoonotic T. gondii infection in Luanda and also in Angola.

Seroprevalence of Toxoplasma gondii (Nicole & Manceaux, 1909) and retroviral status of client-owned pet cats (Felis catus, Linnaeus, 1758) in Rio de Janeiro, Brazil

Cats, as definitive host, play an important role in the transmission of Toxoplasma gondii. This study aimed to establish the seroprevalence of anti-T. gondii immunoglobulins G and M, and determine the frequency of oocysts in the feces of the domestic cat population in Rio de Janeiro, Brazil. We also aimed to study the association between T. gondii infection and age, sex, breed, lifestyle, diet and retroviral infection. A total of 108 cats were included in the study and fecal samples of 54 of those cats were obtained. Only 5.6% of the cats were seropositive for anti-T. gondii immunoglobulins using the indirect hemagglutination test. None of the 54 cats presented oocysts in their fecal samples. Although not statistically significant, males, mixed-breed, free-roaming and cats aged two years and older were found to be more exposed. Age, lifestyle and the use of litter boxes were found to play an important role as risk factors. Anemia and retroviral infections were independent of T. gondii infection. No antibodies were detected in the majority of cats (94.4%), indicating that those cats had never been exposed to the parasite and, therefore, once infected, they could present the risk of shedding large numbers of oocysts into the environment.

Soroepidemiologia de Toxoplasma gondii em idosos atendidos pela Estratégia Saúde da Família, Porto Alegre, Rio Grande do Sul, Brasil

O objetivo desse estudo foi avaliar a soroprevalência para Toxoplasma gondii e a relacionar com as condições socioeconômicas, higiênicas, sanitárias e de saúde nos idosos da Estratégia Saúde da Família - ESF, do município de Porto Alegre, Rio Grande do Sul, Brasil. A pesquisa realizada foi um estudo transversal, no qual foi aplicado um questionário de inquérito epidemiológico e realizada coleta de sangue. A avaliação de IgG e IgM anti-T. gondii foi realizada pela técnica de ELISA. Foram avaliados 599 idosos com soroprevalência para IgG anti-T. gondii de 88,0% e de 0,8% para IgM. Na análise multivariada, as variáveis que se associaram de forma independente para IgG positivo foram: faixa etária, renda pessoal e uso de óculos; e para IgM positivo: faixa etária, autopercepção de saúde e uso de óculos. Os resultados obtidos chamam a atenção pela alta prevalência de IgG anti-T. gondii nos idosos da ESF de Porto Alegre, gerando uma preocupação no caso de ocorrência de reativação da toxoplasmose e desenvolvimento dos sintomas mais graves dessa infecção.

Evaluation of recombinant granule antigens GRA1 and GRA7 for serodiagnosis of Toxoplasma gondii infection in dogs

Background

Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, is an important zoonotic disease worldwide. The precise detection of T. gondii infection in dogs has important public health significance. In this study, recombinant granule antigen proteins GRA1 and GRA7 were evaluated as potential diagnostic markers for T. gondii infection in dogs by an indirect enzyme-linked immunosorbent assay (ELISA).

Results

GRA1 and GRA7 were cloned and expressed in Escherichia coli, and the recombinant GRA1, GRA7- and Toxoplasma lysate antigen (TLA)-based ELISAs were developed and evaluated using the canine positive and negative serum samples for anti-T. gondii antibodies determined by modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT), showing a seroprevalence of 15.1% by TLA- and GRA1-ELISA, and 15.8% by GRA7-ELISA, and no significant difference was observed (P > 0.05). When compared with the two reference assays, MAT and IFAT, the GRA7-ELISA showed the highest co-positivity and co-negativity rates. Receiver operating characteristic (ROC) analysis revealed a largest area under curve (AUC) of 0.973 (95% CI, 0.955 to 0.991), and a highest relative sensitivity (93.2%) and specificity (94.0%) for a cut-off value of 0.809 in GRA7-ELISA.

Conclusions

The results of the present study showed that GRA7-ELISA is highly sensitive and specific, and GRA7 is a potential serodiagnostic marker for the detection of T. gondii infection in dogs.

Prevalence of antibodies against Toxoplasma gondii and Neospora caninum in dogs

Toxoplasmosis and neosporosis are parasitic diseases of global importance. The present study had the objective to determine the influence of age, sex and breed in the prevalence of antibodies against both diseases in dogs from Brotas city, São Paulo State, Brazil. Blood samples of 342 dogs were collected, and the age, sex and breed of each animal were recorded. The serological diagnosis for toxoplasmosis and neosporosis were performed using the immunofluorescent antibody test (IFAT). The Fischer's test was used to calculate the association probability of the variables, with α = 5%. For toxoplasmosis the prevalence of antibodies was 26.9% (CI 95% 22.4-31.8%), and for neosporosis 4.97% (CI 95% 3.1-7.8%). The statistical analysis revealed a higher risk of infection for T. gondii in dogs with more than five years.

Prevalence and Risk Factors of Toxoplasma gondii Infection in Domestic Cats from the Tropics of Mexico Using Serological and Molecular Tests

The aim of this study was to determine the prevalence and risk factors associated with Toxoplasma gondii infection in domestic cats using an indirect-ELISA (IgM and IgG) and PCR. Samples collected from 220 cats from Merida, Yucatan, Mexico, were analyzed. Cases were reported as acute or chronic. Cases when positive to IgM and IgG and PCR were considered as reactivated chronic infection. Risk factors (sex, age, body condition, diet access to hunting, and number of cats in home) were assessed with a multivariate analysis, 75.5% (166/220) of the cats were IgM and 91.8% (202/220) IgG-seropositive and 79% were PCR-positive (173/220). Number of cats per household and low body condition score were associated with reactivated chronic infection (P < 0.05). It is concluded that T. gondii is scattered in the studied population with several periods of reinfection, and therefore an environmental contamination with infecting oocysts exists and there are intrinsic associated factors in cats that increase the risk of becoming infected.

Toxoplasmosis in humans and animals in Brazil: high prevalence, high burden of disease, and epidemiology

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Brazil. The burden of clinical toxoplasmosis in humans is considered to be very high. The high prevalence and encouragement of the Brazilian Government provides a unique opportunity for international groups to study the epidemiology and control of toxoplasmosis in Brazil. Many early papers on toxoplasmosis in Brazil were published in Portuguese and often not available to scientists in English-speaking countries. In the present paper we review prevalence, clinical spectrum, molecular epidemiology, and control of T. gondii in humans and animals in Brazil. This knowledge should be useful to biologists, public health workers, veterinarians, and physicians. Brazil has a very high rate of T. gondii infection in humans. Up to 50% of elementary school children and 50-80% of women of child-bearing age have antibodies to T. gondii. The risks for uninfected women to acquire toxoplasmosis during pregnancy and fetal transmission are high because the environment is highly contaminated with oocysts. The burden of toxoplasmosis in congenitally infected children is also very high. From limited data on screening of infants for T. gondii IgM at birth, 5-23 children are born infected per 10 000 live births in Brazil. Based on an estimate of 1 infected child per 1000 births, 2649 children with congenital toxoplasmosis are likely to be born annually in Brazil. Most of these infected children are likely to develop symptoms or signs of clinical toxoplasmosis. Among the congenitally infected children whose clinical data are described in this review, several died soon after birth, 35% had neurological disease including hydrocephalus, microcephaly and mental retardation, 80% had ocular lesions, and in one report 40% of children had hearing loss. The severity of clinical toxoplasmosis in Brazilian children may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil.

Occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in cats with outdoor access in São Luís, Maranhão, Brazil

The present study aimed to investigate the frequency of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in cats with outdoor access in São Luís, Maranhão, Brazil. The presence of IgG anti-T. gondii and anti-N. caninum antibodies was tested using the Indirect Immunofluorescent Antibody Test (IFAT). IgG anti-T. gondii and anti-N. caninum antibodies were detected in 101 (50.5%) and 54 (27%) sampled cats, respectively. The titers of anti-T. gondii antibodies ranged from 40 (cut-off) to 2560. On the other hand, the titers of anti-N. caninum antibodies ranged from 25 (cut-off) to 400. Twenty-seven cats (13.5%) were shown to be seropositive for both parasites. Seventy-four cats (34%) were seropositive only for T. gondii. Twenty-two cats (11%) were seropositive only for N. caninum. The present study showed that cats with outdoor access in São Luís, Maranhão, are exposed to T. gondii and N. caninum.

Stray dogs as indicators of Toxoplasma gondii distributed in the environment: the first report across an urban-rural gradient in China

Background

Toxoplasmosis is an important parasitic zoonosis caused by the protozoan Toxoplasma gondii that is distributed world-wide and infects a variety of hosts. However, the prevalence of T. gondii in the environment (such as soil, water and food) is largely unknown. Due to the technical difficulty in oocyst counting directly, an alternative assay using the serologic status of T. gondii in free-living animals, such as stray or free-living dogs, as an indicator, can be used to evaluate environmental contamination indirectly, as they are exposed to the same risk of infection as humans and other animals.

Results

In the present study, 231 stray or free-living dogs across an urban-rural gradient were examined to assess the frequency of T. gondii in the environment. Specific antibodies to T. gondii were found in 93 dogs (40.3%) by enzyme-linked immunosorbent assay (ELISA), and no statistically significant differences were observed in seroprevalences of T. gondii between urban dogs (38.7%) and rural dogs (41%) (p > 0.05).

Conclusions

A high seroprevalence of T. gondii in stray or free-living dogs in the present study indicates that there would be a wide distribution and a constant infection pressure of T. gondii across an urban-rural gradient, and the oocysts of T. gondii in the environment would be an important source of infection for humans and other animals both in urban and rural areas in China.

Preliminary report of HIV and Toxoplasma gondii occurrence in pregnant women from Mozambique

Toxoplasmosis, a protozoan disease, causes severe disease in fetuses during pregnancy and deadly encephalitis in HIV patients. There are several studies on its seroprevalence around the world, but studies focusing on African countries are limited in number and mostly anecdotal. We studied two groups of samples from Mozambique by ELISA, using serum samples from 150 pregnant women and six Cerebrospinal fluid (CSF) samples from AIDS patients with encephalitis. HIV status was confirmed, and CD4 blood counts were obtained from HIV-positive pregnant women. IgG seroprevalence of the group as a whole was 18.7% (28/150), with a higher prevalence in HIV-positive individuals compared to those who were HIV-negative (31.3%, [18/58] vs. 10.9%, [10/92]) patients. These data may be biased due to cumulative effects of exposition affecting disease prevalence. If corrected, this data may indicate an interaction of HIV and T. gondii. Prevalence of both diseases increases with age, but this is more clearly seen for toxoplasmosis (p < 0.005) than HIV infection, possibly explained by higher transmission of HIV after childhood. In HIV patients suffering from encephalitis, CSF serology showed that 33% of specific IgG CSF had a high avidity, which was in accordance with the data from the group of pregnant women. Lower prevalence rates of both infections in older groups could be explained by more deaths in the infected groups, resulting in an artificially lower prevalence. Using CD4 counts as a marker of time of HIV infection, and correcting for age, patients with contact with T. gondii had fewer CD4 cells, suggesting prolonged HIV disease or other causes. Toxoplasma IgG prevalence is higher in HIV+ groups, which could be ascribed to HIV- and T. gondii-associated risk factors, such as exposure to higher and more diverse social contacts. The low incidence of Toxoplasma IgG in younger age groups shows that transmission could be related to better access to cyst-containing meat in adulthood, as environmental transmission due to oocysts is usually blamed for higher incidence in children. Taken together, these data support the urgent need of research in toxoplasmosis in Africa, especially in the presence of HIV epidemics.

Quality control of Toxoplasma gondii in meat packages: standardization of an ELISA test and its use for detection in rabbit meat cuts

Toxoplasma gondii causes severe disease both to man and livestock and its detection in meat after slaughtering requires PCR or biological tests. Meat packages contain retained exudate that could be used for serology due to its blood content. Similar studies reported false negative assays in those tests. We standardized an anti-T. gondii IgG ELISA in muscle juices from experimentally infected rabbits, with blood content determination by cyanhemoglobin spectrophotometry. IgG titers and immunoblotting profiles were similar in blood, serum or meat juice, after blood content correction. These assays were adequate regardless of the storage time up to 120 days or freeze-thaw cycles, without false negative results. We also found 1.35% (1/74) positive sample in commercial Brazilian rabbit meat cuts, by this assay. The blood content determination shows ELISA of meat juice may be useful for quality control for toxoplasmosis monitoring.