Oocyst ingestion as an important transmission route of Toxoplasma gondii in Brazilian urban children

Toxoplasmosis is a cosmopolitan protozoan infection. Data regarding risk factors for the post-natal acquisition of Toxoplasma gondii infection in childhood are limited. We conducted a serological survey for T. gondii IgG antibodies and associated risk factors in 1,217 children 4-11-yr-old from Salvador, Brazil, using a commercial ELISA kit; antibodies were found in 17.5% of the children. Age (OR = 2.18; 95% CI: 1.50-3.17) and maternal schooling level (OR = 0.62; 95% CI: 0.42-0.92) were negatively associated with infection. A greater number of siblings (OR = 1.53; 95% CI: 1.12-2.09), cat at home (OR = 1.54; 95% CI: 1.06-2.24), house with non-treated piped water (OR = 2.54; 95% CI: 1.22-5.31), and the absence of a flush toilet at home (OR = 1.45; 95% CI: 1.04-2.01) were positively associated with T. gondii infection. Our data suggest that low socioeconomic levels and poor hygiene habits are important factors in favoring T. gondii infection.     

Seroepidemiology of Toxoplasma gondii infection in human adults from three rural communities in Durango State, Mexico

There is scarce information concerning the epidemiology of Toxoplasma gondii infection in people of rural Mexico. Anti-T. gondii immunoglobulin (Ig)G and IgM antibodies were sought in 462 adult inhabitants from 3 rural communities of Durango, Mexico, using enzyme-linked immunoassays. In total, 110 (23.8%) of 463 persons had IgG anti-T. gondii antibodies. Ten (2.2%) of them also had IgM anti-T. gondii antibodies. Prevalences of T. gondii IgG antibodies in the 3 communities varied from 14.8 to 35.8%. The highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions. Toxoplasma gondii infection was significantly associated with consumption of squirrel (adjusted odds ratio [OR] = 4.22; 95% confidence interval [CI] = 1.11-16.05) and turkey meat (adjusted OR = 4.58; 95% CI = 1.14-18.44). This is the first epidemiological study of T. gondii prevalence in rural Mexico.     

Seroepidemiology of infection with Toxoplasma gondii in workers occupationally exposed to water, sewage, and soil in Durango, Mexico

Water, sewage, and soil are potential sources of infection for Toxoplasma gondii. Therefore, we sought to determine the prevalence of T. gondii infection and associated characteristics in 61 plumbers, 203 construction workers, and 168 gardeners in Durango City, Mexico. Participants were tested for T. gondii IgG and IgM antibodies with the use of enzyme-linked immunoassays. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. IgG T. gondii antibodies were found in 4 (6.6%) plumbers, 17 (8.4%) construction workers, and 10 (6.0%) gardeners; T. gondii IgM antibodies were found in 3 (1.5%) construction workers and 4 (2.4%) gardeners, but in none of the plumbers. In the total population, the prevalence of T. gondii infection was significantly higher in workers living in suburban areas, without education, workers that consumed chorizo, and those who suffered from any disease (P < 0.05). In gardeners, prevalence of infection was significantly higher in those with blood transfusion, and memory impairment (P < 0.05). Multivariate analysis showed that T. gondii infection was positively associated with consumption of unwashed fruits (adjusted odds ratio [OR] = 2.41; 95% confidence interval [CI]: 1.13-5.13), and with raising animals (adjusted OR = 2.53; 95% CI: 1.00-6.37). This is the first report of contributing factors for T. gondii infection in workers occupationally exposed to water, sewage, and soil in a Mexican city, and results will contribute to the design of optimal preventive measures.     

Seroprevalence of acquired toxoplasmosis in HIV-infected and apparently healthy individuals in Jos, Nigeria

Toxoplasma gondii IgG antibody seroprevalence was studied in two different populations of 219 HIV-infected patients and 144 apparently healthy individuals (AHIs). Clinical toxoplasmosis was assessed among the HIV-infected patients. Antibodies to T. gondii were detected in 85 (38.8%, 95% CI: 32.36%-45.26%) of the HIV-infected patients and in 30 (20.8%, 95% CI: 14.20%-27.46%) of the AHIs. Among the AIHs, males represented 22.0% of infections compared to females (20.0%) and individuals within age group 21-30 years accounted for the highest prevalence of 33.3% (95% CI: 11.56%-55.10%). There was no significant difference in the trend (Chi-square, P < or = 0.05). Assessment of epidemiological factors showed higher seroprevalence of Toxoplasma antibodies among those who eat rodents (29.6%) and those who constantly have contact with the soil (21.2%). Among the HIV-infected, individuals 31-40-years-old had the highest T. gondii seroprevalence (36.5%). Evaluation of the clinical findings of patients with concomitant toxoplasmosis and HIV infection greatly implicated fever (63.5%), headache (44.7%), rashes (41.2%) and anorexia (34.1%). This study contributes to the development of guidelines for the prevention and management of toxoplasmosis in HIV-infected patients and in apparently healthy individuals in a resource scarce setting.     

Seroepidemiology of Toxoplasma gondii infection in general population in a northern Mexican city

There is a lack of information about the seroepidemiology of T. gondii infection in the general population of Durango City, Mexico. Anti- Toxoplasma gondii IgG and IgM antibodies were sought in 974 inhabitants in Durango City, Mexico with the use of enzyme-linked immunoassays. in total, 59 (6.1%) of 974 participants (mean age 37 ± 16.1 yr) had IgG anti- T. gondii antibodies. Twenty (2.1%) of them also had IgM anti- T. gondii antibodies. IgG levels of 13-99, 100-150, and >150 International Units (IU)/ml were found in 14 (23.7%), 3 (5.1%), and 42 (71.2%) anti- T. gondii IgG-positive participants, respectively. Prevalence of infection increased with age (P < 0.05), and was significantly lower in participants born in Durango State than those born in other Mexican states (P < 0.01). Toxoplasma gondii infection was significantly associated with consumption of boar meat (adjusted odds ratio [OR] = 3.02; 95% confidence interval [CI]: 1.49-6.13), and squirrel meat (adjusted OR = 2.18; 95% CI: 1.17-4.09). in addition, infection was negatively associated with travel abroad (adjusted OR = 0.42; 95% CI: 0.23-0.77), and salami consumption (adjusted OR = 0.57; 95% CI: 0.32-0.99). This is the first report of seroprevalence and contributing factors for T. gondii infection in general population in Durango City, and of an association of the consumption of boar meat with T. gondii infection. This study provides a basis for the design of successful preventive measures against T. gondii infection.     

Risk factors for Toxoplasma infection in pregnant women in FYR of Macedonia

The aim of the study was to identify risk factors for Toxoplasma gondii infection in pregnant women in FYR of Macedonia. Retrospective analysis of serological and epidemiological data in a series of 235 pregnant women from Macedonia, tested for Toxoplasma infection between January 2004 and December 2005, showed an overall prevalence of infection of 20.4%. Exposure to transmission factors significantly increased the risk of infection (RR = 1.989, 95 % CI = 1.041-3.800, p = 0.037). The single infection transmission factor that was a predictor of infection in the whole series was exposure to soil (RR = 1.946, 95% CI = 1.026-3.692, p = 0.041). Based on prevalence and the established risk factors for Toxoplasma infection in Macedonia, the health education programme as a sustainable measure for the prevention of congenital toxoplasmosis should focus on educating women of generative age to avoid contact with soil (farming, gardening), and/to adhere to strict hygienic practices afterwards.     

Isolation of Toxoplasma gondii from goats from Brazil

Goats are economically important in many countries, and little is known of caprine toxoplasmosis in Brazil. Antibodies to Toxoplasma gondii were assayed in the sera of 143 goats from 3 Brazilian states, using modified agglutination test (MAT titer > or = 1:25); 46 (32.2%) tested positive. Samples of brain, heart, diaphragm, and masseter of seropositive animals were pooled, digested in pepsin, and bioassayed in mice. Viable T. gondii specimens were isolated from tissue homogenates of 12 goats; the isolates were designated TgGtBr1-12. Ten of the 12 isolates killed 100% of infected mice, indicating that goats can harbor mouse-virulent T. gondii and, hence, can serve as a source of infection for humans.     

Seroprevalence and risk factors for Toxoplasma gondii infection on pig farms in central China

Toxoplasma gondii is a protozoan parasite that causes severe diseases in mammals, including humans, around the world. In China, pork is the main meat source; accordingly, T. gondii in pigs is considered an important source for human toxoplasmosis. Understanding the epidemiology of toxoplasmosis in pig farms is thus important for control of the disease in humans. The purpose of the present study was to investigate the epizootiology of T. gondii infections in pig farms in central China by assessing the seroprevalence and risk factors of this disease. In the present study, 3,558 sera samples were collected from pigs in 37 large-scale pig farms in this region and tested by AG-ELISA. The total seroprevalence was 24.5%, with the greatest prevalence in breeding pigs. The risk factors for toxoplasmosis suggest that high frequency of the contact of pigs with cats (P ≤ 0.01; IC 95%), high density of pig breeding (P ≤ 0.01; IC 95%), the presence of mosquitoes and flies (P ≤ 0.01; IC 95%), semi-patency pens (P ≤ 0.05; IC 95%), and low frequency of scavenging (P ≤ 0.01; IC 95%) were all associated with seroprevalence. In addition, the use of sulfonamides (P ≤ 0.01; IC 95%) significantly decreased seroprevalence. This is the first report of anti- T. gondii antibodies in pigs on large-scale pig farms in central China. The findings will provide useful information for designing control strategies of toxoplasmasis in pig farms.     

Prevalence estimation and genotypization of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> in goats

In this study we aimed to determine seroprevalence of antibodies against Toxoplasma gondii and parasite DNA presence in the milk of goats from a farm in eastern Slovakia. Anti-Toxoplasma antibodies were detected in 43 goat sera out of 87 examined (49.43%). The highest prevalence was recorded in the goats aged more than 72 months (76.19%; OR = 4.62; 95% CI = 1.51-14.14) and the lowest one in animals aged from 12 to 36 months (17.65%; OR = 0.09; 95% CI = 0.03-0.27). Statistically significant correlation (P < 0.0001) was found between the prevalence of antibodies against T. gondi and animal age in comparing age groups - goats up to 36 months of age and above 37 months of age. The presence of T. gondii DNA was confirmed in 32.56% of milk samples using molecular methods. Based on the DNA polymorphism at the SAG2 locus of T. gondii we identified the goats as being infected with genotype II of T. gondii. Presence of DNA in milk refers to the risk of human infection through consuming raw milk.     

Prevalence of Toxoplasma gondii antibodies and the relation to risk factors in cats of Colima, Mexico

The prevalence of Toxoplasma gondii antibodies in 80 domestic cats was studied in the city of Colima, Mexico, using an indirect IgG-ELISA. Antibodies were found in 28.8% of the cats, with significantly higher (P = 0.029) prevalence in southern and central zones (33.8%) than the northern zone (6.6%). Prevalence among cats fed with homemade food was higher than those eating commercial pellets (40.6% [vs.] 20.8%; P = 0.055). Overall, the prevalence of T. gondii antibodies in the cats of Colima was lower than in many other countries.     

High prevalence and genotypes of Toxoplasma gondii isolated from goats, from a retail meat store, destined for human consumption in the USA

Little information is available concerning the presence of viable Toxoplasma gondii in tissues of goats worldwide. In the present study, hearts of 234 goats obtained from a local USA grocery store were examined for T. gondii infection. Blood clot or fluid removed from each heart was tested for antibodies to T. gondii by using the modified agglutination test (MAT). Antibodies to T. gondii were found in 125 (53.4%) of 234 goats, with titers of 1:5 in 20, 1:10 in 44, 1:20 in 16, 1:40 in five, 1:160 in five, 1:320 in five, and 1:640 or higher in 30 goats. Hearts of 112 goats (46 goats <1:5, and 66 goats 1:10 or higher) were used for isolation of viable T. gondii by bioassays in mice. For bioassays, 50 g of the myocardium were digested in an acid pepsin solution and the digest inoculated into mice; the recipient mice were examined for T. gondii infection. Toxoplasma gondii was isolated from 29 goats; from hearts of one of 46 with titers of <1:5, one of nine with titers of 1:10, one of three with titers of 1:40, and 26 of 40 with titers of 1:160 or higher. Two isolates were highly virulent to outbred Swiss Webster mice; all infected mice died of toxoplasmosis, irrespective of the dose. All T. gondii isolates were subsequently grown in cell cultures. Genotyping of the 29 T. gondii isolates using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) from DNA obtained from cell culture grown tachyzoites revealed 12 genotypes. Nine isolates were clonal Type II lineage, four isolates had type II alleles at all loci except a type I allele at the Apico locus, and four isolates were clonal Type III. The remaining 12 strains were divided into nine atypical genotypes, including five new and four previously identified genotypes. DNA sequences of four introns (EF1, HP2, UPRT1 and UPRT7) and two genes (GRA6 and GRA7) were generated for the five new genotypes. Comparing these sequences with previously published data revealed no unique sequences in these goat strains. Taken together, these results indicate high parasite prevalence and moderate genetic diversity of T. gondii in goats, which have important implications in public health. We believe this is the first genetic analysis of T. gondii isolates from goats in the USA.     

Prevalence of antibody to Toxoplasma gondii in terrestrial wildlife in a natural area

We conducted a cross-sectional study from 2008 to 2009 to evaluate the occurrence of feral and wild cats and the risk of Toxoplasma gondii infection in terrestrial wildlife in a natural area in Illinois, USA. Felids are definitive hosts for T. gondii and cats are a key component of rural and urban transmission of T. gondii. We selected four forest sites within the interior of the park and four edge sites within 300 m of human buildings. Feline and wildlife occurrence in the natural area was determined with the use of scent stations, motion-detection cameras, and overnight live trapping. Based on scent stations and trapping, feral cats used building sites more than forest sites (scent stations: P=0.010; trapping: P=0.083). Prevalence of T. gondii antibodies was determined with the use of the indirect immunofluorescent antibody test (IFAT) with a titer of 1:25 considered positive; T. gondii antibodies were detected in wildlife at all sites. Wildlife species were classified as having a large home range (LHR) or a small home range (SHR), based on published estimates and using a cutoff of 100 ha. Small-home-range mammals had a higher prevalence of antibody to T. gondii (odds ratio [OR]=4.2; P=0.018) at sites with a high frequency of cat occurrence (defined as ≥ 9 cat occurrences across three detection methods); this finding indicates that feral cats are the most likely source of environmental contamination. Overall, the prevalence of antibody to T. gondii among LHR mammals was significantly higher than the prevalence among SHR mammals (OR=7.1; P<0.001). Small-home-range mammals are an essential part of T. gondii-antibody prevalence studies and can be used as sentinels for risk of disease exposure to humans and wildlife in natural areas. This study improves our understanding of ecologic drivers behind the occurrence of spatial variation of T. gondii within a natural area.     

Frequency and risk factors for toxoplasmosis in ovines of various regions of the State of Colima, Mexico

Infection of ewes by Toxoplasma gondii may induce abortions, thus it has consequences for sheep production. Colima, Western State of Mexico, has favourable climatic conditions for transmission and both domestic and wild cats live there. The aim of this study was to determine the frequency of specific antibodies in sheep from the coast, a mountain, and a hill of Colima. Serum samples from 351 sheep were tested by a previously standardized indirect ELISA. The frequency of infection was estimated and the farm location and flock size, as well as the animals' age and sex were analysed as risk factors for toxoplasmosis. The frequency of antibodies depended on the altitude, being higher at sea level than at 1200 metres above sea level (OR=3.77, 95% CI=1.79-7.94, P<0.0001), and the size of the flock, being higher in the large ones (OR=2.23, 95% CI=1.35-3.71, P=0.002). Older animals were more frequently positive and with a stronger response than young ones (OR=1.77, 95% CI=1.07-2.93, P=0.016). No differences were observed between male and female sheep. In conclusion, toxoplasmosis is present in sheep of Colima with variations related to altitude, flock size and age.     

Prevalence of Toxoplasma gondii in stray cats of Gyeonggi-do, Korea

Toxoplasma gondii is an obligate intracellular zoonotic protozoan with a worldwide distribution. It infects humans as well as a broad spectrum of vertebrate hosts. Cats and wild felidae play crucial roles in the epidemiology of toxoplasmosis. This study was performed to survey the prevalence of T. gondii infection among stray cats in the Gyeonggi-do, Republic of Korea. A total of 174 stray cat blood samples were collected from Gwacheon-si (n=20), Bucheon-si (82), and Yangju-si (72). Positive sera for T. gondii were identified in 14 samples (8.1%) exclusively via the latex agglutination test, 28 (16.1%) via ELISA, and 23 (13.2%) via PCR analysis. The overall infection rate of female stray cats (29.2%) presented as higher than that of male cats (24.0%). This study suggests that T. gondii is widespread in the stray cat population of Gyeonggi-do, Korea. It is urgently needed to control urban stray cat population and to reduce the risk of zoonotic transmission of toxoplasmosis to other animal hosts and humans.     

Seroprevalence of Toxoplasma gondii in swine from slaughterhouses in Lima, Peru, and Georgia, U.S.A

Toxoplasma gondii is an important pathogen transmitted by food, with raw or undercooked meat as the main foodborne source of toxoplasmosis. In Peru, 2-4 million people have antibodies to T. gondii. It is believed that more than 60 million people in the United States are infected with T. gondii. In this study, the prevalence of T. gondii in pigs from Peru and the United States was determined by Western blot. The presence of IgG antibodies to T. gondii from serum samples was determined. Blood samples were collected from 137 pigs at a slaughterhouse in Lima, Peru, and 152 pigs at a slaughterhouse in Georgia. Of the serum samples collected from swine, 27.7% (n = 38) from Peru and 16.4% (n = 25) from the United States were positive for T. gondii. Swine represent a significant source of human infection with T. gondii in Peru and the United States.     

C-X-C chemokine receptor type 5 gene polymorphisms are associated with non-Hodgkin lymphoma

The C-X-C chemokine receptor type 5 (CXCR5) is one of the principal regulators for targeting T cells, B cells and dendritic cells into secondary lymphoid organs. Polymorphism studies of CXCR5 gene remain extremely scarce. The aim of this study was to examine the effect of polymorphisms in the CXCR5 gene on the development of non-Hodgkin lymphoma (NHL) in the Chinese population. Four polymorphisms in CXCR5 gene, rs148351692C/G, rs6421571C/T, rs80202369G/A and rs78440425G/A, were tested by polymerase chain reaction-restriction fragment length polymorphism in 404 NHL cases and 456 age-matched healthy controls. Data were analyzed using the χ(2) test. Results showed that individuals with the rs6421571 CT, rs6421571 TT and rs80202369 AA genotype had significantly increased susceptibility to NHL [Odd ratio (OR) = 1.41, 95 % confidence interval (CI): 1.04-1.92, p = 0.028; OR = 2.30, 95 % CI: 1.44-3.65, p < 0.001; and OR = 3.24, 95 % CI: 1.26-8.32, p = 0.010, respectively]. When analyzing the haplotypes of these polymorphisms, the prevalence of the TGG (rs6421571, rs80202369, and rs78440425) haplotype was significantly higher in NHL cases than in controls (OR = 1.59, 95 % CI: 1.25-2.03, p < 0.001). In addition, numbers of rs6421571 TT genotype and T allele were significantly increased in NHL patients with high Ann Arbor stages (p < 0.03) or NHL with B cell subtype (p < 0.02). These data indicate that CXCR5 gene polymorphisms may be new risk factors for NHL. The finding that the adjacent SNPs, rs6421571C/T and rs80202369G/A, are both associated with NHL suggests that the 87 bp region carrying these 2 polymorphisms may have important functional significance.     

Association between the p73 exon 2 G4C14-to-A4T14 polymorphism and cancer risk: a meta-analysis

The TP53 homolog p73 is structurally and functionally similar to TP53 and plays an important role in modulating cell-cycle control, apoptosis, and cell growth. G4C14-to-A4T14 is the most commonly studied polymorphism of this gene for its association with risk of cancers, but the results are confusing rather than conclusive. We performed a meta-analysis using 21 eligible studies with a total of 7581 patients and 10,413 controls to summarize the data for an association between the p73 G4C14-to-A4T14 polymorphism and cancer risk. Compared with the common GC/GC genotype, the AT carriers (AT/GC, AT/AT) had a 1.18-fold elevated risk of cancer (95% confidence interval [CI]=1.11-1.25, p<0.00001) in a dominant genetic model as estimated in a fixed effect model. The effect of the G4C14-to-A4T14 polymorphism was further evaluated through stratification analysis. In four lung cancer studies, the variant genotypes had a significantly increased risk of lung cancer (odds ratio [OR]=1.16, 95% CI=1.04-1.28, p=0.005). Similar phenomena were also found in two squamous cell carcinoma of the head and neck studies (OR=1.32, 95% CI=1.12-1.56, p=0.0010), two oral cancer studies (OR=1.57, 95% CI=1.26-1.95, p<0.0001), and three colorectal cancer studies (OR=1.23, 95% CI=1.01-1.50, p=0.04). Increased risk of cancer associated with G4C14-to-A4T14 variant genotypes was pronounced in Caucasians (OR=1.21, 95% CI=1.11-1.31, p<0.00001), the Japanese population (OR=1.24, 95% CI=1.01-1.52, p=0.04), and the Korean population (OR=1.27, 95% CI=1.07-1.52, p=0.007). Our meta-analysis suggests that the p73 G4C14-to-A4T14 polymorphism genotypes (GC/AT+AT/AT) may be associated with an increased risk of cancer in most cancer types and ethnicities.     

Prevalence,incidence and mortality from cardiovascular disease in patients with pooled and specific severe mental illness: a large‐scale meta‐analysis of 3,211,768 patients and 113,383,368 controls

People with severe mental illness (SMI) – schizophrenia, bipolar disorder and major depressive disorder – appear at risk for cardiovascular disease (CVD), but a comprehensive meta‐analysis is lacking. We conducted a large‐scale meta‐analysis assessing the prevalence and incidence of CVD; coronary heart disease; stroke, transient ischemic attack or cerebrovascular disease; congestive heart failure; peripheral vascular disease; and CVD‐related death in SMI patients (N=3,211,768) versus controls (N=113,383,368) (92 studies). The pooled CVD prevalence in SMI patients (mean age 50 years) was 9.9% (95% CI: 7.4‐13.3). Adjusting for a median of seven confounders, patients had significantly higher odds of CVD versus controls in cross‐sectional studies (odds ratio, OR=1.53, 95% CI: 1.27‐1.83; 11 studies), and higher odds of coronary heart disease (OR=1.51, 95% CI: 1.47‐1.55) and cerebrovascular disease (OR=1.42, 95% CI: 1.21‐1.66). People with major depressive disorder were at increased risk for coronary heart disease, while those with schizophrenia were at increased risk for coronary heart disease, cerebrovascular disease and congestive heart failure. Cumulative CVD incidence in SMI patients was 3.6% (95% CI: 2.7‐5.3) during a median follow‐up of 8.4 years (range 1.8‐30.0). Adjusting for a median of six confounders, SMI patients had significantly higher CVD incidence than controls in longitudinal studies (hazard ratio, HR=1.78, 95% CI: 1.60‐1.98; 31 studies). The incidence was also higher for coronary heart disease (HR=1.54, 95% CI: 1.30‐1.82), cerebrovascular disease (HR=1.64, 95% CI: 1.26‐2.14), congestive heart failure (HR=2.10, 95% CI: 1.64‐2.70), and CVD‐related death (HR=1.85, 95% CI: 1.53‐2.24). People with major depressive disorder, bipolar disorder and schizophrenia were all at increased risk of CVD‐related death versus controls. CVD incidence increased with antipsychotic use (p=0.008), higher body mass index (p=0.008) and higher baseline CVD prevalence (p=0.03) in patients vs. controls. Moreover, CVD prevalence (p=0.007), but not CVD incidence (p=0.21), increased in more recently conducted studies. This large‐scale meta‐analysis confirms that SMI patients have significantly increased risk of CVD and CVD‐related mortality, and that elevated body mass index, antipsychotic use, and CVD screening and management require urgent clinical attention.     

Ocular toxoplasmosis: evaluation of lacrimal-specific secretory IgA levels in both patients with active and inactive phases of the disease

Ocular toxoplasmosis can result in recurrent uveitis. Studies have shown that a correlation between active ocular toxoplasmosis and the presence of anti-Toxoplasma gondii secretory IgA (SIgA) in tears. This study compares anti-T. gondii SIgA levels in patients' tears during the acute and inactive phases of toxoplasmic uveitis. Twenty-nine positive tear specific SIgA for T. gondii patients with acute toxoplasmic uveitis were selected and were followed-up for at least two years, when the anti-T. gondii SIgA tears levels were determined. Specific SIgA for T. gondii was negative in 22 patients (75.86%) and positive in seven patients (24.13%) of whom six (85.7%) were followed over three years. Average SIgA levels during the acute phase are 1.54 and decrease significantly to 0.72 (p = 0.0001) during the inactive phase of disease. Because anti-T. gondii SIgA in the tear is negative in 75.86% of patients after the acute phase of infection, T. gondii SIgA levels may be used as a complementary diagnostic marker for active ocular toxoplasmosis.     

Prevalence of Toxoplasma gondii infection in wild birds in Durango, Mexico

There is a lack of information concerning the prevalence of Toxoplasma gondii infection in wild birds in Mexico. In the present study, serum samples and tissues from 653 birds from Durango State, Mexico, were evaluated for T. gondii infection. Antibodies to T. gondii (modified agglutination test, titer 1∶25 or higher) were found in 17 (2.6%) of the 653 birds, including 1 of 2 curve-billed thrashers (Toxostoma curvirostre), 2 (1 Anas platyrhynchos, 1 Anas diazi) of 4 ducks, 1 of 2 eagles (Aquila sp.), 5 (27.8%) of 18 great-tailed grackles (Quiscalus mexicanus), 7 (1.3%) of 521 rock pigeons (Columba livia), and 1 (14.3%) of 7 quail (Coturnix coturnix). The seroprevalence of T. gondii infection in birds captured in a park outside the city zoo (11.6%, 8/69) was significantly higher than that found in birds from other regions (1.5%, 9/584, OR = 8.38; 95% CI: 2.82-24.77; P = 0.0001). Brains and hearts of 23 birds (17 seropositive, 6 seronegative) were bioassayed in mice for the isolation of T. gondii . Viable T. gondii was isolated from 1 of 7 seropositive pigeons. The DNA obtained from the T. gondii isolate from the pigeon was genotyped using the PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and revealed an atypical genotype. This is the first report of T. gondii infection in great-tailed grackles, the Mexican duck, and curved-billed thrashers and the first survey of wild birds in Mexico.