Efficacy of Phase I and Phase II Coxiella burnetii Bacterin Vaccines in a Pregnant Ewe Challenge Model.

The bacterium Coxiella burnetii can cause the disease Q-fever in a wide range of animal hosts. Ruminants, including sheep, are thought to play a pivotal role in the transmission of C. burnetii to humans; however, the only existing livestock vaccine, namely, Coxevac® (Ceva Animal Health Ltd., Libourne, France), a killed bacterin vaccine based on phase I C. burnetii strain Nine-Mile, is only approved for use in goats and cattle. In this study, a pregnant ewe challenge model was used to determine the protective effects of Coxevac® and an experimental bacterin vaccine based on phase II C. burnetii against C. burnetii challenge. Prior to mating, ewes (n = 20 per group) were vaccinated subcutaneously with either Coxevac®, the phase II vaccine, or were unvaccinated. A subset of pregnant ewes (n = 6) from each group was then challenged 151 days later (~100 days of gestation) with 106 infectious mouse doses of C. burnetii, Nine-Mile strain RSA493. Both vaccines provided protection against C. burnetii challenge as measured by reductions in bacterial shedding in faeces, milk and vaginal mucus, and reduced abnormal pregnancies, compared to unvaccinated controls. This work highlights that the phase I vaccine Coxevac® can protect ewes against C. burnetii infection. Furthermore, the phase II vaccine provided comparable levels of protection and may offer a safer and cost-effective alternative to the currently licensed vaccine.

Prospective cohort study reveals unexpected aetiologies of livestock abortion in northern Tanzania.

Livestock abortion is an important cause of productivity losses worldwide and many infectious causes of abortion are zoonotic pathogens that impact on human health. Little is known about the relative importance of infectious causes of livestock abortion in Africa, including in subsistence farming communities that are critically dependent on livestock for food, income, and wellbeing. We conducted a prospective cohort study of livestock abortion, supported by cross-sectional serosurveillance, to determine aetiologies of livestock abortions in livestock in Tanzania. This approach generated several important findings including detection of a Rift Valley fever virus outbreak in cattle; high prevalence of C. burnetii infection in livestock; and the first report of Neospora caninum, Toxoplasma gondii, and pestiviruses associated with livestock abortion in Tanzania. Our approach provides a model for abortion surveillance in resource-limited settings. Our findings add substantially to current knowledge in sub-Saharan Africa, providing important evidence from which to prioritise disease interventions.

Validation of a multilocus genotyping scheme for subtyping Cryptosporidium parvum for epidemiological purposes.

Subtyping Cryptosporidium parvum for outbreak investigations or epidemiological surveillance usually relies on DNA sequence analysis of a gene coding for a 60 KDa glycoprotein (gp60). Although gp60 can be useful for allelic discrimination and to help investigate sources and routes of transmission, the presence of common subtypes and recombination during the parasite's sexual life-cycle demand a multilocus-based method for more discriminatory genotyping. While whole genome sequencing would provide the ultimate approach, it is a time consuming and expensive option for faecal parasites such as Cryptosporidium that occur at low density and are difficult to propagate routinely. In this study, we selected and evaluated a panel of previously identified variable-number tandem-repeat (VNTR) markers, to establish a multilocus genotyping scheme based on fragment sizing, appropriate for inter-laboratory surveillance and outbreak investigations. Seven VNTR markers were validated in vitro and demonstrated typeability of 0.85 and discriminatory power of 0.99. The discriminatory power was much greater than the currently used gp60 sequencing (0.74), which identified 26 subtypes, compared to 100 different MLVA profiles within the same sample set. The assay was robust, with repeatable results and reproducibility across three laboratories demonstrating the scheme was suitable for inter-laboratory comparison of C. parvum subtypes. As the majority of genotypes (79%) were unique among epidemiologically unrelated samples, there was efficiency to infer linkage, and epidemiological concordance was observed in historical outbreaks. We propose that the multilocus variable number of tandem repeats analysis scheme is suitable to assist outbreak investigations.

Infectious Causation of Abnormal Host Behavior: Toxoplasma gondii and Its Potential Association With Dopey Fox Syndrome.

The apicomplexan parasite Toxoplasma gondii, the causative agent of toxoplasmosis, can infect all warm-blooded animals. T. gondii can subtly alter host behaviors-either through manipulation to enhance transmission to the feline definitive host or as a side-effect, or "constraint," of infection. In humans, T. gondii infection, either alone or in association with other co-infecting neurotropic agents, has been reliably associated with both subtle behavioral changes and, in some cases, severe neuropsychiatric disorders, including schizophrenia. Research on the potential impact of T. gondii on the behavior of other long-lived naturally infected hosts is lacking. Recent studies reported a large number of wild red foxes exhibiting a range of aberrant behavioral traits, subsequently classified as Dopey Fox Syndrome (DFS). Here we assessed the potential association between T. gondii and/or other neurotropic agents with DFS. Live, captive foxes within welfare centers were serologically tested for T. gondii and, if they died naturally, PCR-tested for vulpine circovirus (FoxCV). Post-mortem pseudo-control wild foxes, obtained from pest management companies, were PCR-tested for T. gondii, FoxCV, canine distemper virus (CDV), canine adenovirus type (CAV)-1 and CAV-2. We also assessed, using non-invasive assays, whether T. gondii-infected foxes showed subtle behavioral alterations as observed among infected rodent (and other) hosts, including altered activity, risk, and stress levels. All foxes tested negative for CAV, CDV, CHV, and DogCV. DFS was found to be associated with singular T. gondii infection (captives vs. pseudo-controls, 33.3% (3/9) vs. 6.8% (5/74)) and singular FoxCV infection (66.7% (6/9) vs. 11.1% (1/9)) and with T. gondii/FoxCV co-infection (33.3% (3/9) vs. 11.1% (1/9)). Overall, a higher proportion of captive foxes had signs of neuroinflammation compared to pseudo-controls (66.7% (4/6) vs. 11.1% (1/9)). Consistent with behavioral changes seen in infected rodents, T. gondii-infected foxes displayed increased attraction toward feline odor (n=6 foxes). These preliminary results suggest that wild foxes with DFS are infected with T. gondii and likely co-infected with FoxCV and/or another co-infecting neurotropic agent. Our findings using this novel system have important implications for our understanding of both the impact of parasites on mammalian host behavior in general and, potentially, of the infectious causation of certain neuropsychiatric disorders.

Detection of Toxoplasma gondii in retail meat samples in Scotland.

Toxoplasma gondii is a globally important zoonotic parasite ranked as one of the most significant causes of disease burden among the major foodborne pathogens. Consumption of undercooked meat is a well-known risk factor for infection so the aim of this study was to investigate the presence of T. gondii in meat samples from retail outlets in Scotland. In Sampling Period 1, 300 meat samples (39 beef, 21 chicken, 87 lamb, 71 pork and 82 venison) were purchased from butchers', farmers' markets, farm shops and supermarkets, and in Sampling Period 2, 67 pure venison samples only were purchased from farmers' markets, farm shops and supermarkets. DNA was extracted and screened for T. gondii using a quantitative PCR targeting the 529 bp repeat element, and any positive samples were genotyped using PCR-RFLP targeting 10 markers. Meat juice was screened for T. gondii antibodies using a commercial ELISA or modified agglutination assay. Toxoplasma gondii DNA was detected in 0/39 (0%) beef samples, 1/21 (4.8%) chicken samples, 6/87 (6.9%) lamb samples, 3/71 (4.2%) pork samples and 29/82 (35.4%; Sampling Period 1) and 19/67 (28.4%; Sampling Period 2) venison samples. Partial PCR-RFLP genotyping revealed both clonal and non-clonal genotypes. Antibodies to T. gondii were detected in the meat juice of 2/38 (5.3%) beef samples, 3/21 (14.3%) chicken samples, 14/85 (16.5%) lamb samples, 2/68 (2.9%) pork samples and 11/78 (14.1%; Sampling Period 1) and 8/50 (16%; Sampling Period 2) venison samples. This is the first study to report the presence of T. gondii in retail meat products in Scotland and has highlighted venison as a potentially high risk meat. Further work is required to determine viability of parasites in this particular meat product.

Description of an atypical Toxoplasma gondii isolate from a case of congenital toxoplasmosis in northeastern Brazil.

We report a case of severe congenital toxoplasmosis that involved an atypical T. gondii genotype in a newborn baby from Alagoas state in Northeastern Brazil. A pregnant woman presented IgM and IgG anti-T. gondii antibodies, as detected by the chemiluminescence immunoassay on the second trimester of pregnancy. A mouse bioassay was performed using umbilical cord blood and one isolate was obtained. The isolate was designated TgCTBrAL1 and genetic characterization revealed genotype ToxoDB #162. Genotype results of the rhoptry genes, ROP5 and ROP18, could predict the high virulence of the isolate in mice, which was confirmed by an in vivo virulence assay. This is the first report of generating a T. gondii isolate from a newborn baby with congenital toxoplasmosis in Northeastern Brazil.

Atypical Toxoplasma gondii genotype from a sheep and a pig on Fernando de Noronha Island, Brazil, showed different mouse virulence profiles.

Toxoplasma gondii is a zoonotic parasite which can infect almost all warm-blooded animals. Toxoplasma gondii isolates from Brazil have greater genetic diversity with a predominance of virulent and atypical genotypes, compared with the Northern Hemisphere. Considering that previous studies have demonstrated a high seroprevalence of T. gondii antibodies in animals from Fernando de Noronha Island, the aim of this study was to isolate, genetically characterize, and determine mouse virulence of isolates of T. gondii from livestock from this Brazilian island. Two T. gondii isolates were obtained by mouse bioassay from brain from one sheep and one pig. Genotyping was performed by PCR-RFLP using 10 genetic markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22- 8, c29-2, PK1, L358, and Apico) and an atypical genotype of T. gondii (ToxoDB #146) was identified for both isolates. Genotyping of four ROP loci indicated different alleles for ROP16 and mouse virulence analysis revealed different profiles (intermediate and low virulence). This is the first report of this genotype being described in a pig and a sheep.

The Sero-epidemiology of Neospora caninum in Cattle in Northern Tanzania.

Neospora caninum is a protozoan intracellular parasite of animals with a global distribution. Dogs act as definitive hosts, with infection in cattle leading to reproductive losses. Neosporosis can be a major source of income loss for livestock keepers, but its impacts in sub-Saharan Africa are mostly unknown. This study aimed to estimate the seroprevalence and identify risk factors for N. caninum infection in cattle in northern Tanzania, and to link herd-level exposure to reproductive losses. Serum samples from 3,015 cattle were collected from 380 households in 20 villages between February and December 2016. Questionnaire data were collected from 360 of these households. Household coordinates were used to extract satellite derived environmental data from open-access sources. Sera were tested for the presence of N. caninum antibodies using an indirect ELISA. Risk factors for individual-level seropositivity were identified with logistic regression using Bayesian model averaging (BMA). The relationship between herd-level seroprevalence and abortion rates was assessed using negative binomial regression. The seroprevalence of N. caninum exposure after adjustment for diagnostic test performance was 21.5% [95% Credibility Interval (CrI) 17.9-25.4]. The most important predictors of seropositivity selected by BMA were age greater than 18 months [Odds ratio (OR) = 2.17, 95% CrI 1.45-3.26], the local cattle population density (OR = 0.69, 95% CrI 0.41-1.00), household use of restricted grazing (OR = 0.72, 95% CrI 0.25-1.16), and an increasing percentage cover of shrub or forest land in the environment surrounding a household (OR = 1.37, 1.00-2.14). There was a positive relationship between herd-level N. caninum seroprevalence and the reported within-herd abortion rate (Incidence Rate Ratio = 1.03, 95% CrI 1.00-1.06). Our findings suggest N. caninum is likely to be an important cause of abortion in cattle in Tanzania. Management practices, such as restricted grazing, are likely to reduce the risk of infection and suggest contamination of communal grazing areas may be important for transmission. Evidence for a relationship between livestock seropositivity and shrub and forest habitats raises questions about a potential role for wildlife in the epidemiology of N. caninum in Tanzania.

Infections and pathology of free-roaming backyard chickens on St. Kitts, West Indies.

Free-roaming chickens on Caribbean islands are important sentinels for local avian diseases and those introduced by birds migrating through the Americas. We studied 81 apparently healthy unvaccinated free-roaming chickens from 9 parishes on St. Kitts, an eastern Caribbean island. Using commercial ELISAs, no chickens had antibodies against avian influenza virus, West Nile virus, or Salmonella Enteritidis, although seropositivity was high to infectious bursal disease virus (86%), infectious bronchitis virus (84%), Mycoplasma (37%), and avian avulavirus 1 (Newcastle disease virus, 31%). Examination of small and large intestinal contents revealed cestodes in 79% and nematodes in 75% of the chickens. Although ectoparasites and endoparasites were common (74% and 79%, respectively), only a few chickens had lesions at postmortem examination, mainly intestinal serosal nodules (12%) and feather loss (6%). Histologic examination of 18 organs from each bird revealed lesions in high percentages of organs, mainly the liver (86%), lung (75%), spleen (60%), small intestine (56%), skin (42%), and kidney (40%). Lesions included degenerative, reactive, inflammatory, and neoplastic, and were not correlated with the serologic status of the chickens except in one case of infectious bursal disease. Microscopically, Paratanaisia bragai was seen in the kidneys of 3 chickens and intestinal coccidiasis in 1 chicken. Pulmonary silicate aggregates were common, were present in intestinal serosal nodules, and were suggestive of environmental exposure.

Comparative virulence of Caribbean, Brazilian and European isolates of Toxoplasma gondii.

BACKGROUND: Toxoplasma gondii is a zoonotic parasite of global importance. The outcome of infection in humans can depend on a number of factors including the infecting stage of the parasite, inoculating dose and virulence of the infecting strain. Molecular epidemiological studies have demonstrated an abundance of atypical strains of T. gondii in South America, many of which have been associated with more severe sequelae of infection. The aim of this study was to compare the virulence of T. gondii strains isolated in the Caribbean to a virulent Brazilian strain and an avirulent European strain. METHODS: One hundred and twenty Swiss CD-1 mice were split into 8 groups of 15 mice and each group was inoculated with 200 tachyzoites of one of 8 isolates, comprising ToxoDB genotypes #1, #141, #265, #13, #3 and #6. Five mice per group were euthanized at day 8 post-inoculation (p.i.) and parasite burden was determined in heart, lungs and eyes using quantitative PCR. Lungs and brain were also examined by histopathology and immunohistochemistry. The remaining 10 mice per group were part of a survival experiment to assess virulence. DNA was extracted from tachyzoites of each of the 8 T. gondii isolates and genotyped at four ROP gene loci, including ROP5, ROP16, ROP17 and ROP18 to look for association with markers of virulence. RESULTS: Infection with ToxoDB genotype #13 from the Caribbean resulted in 100% of mice being euthanized which was comparative to infection with the virulent Brazilian strain (ToxoDB genotype #6). Significantly higher parasite burdens were recorded in the lungs and eyes of mice infected with ToxoDB genotypes #13 and #6. Genotyping of ROP loci revealed that the virulent Caribbean isolates had a different ROP18/ROP5 allelic profile (3/1) to the virulent Brazilian isolate (1/3); however, the avirulent Caribbean isolate (ToxoDB genotype #1) had the same ROP18/ROP5 profile as the avirulent European isolate (ToxoDB #3) (both 2/2). Caribbean isolates of intermediate virulence (ToxoDB #141 and #265) all had the same ROP18/ROP5 allelic profile (2/2). CONCLUSIONS: Isolates from the Caribbean with ToxoDB genotype #13 were acutely virulent for mice and comparable to a known virulent Brazilian isolate. The ROP protein allelic profile of the virulent Caribbean and Brazilian isolates differed indicating that perhaps other factors are involved in predicting virulence. Understanding virulence is important for predicting disease outcome in humans and may also aid vaccine design as well as drug discovery.

A one health approach to vaccines against Toxoplasma gondii.

Toxoplasmosis is a serious disease with global impact, now recognised as one of the most important food borne diseases worldwide and a major cause of production loss in livestock. A one health approach to develop a vaccination programme to tackle toxoplasmosis is an attractive and realistic prospect. Knowledge of disease epidemiology, parasite transmission routes and main risk groups has helped to target key host species and outcomes for a vaccine programme and these would be to prevent/reduce congenital disease in women and sheep; prevent/reduce T. gondii tissue cysts in food animal species and to prevent/reduce T. gondii oocyst shedding in cats. Most animals, including humans, develop good protective immunity following infection, involving cell mediated immune responses, which may explain why live vaccines are generally more effective to protect against T. gondii. Recent advances in our knowledge of parasite genetics and gene manipulation, strain variation, key antigenic epitopes, delivery systems and induction of immune responses are all contributing to the prospects of developing new vaccines which may be more widely applicable. A key area in progressing vaccine development is to devise standard vaccine efficacy models in relevant animal hosts and this is where a one health approach bringing together researchers across different disciplines can be of major benefit. The tools and technologies are in place to make a real impact in tackling toxoplasmosis using vaccination and it just requires a collective will to make it happen.

Predominance of atypical genotypes of Toxoplasma gondii in free-roaming chickens in St. Kitts, West Indies.

BACKGROUND: Toxoplasma gondii is a worldwide protozoan parasite of felids which can infect almost all warm-blooded animals, including humans. Free-roaming chickens are good indicators of environmental contamination with T. gondii oocysts because they feed from the ground. Previous research has demonstrated a high seroprevalence of T. gondii in domestic animals on St. Kitts but little is known about the genotypes circulating in the environment. METHODS: Hearts and brains from 81 free-roaming chickens in St. Kitts were digested and inoculated into 243 Swiss Webster mice in a bioassay. DNA was extracted from digested chicken tissues and the brains of all mice, and screened for T. gondii. Positive samples were genotyped using restriction fragment length polymorphism. Chicken sera were also screened for T. gondii antibodies using a modified agglutination test (MAT). RESULTS: Overall, 41% (33 out of 81) of chickens were positive for T. gondii either by serology and/or by PCR. Antibodies to T. gondii were detected by MAT in 32% (26 out of 81) of chickens, and T. gondii DNA was detected in mouse brains representing 26% (21 out of 81) of chickens. Genotyping of 21 DNA isolates, using polymorphisms at 10 loci, including SAG1, SAG2 (5'-3' SAG2 and alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, revealed that 7 were ToxoDB genotype #141, 6 were #1 (Type II), 3 were #13, 3 were #265, one was #264 and one was #2 (Type III). Genotypes #13 and #141 appear to be more virulent. CONCLUSIONS: The results of this study highlight the greater genetic diversity of T. gondii circulating in the Caribbean region, with potentially different degrees of virulence to humans.

Detection of Babesia annae DNA in lung exudate samples from Red foxes (Vulpes vulpes) in Great Britain.

BACKGROUND: This study aimed to determine the prevalence of Babesia species DNA in lung exudate samples collected from red foxes (Vulpes vulpes) from across Great Britain. Babesia are small piroplasmid parasites which are mainly transmitted through the bite of infected ticks of the family Ixodidae. Babesia can cause potentially fatal disease in a wide-range of mammalian species including humans, dogs and cattle, making them of significant economic importance to both the medical and veterinary fields. METHODS: DNA was extracted from lung exudate samples of 316 foxes. A semi-nested PCR was used to initially screen samples, using universal Babesia-Theileria primers which target the 18S rRNA gene. A selection of positive PCR amplicons were purified and sequenced. Subsequently specific primers were designed to detect Babesia annae and used to screen all 316 DNA samples. Randomly selected positive samples were purified and sequenced (GenBank accession KT580786). Clones spanning a 1717 bp region of the 18S rRNA gene were generated from 2 positive samples, the resultant consensus sequence was submitted to GenBank (KT580785). Sequence KT580785 was used in the phylogenetic analysis RESULTS: Babesia annae DNA was detected in the fox samples, in total 46/316 (14.6%) of samples tested positive for the presence of Babesia annae DNA. The central region of England had the highest prevalence at 36.7%, while no positive samples were found from Wales, though only 12 samples were tested from this region. Male foxes were found to have a higher prevalence of Babesia annae DNA than females in all regions of Britain. Phylogenetic and sequence analysis of the GenBank submissions (Accession numbers KT580785 and KT580786) showed 100% identity to Babesia sp.-'Spanish Dog' (AY534602, EU583387 and AF188001). CONCLUSIONS: This is the first time that Babesia annae DNA has been reported in red foxes in Great Britain with positive samples being found across England and Scotland indicating that this parasite is well established within the red fox population of Britain. Phylogenetic analysis demonstrated that though B. annae is closely related to B. microti it is a distinct species.

Development of an in vitro model of the early-stage bovine tuberculous granuloma using Mycobacterium bovis-BCG.

Mycobacterium bovis causes 3.1% of human tuberculosis cases, as described by the World Health Organisation. In cattle, this organism causes bovine tuberculosis (BTB) which can have a prevalence of up to 39.5% in some developing countries. In developed countries, although the prevalence of BTB has been reduced through eradication programmes, complete eradication has in some cases proved elusive, with prevalences in cattle of 0.5% in the Republic of Ireland and of 4.3% in the UK. As the tuberculous granuloma is the fundamental lesion that reflects the pathogenesis, immune control and progression of BTB, we aimed to develop an in vitro model of the early-stage bovine tuberculous granuloma, in order to model the early stages of BTB, while also reducing the use of experimentally infected animals. In vitro models of human and ovine mycobacterial granulomas have previously been developed; however, so far, there is no model for the BTB granuloma. As the disease in cattle differs in a number of ways from that in other species, we consider this to be a significant gap in the tools available to study the pathogenesis of BTB. By combining bovine monocyte-derived macrophages infected with M. bovis-BCG and autologous lymphocytes we have developed an early-stage tuberculous bovine granuloma model. In the model, 3D cell aggregations formed a spherical-shape that grew for up to 11 days post-infection. This bovine tuberculous granuloma model can aid in the study of such lesion development, and in comparative studies of pathogenesis, such as, for example, the question of mycobacterial latency in bovine tuberculosis.

Toxoplasma gondii in livestock in St. Kitts and Nevis, West Indies.

BACKGROUND: Toxoplasma gondii is a ubiquitous protozoan parasite capable of infecting all warm-blooded animals including livestock. In these animals, the parasite forms cysts in the tissues which may pose a risk to public health if infected meat is consumed undercooked or raw. The aim of this study was to determine the exposure of livestock to T. gondii in St. Kitts and Nevis. METHODS: Sera and/or heart tissue and meat juice were collected from pigs (n = 124), sheep (n = 116) and goats (n = 66) at the St. Kitts Abattoir. Sera and meat juice were screened for reactive antibodies to T. gondii using an in-house ELISA. Heart tissue was screened for T. gondii DNA using quantitative PCR and positive samples were genotyped using RFLP. RESULTS: Antibodies to T. gondii were detected in sera from 48% of pigs, 26% of sheep and 34% of goats tested. Antibodies were also detected in the meat juice from 55% of pig hearts, 22% of sheep hearts and 31% of goat hearts tested. There was a significant positive correlation between serology and meat juice results. T. gondii DNA was detected in heart tissue of 21% of pigs, 16% of sheep and 23% of goats tested. Preliminary PCR-RFLP analysis identified a predominance of the Type III genotype of T. gondii. CONCLUSIONS: These results suggest widespread environmental contamination with T. gondii oocysts and that livestock could be a potentially important source of T. gondii infection if their infected meat is consumed (or handled) undercooked.

First report of Toxoplasma gondii seroprevalence in wild-caught Caribbean African green monkeys.

BACKGROUND: Toxoplasma gondii is a protozoan parasite capable of infecting all warm-blooded animals. Humans can become infected by ingesting infective oocysts from the environment or contaminated food or water, or by ingesting tissue cysts in undercooked infected meat or by handling infected meat. Caribbean African green monkeys (Chlorocebus sabaeus) are present in large numbers on the island of St. Kitts in the Caribbean, and it is not uncommon for these animals to be trapped and eaten by islanders. The aim of this study was to determine T. gondii infection in Caribbean African green monkeys. FINDINGS: Sera collected from 79 wild-caught Caribbean African green monkeys were examined for T. gondii antibodies by ELISA. Antibodies were detected in 38 out of 79 (48.1%) monkeys. Significantly more females were infected than males but there was no significant effect of age or location on antibody status. CONCLUSIONS: Results indicate that Caribbean African green monkeys can be infected with T. gondii and that there is widespread environmental contamination of St. Kitts with oocysts. These monkeys could present a potential source of T. gondii infection if their meat is consumed undercooked. This is the first report of T. gondii antibodies in this species.

Seroprevalence of Toxoplasma gondii in small ruminants from four Caribbean islands.

BACKGROUND: Toxoplasma gondii is a protozoan parasite capable of infecting all warm-blooded animals including livestock. In these animals, the parasite forms cysts in the tissues which may pose a risk to public health if infected meat is consumed undercooked or raw. Little is known of the epidemiology of T. gondii in the Caribbean; therefore, the aim of this study was to determine T. gondii exposure in small ruminants from four Caribbean island nations. FINDINGS: Sera from 305 sheep and 442 goats from Dominica, Grenada, Montserrat and St. Kitts and Nevis were examined for T. gondii antibodies using an in house ELISA. Reactive antibodies were detected in sheep and goats, respectively, from Dominica (67%, 37/55; 58%, 79/136), Grenada (48%, 40/84; 57%, 54/94), Montserrat (89%, 25/28; 80%, 25/31) and St. Kitts and Nevis (57%, 78/138; 42%, 76/181). CONCLUSIONS: Our results suggest widespread environmental contamination with T. gondii oocysts and that small ruminants could be a potentially important source of T. gondii infection if their infected meat is consumed undercooked.

Identification of the major proteins of an immune modulating fraction from adult Fasciola hepatica released by Nonidet P40.

Fasciola hepatica NP-40 released protein extract (FhNPE) exhibits potent Th1 immunosuppressive properties in vitro and in vivo. However, the protein composition of this active fraction, responsible for Th1 immune modulatory activity, has yet to be resolved. Therefore, FhNPE, a Nonidet P-40 extract, was subjected to a proteomic analysis in order to identify individual protein components. This was performed using an in house F. hepatica EST database following 2D electrophoresis combined with de novo sequencing based mass spectrometry. The identified proteins, a mixture of excretory/secretory and membrane-associated proteins, are associated with stress response and chaperoning, energy metabolism and cytoskeletal components. The immune modulatory properties of these identified protein(s) are discussed and HSP70 from F. hepatica is highlighted as a potential host immune modulator for future study.